diff --git a/published/20091104 Linux-Unix App For Prevention Of RSI (Repetitive Strain Injury).md b/published/20091104 Linux-Unix App For Prevention Of RSI (Repetitive Strain Injury).md new file mode 100644 index 0000000000..80980b29bb --- /dev/null +++ b/published/20091104 Linux-Unix App For Prevention Of RSI (Repetitive Strain Injury).md @@ -0,0 +1,159 @@ +Linux 下如何避免重复性压迫损伤（RSI） +====== + +![workrave-image][1] + +[重复性压迫损伤][2]Repetitive Strain Injury（RSI）是职业性损伤综合症，非特异性手臂疼痛或工作引起的上肢障碍。RSI 是由于过度使用双手从事重复性任务导致的，如打字、书写和使用鼠标. 不幸的是，大部分人不了解什么是 RSI 以及它的危害有多大。你可以使用名叫 Workrave 的开源软件轻松的预防 RSI。 + +### RSI 有哪些症状？ + +我从这个[页面][3]引用过来的，看看哪些你被说中了： + + 1. 疲惫缺乏忍耐力？ + 2. 手掌及上肢乏力 + 3. 疼痛麻木甚至失去知觉？ + 4. 沉重：你有没有感觉手很沉？ + 5. 笨拙: 你有没有感觉抓不紧东西？ + 6. 你有没有感觉手上无力？很难打开罐子或切菜无力？ + 7. 缺乏协调和控制？ + 8. 手总是冰凉的？ + 9. 健康意识有待提高？稍不注意身体就发现有毛病了。 + 10. 是否过敏？ + 11. 频繁的自我按摩（潜意识的）？ + 12. 共鸣的疼痛？当别人在谈论手痛的时候，你是否也感觉到了手疼？ + +### 如何减少发展为 RSI 的风险 + + * 使用计算机的时候每隔 30 分钟间隔休息一下。借助软件如 workrave 预防 RSI。 + * 有规律的锻炼可以预防各种损伤，包括 RSI。 + * 使用合理的姿势。调整你的电脑桌和椅子使身体保持一个肌肉放松状态。 + +### Workrave + +Workrave 是一款预防计算机用户发展为 RSI 或近视的自由开源软件。软件会定期锁屏为一个动画： “Workrave 小姐”，引导用户做各种伸展运动并敦促其休息一下。这个软件经常提醒你暂停休息一下，并限制你每天的限度。程序可以运行在 MS-Window、Linux 以及类 UNIX 操作系统下。 + +#### 安装 workrave + +在 Debian/Ubuntu Linux 系统运行以下 [apt 命令][4]/[apt-get 命令][5]： + +``` +$ sudo apt-get install workrave +``` + +Fedora Linux 发行版用户运行以下 dnf 命令： + +``` +$ sudo dnf install workrave +``` + +RHEL/CentOS Linux 用户可以启动 EPEL 仓库并用 [yum 命令][6]安装： + +``` +### [ **在CentOS/RHEL 7.x 及衍生版本上测试** ] ### +$ sudo yum install epel-release +$ sudo yum install https://rpms.remirepo.net/enterprise/remi-release-7.rpm +$ sudo yum install workrave +``` + +Arch Linux 用户运行以下 pacman 命令来安装： + +``` +$ sudo pacman -S workrave +``` + +FreeBSD 用户可用以下 pkg 命令安装： + +``` +# pkg install workrave +``` + +OpenBSD 用户可用以下 pkg_add 命令安装： + +``` +$ doas pkg_add workrave +``` + +#### 如何配置 workrave + +Workrave 以一个小程序运行，它的用户界面位于面板中。你可以为 workrave 增加一个面板来控制软件的动作和外观。 + +增加一个新 workrave 对象到面板： + + * 在面板空白区域右键，打开面板弹出菜单 + * 选择新增到面板 + * 新增面板对话框打开，在加载器顶部，可以看到可用的面板对象按照字母排列。选中 workrave 程序并单击新增。 + +![图 01：新增 workrave 对象到面板][7] + +*图 01：新增 workrave 对象到面板* + +如果修改 workrave 对象的属性，执行以下步骤： + + * 右键 workrave 对象打开面板对象弹出 + * 选中偏好。使用属性对话框修改对应属性 + +![图 02：修改 Workrave 对象属性](https://www.cyberciti.biz/media/new/tips/2009/11/linux-gnome-workwave-preferences-.png) + +*图 02：修改 Workrave 对象属性* + +#### Workrave 运行展示 + +主窗口显示下一次提醒休息的剩余时间，这个窗口可以关闭，时间提示窗口会显示在面板上。 + +![图 03：时间计数器][8] + +*图 03：时间计数器* + +![图 04：Workrave 小姐 - 引导你做伸展运动的动画][9] + +*图 04：Workrave 小姐 - 引导你做伸展运动的动画* + +休息提示窗口，请求你暂停一下工作： + +![图 05：休息提示倒计时][10] + +*图 05：休息提示倒计时* + +![图 06：你可以跳过休息][11] + +*图 06：你可以跳过休息* + +#### 参考链接: + + 1. [Workrave 项目][12] 主页 + 2. [pokoy][13] 防止 RSI 和其他计算机压力的轻量级守护进程 + 3. GNOME3 下的 [Pomodoro][14] 计数器 + 4. [RSI][2] 的维基百科 + +### 关于作者 + +作者是 nixCraft 创始人，经验丰富的系统管理员，同时也是一个 Linux/Unix 系统下的 shell 脚本培训师。他曾服务于全球客户，并与多个行业合作包括 IT、教育、国防和航天研究，以及非盈利机构。可以在 [Twitter][15]、[Facebook][16]、[Google+][17] 上关注他。 + +-------------------------------------------------------------------------------- + +via: https://www.cyberciti.biz/tips/repetitive-strain-injury-prevention-software.html + +作者：[Vivek Gite][a] +译者：[guevaraya](https://github.com/guevaraya) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://www.cyberciti.biz/ +[1]:https://www.cyberciti.biz/media/new/tips/2009/11/workrave-image.jpg +[2]:https://en.wikipedia.org/wiki/Repetitive_strain_injury +[3]:https://web.eecs.umich.edu/~cscott/rsi.html##symptoms +[4]:https://www.cyberciti.biz/faq/ubuntu-lts-debian-linux-apt-command-examples/ +[5]:https://www.cyberciti.biz/tips/linux-debian-package-management-cheat-sheet.html +[6]:https://www.cyberciti.biz/faq/rhel-centos-fedora-linux-yum-command-howto/ +[7]:https://www.cyberciti.biz/media/new/tips/2009/11/add-workwave-to-panel.png +[8]:https://www.cyberciti.biz/media/new/tips/2009/11/screenshot-workrave.png +[9]:https://www.cyberciti.biz/media/new/tips/2009/11/miss-workrave.png +[10]:https://www.cyberciti.biz/media/new/tips/2009/11/time-for-micro-pause.gif +[11]:https://www.cyberciti.biz/media/new/tips/2009/11/Micro-break.png +[12]:http://www.workrave.org/ +[13]:https://github.com/ttygde/pokoy +[14]:http://gnomepomodoro.org +[15]:https://twitter.com/nixcraft +[16]:https://facebook.com/nixcraft +[17]:https://plus.google.com/+CybercitiBiz diff --git a/published/20180626 How To Search If A Package Is Available On Your Linux Distribution Or Not.md b/published/20180626 How To Search If A Package Is Available On Your Linux Distribution Or Not.md new file mode 100644 index 0000000000..c1490ee980 --- /dev/null +++ b/published/20180626 How To Search If A Package Is Available On Your Linux Distribution Or Not.md @@ -0,0 +1,339 @@ +如何搜索一个包是否在你的 Linux 发行版中 +====== + +如果你知道包名称，那么你可以直接安装所需的包。 + +在某些情况下，如果你不知道确切的包名称或者你想搜索某些包，那么你可以在发行版的包管理器的帮助下轻松搜索该包。搜索会自动包括已安装和可用的包。结果的格式取决于选项。如果你的查询没有输出任何信息，那么意味着没有匹配条件的包。这可以通过发行版的包管理器的各种选项来完成。我已经在本文中添加了所有可能的选项，你可以选择最好的和最合适你的选项。 + +或者，我们可以通过 `whohas` 命令实现这一点。它会从所有的主流发行版（例如 Debian、Ubuntu、 Fedora 等）中搜索，而不仅仅是你自己的系统发行版。 + +建议阅读： + +- [适用于 Linux 的命令行包管理器列表以及用法][1] +- [Linux 包管理器的图形前端工具][2] + +### 如何在 Debian/Ubuntu 中搜索一个包 + +我们可以使用 `apt`、`apt-cache` 和 `aptitude` 包管理器在基于 Debian 的发行版上查找给定的包。我为这个包管理器中包括了大量的选项。 + +我们可以在基于 Debian 的系统中使用三种方式完成此操作。 + + * `apt` 命令 + * `apt-cache` 命令 + * `aptitude` 命令 + +#### 如何使用 apt 命令搜索一个包 + +APT 代表高级包管理工具Advanced Packaging Tool（APT），它取代了 `apt-get`。它有功能丰富的命令行工具，包括所有功能包含在一个命令（`apt`）里，包括 `apt-cache`、`apt-search`、`dpkg`、`apt-cdrom`、`apt-config`、`apt-key` 等，还有其他几个独特的功能。 + +APT 是一个强大的命令行工具，它可以访问 libapt-pkg 底层库的所有特性，它可以用于安装、下载、删除、搜索和管理以及查询包的信息，另外它还包含一些较少使用的与包管理相关的命令行实用程序。 + +``` +$ apt -q list nano vlc +Listing... +nano/artful,now 2.8.6-3 amd64 [installed] +vlc/artful 2.2.6-6 amd64 +``` + +或者，我们可以使用以下格式搜索指定的包。 + +``` +$ apt search ^vlc +Sorting... Done +Full Text Search... Done +vlc/artful 2.2.6-6 amd64 + multimedia player and streamer + +vlc-bin/artful 2.2.6-6 amd64 + binaries from VLC + +vlc-data/artful,artful 2.2.6-6 all + Common data for VLC + +vlc-l10n/artful,artful 2.2.6-6 all + Translations for VLC + +vlc-plugin-access-extra/artful 2.2.6-6 amd64 + multimedia player and streamer (extra access plugins) + +vlc-plugin-base/artful 2.2.6-6 amd64 + multimedia player and streamer (base plugins) +``` + +#### 如何使用 apt-cache 命令搜索一个包 + +`apt-cache` 会在 APT 的包缓存上执行各种操作。它会显示有关指定包的信息。`apt-cache` 不会改变系统的状态，但提供了从包的元数据中搜索和生成有趣输出的操作。 + +``` +$ apt-cache search nano | grep ^nano +nano - small, friendly text editor inspired by Pico +nano-tiny - small, friendly text editor inspired by Pico - tiny build +nanoblogger - Small weblog engine for the command line +nanoblogger-extra - Nanoblogger plugins +nanoc - static site generator written in Ruby +nanoc-doc - static site generator written in Ruby - documentation +nanomsg-utils - nanomsg utilities +nanopolish - consensus caller for nanopore sequencing data +``` + +或者，我们可以使用以下格式搜索指定的包。 + +``` +$ apt-cache policy vlc +vlc: + Installed: (none) + Candidate: 2.2.6-6 + Version table: + 2.2.6-6 500 + 500 http://in.archive.ubuntu.com/ubuntu artful/universe amd64 Packages +``` + +或者，我们可以使用以下格式搜索给定的包。 + +``` +$ apt-cache pkgnames vlc +vlc-bin +vlc-plugin-video-output +vlc-plugin-sdl +vlc-plugin-svg +vlc-plugin-samba +vlc-plugin-fluidsynth +vlc-plugin-qt +vlc-plugin-skins2 +vlc-plugin-visualization +vlc-l10n +vlc-plugin-notify +vlc-plugin-zvbi +vlc-plugin-vlsub +vlc-plugin-jack +vlc-plugin-access-extra +vlc +vlc-data +vlc-plugin-video-splitter +vlc-plugin-base +``` + +#### 如何使用 aptitude 命令搜索一个包 + +`aptitude` 是一个基于文本的 Debian GNU/Linux 软件包系统的命令行界面。它允许用户查看包列表，并执行包管理任务，例如安装、升级和删除包，它可以从可视化界面或命令行执行操作。 + +``` +$ aptitude search ^vlc +p vlc - multimedia player and streamer +p vlc:i386 - multimedia player and streamer +p vlc-bin - binaries from VLC +p vlc-bin:i386 - binaries from VLC +p vlc-data - Common data for VLC +v vlc-data:i386 - +p vlc-l10n - Translations for VLC +v vlc-l10n:i386 - +p vlc-plugin-access-extra - multimedia player and streamer (extra access plugins) +p vlc-plugin-access-extra:i386 - multimedia player and streamer (extra access plugins) +p vlc-plugin-base - multimedia player and streamer (base plugins) +p vlc-plugin-base:i386 - multimedia player and streamer (base plugins) +p vlc-plugin-fluidsynth - FluidSynth plugin for VLC +p vlc-plugin-fluidsynth:i386 - FluidSynth plugin for VLC +p vlc-plugin-jack - Jack audio plugins for VLC +p vlc-plugin-jack:i386 - Jack audio plugins for VLC +p vlc-plugin-notify - LibNotify plugin for VLC +p vlc-plugin-notify:i386 - LibNotify plugin for VLC +p vlc-plugin-qt - multimedia player and streamer (Qt plugin) +p vlc-plugin-qt:i386 - multimedia player and streamer (Qt plugin) +p vlc-plugin-samba - Samba plugin for VLC +p vlc-plugin-samba:i386 - Samba plugin for VLC +p vlc-plugin-sdl - SDL video and audio output plugin for VLC +p vlc-plugin-sdl:i386 - SDL video and audio output plugin for VLC +p vlc-plugin-skins2 - multimedia player and streamer (Skins2 plugin) +p vlc-plugin-skins2:i386 - multimedia player and streamer (Skins2 plugin) +p vlc-plugin-svg - SVG plugin for VLC +p vlc-plugin-svg:i386 - SVG plugin for VLC +p vlc-plugin-video-output - multimedia player and streamer (video output plugins) +p vlc-plugin-video-output:i386 - multimedia player and streamer (video output plugins) +p vlc-plugin-video-splitter - multimedia player and streamer (video splitter plugins) +p vlc-plugin-video-splitter:i386 - multimedia player and streamer (video splitter plugins) +p vlc-plugin-visualization - multimedia player and streamer (visualization plugins) +p vlc-plugin-visualization:i386 - multimedia player and streamer (visualization plugins) +p vlc-plugin-vlsub - VLC extension to download subtitles from opensubtitles.org +p vlc-plugin-zvbi - VBI teletext plugin for VLC +p vlc-plugin-zvbi:i386 +``` + +### 如何在 RHEL/CentOS 中搜索一个包 + +Yum（Yellowdog Updater Modified）是 Linux 操作系统中的包管理器实用程序之一。Yum 命令用于在一些基于 RedHat 的 Linux 发行版上，它用来安装、更新、搜索和删除软件包。 + +``` +# yum search ftpd +Loaded plugins: fastestmirror, refresh-packagekit, security +Loading mirror speeds from cached hostfile + * base: centos.hyve.com + * epel: mirrors.coreix.net + * extras: centos.hyve.com + * rpmforge: www.mirrorservice.org + * updates: mirror.sov.uk.goscomb.net +============================================================== N/S Matched: ftpd =============================================================== +nordugrid-arc-gridftpd.x86_64 : ARC gridftp server +pure-ftpd.x86_64 : Lightweight, fast and secure FTP server +vsftpd.x86_64 : Very Secure Ftp Daemon + + Name and summary matches only, use "search all" for everything. +``` + +或者，我们可以使用以下命令搜索相同内容。 + +``` +# yum list ftpd +``` + +### 如何在 Fedora 中搜索一个包 + +DNF 代表 Dandified yum。我们可以说 DNF 是下一代 yum 包管理器（Yum 的衍生品），它使用 hawkey/libsolv 库作为底层。Aleš Kozumplík 从 Fedora 18 开始开发 DNF，最终在 Fedora 22 中发布。 + +``` +# dnf search ftpd +Last metadata expiration check performed 0:42:28 ago on Tue Jun 9 22:52:44 2018. +============================== N/S Matched: ftpd =============================== +proftpd-utils.x86_64 : ProFTPD - Additional utilities +pure-ftpd-selinux.x86_64 : SELinux support for Pure-FTPD +proftpd-devel.i686 : ProFTPD - Tools and header files for developers +proftpd-devel.x86_64 : ProFTPD - Tools and header files for developers +proftpd-ldap.x86_64 : Module to add LDAP support to the ProFTPD FTP server +proftpd-mysql.x86_64 : Module to add MySQL support to the ProFTPD FTP server +proftpd-postgresql.x86_64 : Module to add PostgreSQL support to the ProFTPD FTP + : server +vsftpd.x86_64 : Very Secure Ftp Daemon +proftpd.x86_64 : Flexible, stable and highly-configurable FTP server +owfs-ftpd.x86_64 : FTP daemon providing access to 1-Wire networks +perl-ftpd.noarch : Secure, extensible and configurable Perl FTP server +pure-ftpd.x86_64 : Lightweight, fast and secure FTP server +pyftpdlib.noarch : Python FTP server library +nordugrid-arc-gridftpd.x86_64 : ARC gridftp server +``` + +或者，我们可以使用以下命令搜索相同的内容。 + +``` +# dnf list proftpd +Failed to synchronize cache for repo 'heikoada-terminix', disabling. +Last metadata expiration check: 0:08:02 ago on Tue 26 Jun 2018 04:30:05 PM IST. +Available Packages +proftpd.x86_64 +``` + +### 如何在 Arch Linux 中搜索一个包 + +pacman 代表包管理实用程序（pacman）。它是一个用于安装、构建、删除和管理 Arch Linux 软件包的命令行实用程序。pacman 使用 libalpm（Arch Linux Package Management（ALPM）库）作为底层来执行所有操作。 + +在本例中，我将要搜索 chromium 包。 + +``` +# pacman -Ss chromium +extra/chromium 48.0.2564.116-1 + The open-source project behind Google Chrome, an attempt at creating a safer, faster, and more stable browser +extra/qt5-webengine 5.5.1-9 (qt qt5) + Provides support for web applications using the Chromium browser project +community/chromium-bsu 0.9.15.1-2 + A fast paced top scrolling shooter +community/chromium-chromevox latest-1 + Causes the Chromium web browser to automatically install and update the ChromeVox screen reader extention. Note: This + package does not contain the extension code. +community/fcitx-mozc 2.17.2313.102-1 + Fcitx Module of A Japanese Input Method for Chromium OS, Windows, Mac and Linux (the Open Source Edition of Google Japanese + Input) +``` + +默认情况下，`-s` 选项内置 ERE（扩展正则表达式）会导致很多不需要的结果。使用以下格式会仅匹配包名称。 + +``` +# pacman -Ss '^chromium-' +``` + +`pkgfile` 是一个用于在 Arch Linux 官方仓库的包中搜索文件的工具。 + +``` +# pkgfile chromium +``` + +### 如何在 openSUSE 中搜索一个包 + +Zypper 是 SUSE 和 openSUSE 发行版的命令行包管理器。它用于安装、更新、搜索和删除包以及管理仓库，执行各种查询等。Zypper 命令行对接到 ZYpp 系统管理库（libzypp）。 + +``` +# zypper search ftp +or +# zypper se ftp +Loading repository data... +Reading installed packages... +S | Name | Summary | Type +--+----------------+-----------------------------------------+-------- + | proftpd | Highly configurable GPL-licensed FTP -> | package + | proftpd-devel | Development files for ProFTPD | package + | proftpd-doc | Documentation for ProFTPD | package + | proftpd-lang | Languages for package proftpd | package + | proftpd-ldap | LDAP Module for ProFTPD | package + | proftpd-mysql | MySQL Module for ProFTPD | package + | proftpd-pgsql | PostgreSQL Module for ProFTPD | package + | proftpd-radius | Radius Module for ProFTPD | package + | proftpd-sqlite | SQLite Module for ProFTPD | package + | pure-ftpd | A Lightweight, Fast, and Secure FTP S-> | package + | vsftpd | Very Secure FTP Daemon - Written from-> | package +``` + +### 如何使用 whohas 命令搜索一个包 + +`whohas` 命令是一个智能工具，从所有主流发行版中搜索指定包，如 Debian、Ubuntu、Gentoo、Arch、AUR、Mandriva、Fedora、Fink、FreeBSD 和 NetBSD。 + +``` +$ whohas nano +Mandriva nano-debug 2.3.1-1mdv2010.2.x http://sophie.zarb.org/rpms/0b33dc73bca710749ad14bbc3a67e15a +Mandriva nano-debug 2.2.4-1mdv2010.1.i http://sophie.zarb.org/rpms/d9dfb2567681e09287b27e7ac6cdbc05 +Mandriva nano-debug 2.2.4-1mdv2010.1.x http://sophie.zarb.org/rpms/3299516dbc1538cd27a876895f45aee4 +Mandriva nano 2.3.1-1mdv2010.2.x http://sophie.zarb.org/rpms/98421c894ee30a27d9bd578264625220 +Mandriva nano 2.3.1-1mdv2010.2.i http://sophie.zarb.org/rpms/cea07b5ef9aa05bac262fc7844dbd223 +Mandriva nano 2.2.4-1mdv2010.1.s http://sophie.zarb.org/rpms/d61f9341b8981e80424c39c3951067fa +Mandriva spring-mod-nanoblobs 0.65-2mdv2010.0.sr http://sophie.zarb.org/rpms/74bb369d4cbb4c8cfe6f6028e8562460 +Mandriva nanoxml-lite 2.2.3-4.1.4mdv2010 http://sophie.zarb.org/rpms/287a4c37bc2a39c0f277b0020df47502 +Mandriva nanoxml-manual-lite 2.2.3-4.1.4mdv2010 http://sophie.zarb.org/rpms/17dc4f638e5e9964038d4d26c53cc9c6 +Mandriva nanoxml-manual 2.2.3-4.1.4mdv2010 http://sophie.zarb.org/rpms/a1b5092cd01fc8bb78a0f3ca9b90370b +Gentoo nano 9999 http://packages.gentoo.org/package/app-editors/nano +Gentoo nano 9999 http://packages.gentoo.org/package/app-editors/nano +Gentoo nano 2.9.8 http://packages.gentoo.org/package/app-editors/nano +Gentoo nano 2.9.7 +``` + +如果你希望只从当前发行版仓库中搜索指定包，使用以下格式： + +``` +$ whohas -d Ubuntu vlc +Ubuntu vlc 2.1.6-0ubuntu14.04 1M all http://packages.ubuntu.com/trusty/vlc +Ubuntu vlc 2.1.6-0ubuntu14.04 1M all http://packages.ubuntu.com/trusty-updates/vlc +Ubuntu vlc 2.2.2-5ubuntu0.16. 1M all http://packages.ubuntu.com/xenial/vlc +Ubuntu vlc 2.2.2-5ubuntu0.16. 1M all http://packages.ubuntu.com/xenial-updates/vlc +Ubuntu vlc 2.2.6-6 40K all http://packages.ubuntu.com/artful/vlc +Ubuntu vlc 3.0.1-3build1 32K all http://packages.ubuntu.com/bionic/vlc +Ubuntu vlc 3.0.2-0ubuntu0.1 32K all http://packages.ubuntu.com/bionic-updates/vlc +Ubuntu vlc 3.0.3-1 33K all http://packages.ubuntu.com/cosmic/vlc +Ubuntu browser-plugin-vlc 2.0.6-2 55K all http://packages.ubuntu.com/trusty/browser-plugin-vlc +Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/xenial/browser-plugin-vlc +Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/artful/browser-plugin-vlc +Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/bionic/browser-plugin-vlc +Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/cosmic/browser-plugin-vlc +Ubuntu libvlc-bin 2.2.6-6 27K all http://packages.ubuntu.com/artful/libvlc-bin +Ubuntu libvlc-bin 3.0.1-3build1 17K all http://packages.ubuntu.com/bionic/libvlc-bin +Ubuntu libvlc-bin 3.0.2-0ubuntu0.1 17K all +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/how-to-search-if-a-package-is-available-on-your-linux-distribution-or-not/ + +作者：[Prakash Subramanian][a] +选题：[lujun9972](https://github.com/lujun9972) +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://www.2daygeek.com/author/prakash/ +[1]:https://www.2daygeek.com/list-of-command-line-package-manager-for-linux/ +[2]:https://www.2daygeek.com/list-of-graphical-frontend-tool-for-linux-package-manager/ diff --git a/published/20180809 Two Years With Emacs as a CEO (and now CTO).md b/published/20180809 Two Years With Emacs as a CEO (and now CTO).md new file mode 100644 index 0000000000..f82d75b2f6 --- /dev/null +++ b/published/20180809 Two Years With Emacs as a CEO (and now CTO).md @@ -0,0 +1,87 @@ +[#]: collector: (lujun9972) +[#]: translator: (oneforalone) +[#]: reviewer: (acyanbird wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10510-1.html) +[#]: subject: (Two Years With Emacs as a CEO (and now CTO)) +[#]: via: (https://www.fugue.co/blog/2018-08-09-two-years-with-emacs-as-a-cto.html) +[#]: author: (Josh Stella https://www.fugue.co/blog/author/josh-stella) + +作为 CEO 使用 Emacs 的两年经验之谈 +====== + +两年前，我写了一篇[博客][1]，并取得了一些反响。这让我有点受宠若惊。那篇博客写的是我准备将 Emacs 作为我的主办公软件，当时我还是 CEO，现在已经是 CTO 了。现在回想起来，我发现我之前不是做程序员就是做软件架构师，而且那时我也喜欢用 Emacs 写代码。重新考虑使用 Emacs 是一次令我振奋的尝试，但我不太清楚这次行动会造成什么反响。在网上，那篇博客的评论也是褒贬不一，但是还是有数万的阅读量，所以总的来说，我写的是一个蛮有意思的题材。在 [Reddit][2] 和 [HackerNews][3] 上有些令人哭笑不得的回复，说我的手会变成鸡爪，或者说我会因白色的背景而近视。在这里我可以很高兴地回答，到目前为止并没有出现什么特别糟糕的后果，相反，我的手腕还因此变得更灵活了。还有一些人担心，说使用 Emacs 会耗费一个 CEO 的精力。把 Fugue 从一个在我家后院的灵感变成强大的产品，并有一大批忠实的顾客，我发现在做这种真正复杂之事的时候，Emacs 可以给你带来安慰。还有，我现在仍然在用白色的背景。 + +近段时间那篇博客又被翻出来了，并发到了 [HackerNews][4] 上。我收到了大量的跟帖者问我现在使用状况如何，所以我写了这篇博客来回应他们。在本文中，我还将重点讨论为什么 Emacs 和函数式编程有很高的关联性，以及我们是怎样使用 Emacs 来开发我们的产品 —— Fugue，一个使用函数式编程的自动化的云计算平台的。由于我收到了很多反馈，其众多细节和评论很有用，因此这篇博客比较长，而我确实也需要费点精力来解释我如此作为时的想法，但这篇文章的主要内容还是反映了我担任 CEO 时处理的事务。而我想在之后更频繁地用 Emacs 写代码，所以需要提前做一些准备。一如既往，本文因人而异，后果自负。 + +### 意外之喜 + +我大部分时间都在不断的处理公司内外沟通。交流是解决问题的唯一方法，但也是反思及思考困难或复杂问题的敌人。对我来说，作为创业公司的 CEO，最需要的是能专注工作而不被打扰的时间。一旦你决定投入时间来学习一些有用的命令，Emacs 就能帮助创造这种不被打扰的可贵环境。其他的应用会弹出提示，但是一个配置好了的 Emacs 可以完全不影响你 —— 无论是视觉上还是精神上。除非你想，否则的话它不会改变，况且没有比空白屏幕和漂亮的字体更干净的界面了。不断被打扰是我的日常状况，因此这种简洁让我能够专注于我在想的事情，而不是电脑本身。好的程序能够默默地操纵电脑，并且不会夺取你的注意力。 + +一些人指出，我原来的博客有太多对现代图形界面的批判和对 Emacs 的赞许。我既不赞同，也不否认。现代的界面，特别是那些以应用程序为中心的方法（相对于以内容为中心的方法），既不是以用户为中心的，也不是面向任务的。Emacs 避免了这种错误，这也是我如此喜欢它的部分原因，而它也带来了其他优点。Emacs 是带领你体会计算机魅力的传送门，一个值得跳下去的兔子洞（LCTT 译注：爱丽丝梦游仙境里的兔子洞，跳进去会有新世界）。它的核心是发现和创造属于自己的道路，对我来说这本身就是创造了。现代计算的悲哀之处在于，它很大程度上是由带有闪亮界面的黑盒组成的，这些黑盒提供的是瞬间的喜悦，而不是真正的满足感。这让我们变成了消费者，而不是技术的创造者。无论你是谁或者你的背景是什么；你都可以理解你的电脑，你可以用它创造事物。它很有趣，能令人满意，而且不是你想的那么难学! + +我们常常低估了环境对我们心理的影响。Emacs 给人一种平静和自由的感觉，而不是紧迫感、烦恼或兴奋 —— 后者是思考和沉思的敌人。我喜欢那些持久的、不碍事的东西，当我花时间去关注它们的时候，它们会给我带来真知灼见。Emacs 满足我的所有这些标准。我每天都使用 Emacs 来工作，我也很高兴我很少需要注意到它。Emacs 确实有一个学习曲线，但不会比学自行车的学习曲线来的更陡，而且一旦你掌握了它，你会得到相应的回报，而且不必再去想它了。它赋予你一种其他工具所没有的自由感。这是一个优雅的工具，来自一个更加文明的计算时代。我很高兴我们步入了另一个文明的计算时代，我相信 Emacs 也将越来越受欢迎。 + +### 弃用 Org 模式处理日程和待办事项 + +在原来的文章中，我花了一些时间介绍如何使用 Org 模式来规划日程。不过现在我放弃了使用 Org 模式来处理待办事项一类的事物，因为我每天都有很多会议要开，很多电话要打，我也不能让其他人来适应我选的工具，而且也没有时间将事务转换或是自动移动到 Org 上。我们主要是 Mac 一族，使用谷歌日历等工具，而且原生的 Mac OS/iOS 工具可以很好的进行团队协作。我还有支老钢笔用来在会议中做笔记，因为我发现在会议中使用笔记本电脑或者说键盘记录很不礼貌，而且这也限制了我的聆听和思考。因此，我基本上放弃了用 Org 模式帮我规划日程或安排生活。当然，Org 模式对其他的方面也很有用，它是我编写文档的首选，包括本文。换句话说，我使用它的方式与其作者的想法背道而驰，但它的确做得很好。我也希望有一天也有人如此评价并使用我们的 Fugue。 + +### Emacs 已经在 Fugue 公司中扩散 + +我在上篇博客就有说，你可能会喜欢 Emacs，也可能不会。因此，当 Fugue 的文档组将 Emacs 作为标准工具时，我是有点担心的，因为我觉得他们可能是受了我的影响才做出这种选择。不过在两年后，我确信他们做出了正确的选择。文档组的组长是一个很聪明的程序员，但是另外两个编写文档的人却没有怎么接触过技术。我想，如果这是一个经理强迫员工使用错误工具的案例，我就会收到投诉要去解决它，因为 Fugue 有反威权文化，大家不怕挑战任何事和任何人。之前的组长在去年辞职了，但[文档组][5]现在有了一个灵活的集成的 CI/CD 工具链，并且文档组的人已经成为了 Emacs 的忠实用户。Emacs 有一条学习曲线，但即使在最陡的时候，也不至于多么困难，并且翻过顶峰后，对生产力和总体幸福感都得到了提升。这也提醒我们，学文科的人在技术方面和程序员一样聪明，一样能干，也许不那么容易受到技术崇拜与习俗产生的影响。 + +### 我的手腕感激我的决定 + +上世纪 80 年代中期以来，我每天花 12 个小时左右在电脑前工作，这给我的手腕（以及后背）造成了很大的损伤（因此我强烈安利 Tag Capisco 的椅子）。Emacs 和人机工程学键盘的结合让手腕的 [RSI][10]（重复性压迫损伤Repetitive Strain Injury）问题消失了，我已经一年多没有想过这种问题了。在那之前，我的手腕每天都会疼，尤其是右手。如果你也有这种问题，你就知道这疼痛很让人分心和忧虑。有几个人问过关于选购键盘和鼠标的问题，如果你也对此有兴趣，那么在过去两年里，我主要使用的是 Truly Ergonomic 键盘，不过我现在用的是[这款键盘][6]。我已经换成现在的键盘有几个星期，而且我爱死它了。大写键的形状很神奇，因为你不用看就能知道它在哪里。而人体工学的拇指键也设计的十分合理，尤其是对于 Emacs 用户而言，Control 和 Meta 是你的坚实伴侣，不要再需要用小指做高度重复的任务了！ + +我使用鼠标的次数比使用 Office 和 IDE 时要少得多，这对我的工作效率有很大帮助，但我还是需要一个鼠标。我一直在使用外观相当过时，但功能和人体工程学非常优秀的 Clearly Superior 轨迹球，恰如其名。 + +撇开具体的工具不谈，事实证明，一个很棒的键盘，再加上避免使用鼠标，在减少身体的磨损方面很有效。Emacs 是达成这方面的核心，因为我不需要在菜单上滑动鼠标来完成任务，而且导航键就在我的手指下面。我现在十分肯定，我的手离开标准打字位置会给我的肌腱造成很大的压力。不过这也因人而异，我不是医生不好下定论。 + +### 我并没有做太多配置…… + +有人说我会在界面配置上耗费很多的时间。我想验证下他们说的对不对，所以我特别留意了下。我不仅在很多程度上不用配置，关注这个问题还让我意识到，我使用的其他工具是多么的耗费我的精力和时间。Emacs 是我用过的维护成本最低的软件。Mac OS 和 Windows 一直要求我更新它，但在我看来，这远没有 Adobe 套件和 Office 的更新给我带来的困扰那么大。我只是偶尔更新 Emacs，但对我来说它也没什么变化，所以从我的个人观点而言，更新基本上是一个接近于零成本的操作，我高兴什么时候更新就什么时候更新。 + +有一点让你们失望了，因为许多人想知道我为跟上重新打造的 Emacs 社区的更新做了些什么，但是在过去的两年中，我只在配置中添加了少部分内容。我认为这也是一种成功，因为 Emacs 只是一个工具，而不是我的爱好。但即便如此，如果你想和我分享关于 Emacs 的新鲜事物，我很乐意聆听。 + +### 期望实现云端控制 + +在我们 Fugue 公司有很多 Emacs 的粉丝，所以我们有一段时间在用 [Ludwing 模式][7]。Ludwig 模式是我们用于自动化云基础设施和服务的声明式、功能性的 DSL。最近，Alex Schoof 利用在飞机上和晚上的时间来构建 fugue 模式，它在 Fugue CLI 上充当 Emacs 控制台。要是你不熟悉 Fugue，这是我们开发的一个云自动化和治理工具，它利用函数式编程为用户提供与云的 API 交互的良好体验。但它做的不止这些。fugue 模式很酷的原因有很多，它有一个不断报告云基础设施状态的缓冲区，由于我经常修改这些基础设施，这样我就可以快速看到代码的效果。Fugue 将云工作负载当成进程处理，fugue 模式非常类似于为云工作负载设计的 `top` 工具。它还允许我执行一些操作，比如创建新的设备或删除过期的东西，而且也不需要太多输入。Fugue 模式只是个雏形，但它非常方便，而我现在也经常使用它。 + +![fugue-mode-edited.gif][8] + +### 模式及监控 + +我添加了一些模式和集成插件，但并不是真正用于工作或 CEO 职能。我喜欢在周末时写写 Haskell 和 Scheme 娱乐，所以我添加了 haskell 模式和 geiser。Emacs 很适合拥有 REPL 的语言，因为你可以在不同的窗口中运行不同的模式，包括 REPL 和 shell。geiser 和 Scheme 很配，要是你还没有用过 Scheme，那么阅读《计算机程序的构造和解释》（SICP）也不失为一种乐趣，在这个有很多货物崇拜编程（LCTT 译注：是一种计算机程序设计中的反模式，其特征为不明就里地、仪式性地使用代码或程序架构）例子的时代，阅读此书或许可以启发你。安装 MIT Scheme 和 geiser，你就会感觉有点像 lore 的符号环境。 + +这就引出了我在 2015 年的文章中没有提到的另一个话题：屏幕管理。我喜欢使用单独一个纵向模式的显示器来写作，我在家里和我的主要办公室都有这个配置。对于编程或混合使用，我喜欢我们提供给所有 Fugue 人的新型超宽显示器。对于它来说，我更喜欢将屏幕分成三列，中间是主编辑缓冲区，左边是水平分隔的 shell 和 fugue 模式缓冲区，右边是文档缓冲区或另外一、两个编辑缓冲区。这个很简单，首先按 `Ctl-x 3` 两次，然后使用 `Ctl-x =` 使窗口的宽度相等。这将提供三个相等的列，你也可以使用 `Ctl-x 2` 对分割之后的窗口再次进行水平分割。以下是我的截图。 + +![Emacs Screen Shot][9] + +### 这将是最后一篇 CEO/Emacs 文章 + +首先是因为我现在是 Fugue 的 CTO 而并非 CEO，其次是我有好多要写的博客主题，而我现在刚好有时间。我还打算写些更深入的东西，比如说函数式编程、基础设施即代码的类型安全，以及我们即将推出的一些 Fugue 的新功能、关于 Fugue 在云上可以做什么的博文等等。 + +-------------------------------------------------------------------------------- + +via: https://www.fugue.co/blog/2018-08-09-two-years-with-emacs-as-a-cto.html + +作者：[Josh Stella][a] +选题：[lujun9972][b] +译者：[oneforalone](https://github.com/oneforalone) +校对：[acyanbird](https://github.com/acyanbird), [wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.fugue.co/blog/author/josh-stella +[b]: https://github.com/lujun9972 +[1]: https://linux.cn/article-10401-1.html +[2]: https://www.reddit.com/r/emacs/comments/7efpkt/a_ceos_guide_to_emacs/ +[3]: https://news.ycombinator.com/item?id=10642088 +[4]: https://news.ycombinator.com/item?id=15753150 +[5]: https://docs.fugue.co/ +[6]: https://shop.keyboard.io/ +[7]: https://github.com/fugue/ludwig-mode +[8]: https://www.fugue.co/hubfs/Imported_Blog_Media/fugue-mode-edited-1.gif +[9]: https://www.fugue.co/hs-fs/hubfs/Emacs%20Screen%20Shot.png?width=929&name=Emacs%20Screen%20Shot.png +[10]: https://baike.baidu.com/item/RSI/21509642 diff --git a/published/20181212 Top 5 configuration management tools.md b/published/20181212 Top 5 configuration management tools.md new file mode 100644 index 0000000000..0f1c42cdf6 --- /dev/null +++ b/published/20181212 Top 5 configuration management tools.md @@ -0,0 +1,140 @@ +[#]: collector: (lujun9972) +[#]: translator: (HankChow) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10497-1.html) +[#]: subject: (Top 5 configuration management tools) +[#]: via: (https://opensource.com/article/18/12/configuration-management-tools) +[#]: author: (Marco Bravo https://opensource.com/users/marcobravo) + +五大最流行的配置管理工具 +====== + +> 了解一下配置管理工具，以找出哪个最适合你的 DevOps 组织。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/innovation_lightbulb_gears_devops_ansible.png?itok=TSbmp3_M) + +DevOps 正因为有提高产品质量、缩短产品开发时间等优势，目前备受业界关注，同时也在长足发展当中。 + +[DevOps 的核心价值观][1]是团队文化Culture、自动化Automation、评估Measurement和分享Sharing（CAMS），同时，团队对 DevOps 的执行力也是 DevOps 能否成功的重要因素。 + + * **团队文化**让大家团结一致； + * **自动化**是 DevOps 的基础； + * **评估**保证了及时的改进； + * **分享**让 CAMS 成为一个完整的循环过程。 + +DevOps 的另一个思想是任何东西，包括服务器、数据库、网络、日志文件、应用配置、文档、自动化测试、部署流程等，都可以通过代码来管理。 + +在本文中，我主要介绍配置管理的自动化。配置管理工具作为[基础架构即代码Infrastructure as Code][2]（IaC）的一部分，支持使用经过测试和验证的软件开发实践，通过明文定义文件管理和配置数据中心。 + +DevOps 团队只需要通过操作简单的配置文件，就可以实现应用开发中包括版本控制、测试、小型部署、设计模式在内的这些最佳实践。总而言之，配置管理工具实现了通过编写代码来使基础架构的配置和管理变得自动化。 + +### 为什么要使用配置管理工具？ + +配置管理工具可以提高应用部署和变更的效率，还可以让这些流程变得可重用、可扩展、可预测，甚至让它们维持在期望的状态，从而让资产的可控性提高。 + +使用配置管理工具的优势还包括： + + * 让代码遵守编码规范，提高代码可读性； + * 具有幂等性Idempotency，也就是说，无论执行多少次重复的配置管理操作，得到的结果都是一致的； + * 分布式的设计可以方便地管理大量的远程服务器。 + +配置管理工具主要分为拉取pull模式和推送push模式。拉取模式是指安装在各台服务器上的代理agent定期从中央存储库central repository拉取最新的配置并应用到对应的服务器上；而推送模式则由中央服务器central server的中央服务器会触发其它受管服务器的更新。 + +### 五大最流行的配置管理工具 + +目前配置管理工具有很多，不同的配置管理工具都有自己最适合的使用场景。而对于下面五个我按照字母顺序列出的配置管理工具，都对 DevOps 有明显的帮助：全都具有开源许可证、使用外部配置文件、支持无人值守运行、可以通过脚本自定义运行。下面对它们的介绍都来源于它们的软件库和官网内容。 + +#### Ansible + +“Ansible 是一个极其简洁的 IT 自动化平台，可以让你的应用和系统以更简单的方式部署。不需要安装任何代理，只需要使用 SSH 的方式和简单的语言，就可以免去脚本或代码部署应用的过程。”——[GitHub Ansible 代码库][3] + +- [官网](https://www.ansible.com/) +- [文档](https://docs.ansible.com/ansible/) +- [社区](https://www.ansible.com/community) + +Ansible 是我最喜欢的工具之一，我在几年前就开始使用了。你可以使用 Ansible 在命令行中让多个服务器执行同一个命令，也可以使用 YAML 格式的剧本playbook来让它自动执行特定的操作，这促进了技术团队和非技术团队之间的沟通。简洁、无代理、配置文件对非技术人员友好是它的几个主要优点。 + +由于 Ansible 不需要代理，因此对服务器的资源消耗会很少。Ansible 默认使用的推送模式需要借助 SSH 连接，但 Ansible 也支持拉取模式。[剧本][4] 可以使用最少的命令集编写，当然也可以扩展为更加精细的自动化任务，包括引入角色、变量和其它人写的模块。 + +你可以将 Ansible 和其它工具（包括 Ansible Works、Jenkins、RunDeck、[ARA][5] 等）结合起来使用，因为这些工具 [提供了运行剧本时的可追溯性][6]，这样就可以创建控制流程的中央控制台。 + +### CFEngine + +“CFEngine 3 是一个流行的开源配置管理系统，它主要用于为大规模的系统提供自动化配置和维护。”——[GitHub CFEngine 代码库][7] + +- [官网](https://cfengine.com/) +- [文档](https://docs.cfengine.com/docs/3.12/) +- [社区](https://cfengine.com/community/) + +CFEngine 最早在 1993 年由 Mark Burgess 作为自动配置管理的科学方法提出，目的是降低计算机系统配置中的熵，最终收敛到期望的配置状态，同时还阐述了幂等性是让系统达到期望状态的能力。Burgess 在 2004 年又提出了[承诺理论][8]Promise Theory，这个理论描述了代理之间自发合作的模型。 + +CFEngine 的最新版本已经用到了承诺理论，在各个服务器上的代理程序会从中央存储库拉取配置。CFEngine 的配置对专业技能要求较高，因此它比较适合技术团队使用。 + +### Chef + +“为整个基础架构在配置管理上带来便利的一个系统集成框架。”——[GitHub Chef 代码库][9] + +- [官网](http://www.chef.io/chef/) +- [文档](https://docs.chef.io/) +- [社区](https://www.chef.io/community/) + +Chef 通过由 Ruby 编写的“菜谱recipe”来让你的基础架构保持在最新、最兼容的状态，这些“菜谱”描述了一系列应处于某种状态的资源。Chef 既可以通过客户端-服务端的模式运行，也可以在 [chef-solo][10] 这种独立配置的模式下运行。大部分云提供商都很好地集成了 Chef，因此可以使用它为新机器做自动配置。 + +Chef 有广泛的用户基础，同时也提供了完备的工具包，让不同技术背景的团队可以通过“菜谱”进行沟通。尽管如此，它仍然算是一个技术导向的工具。 + +### Puppet + +“Puppet 是一个可以在 Linux、Unix 和 Windows 系统上运行的自动化管理引擎，它可以根据集中的规范来执行诸如添加用户、安装软件包、更新服务器配置等等管理任务。”——[GitHub Puppet 代码库][11] + +- [官网](https://puppet.com/) +- [文档](https://puppet.com/docs) +- [社区](https://puppet.com/community) + +Puppet 作为一款面向运维工程师和系统管理员的工具，在更多情况下是作为配置管理工具来使用。它通过客户端-服务端的模式工作，使用代理从主服务器获取配置指令。 + +Puppet 使用声明式语言declarative language或 Ruby 来描述系统配置。它包含了不同的模块，并使用清单文件manifest files记录期望达到的目标状态。Puppet 默认使用推送模式，但也支持拉取模式。 + +### Salt + +“为大规模基础结构或应用程序实现自动化管理的软件。”——[GitHub Salt 代码库][12] + +- [官网](https://www.saltstack.com/) +- [文档](https://docs.saltstack.com/en/latest/contents.html) +- [社区](https://www.saltstack.com/resources/community/) + +Salt 的专长就是快速收集数据，即使是上万台服务器也能够轻松完成任务。它使用 Python 模块来管理配置信息和执行特定的操作，这些模块可以让 Salt 实现所有远程操作和状态管理。但配置 Salt 模块对技术水平有一定的要求。 + +Salt 使用客户端-服务端的结构（Salt minions 是客户端，而 Salt master 是服务端），并以 Salt 状态文件记录需要达到的目标状态。 + +### 总结 + +DevOps 工具领域一直在发展，因此必须时刻关注其中的最新动态。希望这篇文章能够鼓励读者进一步探索相关的概念和工具。为此，云原生计算基金会Cloud Native Computing Foundation（CNCF）在 [Cloud Native Landscape Project][13] 中也提供了很好的参考案例。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/12/configuration-management-tools + +作者：[Marco Bravo][a] +选题：[lujun9972][b] +译者：[HankChow](https://github.com/HankChow) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/marcobravo +[b]: https://github.com/lujun9972 +[1]: https://www.oreilly.com/learning/why-use-terraform +[2]: https://www.oreilly.com/library/view/infrastructure-as-code/9781491924334/ch04.html +[3]: https://github.com/ansible/ansible +[4]: https://opensource.com/article/18/8/ansible-playbooks-you-should-try +[5]: https://github.com/openstack/ara +[6]: https://opensource.com/article/18/5/analyzing-ansible-runs-using-ara +[7]: https://github.com/cfengine/core +[8]: https://en.wikipedia.org/wiki/Promise_theory +[9]: https://github.com/chef/chef +[10]: https://docs.chef.io/chef_solo.html +[11]: https://github.com/puppetlabs/puppet +[12]: https://github.com/saltstack/salt +[13]: https://github.com/cncf/landscape + diff --git a/published/20120104 Computer Laboratory - Raspberry Pi- Lesson 0 Introduction.md b/published/201901/20120104 Computer Laboratory - Raspberry Pi- Lesson 0 Introduction.md similarity index 100% rename from published/20120104 Computer Laboratory - Raspberry Pi- Lesson 0 Introduction.md rename to published/201901/20120104 Computer Laboratory - Raspberry Pi- Lesson 0 Introduction.md diff --git a/published/20120201 Computer Laboratory - Raspberry Pi- Lesson 1 OK01.md b/published/201901/20120201 Computer Laboratory - Raspberry Pi- Lesson 1 OK01.md similarity index 100% rename from published/20120201 Computer Laboratory - Raspberry Pi- Lesson 1 OK01.md rename to published/201901/20120201 Computer Laboratory - Raspberry Pi- Lesson 1 OK01.md diff --git a/published/201901/20120202 Computer Laboratory - Raspberry Pi- Lesson 2 OK02.md b/published/201901/20120202 Computer Laboratory - Raspberry Pi- Lesson 2 OK02.md new file mode 100644 index 0000000000..04d233bcae --- /dev/null +++ b/published/201901/20120202 Computer Laboratory - Raspberry Pi- Lesson 2 OK02.md @@ -0,0 +1,68 @@ +[#]: collector: (lujun9972) +[#]: translator: (qhwdw) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10478-1.html) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 2 OK02) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok02.html) +[#]: author: (Robert Mullins http://www.cl.cam.ac.uk/~rdm34) + +计算机实验室之树莓派：课程 2 OK02 +====== + +OK02 课程构建于 OK01 课程的基础上，通过不停地打开和关闭 OK 或 ACT LED 指示灯来实现闪烁。假设你已经有了 [课程 1：OK01][1] 操作系统的代码，它将是这一节课的基础。 + +### 1、等待 + +等待是操作系统开发中非常有用的部分。操作系统经常发现自己无事可做，以及必须要延迟。在这个例子中，我们希望通过等待，让 LED 灯打开、关闭的闪烁可以看到。如果你只是打开和关闭它，你将看到这个视觉效果，因为计算机每秒种可以打开和关闭它好几千次（LCTT 译注：视觉暂留效应会使你难以发觉它的闪烁）。在后面的课程中，我们将看到精确的等待，但是现在，我们只要简单地去消耗时间就足够了。 + +``` +mov r2,#0x3F0000 +wait1$: +sub r2,#1 +cmp r2,#0 +bne wait1$ +``` + +> `sub reg,#val` 从寄存器 `reg` 中的值上减去数字 `val` +> +> `cmp reg,#val` 将寄存器中的值与数字 `val` 进行比较。 +> +> 如果最后的比较结果是不相等，那么执行后缀了 `ne` 的 `b` 命令。 + +上面是一个很常见的产生延迟的代码片段，由于每个树莓派基本上是相同的，所以产生的延迟大致也是相同的。它的工作原理是，使用一个 `mov` 命令将值 3F000016 推入到寄存器 `r2` 中，然后将这个值减 1，直到这个值减到 0 为止。在这里使用了三个新命令 `sub`、 `cmp` 和 `bne`。 + +`sub` 是减法命令，它只是简单地从第一个参数中的值减去第二个参数中的值。 + +`cmp` 是个很有趣的命令。它将第一个参数与第二个参数进行比较，然后将比较结果记录到一个称为当前处理器状态寄存器的专用寄存器中。你其实不用担心它，它记住的只是两个数谁大或谁小，或是相等而已。[^1] + +`bne` 其实是一个伪装的分支命令。在 ARM 汇编语言家族中，任何指令都可以有条件地运行。这意味着如果上一个比较结果是某个确定的结果，那个指令才会运行。这是个非常有意思的技巧，我们在后面将大量使用到它，但在本案例中，我们在 `b` 命令后面的 `ne` 后缀意思是 “只有在上一个比较的结果是值不相等，才去运行该分支”。`ne` 后缀可以使用在任何命令上，其它几个（总共 16 个）条件也是如此，比如 `eq` 表示等于，而 `lt` 表示小于。 + +### 2、组合到一起 + +上一节讲我提到过，通过将 GPIO 地址偏移量设置为 28（即：`str r1,[r0,#28]`）而不是 40 即可实现 LED 的关闭。因此，你需要去修改课程 OK01 的代码，在打开 LED 后，运行等待代码，然后再关闭 LED，再次运行等待代码，并包含一个回到开始位置的分支。注意，不需要重新启用 GPIO 的 16 号针脚的输出功能，这个操作只需要做一次就可以了。如果你想更高效，我建议你复用 `r1` 寄存器的值。所有课程都一样，你可以在 [下载页面][2] 找到所有的解决方案。需要注意的是，必须保证你的所有标签都是唯一的。当你写了 `wait1$:` 你其它行上的标签就不能再使用 `wait1$` 了。 + +在我的树莓派上，它大约是每秒闪两次。通过改变我们所设置的 `r2` 寄存器中的值，可以很轻松地修改它。但是，不幸的是，我不能够精确地预测它的运行速度。如果你的树莓派未按预期正常工作，请查看我们的故障排除页面，如果它正常工作，恭喜你。 + +在这个课程中，我们学习了另外两个汇编命令：`sub` 和 `cmp`，同时学习了 ARM 中如何实现有条件运行。 + +在下一个课程，[课程 3：OK03][3] 中我们将学习如何编写代码，以及建立一些代码复用的标准，并且如果需要的话，可能会使用 C 或 C++ 来写代码。 + +[^1]: 如果你点了这个链接，说明你一定想知道它的具体内容。CPSR 是一个由许多独立的比特位组成的 32 比特寄存器。它有一个位用于表示正数、零和负数。当一个 `cmp` 指令运行后，它从第一个参数上减去第二个参数，然后用这个位记下它的结果是正数、零还是负数。如果是零意味着它们相等（`a-b=0` 暗示着 `a=b`）如果为正数意味着 a 大于 b（`a-b>0` 暗示着 `a>b`），如果为负数意味着小于。还有其它比较指令，但 `cmp` 指令最直观。 + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok02.html + +作者：[Robert Mullins][a] +选题：[lujun9972][b] +译者：[qhwdw](https://github.com/qhwdw) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.cl.cam.ac.uk/~rdm34 +[b]: https://github.com/lujun9972 +[1]: https://linux.cn/article-10458-1.html +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/downloads.html +[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html diff --git a/published/201901/20150717 The History of Hello World.md b/published/201901/20150717 The History of Hello World.md new file mode 100644 index 0000000000..5d2af398dd --- /dev/null +++ b/published/201901/20150717 The History of Hello World.md @@ -0,0 +1,144 @@ +[#]: collector: "lujun9972" +[#]: translator: "zzzzzzmj" +[#]: reviewer: "wxy" +[#]: publisher: "wxy" +[#]: url: "https://linux.cn/article-10485-1.html" +[#]: subject: "The History of Hello World" +[#]: via: "https://www.thesoftwareguild.com/blog/the-history-of-hello-world/" +[#]: author: "thussong https://www.thesoftwareguild.com/blog/author/thussong/" + +Hello World 的由来 +========= + +资深软件开发人员都知道 [Hello World][2] 程序，这是一个能在设备显示器上输出某种变体的 “Hello, World!” 的程序，是学习编程的第一步。在这个编程中只涉及到一些最基本语法的程序，可以用大多数编程语言了来编写。事实上，路易斯安纳理工学院计算机协会（ACM）在最近统计[发现][3]这个程序至少有 204 个版本。 + +传统意义上，Hello World 程序是用于说明编码过程是如何工作的，以及确保编程语言或系统能正常运行。它们经常是新手程序员学习的第一个程序，因为即使是经验很少或者没有经验的人也能轻松正确的执行 Hello World。 + +首先，Hello World 简单，这就是为什么它经常被用做程序执行成功的晴雨表。如果 Hello World 在该框架中无法有效执行，那么其它更复杂的程序中也可能会失败。正如 [Win-Vector][4] 的一位专家所说，Hello World 实际上是一个对抗性程序。“该作者还说道，‘你的计算机系统能不能工作并不是一目了然，除非我能看到它至少能打印一行文字，否则我不会在上面浪费太多时间。’” Win-Vector 博主 John Mount 说。 + +但是这个两词短语在计算机科学领域有着重大的影响。以 Hello World 为基础，新手程序员可以轻松的理解计算机科学原理或元素，而拥有多年编码经验的程序员可以用它来学习编程语言的工作原理，特别是在结构与语法方面。这样的一个小程序，在任何难度的应用程序和几乎所有语言中都有着悠久的历史。 + +### 用途 + +以上概括了 Hello World 程序的主要用途：这是新手程序员熟悉新语言的一种方式。然而，这些程序不仅仅是对编码世界的介绍。例如，Hello World 可以作为测试，以确保语言的组件（编译器、开发和运行环境）安装正确。因为配置完整的编程工具链的过程复杂而漫长，所以像 Hello World 这样简单的程序通常用作新工具链的首次运行测试。 + +根据 Cunningham & Cunningham（C2）的编程顾问所说，在系统设计人员并不预期可以执行代码的地方，黑客经常使用 Hello World 程序作为一个可以通过漏洞执行任意代码的概念验证（POC）。事实上，它是在设备上使用自制内容或者“自酿”的第一步，当[有经验的编码人员][5]正在配置环境或在学习新事物时，他们会通过 Hello World 来验证其行为是否正确。 + +它也作为调试过程的一部分，允许程序员检查他们是否正确地编辑了可在运行时修改的程序并重新加载。 + +Hello World 的一个更常用的用途是作为基础比较。根据 C2 的 wiki 所讲，程序员可以“比较语言生成的可执行文件的大小，以及程序背后必须存在多少支持的基础设施才能执行。” + +### 开端 + +虽然 Hello World 的起源还有些不太明了，不过人们普遍认为它作为测试用语，最早出现在 Brian Kernigham 在 1972 年发布的《B 语言简介教程A Tutorial Introduction to the Language B》中。在此文中，该程序的第一个已知版本用于说明外部变量。因为该教程中的前一个例子在终端上打印了 “hi!”，而需要更多的字符常量来表达相对复杂的 “hello,world!”，这是学习过程的下一步。 + +在那以后，它还被用于 1974 年的贝尔实验室备忘录，以及 1987 年的《C 语言程序设计The C Programming Language》。这两篇著名的文字是让 Hello World 闻名于世的主要原因。在书中的一个例子（第一个，也是最著名的例子）打印了没有大写字母和感叹号的 “hello,world”。此时的 Hello World 几乎只是用于说明语言的一些功能，而不是测试系统是否正常运行。 + +在 Kernigham 的关于 B 语言和 C 语言的开创性文章之前，没有真正意义上的第一个程序，甚至直到 1974 年，它也没被广泛使用。著名的 BASIC 教程 “我的电脑喜欢我用 BASIC 跟它讲话My Computer Likes Me，When I Speak BASIC”，从一个写一行文本的简单程序开始，不过那句话是 “MY HUMAN UNDERSTANDS ME”，跟如今程序员侃侃而谈的这个双词问候语差的有点远。不过，当 Hello World 被发明后，它就迅速传播，并在 20 世纪 70 年代后变成了众所周知。直到今天它也依然受欢迎。 + +### 一个声明，多种语言 + +以下是目前正在被使用的一些流行的编程语言中的 Hello World 代码。 + +#### Java + +``` +class HelloWorld { + public static void main(String[] args) { + System.out.println("Hello, world!"); + } +} +``` + +#### C# + +``` +using System; +class Program +{ + public static void Main(string[] args) + { + Console.WriteLine("Hello, world!"); + } +} +``` + +#### Python + +``` +print("Hello, world!") +``` + +#### Ruby + +``` +puts "Hello, world!" +``` + +#### Scala + +``` +object HelloWorld extends App { + println("Hello, world!") +} +``` + +#### ASP.NET + +``` +Response.Write("Hello World!"); +``` + +#### Lisp + +``` +(princ "Hello, world!") +``` + +#### Haskell + +``` +main = putStrLn "Hello, world!" +``` + +#### Malbolge + +``` +('&%:9]!~}|z2Vxwv-,POqponl$Hjig%eB@@>}= +``` + +#### Go + +``` +package main +import "fmt" +func main() { + fmt.Println("Hello, world!") +} +``` + +### 如今的 Hello world：各种形式下的标准实践 + +在现在的编程语言中，Hello World 有着不同的复杂程度。例如，Go 语言中引入一个多语言版的 Hello World 程序，XL 则会提供一个具有图形、可旋转的 3D 版本。一些编程语言，像 Ruby、Python，仅仅需要一个语句去打印“Hello World”，但是低级汇编语言则需要几个命令才能做到这样。现在的编程语言还引入对标点符号和大小写的变化，包括是否有逗号或者感叹号，以及两个词的大写形式。举个例子，当系统只支持大写字母，会呈现像“HELLO WORLD”的短语。值得纪念的第一个 Malbolge 程序打印出了“HEllO WORld”（LCTT 译注：Malbolge 是最难的编程语言之一。事实上，在它诞生后，花了 2 年时间才完成第一个 Malbolge 程序）。它的变体跨越了原本的字面意思。像 Lisp、Haskell 这样函数语言，用阶乘程序替代了 Hello World，从而注重递归技术。这与原来的示例不同，后者更强调 I/O 以及产生的副作用。 + +随着现在的编程语言越来越复杂，Hello World 比以往显得更加重要。作为测试和教学工具，它已经成为程序员测试配置的编程环境的标准方法。没有人能确切说出为什么 Hello World 能在快速创新著称的行业中经受住时间的考验，但是它又确实留下来了。 + +-------------------------------------------------------------------------------- + +via: https://www.thesoftwareguild.com/blog/the-history-of-hello-world/ + +作者：[thussong][a] +选题：[lujun9972][b] +译者：[zzzzzzmj](https://github.com/zzzzzzmj) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.thesoftwareguild.com/blog/author/thussong/ +[b]: https://github.com/lujun9972 +[1]: https://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.thesoftwareguild.com%2Fblog%2Fthe-history-of-hello-world%2F&title=The%20History%20of%20Hello%20World +[2]: http://en.wikipedia.org/wiki/%22Hello,_World!%22_program +[3]: http://whatis.techtarget.com/definition/Hello-World +[4]: http://www.win-vector.com/blog/2008/02/hello-world-an-instance-rhetoric-in-computer-science/ +[5]: http://c2.com/cgi/wiki?HelloWorld diff --git a/published/20170523 Best Websites to Download Linux Games.md b/published/201901/20170523 Best Websites to Download Linux Games.md similarity index 100% rename from published/20170523 Best Websites to Download Linux Games.md rename to published/201901/20170523 Best Websites to Download Linux Games.md diff --git a/published/20170921 The Rise and Rise of JSON.md b/published/201901/20170921 The Rise and Rise of JSON.md similarity index 100% rename from published/20170921 The Rise and Rise of JSON.md rename to published/201901/20170921 The Rise and Rise of JSON.md diff --git a/published/20170928 How to create a free baby monitoring system with Gonimo.md b/published/201901/20170928 How to create a free baby monitoring system with Gonimo.md similarity index 100% rename from published/20170928 How to create a free baby monitoring system with Gonimo.md rename to published/201901/20170928 How to create a free baby monitoring system with Gonimo.md diff --git a/translated/talk/20171119 The Ruby Story.md b/published/201901/20171119 The Ruby Story.md similarity index 100% rename from translated/talk/20171119 The Ruby Story.md rename to published/201901/20171119 The Ruby Story.md diff --git a/published/20171206 Getting started with Turtl, an open source alternative to Evernote.md b/published/201901/20171206 Getting started with Turtl, an open source alternative to Evernote.md similarity index 100% rename from published/20171206 Getting started with Turtl, an open source alternative to Evernote.md rename to published/201901/20171206 Getting started with Turtl, an open source alternative to Evernote.md diff --git a/published/201901/20171222 10 keys to quick game development.md b/published/201901/20171222 10 keys to quick game development.md new file mode 100644 index 0000000000..34a63f44dc --- /dev/null +++ b/published/201901/20171222 10 keys to quick game development.md @@ -0,0 +1,100 @@ +快速开发游戏的十个关键 +====== + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/computer_keyboard_laptop_development_code_woman.png?itok=vbYz6jjb) + +十月初，由 Opensource.com 赞助的首届 [Open Jam][1] 吸引了来自世界各地的团队的 45 个参赛项目。这些队伍只用了三天时间就用开源软件制作出一个游戏来参与角逐，[有三支队伍取得了胜利][2]。 + +我们在我们的大学为每一位愿意参与的人举办了我们自己的 Open Jam 活动。我们预留了周末的计算机实验室，并教大家使用开源软件来创建游戏和游戏素材：游戏引擎：[Godot][3]、音乐：[LMMS][4]、2D 素材：[GIMP][5]、3D 素材：[Blender][6]。我们的活动产出了三个游戏：[Loathsome][7]、[Lost Artist][8] 和 [Paint Rider][9]（我做的）。 + +根据我在游戏开发和游戏开发方面的经验，这里有 10 条关于游戏引擎、编码和快速游戏开发的经验教训。 + +### 1、限定规模 + +很容易想要去做一个规模宏大的冒险游戏或者可以比拟你最喜欢的游戏的东西。如果你有一些经验，追求超乎游戏 Jam 活动的东西可能很酷，但不要高估自己拥有的时间。我欣赏游戏 Jam 活动的一点是它强制你快速将一个游戏从概念阶段变成最终产品，因为你的时间非常有限。这也就是限定规模如此重要的原因。 + +这个 Open Jam 的主题是“留下痕迹”，题目一出来，我和朋友就开始讨论什么样的游戏适合该主题。一个想法就是做玩家能在敌人身上留下伤痕的 3D 拳击游戏。我几乎没有做 3D 游戏的经验，我想做好的话，在我甚至还没发掘出可玩性之前，就得花太多时间在学习如何让痕迹合理和打击有效。 + +### 2、尽早可玩 + +这是我对游戏 Jam 活动最中肯的建议。试着做出核心机制，快速写出代码，这样你就可以测试并决定它是否值得做成一个完整的游戏。不应该只剩几个小时截止了，你的游戏才可玩。像 Open Jam 这样的三天的活动，不应该花费几个小时以上来做一个可以运行的演示。 + +### 3、保持简单 + +你想加入的每个特性都会延长整个开发时间。因为你不能迅速使之运行，所以无从得知提交一个新特性是否会消耗大量时间。街机风格的高分作品往往会在游戏 Jam 活动中表现良好，它们天生就很简单。一旦核心部分完成，你可以开始加入特性并润色，无需担心最后游戏是否功能正常。 + +### 4、从其他游戏获取灵感 + +可能你想做出完全原创的作品，但有个可以基于它开发的原型极其有用。这将节省重复劳动的时间，因为你已经知道什么有趣。告诉自己实践的经验越多，越容易做出包含自己想法的大型游戏，所以你也能从再创作其他人的作品中得到很好地练习。 + +考虑到 Open Jam 的“留下痕迹”主题，我觉得创作一个玩的时候可以留下颜料痕迹的游戏会很有趣，这样也可以看到你留下的标记。我记得有款老式动画游戏 [Line Rider 2 Beta][10] （后来叫 Paint Rider），而且知道玩的时候按住 Control 键可以画出痕迹的彩蛋。我简化了这个概念，甚至只需要一个按键来垂直移动。（更像老式飞机游戏）。进入到 Jam 活动大概一两个小时后，我就有了基本模型，可以用一个按钮上下移动和留下小黑圈的痕迹。 + +### 5、不要忽视可得性 + +确保尽可能多的人能玩你的游戏。某个提交到 Open Jam 的游戏是虚拟现实游戏。尽管那很酷，但几乎没有人可以玩，因为拥有 VR 设备的人不多。所幸它的开发者并不期望取得好名次，只是想练手。但如果你想和人们分享你的游戏（或者赢得游戏 Jam 活动），注意可得性是很重要的。 + +Godot （和其他大多数游戏引擎）允许你在所有主流平台发布游戏。提交游戏时，特别是在 [Itch.io][11]，有个浏览器版本就可以支持大多数人玩。但尽你所能去发布在更多的平台和操作系统上。我甚至试着在移动端发布 Paint Rider，但技术有限。 + +### 6、不要做得太难 + +如果游戏需要花费过多精力去学或者玩，你将失去一部分玩家。要保持简单和限定规模，这在游戏计划阶段非常重要。再次重申，想出一个需要花上十天半个月开发的宏大的游戏创意很容易；难的是做出好玩、简单的游戏。 + +给我的妈妈介绍了 Paint Rider 之后，她很快开始玩起来，我认为不需要跟她说明更多。 + +### 7、不用太整洁 + +如果你习惯于花时间在设计模式上和确保代码可复用、可适应，试着放松一点。如果你花太多时间考虑设计，当你最后到了可以玩游戏的时候，你可能发现游戏不是很有趣，那时候就来不及修改了。 + +这过程也适用于简化更严格的游戏：快速码出验证概念性展示模型，直到找出值得做成完整游戏的，然后你可以潜心建立完美的代码来支持它。为游戏 Jame 活动创作的游戏就像是个快速开发一个可验证的模型一样。 + +### 8、但也不要太随意 + +另一方面， [意大利面式代码][12] 容易失控，即使游戏开发没有大量代码。还好大多是游戏引擎都考虑到了设计模式。就拿 Godot 的[信号][13] 功能来说，节点可以发送数据信息给它们“连上了”的节点 —— 这是你的设计自动成型的[观察者模式][14]。只要你知道如何利用这种游戏引擎的特性的优势，就可以快速写代码，你的代码也不会特别难读。 + +### 9、取得反馈 + +向人们展示你正在做的。让他们试一试并看看他们说些啥。看看他们如何玩你的游戏，找找他们有没有发现你预料之外的事。如果游戏 Jam 活动有 [Discord][15] 频道或者类似的，把你的游戏放上去，人们会反馈给你想法。Paint Rider 的一个确定的功能是画布循环，所以你可以看到之前留下来的画。在有人问我为什么这个游戏没有之前，我甚至没有考虑那个机制。 + +团队协作的话，确保有可以传递周围反馈的人参与这个开发。 + +而且不要忘了用相同的方式帮助其他人；如果你在玩其他人游戏的时候发现了有助于你游戏的东西，这就是双赢。 + +### 10、哪里找资源 + +做出所有你自己的资源真的会拖你后腿。Open Jam 期间，当我忙于组装新特性和修漏洞时，我注意到 Loathsome 的开发者花了大量时间在绘制主要角色上。你可以简化游戏的艺术风格创作并且用一些视听效果尚可的东西，但这里还有其他选择。试着寻找 [Creative Commons][16] 许可的或免费音乐站点（比如 [Anttis Instrumentals][17]）的资源。或者，可行的话，组建一个有专门艺术家、作家或者音乐家的团队。 + +其他你可能觉得有用的软件有 [Krita][18]，这是一款适合数字绘画的开源 2D 图像生成软件，特别是如果你有一块绘图板的话；还有 [sfxr][19]，这是一款游戏音效生成软件，很多参数可以调，但正如它的开发者所说：“它的基本用法包括了按下随机按钮。”（Paint Rider 的所有音效都是用 Sfxr 做的。）你也可以试试 [Calinou][20] 的众多但有序的开源游戏开发软件列表。 + +你参加 Open Jam 或者其他游戏 Jam 并有别的建议吗？对我未提及的有问题吗？有的话，请在评论中分享。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/17/12/10-keys-rapid-open-source-game-development + +作者：[Ryan Estes][a] +译者：[XYenChi](https://github.com/XYenChi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/figytuna +[1]:https://itch.io/jam/open-jam-1 +[2]:https://opensource.com/article/17/11/open-jam +[3]:https://godotengine.org/ +[4]:https://lmms.io/ +[5]:https://www.gimp.org/ +[6]:https://www.blender.org/ +[7]:https://astropippin.itch.io/loathsome +[8]:https://masonraus.itch.io/lost-artist +[9]:https://figytuna.itch.io/paint-rider +[10]:http://www.andkon.com/arcade/racing/lineriderbeta2/ +[11]:https://itch.io/ +[12]:https://en.wikipedia.org/wiki/Spaghetti_code +[13]:http://kidscancode.org/blog/2017/03/godot_101_07/ +[14]:https://en.wikipedia.org/wiki/Observer_pattern +[15]:https://discordapp.com/ +[16]:https://creativecommons.org/ +[17]:http://www.soundclick.com/bands/default.cfm?bandID=1277008 +[18]:https://krita.org/en/ +[19]:http://www.drpetter.se/project_sfxr.html +[20]:https://notabug.org/Calinou/awesome-gamedev/src/master/README.md diff --git a/published/20171227 YAML- probably not so great after all.md b/published/201901/20171227 YAML- probably not so great after all.md similarity index 100% rename from published/20171227 YAML- probably not so great after all.md rename to published/201901/20171227 YAML- probably not so great after all.md diff --git a/published/20180108 5 arcade-style games in your Linux repository.md b/published/201901/20180108 5 arcade-style games in your Linux repository.md similarity index 100% rename from published/20180108 5 arcade-style games in your Linux repository.md rename to published/201901/20180108 5 arcade-style games in your Linux repository.md diff --git a/published/201901/20180130 tmux - A Powerful Terminal Multiplexer For Heavy Command-Line Linux User.md b/published/201901/20180130 tmux - A Powerful Terminal Multiplexer For Heavy Command-Line Linux User.md new file mode 100644 index 0000000000..a227f86d7d --- /dev/null +++ b/published/201901/20180130 tmux - A Powerful Terminal Multiplexer For Heavy Command-Line Linux User.md @@ -0,0 +1,261 @@ +tmux：适用于重度命令行 Linux 用户的终端复用器 +====== + +tmux 是终端复用器terminal multiplexer的缩写，它允许用户在单个窗口中创建或启用多个终端（垂直或水平），当你处理不同的问题时，可以在单个窗口中轻松访问和控制它们。 + +它使用客户端-服务器模型，允许在用户之间共享会话，也可以将终端连接到 tmux 会话。我们可以根据需要轻松移动或重新排列虚拟控制台。终端会话可以从一个虚拟控制台自由切换到另一个。 + +tmux 依赖于 `libevent` 和 `ncurses` 库。tmux 在屏幕底部提供了一个状态行，它显示当前 tmux 会话的有关信息，例如当前窗口编号、窗口名称、用户名、主机名、当前时间和日期。 + +启动 tmux 时，它会在一个单独窗口上创建一个新的会话，并将其显示在屏幕上。它允许用户在同一个会话中创建任意数量的窗口。 + +许多人说它类似于 `screen`，但我不这么认为，因为它提供了许多配置选项。 + +**注意：** `Ctrl+b` 是 tmux 中的默认命令前缀，因此，要在 tmux 中执行任何操作，你必须先输入该前缀然后输入所需的选项。 + +### tmux 特性 + + * 创建任意数量的窗口 + * 在一个窗口中创建任意数量的窗格 + * 它允许垂直和水平分割 + * 分离并重新连接窗口 + * 客户端-服务器架构，这允许用户之间共享会话 + * tmux 提供许多配置技巧 + +**建议阅读：** + +- [tmate - 马上与其他人分享你的终端会话][2] +- [Teleconsole - 一个与其他人分享终端会话的工具][3] + +### 如何安装 tmux 命令 + +大多数 Linux 系统默认预安装 tmux 命令。如果没有，按照以下步骤安装。 + +对于 Debian/Ubuntu，使用 [APT-GET 命令][4]或 [APT 命令][5]来安装： + +``` +$ sudo apt install tmux +``` + +对于 RHEL/CentOS，使用 [YUM 命令][6]来安装： + +``` +$ sudo yum install tmux +``` + +对于 Fedora，使用 [DNF 命令][7]来安装： + +``` +$ sudo dnf install tmux +``` + +对于 Arch Linux，使用 [Pacman 命令][8]来安装： + +``` +$ sudo pacman -S tmux +``` + +对于 openSUSE，使用 [Zypper 命令][9]来安装： + +``` +$ sudo zypper in tmux +``` + +### 如何使用 tmux + +在终端上运行以下命令来启动 tmux 会话。启动 tmux 后，它会在一个新窗口中创建新会话，并将使用你的用户账户自动登录到你的默认 shell。 + +``` +$ tmux +``` + +![][11] + +你会得到类似于我们上面的截图。tmux 附带状态栏，显示有关当前会话详细信息、日期、时间等。 + +状态栏信息如下： + + * `[0]`：它表示由 tmux 服务器创建的会话号。默认情况下，它从 0 开始。 + * `0:bash`：表示会话号、命令行提示符（这里的 `bash` 表示 shell 名称）。 + * `*`：这表示该窗口现在处于活动状态。 + * 主机名：显示服务器的完全主机名。 + * 日期与时间：显示当前日期和时间。 + +（LCTT 译注：tmux 的状态可以根据需要定制，也会因环境、版本的不同而不同。） + +### 如何拆分窗口 + +tmux 允许用户垂直或水平分割窗口，称为窗格。每个窗格都包含自己独立运行的终端实例。我们来看看如何做到这一点。 + +按下 `Ctrl+b, %` 来垂直分割窗格。 + +![][13] + +按下 `Ctrl+b, "` 来水平分割窗格。 + +![][14] + +### 如何在窗格之间移动 + +假设，我们创建了一些窗格，希望在它们之间移动，这该怎么做？如果你不知道怎么做，那么使用 tmux 就没有意义了。使用以下控制键执行操作。在窗格之间移动有许多方法。 + +- 按 `Ctrl+b, ←` - 选择左边的窗格 +- 按 `Ctrl+b, →` - 选择右边的窗格 +- 按 `Ctrl+b, ↑` - 选择上边的窗格 +- 按 `Ctrl+b, ↓` - 选择下边的窗格 +- 按 `Ctrl+b, {` - 来向左交换窗格 +- 按 `Ctrl+b, }` - 来向右交换窗格 +- 按 `Ctrl+b, o` - 切换到下一个窗格（从左到右，从上到下） +- 按 `Ctrl+b, ;` - 移动到先前活动的窗格 + +出于测试目的，我们将在窗格之间移动。现在我们在 `pane2` 中，它展示了 `lsb_release -a` 命令的输出。 + +![][15] + +我们将移动到 `pane0`，它显示 `uname -a` 命令的输出。 + +![][16] + +### 如何打开/创建新窗口 + +你可以在一个终端内打开任意数量的窗口。 + +- 按 `Ctrl+b, c` 来创建一个新窗口。 +- 按 `Ctrl+b, n` 移动到下一个窗口。 +- 按 `Ctrl+b, p` 移动到上一个窗口。 +- 按 `Ctrl+b, 0` ~ `Ctrl+b, 9` 立即移动到特定窗口。 +- 按 `Ctrl+b, l` 移动到先前选择的窗口。 + +我有两个窗口，第一个窗口有三个窗格，其中包含操作系统版本信息，`top` 命令输出和内核信息。 + +![][17] + +第二个窗口有两个窗格，其中包含 Linux 发行版 logo 信息。使用以下命令执行操作： + +![][18] + +按 `Ctrl+b, w` 以交互方式选择当前窗口。 + +![][19] + +### 如何缩放窗格 + +你正在一些非常小的窗格中工作，并且你希望将其缩小以进行进一步的工作。要做到这一点，使用以下键绑定。 + +目前我们有三个窗格，我在 `pane1` 工作，它使用 `top` 命令显示系统活动信息，我将缩放它。 + +![][17] + +缩放窗格时，它将隐藏所有其它窗格，并只显示窗口中的缩放窗格。 + +![][20] + +按 `Ctrl+b, z` 缩放窗格，并再次按下它使缩放窗格恢复原状。 + +### 显示窗格信息 + +要了解窗格编号及其大小，运行以下命令。 + +按 `Ctrl+b, q` 可简单显示窗格索引。 + +![][21] + +### 显示窗口信息 + +要知道窗口编号、布局大小，与窗口关联的窗格数量及其大小等，运行以下命令。 + +只需运行 `tmux list-windows` 即可查看窗口信息。 + +![][22] + +### 如何调整窗格大小 + +你可能需要调整窗格大小来满足你的要求。你必须按下 `Ctrl+b, :`，然后在页面底部的黄色颜色条上输入以下详细信息。 + +![][23] + +在上一部分中，我们打印了窗格索引，它同时也显示了窗格大小。为了测试，我们要向增加 `10` 个单元。参考以下输出，该窗格将 pane1 和 pane2 的大小从 `55x21` 增加到 `55x31`。 + +![][24] + +**语法：** `Ctrl+b, :` 然后输入 `resize-pane [options] [cells size]` + +- `Ctrl+b, :` 然后输入 `resize-pane -D 10` 将当前窗格大小向下调整 10 个单元。 +- `Ctrl+b, :` 然后输入 `resize-pane -U 10` 将当前窗格大小向上调整 10 个单元。 +- `Ctrl+b, :` 然后输入 `resize-pane -L 10` 将当前窗格大小向左调整 10 个单元。 +- `Ctrl+b, :` 然后输入 `resize-pane -R 10` 将当前窗格大小向右调整 10 个单元。 + +### 分离并重新连接 tmux 会话 + +tmux 最强大的功能之一是能够在需要时分离和重新连接会话。 + +运行一个长时间运行的进程，然后按下 `Ctrl+b`，接着按 `d`，通过离开正在运行的进程安全地分离你的 tmux 会话。 + +**建议阅读：** [如何在断开 SSH 会话后保持进程/命令继续运行][25] + +现在，运行一个长时间运行的进程。出于演示目的，我们将把此服务器备份移动到另一个远程服务器以进行灾难恢复（DR）。 + +``` +$ rsync -avzhe ssh /backup root@192.168.0.161:/backups/week-1/ +``` + +在分离 tmux 会话之后，你将获得类似下面的输出。 + +``` +[detached (from session 0)] +``` + +运行以下命令以列出可用的 tmux 会话。 + +``` +$ tmux ls +0: 3 windows (created Tue Jan 30 06:17:47 2018) [109x45] +``` + +现在，使用适当的会话 ID 重新连接 tmux 会话，如下所示： + +``` +$ tmux attach -t 0 +``` + +### 如何关闭窗格和窗口 + +只需在相应的窗格中输入 `exit` 或按下 `Ctrl-d` 即可关闭它，和终端关闭类似。要关闭窗口，按下 `Ctrl+b, &`。 + +好了，就到这里了，希望你喜欢上它。 + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/tmux-a-powerful-terminal-multiplexer-emulator-for-linux/ + +作者：[Magesh Maruthamuthu][a] +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://www.2daygeek.com/author/magesh/ +[1]:https://www.2daygeek.com/category/terminal-emulator/ +[2]:https://www.2daygeek.com/tmate-instantly-share-your-terminal-session-to-anyone-in-seconds/ +[3]:https://www.2daygeek.com/teleconsole-share-terminal-session-instantly-to-anyone-in-seconds/ +[4]:https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/ +[5]:https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/ +[6]:https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/ +[7]:https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ +[8]:https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/ +[9]:https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/ +[10]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[11]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-1.png +[13]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-2.png +[14]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-3.png +[15]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-4.png +[16]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-5.png +[17]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-8.png +[18]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-6.png +[19]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-7.png +[20]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-9.png +[21]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-10.png +[22]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-14.png +[23]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-11.png +[24]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-13.png +[25]:https://www.2daygeek.com/how-to-keep-a-process-command-running-after-disconnecting-ssh-session/ diff --git a/published/20180302 How to manage your workstation configuration with Ansible.md b/published/201901/20180302 How to manage your workstation configuration with Ansible.md similarity index 100% rename from published/20180302 How to manage your workstation configuration with Ansible.md rename to published/201901/20180302 How to manage your workstation configuration with Ansible.md diff --git a/published/20180307 Protecting Code Integrity with PGP - Part 4- Moving Your Master Key to Offline Storage.md b/published/201901/20180307 Protecting Code Integrity with PGP - Part 4- Moving Your Master Key to Offline Storage.md similarity index 100% rename from published/20180307 Protecting Code Integrity with PGP - Part 4- Moving Your Master Key to Offline Storage.md rename to published/201901/20180307 Protecting Code Integrity with PGP - Part 4- Moving Your Master Key to Offline Storage.md diff --git a/published/20180314 Protecting Code Integrity with PGP - Part 5- Moving Subkeys to a Hardware Device.md b/published/201901/20180314 Protecting Code Integrity with PGP - Part 5- Moving Subkeys to a Hardware Device.md similarity index 100% rename from published/20180314 Protecting Code Integrity with PGP - Part 5- Moving Subkeys to a Hardware Device.md rename to published/201901/20180314 Protecting Code Integrity with PGP - Part 5- Moving Subkeys to a Hardware Device.md diff --git a/published/201901/20180319 6 common questions about agile development practices for teams.md b/published/201901/20180319 6 common questions about agile development practices for teams.md new file mode 100644 index 0000000000..045db356ba --- /dev/null +++ b/published/201901/20180319 6 common questions about agile development practices for teams.md @@ -0,0 +1,62 @@ +关于团队敏捷开发实践的 6 个常见问题 +====== + +> 专家回答了敏捷实践如何帮助团队更有效的 6 个常见问题。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/collab-team-pair-programming-code-keyboard.png?itok=kBeRTFL1) + +”有问题么？“ + +你可能听过演讲者在演讲结束的时候提出这个问题。这是演讲中最重要的部分 —— 毕竟，你不仅仅是听讲座, 而是参加讨论和社群交流。 + +最近，我有机会听到我的同伴 Red Hatters 给当地一所大学的一群技术型学生做一个名为 “[敏捷实践][1]” 的讲座。讲座中有软件工程师 Tomas Tomecek 和敏捷开发的从业者 Fernando Colleone 、Pavel Najman 合作解释了敏捷开发方法的基础，并展示最佳实践在日常活动中的应用。 + +知道了学生们参加这个课程是为了了解什么是敏捷实践以及如何将其应用于项目，我想知道学生们的问题会与我作为敏捷从业者在 Red Hat 每天听到的问题相比有什么不同。结果学生的疑问和我的同事们如出一辙。这些问题都直指敏捷实践的核心。 + +### 1、完美的团队规模是多大？ + +学生们想知道一个小团队和一个大团队的规模是多少。这个问题与任何曾经合作过做项目的人都是相关的。根据 Tomas 作为技术领导的经验，12 个人从事的项目被认为是一个大型团队。现实中，团队规模通常与生产力没有直接关系。在有些时候，在一个地方或同一个时区的小团队也许会比一个成员分布在满世界的大团队更具有生产力。最终，该讲座建议理想的团队大小大概是 5 个人（正如 scrum 开发方法的 7，+-2）。 + +### 2、团队会面临哪些实际挑战？ + +演讲者比较了由本地团队组成的项目（团队成员都是一个办公室的，或者相邻近的人）与分散型的团队（位于不同时区）。当项目需要团队成员之间密切合作时，工程师更喜欢本地的团队，因为时间差异造成的延迟可能会破坏软件开发的“流”。同时，分散型团队可以将可能不适用与当地项目但适用于某些开发用例的技能集合在一起。此外，还有各种最佳方法可用于改进分散型团队中的合作方式。 + +### 3、整理堆积的工作需要多少时间？ + +因为这是一个对于新学习敏捷的学生的介绍性质的演讲，演讲者着重把 [Scrum][2] 和 [Kanban][3] 作为介绍敏捷开发的方法。他们使用 Scrum 框架来作为说明软件编写的方法，并且用 Kanban 作为工作规划和沟通的系统。关于需要多少时间来整理项目堆积的工作，演讲者解释说并没有固定的准则，相对的，实践出真知：在开发的早期阶段，当一个崭新的项目 —— 特别如果团队里有新人 —— 每周可能会花费数个小时在整理工作上。随着时间推移和不断地练习，会越来越高效。 + +### 4、产品负责人是否是必要的? 他们扮演什么样的角色？ + +产品负责人会帮助团队更方便的拓展，然而，职位名称并不重要，重要的是你的团队中有人能够传递用户的意愿。在许多团队中，特别是在大型团队中从事单个任务的团队，首席工程师就可以担任产品负责人。 + +### 5、建议使用哪些敏捷开发的工具？使用 Scrum 或 Kanban 做敏捷开发的时候必须用特定的软件么？ + +尽管使用一些专业软件例如 Jira 或 Trello 会很有帮助，特别是在与大量从事大型企业项目的工作者合作时，但它们不是必需的。Scrum 和 Kanban 可以使用像纸卡这样简单的工具完成。关键是在团队中要有一个清晰的信息来源和紧密的交流。推荐两个优秀的 kanban 开源工具 [Taiga][4] 和 [Wekan][5]。更多信息请查看 [Trello 的 5 个开源替代品][6] 和 [敏捷团队的最好的 7 个开源项目管理工具][7] 。 + +### 6、学生如何在学校项目中使用敏捷开发技术? + +演讲者鼓励学生使用 kanban 在项目结束前使用可视化和概述要完成的任务。关键是要创建一个公共板块，这样整个团队就可以看到项目的状态。通过使用 kanban 或者类似的高度可视化的策略，学生不会在项目后期才发现个别成员没有跟上进度。 + +Scrum 实践比如 sprints 和 daily standups 也是确认每个人都在进步以及项目的各个部分最终会一起发挥作用的绝佳方法。定期检查和信息共享也至关重要。更多关于 Scrum 的信息，访问 [什么是 scrum？][8] 。 + +牢记 Kanban 和 Scrum 只是敏捷开发中众多框架和工具中的两个而已。它们可能不是应对每一种情况的最佳方法。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/3/agile-mindset + +作者：[Dominika Bula][a] +译者：[lixinyuxx](https://github.com/lixinxyuxx) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/dominika +[1]:http://zijemeit.cz/sessions/agile-in-practice/ +[2]:https://www.scrum.org/resources/what-is-scrum +[3]:https://en.wikipedia.org/wiki/Kanban +[4]:https://taiga.io/ +[5]:https://wekan.github.io/ +[6]:https://opensource.com/alternatives/trello +[7]:https://opensource.com/article/18/2/agile-project-management-tools +[8]:https://opensource.com/resources/scrum diff --git a/published/20180321 Protecting Code Integrity with PGP - Part 6- Using PGP with Git.md b/published/201901/20180321 Protecting Code Integrity with PGP - Part 6- Using PGP with Git.md similarity index 100% rename from published/20180321 Protecting Code Integrity with PGP - Part 6- Using PGP with Git.md rename to published/201901/20180321 Protecting Code Integrity with PGP - Part 6- Using PGP with Git.md diff --git a/published/20180326 Manage your workstation with Ansible- Automating configuration.md b/published/201901/20180326 Manage your workstation with Ansible- Automating configuration.md similarity index 100% rename from published/20180326 Manage your workstation with Ansible- Automating configuration.md rename to published/201901/20180326 Manage your workstation with Ansible- Automating configuration.md diff --git a/published/20180327 Protecting Code Integrity with PGP - Part 7- Protecting Online Accounts.md b/published/201901/20180327 Protecting Code Integrity with PGP - Part 7- Protecting Online Accounts.md similarity index 100% rename from published/20180327 Protecting Code Integrity with PGP - Part 7- Protecting Online Accounts.md rename to published/201901/20180327 Protecting Code Integrity with PGP - Part 7- Protecting Online Accounts.md diff --git a/published/201901/20180411 How To Setup Static File Server Instantly.md b/published/201901/20180411 How To Setup Static File Server Instantly.md new file mode 100644 index 0000000000..b0f4fd29b5 --- /dev/null +++ b/published/201901/20180411 How To Setup Static File Server Instantly.md @@ -0,0 +1,176 @@ +如何即时设置一个静态文件服务器 +====== + +![](https://www.ostechnix.com/wp-content/uploads/2018/04/serve-720x340.png) + +曾经想通过网络共享你的文件或项目，但不知道怎么做？别担心！这里有一个名为 **serve** 的简单实用程序，可以通过网络即时共享你的文件。这个简单的实用程序会立即将你的系统变成一个静态文件服务器，允许你通过网络提供文件。你可以从任何设备访问这些文件，而不用担心它们的操作系统是什么。你所需的只是一个 Web 浏览器。这个实用程序还可以用来服务静态网站。它以前称为 “list” 或 “micri-list”，但现在名称已改为 “serve”（提供），这更适合这个实用程序的目的。 + +### 使用 Serve 来设置一个静态文件服务器 + +要安装 serve，首先你需要安装 NodeJS 和 NPM。参考以下链接在 Linux 中安装 NodeJS 和 NPM。 + +* [如何在 Linux 上安装 NodeJS](https://www.ostechnix.com/install-node-js-linux/) + +NodeJS 和 NPM 安装完成后，运行以下命令来安装 serve： + +``` +$ npm install -g serve +``` + +完成！现在是时候 serve 文件或文件夹了。 + +使用 serve 的典型语法是： + +``` +$ serve [options] +``` + +### 提供特定文件或文件夹 + +例如，让我们共享 `Documents` 目录里的内容。为此，运行： + +``` +$ serve Documents/ +``` + +示例输出： + +![][2] + +正如你在上图中看到的，给定目录的内容已通过两个 URL 提供网络支持。 + +要从本地系统访问内容，你只需打开 Web 浏览器，输入 URL `http://localhost:5000/`： + +![][3] + +serve 实用程序以简单的布局显示给定目录的内容。你可以下载（右键单击文件并选择“将链接另存为...”）或只在浏览器中查看它们。 + +如果想要在浏览器中自动打开本地地址，使用 `-o` 选项。 + +``` +$ serve -o Documents/ +``` + +运行上述命令后，serve 实用程序将自动打开 Web 浏览器并显示共享项的内容。 + +同样，要通过网络从远程系统访问共享目录，可以在浏览器地址栏中输入 `http://192.168.43.192:5000`。用你系统的 IP 替换 192.168.43.192。 + +### 通过不同的端口提供内容 + +你可能已经注意到，默认情况下，serve 实用程序使用端口 5000。因此，确保防火墙或路由器中允许使用端口 5000。如果由于某种原因被阻止，你可以使用 `-p` 选项使用不同端口来提供内容。 + +``` +$ serve -p 1234 Documents/ +``` + +上面的命令将通过端口 1234 提供 `Documents` 目录的内容。 + +![][4] + +要提供文件而不是文件夹，只需给它完整的路径，如下所示。 + +``` +$ serve Documents/Papers/notes.txt +``` + +只要知道路径，网络上的任何用户都可以访问共享目录的内容。 + +### 提供整个 `$HOME` 目录 + +打开终端输入 + +``` +$ serve +``` + +这将通过网络共享整个 `$HOME` 目录的内容。 + +要停止共享，按下 `CTRL+C`。 + +### 提供选定的文件或文件夹 + +你可能不想共享所有文件或目录，只想共享其中的一些。你可以使用 `-i` 选项排除文件或目录。 + +``` +$ serve -i Downloads/ +``` + +以上命令将提供整个文件系统，除了 `Downloads` 目录。 + +### 仅在本地主机上提供内容 + +有时，你只想在本地系统而不是整个网络上提供内容。为此，使用 `-l` 标志，如下所示： + +``` +$ serve -l Documents/ +``` + +此命令会仅在本地提供 `Documents` 目录。 + +![][5] + +当你在共享服务器上工作时，这可能会很有用。系统中的所有用户都可以访问共享，但远程用户不能。 + +### 使用 SSL 提供内容 + +由于我们通过本地网络提供内容，因此我们不需要使用 SSL。但是，serve 实用程序可以使用 `-ssl` 选项来使用 SSL 共享内容。 + +``` +$ serve --ssl Documents/ +``` + +![][6] + +要通过 Web 浏览器访问共享，输入 `https://localhost:5000` 或 `https://ip:5000`。 + +![][7] + +### 通过身份验证提供内容 + +在上面的所有示例中，我们在没有任何身份验证的情况下提供内容，所以网络上的任何人都可以在没有任何身份验证的情况下访问共享内容。你可能会觉得应该使用用户名和密码访问某些内容。 + +为此，使用： + +``` +$ SERVE_USER=ostechnix SERVE_PASSWORD=123456 serve --auth +``` + +现在用户需要输入用户名（即 `ostechnix`）和密码（`123456`）来访问共享。（LCTT 译注：123456 是非常不好的密码，仅在实验情况下使用） + +![][8] + +serve 实用程序还有一些其它功能，例如禁用 [Gzip 压缩][9]，设置 CORS 头以允许来自任河源的请求，防止自动复制地址到剪贴板等。通过以下命令，你可以阅读完整的帮助部分。 + +``` +$ serve help +``` + +好了，这就是全部了。希望这可以帮助到你。更多好东西要来了，敬请关注！ + +共勉！ + +资源： + +* [Serve GitHub 仓库](https://github.com/zeit/serve) + +-------------------------------------------------------------------------------- + +via: https://www.ostechnix.com/how-to-setup-static-file-server-instantly/ + +作者：[SK][a] +选题：[lujun9972](https://github.com/lujun9972) +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://www.ostechnix.com/author/sk/ +[1]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[2]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-1.png +[3]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-2.png +[4]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-4.png +[5]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-3.png +[6]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-6.png +[7]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-5-1.png +[8]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-7-1.png +[9]:https://www.ostechnix.com/how-to-compress-and-decompress-files-in-linux/ diff --git a/published/20180419 5 guiding principles you should know before you design a microservice.md b/published/201901/20180419 5 guiding principles you should know before you design a microservice.md similarity index 100% rename from published/20180419 5 guiding principles you should know before you design a microservice.md rename to published/201901/20180419 5 guiding principles you should know before you design a microservice.md diff --git a/published/20180428 A Beginners Guide To Flatpak.md b/published/201901/20180428 A Beginners Guide To Flatpak.md similarity index 100% rename from published/20180428 A Beginners Guide To Flatpak.md rename to published/201901/20180428 A Beginners Guide To Flatpak.md diff --git a/published/20180503 11 Methods To Find System-Server Uptime In Linux.md b/published/201901/20180503 11 Methods To Find System-Server Uptime In Linux.md similarity index 100% rename from published/20180503 11 Methods To Find System-Server Uptime In Linux.md rename to published/201901/20180503 11 Methods To Find System-Server Uptime In Linux.md diff --git a/published/201901/20180507 Modularity in Fedora 28 Server Edition.md b/published/201901/20180507 Modularity in Fedora 28 Server Edition.md new file mode 100644 index 0000000000..b4247bae8c --- /dev/null +++ b/published/201901/20180507 Modularity in Fedora 28 Server Edition.md @@ -0,0 +1,67 @@ +Fedora 28 服务器版的模块化 +======== + +![](https://fedoramagazine.org/wp-content/uploads/2018/05/f28-server-modularity-1024x433.jpg) + +### 什么是模块化 + +所有开源发行版都面临的一个经典难题是“太快/太慢”的问题。用户安装操作系统是为了能够使用其应用程序。像 Fedora 这样的全面的发行版在大量可用软件方面有其优势和劣势。虽然有用户想要的软件包，但可能无法使用其所需的版本。以下是模块化Modularity如何帮助解决该问题。 + +对于某些用户，Fedora 有时升级得太快。其快速发布周期以及尽可能提供最新稳定软件的愿望可能导致与应用程序的兼容性下降。如果因为 Fedora 将 Web 框架升级为不兼容的版本而导致用户无法运行 Web 应用程序，则会非常令人沮丧。对“太快”问题的经典回答是“Fedora 应该有一个 LTS 版本。”然而，这种方法只能解决问题的一半，并使这个难题的另一面变得更糟。 + +有时候 Fedora 对某些用户而言又升级速度太慢。例如，Fedora 的发布可能与其它想要的软件的发布时间不匹配。一旦 Fedora 版本宣布稳定，打包者必须遵守 [稳定更新政策][1] 并且不能在系统中引入不兼容的更改。 + +Fedora 的模块化从两个方面解决了这个问题。Fedora 仍将根据其传统政策发布标准版本。但是，它还将提供一组模块给出流行软件的限定替代版本。那些处于“太快”阵营的人仍然可以享受 Fedora 的新内核和其它通用平台增强功能。此外，他们仍然可以访问支持其应用程序的旧框架或工具链。 + +此外，那些喜欢更新潮一些的用户可以访问比发布时更新的软件。 + +### 模块化不是什么？ + +模块化不是 [软件集合][2]Software Collections 的直接替代品。这两种技术试图解决许多相同的问题，但有明显的差异。 + +软件集合可以在系统上并行安装不同版本的软件包。但是，它们的缺点是每份安装包都存在于文件系统上的它们自己的命名空间里面。此外，需要告诉每个依赖它们的应用程序在哪里找到它们。 + +使用模块化，系统上只存在一个版本的软件包，但用户可以选择哪个版本。优点是该版本位于系统的标准位置。该程序包不需要对依赖它的应用程序进行特殊更改。来自用户研究的反馈表明，大多数用户实际上并不依赖于并行安装。容器化和虚拟化解决了这个问题。 + +### 为什么不干脆使用容器化？ + +这是另一个常见问题。为什么用户在可以使用容器时还需要模块？答案是，人们仍然需要维护容器中的软件。 模块为那些用户不需要自己维护、更新和修补的容器提供预打包的内容。这就是 Fedora 如何利用发行版的传统价值并将其转移到新的容器化的世界。 + +以下是模块化如何为 Node.js 和 Review Board 的用户解决问题的示例。 + +### Node.js + +许多读者可能熟悉 Node.js，这是一个流行的服务器端 JavaScript 运行时环境。Node.js 采用偶数/奇数版本策略。它的社区支持偶数版本（6.x、8.x、10.x 等）约 30 个月。同时，他们也支持奇数版本，基本上是 9 个月的开发者预览版。 + +由于这个周期的原因，Fedora 在其稳定的仓库中只携带最新的偶数版本的 Node.js。它完全避免了奇数版本，因为它们的生命周期比 Fedora 短，并且通常与 Fedora 发布周期不一致。对于一些希望获得最新和最大增强功能的 Fedora 用户来说，这并不合适。 + +由于模块化，Fedora 28 不是提供了一个版本，而是提供了三个版本的 Node.js，以满足开发人员和稳定部署的需求。Fedora 28 的传统仓库带有 Node.js 8.x。此版本是发布时最新的长期稳定版本。模块仓库（默认情况下在 Fedora 28 Server 版本上可用）也使得更旧的 Node.js 6.x 版本和更新的 Node.js 9.x 开发版本可用。 + +另外，Node.js 在 Fedora 28 之后几天发布了 10.x 上游版本。过去，想要部署该版本的用户必须等到 Fedora 29，或者使用来自 Fedora 之外的源代码。但是，再次感谢模块化，Node.js 10.x 已经在 Fedora 28 的 Modular Updates-Testing 仓库中 [可用][3] 了。 + +### Review Board + +Review Board 是一个流行的 Django 应用程序，用于执行代码审查。Fedora 从 Fedora 13 到 Fedora 21 都包括了 Review Board。此时，Fedora 转移到了 Django 1.7。由于 Django 数据库支持的向后兼容性在不断变化，而 Review Board 无法跟上。它在 RHEL / CentOS 7 的 EPEL 仓库中仍然存在，而仅仅是因为这些发行版的版本幸运地被冻结在 Django 1.6上。尽管如此，它在 Fedora 的时代显然已经过去了。 + +然而，随着模块化的出现，Fedora 能够再次将旧的 Django 作为非默认模块流发布。因此，Review Board 已作为一个模块在 Fedora 上恢复了。Fedora 承载了来自上游的两个受支持的版本：2.5.x 和 3.0.x。 + +### 组合在一起 + +Fedora 一直为用户提供非常广泛的软件使用。Fedora 模块化现在为他们所需的软件版本提供了更深入的选择。接下来的几年对于 Fedora 来说将是非常令人兴奋的，因为开发人员和用户可以以新的和令人兴奋的（或旧的和令人兴奋的）方式组合他们的软件。 + +------ + +via: https://fedoramagazine.org/working-modules-fedora-28/ + +作者：[Stephen Gallagher][a] +选题：[wxy](https://github.com/wxy) +译者：[wxy](https://github.com/wxy) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/author/sgallagh/ +[1]: https://fedoraproject.org/wiki/Updates_Policy#Stable_Releases +[2]: https://www.softwarecollections.org/ +[3]: https://bodhi.fedoraproject.org/updates/FEDORA-MODULAR-2018-2b0846cb86 + diff --git a/published/201901/20180604 4 Firefox extensions worth checking out.md b/published/201901/20180604 4 Firefox extensions worth checking out.md new file mode 100644 index 0000000000..2f71b390b7 --- /dev/null +++ b/published/201901/20180604 4 Firefox extensions worth checking out.md @@ -0,0 +1,111 @@ +4 个值得一提的 Firefox 扩展插件 +====== + +> 这些扩展可以使火狐更具生产力和使用乐趣。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/firefox_blue_lead.jpg?itok=gYaubJUv) + +自从大约 12 年前 Firefox（火狐浏览器）v2.0 推出以来, 我一直是它的用户。它不是那时最好的网络浏览器，但是总会有一个理由让我回到它：我最喜爱的浏览器扩展插件不能工作在其它浏览器上。 + +如今，我喜欢现下的 Firefox，因为它快速、可定制和开源，我也很欣赏那些体现了原开发人员从未想到过的想法的扩展插件：如果你想在没有鼠标的情况下浏览网页呢？如果你不喜欢盯着晚上从显示器里发出来的强光呢？如何在 YouTube 和其他视频托管网站上使用一个更专业的播放器来获得更好的性能和更多播放控制呢？如果你需要更复杂的方法来禁用跟踪器和加快加载页面，该怎么办？ + +幸运的是，这些问题都有答案，我将展现给你我最喜爱的扩展 —— 所有这些都是免费软件或开源的 (即，在 [GNU GPL][1]、[MPL][2] 或 [Apache][3] 许可帧下) ，它们可以使一个优秀的浏览器更优秀。 + +尽管术语加载项add-on和扩展extension的含义稍微不同，但我在本文中的使用不会区分它们。 + +### Tridactyl + +![Tridactyl screenshot][5] + +*Tridactyl 的新选项卡页面，展示了链接的指引。* + +[Tridactyl][6] 使你能够在大多数浏览活动中使用键盘。它的灵感来自于现已不复存在的 [Vimperator][7] 和 [Pentadactyl][8]，而它们受到了 [Vim][9] 的默认键绑定的启发。由于我已经习惯了 Vim 和其他命令行应用程序，我发现了它的功能类似于使用键值 `h/j/k/l` 进行导航，用 `f/F` 可以与超链接进行交互，而且创建自定义的键绑定和命令非常方便。 + +Tridactyl 最近刚刚实现了一个可选的本地信使（目前，仅适用于 GNU/Linux 和 Mac OSX），提供了更酷的功能。例如，有了它，你可以隐藏 Firefox 用户界面上的一些元素（以 Vimperator 和 Pentadactyl 的方式）、在外部程序中打开链接或当前页（我经常用 [mpv][10] 和 [youtube-dl][11] 播放视频）、通过按 `Ctrl-I`（或者任意你选择的组合键）用你喜爱的编辑器来编辑文本框的内容。 + +话虽如此，但要记住，这是一个相对早期的项目，细节可能还是很粗糙。另一方面，它的开发非常活跃，当你回顾它早期的缺陷时，未尝不是一种乐趣。 + +### Open With + +![Open With Screenshot][13] + +*Open With 提供的菜单。我可以用这里列出的一个外部程序打开当前页面。* + +说到与外部程序的互动，有时能够用鼠标来做到这一点还是让人很高兴的。这是 [Open With][14] 的用武之地。 + +除了添加的上下文菜单（如屏幕截图所示）之外，你还可以通过单击加载项栏上的扩展图标来找到自己定义的命令。如[它在 Mozilla Add-ons 页面上][14] 的图标和描述所示，它主要是为了切换到其它的 web 浏览器，但我也可以轻松地将它与 mpv 和 youtube-dl 相配合。 + +它也提供了键盘快捷方式，但它们受到了严重限制。可以在扩展设置的下拉列表中选择的组合不超过三种。相反，Tridactyl 允许我将命令分配给几乎任何没有被 Firefox 所阻止的东西。没错，Open With 目前为鼠标而准备的。 + +### Stylus + +![Stylus Screenshot][16] + +*在这个屏幕截图中，我刚刚搜索并为当前正在浏览的 Stylus 的网站安装了一个黑暗主题。即使是弹出窗口也可以定制风格（称为 Deepdark Stylus）！* + +[Stylus][17] 是一个用户样式管理器，这意味着可以通过编写自定义 CSS 规则并将其加载到 Stylus 中来更改任何网页的外观。如果你不懂 CSS，在如 [userstyles.org][18] 这样网站上有大量的其他人制作的样式。 + +现在，你可能会问，“这不就是 [Stylish][19] 么？” 你是对的！Stylus 是基于 Stylish 的，并提供了更多的改进：它不包含任何远程记录、尊重你的隐私，所有开发都是公开的（尽管 Stylish 仍在积极开发，我一直未能找到最新版本的源代码），而且它还支持 [UserCSS][20]。 + +UserCSS 是一种有趣的格式，尤其是对于开发人员来说。我已经为不同的网站写了几种用户样式（主要是黑暗主题，和为了提高可读性的调整），虽然 Stylus 的内部编辑器很好，我还是喜欢用 Neovim 编辑代码。为了做到这样我所需要做的就是用 “.user.css” 作为本地加载文件的后缀名，在 Stylus 里启动 “Live Reload” 选项，只要我在 Neovim 中保存文件就会应用所有的更改。它也支持远程 UserCSS 文件，因此，每当我将更改推送到 GitHub 或任何基于 git 的开发平台时，它们将自动对用户可用。（我提供了指向该文件的原始版本的链接，以便他们可以轻松地访问它。） + +### uMatrix + +![uMatrix Screenshot][22] + +*uMatrix 的用户界面，显示当前访问过的网页的当前规则。* + +Jeremy Garcia 在他发表在 Opensource.com 的[文章][23]中提到了一个优秀的拦截器 uBlock Origin。我想提请大家关注另一个由 [gorhill][24] 开发的扩展插件: uMatrix 。 + +[uMatrix][25] 允许你为网页上的某些请求设置拦截规则，可以通过点击该加载项的弹出窗口来切换（在上面的屏幕截图中可以看到）。这些请求的区别在于脚本的类别、脚本发起的请求、cookies、CSS 规则、图像、媒体、帧，和被 uMatrix 标记为“other” 的其它内容。例如，你可以设置全局规则，以便在默认情况下允许所有请求，并将特定的请求添加到黑名单中（更方便的方法），或在默认情况下阻止所有内容，并手动将某些请求列入白名单（更安全的方法）。如果你一直在使用 NoScript 或 RequestPolicy，你可以从它们 [导入][26] 你的白名单规则。 + +另外 uMatrix 支持 [hosts 文件][27]，可用于阻止来自某些域的请求。不要与 uBlock Origin 所使用的筛选列表混淆，它使用的语法同 Adblock Plus 一样。默认情况下，uMatrix 会通过几个 hosts 文件阻止已知的分发广告、跟踪器和恶意软件的服务器，如果需要，你可以添加更多外部数据源。 + +那么你将选择哪一个：uBlock Origin 或 uMatrix ？就个人而言，我在电脑上两个都用，而只在安卓手机上用 uMatrix 。[据 gorhill 所说][28]，两者之间存在某种重叠，但它们有不同的目标用户和目地。如果你想要的只是阻止跟踪器和广告的简单方法，uBlock Origine 是更好的选择；另一方面，如果你希望对网页在浏览器中可以执行或不能执行的操作进行精细的控制，即使需要一些时间来进行配置，并且可能会阻止某些网站如预期的工作，uMatrix 也是更好的选择。 + +### 结论 + +目前，这些是 Firefox 里我最喜欢的扩展。Tridactyl 通过依靠键盘和与外部程序交互，加快了浏览导航速度；Open With 能让我用鼠标在另外一个程序中打开页面；Stylus 是全面的用户样式管理器，对用户和开发人员都很有吸引力；uMatrix 本质上是 Firefox 的防火墙，可以用于过滤未知的请求。 + +尽管我基本上只是讨论了这些加载项的好处，但没有一个软件是完美的。如果你喜欢它们中的任何一个，并认为它们的某些方面可以改进，我建议你去它们的 Github 页面，并查看它们的贡献指南。通常情况下，自由开源软件的开发人员是欢迎错误报告和提交请求的。告诉你的朋友或道谢也是帮助开发者的好方法，特别是如果这些开发者是在业余时间从事他们的项目的话。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/6/firefox-open-source-extensions + +作者：[Zsolt Szakács][a] +选题：[lujun9972](https://github.com/lujun9972) +译者：[lixinyuxx](https://github.com/lixinyuxx) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/zsolt +[1]:https://www.gnu.org/licenses/gpl-3.0.en.html +[2]:https://www.mozilla.org/en-US/MPL/ +[3]:https://www.apache.org/licenses/LICENSE-2.0 +[4]:/file/398411 +[5]:https://opensource.com/sites/default/files/uploads/tridactyl.png "Tridactyl's new tab page, showcasing link hinting" +[6]:https://addons.mozilla.org/en-US/firefox/addon/tridactyl-vim/ +[7]:https://github.com/vimperator/vimperator-labs +[8]:https://addons.mozilla.org/en-US/firefox/addon/pentadactyl/ +[9]:https://www.vim.org/ +[10]:https://mpv.io/ +[11]:https://rg3.github.io/youtube-dl/index.html +[12]:/file/398416 +[13]:https://opensource.com/sites/default/files/uploads/openwith.png "A context menu provided by Open With. I can open the current page with one of the external programs listed here." +[14]:https://addons.mozilla.org/en-US/firefox/addon/open-with/ +[15]:/file/398421 +[16]:https://opensource.com/sites/default/files/uploads/stylus.png "In this screenshot, I've just searched for and installed a dark theme for the site I'm currently on with Stylus. Even the popup has custom style (called Deepdark Stylus)!" +[17]:https://addons.mozilla.org/en-US/firefox/addon/styl-us/ +[18]:https://userstyles.org/ +[19]:https://addons.mozilla.org/en-US/firefox/addon/stylish/ +[20]:https://github.com/openstyles/stylus/wiki/Usercss +[21]:/file/398426 +[22]:https://opensource.com/sites/default/files/uploads/umatrix.png "The user interface of uMatrix, showing the current rules for the currently visited webpage." +[23]:https://opensource.com/article/18/5/firefox-extensions +[24]:https://addons.mozilla.org/en-US/firefox/user/gorhill/ +[25]:https://addons.mozilla.org/en-US/firefox/addon/umatrix +[26]:https://github.com/gorhill/uMatrix/wiki/FAQ +[27]:https://en.wikipedia.org/wiki/Hosts_(file) +[28]:https://github.com/gorhill/uMatrix/issues/32#issuecomment-61372436 diff --git a/translated/tech/20180606 Working with modules in Fedora 28.md b/published/201901/20180606 Working with modules in Fedora 28.md similarity index 90% rename from translated/tech/20180606 Working with modules in Fedora 28.md rename to published/201901/20180606 Working with modules in Fedora 28.md index bf5c4237f2..338e6accc6 100644 --- a/translated/tech/20180606 Working with modules in Fedora 28.md +++ b/published/201901/20180606 Working with modules in Fedora 28.md @@ -23,7 +23,7 @@ sudo dnf -y update dnf module list ``` -输出列出了一组模块，这些模块显示了每个模块的关联流、版本和可用安装配置文件。模块流旁边的 `[d]` 表示安装命名模块时使用的默认流。 +输出列出了一组模块，这些模块显示了每个模块的关联的流、版本和可用安装配置文件。模块流旁边的 `[d]` 表示安装命名模块时使用的默认流。 输出还显示大多数模块都有名为 `default` 的配置文件。这不是巧合，因为 `default` 是默认配置文件使用的名称。 @@ -83,22 +83,22 @@ sudo dnf -y module install reviewboard/server 但是，安装 reviewboard:3.0/server 配置非常平常。reviewboard:3.0 模块的服务器配置与默认配置文件相同 —— 因此无需安装。 -### 启动 Review Board 网站 +### 启动 Review Board 网站 现在已经安装了 Review Board 3.0 模块及其相关软件包，[创建一个本地运行的 Review Board 网站][6]。无需解释，请复制并粘贴以下命令： ``` sudo rb-site install --noinput \ - --domain-name=localhost --db-type=sqlite3 \ - --db-name=/var/www/rev.local/data/reviewboard.db \ - --admin-user=rbadmin --admin-password=secret \ - /var/www/rev.local + --domain-name=localhost --db-type=sqlite3 \ + --db-name=/var/www/rev.local/data/reviewboard.db \ + --admin-user=rbadmin --admin-password=secret \ + /var/www/rev.local sudo chown -R apache /var/www/rev.local/htdocs/media/uploaded \ - /var/www/rev.local/data + /var/www/rev.local/data sudo ln -s /var/www/rev.local/conf/apache-wsgi.conf \ - /etc/httpd/conf.d/reviewboard-localhost.conf + /etc/httpd/conf.d/reviewboard-localhost.conf sudo setsebool -P httpd_can_sendmail=1 httpd_can_network_connect=1 \ - httpd_can_network_memcache=1 httpd_unified=1 + httpd_can_network_memcache=1 httpd_unified=1 sudo systemctl enable --now httpd ``` @@ -131,7 +131,7 @@ via: https://fedoramagazine.org/working-modules-fedora-28/ 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 [a]:https://fedoramagazine.org/author/merlinm/ -[1]:https://fedoramagazine.org/modularity-fedora-28-server-edition/ +[1]:https://linux.cn/article-10479-1.html [2]:https://getfedora.org/server/ [3]:https://fedoramagazine.org/howto-use-sudo/ [4]:https://fedoramagazine.org/modularity-fedora-28-server-edition/#comment-476696 diff --git a/published/20180625 8 reasons to use the Xfce Linux desktop environment.md b/published/201901/20180625 8 reasons to use the Xfce Linux desktop environment.md similarity index 100% rename from published/20180625 8 reasons to use the Xfce Linux desktop environment.md rename to published/201901/20180625 8 reasons to use the Xfce Linux desktop environment.md diff --git a/published/201901/20180625 The life cycle of a software bug.md b/published/201901/20180625 The life cycle of a software bug.md new file mode 100644 index 0000000000..672a797015 --- /dev/null +++ b/published/201901/20180625 The life cycle of a software bug.md @@ -0,0 +1,69 @@ +软件 bug 的生命周期 +====== + +> 从发现软件故障到解决它们，这里讲述是开发团队如何压制软件 bug。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/bug_software_issue_tracking_computer_screen.jpg?itok=6qfIHR5y) + +1947 年，发现了第一个计算机 bug —— 被困在计算机继电器中的飞蛾。 + +要是所有的 bug 都能如此简单地发现就好了。随着软件变得越来越复杂，测试和调试的过程也变得更加复杂。如今，软件 bug 的生命周期可能会很长，尽管正确的技术和业务流程可能会有所帮助。对于开源软件，开发人员使用严格的工单服务和协作来查找和解决 bug。 + +### 确认计算机 bug + +在测试过程中，发现的 bug 会报告给开发团队。质量保证测试人员尽可能详细地描述 bug ，报告他们的系统状态、他们正在进行的过程以及 bug 是如何表现出来的。 + +尽管如此，一些 bug 从未得到确认；它们可能会在测试中报告，但永远无法在可控环境中重现。在这种情况下，它们可能得不到解决，而是被关闭。 + +有些计算机 bug 可能很难确认，因为使用的平台种类繁多，用户行为也非常多。有些 bug 只是间歇性地或在非常特殊的情况下发生的，而另一些 bug 可能会出现在随机的情况下。 + +许多人使用开源软件并与之交互，许多 bug 和问题可能是不可重复的，或者可能没有得到充分的描述。不过，由于每个用户和开发人员也都扮演质量保证测试人员的角色，至少在一定程度上，bug 还是很有可能会发现的。 + +确认 bug 后，修复工作就开始了。 + +### 分配要修复的 bug + +已确认的 bug 被分配给负责解决的开发人员或开发团队。在此阶段，需要重现 bug，发现问题，并修复相关代码。如果 bug 的优先级较低，开发人员可以将此 bug 分类为稍后要修复的问题，也可以在该 bug 具有高优先级的情况下直接指派某人修复。无论哪种方式，都会在开发过程中打开一个工单，并且 bug 将成为已知的问题。 + +在开源解决方案中，开发人员可以进行选择他们想要解决的 bug，要么选择他们最熟悉的程序区域，要么从优先级最高的的开始。综合解决方案，如 [GitHub][1] 使得多个开发人员能够轻松地着手解决，而不会干扰彼此的工作。 + +当将 bug 设置为需要修复时，bug 报告者还可以为该 bug 选择优先级。主要的 bug 可能具有较高的优先级，而仅与外观相关的 bug 可能具有较低的级别。优先级确定开发团队解决这些问题的方式和时间。无论哪种方式，所有的 bug 都需要先解决，然后才能认为产品已完成。在这方面，适当的回溯到优先级高的需求也会很有帮助。 + +### 解决 bug + +一旦修复了 bug ，通常会将其作为已解决的 bug 发送回质量保证测试人员。然后，质量保证测试人员再次将产品置于其工作中，以重现 bug。如果无法重现 bug ，质量保证测验人员将假定它已得到适当解决。 + +在开源情况下，任何更改都会被分发，通常是作为正在测试的暂定版本。此测试版本分发给用户，用户再次履行质量保证测试人员的职责并测试产品。 + +如果 bug 再次出现，问题将被发送回开发团队。在此阶段，该 bug 将重新触发，开发团队有责任重复解决该 bug 的循环。这种情况可能会发生多次，尤其是在 bug 不可预知或间歇性发生的情况下。众所周知，间歇性的 bug 很难解决。 + +如果该 bug 不再出现，则该问题将被标记为已解决。在某些情况下，最初的 bug 得到了解决，但由于所做的更改，会出现其他 bug。发生这种情况时，可能需要新的 bug 报告，然后重新开始该过程。 + +### 关闭 bug + +在处理、识别和解决 bug 后，该 bug 将被关闭，开发人员可以转到软件开发和测试的其他阶段。如果始终找不到 bug ，或者开发人员无法重现 bug ，则该 bug 也将被关闭 —— 无论哪种方式，都将开始开发和测试的下一阶段。 + +在测试版本中对解决方案所做的任何更改都将滚动到产品的下一个版本中。如果 bug 是严重的，则在下一个版本发布之前，可能会为当前用户提供修补程序或修补程序。这在安全问题中很常见。 + +软件 bug 可能很难找到，但通过遵循过程，开发人员可以使开发更快、更容易、更一致。质量保证是这一过程的重要组成部分，因为质量保证测试人员必须发现和识别 bug ，并帮助开发人员重现这些 bug 。在 bug 不再发生之前，无法关闭和解决 bug。 + +开源的解决方案分散了质量保证测试、开发和缓解的负担，这往往导致 bug 被更快、更全面地发现和缓解。但是，由于开源技术的性质，此过程的速度和准确性通常取决于解决方案的受欢迎程度及其维护和开发团队的敬业精神。 + +Rich Butkevic 是一个 PMP 项目经理认证,，敏捷开发框架认证（certified scrum master） 并且 维护 [Project Zendo][2]，这是供项目管理专业人员去发现、简化和改进其项目成果策略的网站。可以在 [Richbutkevic.com][3] 或者使用 [LinkedIn][4] 与 Rich 联系。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/6/life-cycle-software-bug + +作者：[Rich Butkevic][a] +选题：[lujun9972](https://github.com/lujun9972) +译者：[lixinyuxx](https://github.com/lixinyuxx) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/rich-butkevic +[1]:https://github.com/ +[2]:https://projectzendo.com +[3]:https://richbutkevic.com +[4]:https://www.linkedin.com/in/richbutkevic diff --git a/published/20180703 10 killer tools for the admin in a hurry.md b/published/201901/20180703 10 killer tools for the admin in a hurry.md similarity index 100% rename from published/20180703 10 killer tools for the admin in a hurry.md rename to published/201901/20180703 10 killer tools for the admin in a hurry.md diff --git a/published/201901/20180722 Dawn of the Microcomputer- The Altair 8800.md b/published/201901/20180722 Dawn of the Microcomputer- The Altair 8800.md new file mode 100644 index 0000000000..2ebac634ff --- /dev/null +++ b/published/201901/20180722 Dawn of the Microcomputer- The Altair 8800.md @@ -0,0 +1,140 @@ +微型计算机的始祖：Altair 8800 +====== + +《大众电子Popular Electronics》的订阅者们是个复杂的群体，该杂志的编辑 Arthur Salsberg 不得不在 [1974 年 12 月刊][1] 中的前言部分指出这点。此前，杂志编辑组曾收到了对《如何搭建家庭媒体中心》文章的抱怨，称这篇文章激励了许多业余电视爱好者走出去，削弱了专业修理人员存在的必要性，这对许多人的电视造成了极大伤害。Salsberg 认为，这个担忧的产生可能是因为大家不清楚《大众电子》读者们的真实水平。他解释道，据杂志内部调查的数据显示，52% 的订阅者都是某方面的电子专家，并且其中的 150,000 人在最近 60 天之内都修过电视。此外，订阅者们平均在电子产品上花费了 470 美金（2018 年则是 3578 美金），并且他们拥有万用表、真空管伏特计、电子管测试仪、晶体管测试仪、射频讯号产生器和示波器等必要设备。“《大众电子》的读者们并不全都是新手。”Salsberg 总结道。 + +熟悉《大众电子》的人居然会质疑它的订阅者，这令我十分吃惊。不过最近 60 天我的确没修过电视。我的电脑对我来说就是一块铝，我甚至没把它拆开看过。1974 年 12 月的《大众电子》刊登的像《驻波比是什么以及如何处理它》和《对万用表的测试》之类的特色文章，甚至连广告都令人生畏。它们中有个看起来像某种立体声系统的东西大胆地写道“除了‘四通道单元（即内建的 SQ、RM 和 CD-4 解码接收器）’，没有任何音频设备是值得期待的”。这也表明了《大众电子》的订阅者一定对电子有很多深入的了解。 + +不过在 [1975 年 1 月刊][2] 中，该杂志为读者们带来了一些他们从没见过的东西。在标题“突破性项目”下面，杂志的封面是一个大大的黑灰色盒子，其前面板上有一组复杂开关和灯。这便是 Altair 8800，“世界上首个有商业竞争力的小型机”，它的售价低于 400 美元。尽管 Altair 被宣传作“小型机minicomputer”，但它实际上是首个商业上成功的新型计算机成员，它首先被称为“微型计算机microcomputers”，最终被称为 PC（个人计算机Personal Computer）。Altair 十分小巧而且很便宜，以至于它成为了当时家家户户都能用起的电脑。正如 Salsberg 所写道，它在《大众电子》上的出现意味着：“家用电脑的时代终于到来了。” + +![《大众电子》1975 年 1 月刊的封面][3] + +此前，我曾写过 [关于 Altair 的文章][4]，但我觉得 Altair 值得重新审视。与当时其它的计算机相比，它并不是一台性能强劲的计算机（尽管它的成本要低得多），它也不是首个采用微处理器的通用计算机（在它之前已经至少有三个基于微处理器的计算机）。但是 Altair 是一种可供我们所有人使用的计算机。它是历史上我们所拥有的设备中首台流行的计算机，而早于 Altair 计算机都是完全不同的机器，那些大型机和笨重的迷你计算机由穿孔卡编程并且很少与之直接交互。不过 Altair 也是台极其简单的计算机，它没有附带任何操作系统甚至是引导程序。除非你为它购买外围设备，否则 Altair 就是一台装配了 RAM、前面板只有一组开关和灯泡的机器。由于 Altair 操作简单，使得重新理解基本的计算概念都成了十分简单的事情，正如模拟信号时代的人们第一次接触到数字设备一样。 + +### Roberts 和他的公司 + +Altair 是由一家名为微型仪器和遥测系统Micro Instrumentation and Telemetry Systems（MITS）的公司所设计制造，这家公司位于美国新墨西哥州的阿尔布开克。MITS 由一个叫 H. Edward Roberts 的人经营。在进入计算器市场之前，该公司已经开始制造模型火箭的遥测系统，该市场在 20 世纪 70 年代初期蓬勃发展。集成电路大大降低了计算器的成本，突然之间它就成了美国每个在职的专业人士的必需品。不幸的是，由于计算器市场竞争过于激烈，到了 1974 年初，MITS 便负债累累。 + +1974 年在计算机界是奇迹迭出的一年annus mirabilis。[^1] 一月的时候，惠普公司推出了世界首个可编程的手持计算器 HP-65。四月的时候，Intel 发布了 Intel 8080，这是他们的第二款 8 位微处理器，它也是首款广受欢迎的微处理器。接着，六月的时候，《无线电电子Radio Electronics》杂志宣传了一台名为 Mark-8 的自制小型计算机，它使用了 Intel 在 1972 年推出的 Intel 8008 微处理器。Mark-8 是有史以来使用微处理器搭建的第三台电脑，它的首次登场是在杂志的封面上。[^2] Mark-8 在《无线电电子》上的出现促使了《大众电子》寻找他们要自己宣传的小型机项目。 + +《大众电子》的订阅者们其实早在 1974 年 12 月就通过邮件获得了 1975 年 1 月刊的刊物。[^3] 所以 Altair 的宣布为这个奇迹迭出的一年annus mirabilis画上了圆满的句号。Altair 的出现是十分重要的，因为此前从未有过向公众提供的价格公道而又功能齐全的电脑。当时，作为最受欢迎的小型计算机之一的 PDP-8 要几千美金才能买到。然而作为 Altair 核心的 Intel 8080 芯片几乎能与 PDP-8 匹敌，甚至更强；8080 支持更广泛的指令集，而且 Altair 可以扩展到 64 kb 内存，显然强于仅有 4 kb 内存的 PDP-8。并且，Mark-8 也不是它的对手，因为它搭载的是只能处理 16 kb 内存的 Intel 8008。在 Mark-8 必须由用户按照说明书在印刷电路板上手动拼装的情况下，Altair 在购买时就已经被组装好了（不过由于后来 MITS 被大量订单淹没，最后真正能获得 Altair 的方式也只有买套件拼装了）。 + +对许多《大众电子》的读者来说，Altair 是他们了解数字计算的起点。1975 年 1 月刊上那篇介绍 Altair 的文章由 Roberts 和 Altair 的共同设计师 William Yates 所写。Roberts 和 Yates 煞费苦心地用电工和无线电狂热者们所熟悉的词汇来介绍了数字硬件和计算机编程的基本概念。他们写道：“一台计算机其实由一块可变的硬件。仅需修改储存于内存之中的位组合形式，便可改变硬件设备的种类。”同时，Roberts 和 Yates 认为编程的基本概念是“足够简单并能在较短时间内掌握，但是想要成为一个高效的程序员必须经验丰富且富有创造力。”对此我十分认同。尽管该部分已经完全组装好了，文章仍包含了用来讲解 Intel 8080 的组成电路的详细图表。文章解释了 CPU 和计算机内存单元的区别，堆栈指针的用法，和汇编语言以及更高级的语言（例如 FORTRAN 和 BASIC）比起手动输入机器码所带来的巨大优势。 + +其实，《大众电子》在 1975 年 1 月刊之前就出版过 Roberts 撰写的系列文章。这一系列作为短期课程被收录在“数字逻辑”专栏中。在 1974 年 12 月刊中，Roberts 为读者们带来了关于构建“超低成本计算机终端”的文章，文章中介绍了可以用于 8 位电脑中输入值的八进制键盘。在介绍这个键盘时，Roberts 解释了晶体管到晶体管的逻辑工作原理，以及关于构建一种可以“记住”数字值的触发器的方法。Roberts 承诺说，这个键盘可以在下个月即将公布的 Altair 电脑中使用。 + +有多少《大众电子》的读者制作了这个键盘我们无从得知，但是那个键盘的确是个很有用的东西。如果没有键盘和其它输入设备，我们只能通过拨动 Altair 面板上的开关来输入值。Altair 的前面板上有一行 16 个开关被用来设置地址，而下方的 8 个则是用来操作计算机的。一行 16 个开关中最右边的 8 个开关也能用来指定要储存在内存中的值。这么做不无道理，因为 Intel 8080 使用 16 位的值来寻址 8 位的字。而前面板的这 16 个开关每一个都代表了一个位，当开关向上时代表 1，向下则代表 0。用这样的方式与计算机交互是个启示（一会儿我们就会讲到），因为 Altair 的面板是真正的二进制界面。这使得你可以尽可能地接触到计算机实体。 + +尽管在当下 Altair 的界面对我们来说完全不像是人用的，不过在那个时代却并不罕见。比如 PDP-8 的面板上有个类似的但更漂亮的二进制输入装置，而且它被涂上了吸引人的黄色和橙色，不过讲真，它真的应该卷土重来。然而 PDP-8 经常与纸带阅读器或电传打字机配合使用，这使得程序输入更加容易。这些 I/O 设备价格高昂，这意味着 Altair 的用户们大都会被那个前面板拦住。正如你可能想象的那样，通过这一堆开关输入一个大型程序是个苦差事。不过幸运的是，Altair 可以与盒式记录器连接，这样一来载入程序就不是什么难事了。Bill Gates 和 Paul Allen 在 MITS 的授权下为 Altair 编写了一个 BASIC 语言版本，并在 1975 年中期发行，这成为了微软有史以来的首次商业尝试。此后，那些买得起电传打字机的用户就能 [通过纸带来将 BASIC 载入 Altair][5] 了，并能使得用户能够通过文字与 Altair 交互。之后，BASIC 便成为了学生们最爱的入门编程语言，并成了早期小型机时代的标准接口。 + +### z80pack + +多亏了网络上一些人，特别是 Udo Munk 的努力，你可以在你的计算机上运行 Altair 的模拟器。这个模拟器是在 Zilog Z80 CPU 的虚拟套件上构建的，这个 CPU 可以运行 Intel 8080 的软件。Altair 模拟器允许你像 Altair 的早期用户们一样拨动前面板上的开关。尽管点击这些开关的感觉不如拨动真实开关的触觉，但是使用 Altair 模拟器仍是一个能让你感受二进制人机交互效率有多低的途径，至少在我看来这非常简明直观。 + +z80pack 是 Udo Munk 开发的 Z80 模拟器套件，你可以在 z80pack 的官网上找到它的下载链接。我在 [上一篇介绍 Altair 的文章中][4] 写到过在 macOS 上使用它的详细过程。如果你能编译 FrontPanel 库和 `altairsim` 可执行程序，你应该能直接运行 `altairsim` 并看到这个窗口： + +![模拟器中的 Altair 面板][6] + +在新版的 z80pack 中（比如我正在使用的 1.36 版本），你可以使用一个叫 Tarbell boot ROM 的功能，我觉得这是用来加载磁盘镜像的。经我测试，这意味着你不能写入到 RAM 中的前几个字。在编辑 `/altairsim/conf/system.conf` 之后，你可以构建带有一个 16 页 RAM 且没有 ROM 或引导加载器的 Altair。除此之外，你还可以用这个配置文件来扩大运行模拟器的窗口大小，不得不说这还是挺方便的。 + +Altair 的面板看起来令人生畏，不过事实上并没有我们想象中的这么可怕。[Altair 说明书][7] 对解释开关和指示灯起到了很大的作用，这个 [YouTube 视频][8] 也是如此。若想输入和运行一个简易的程序，你只需要了解一点点东西。Altair 右上方标签为 D0 到 D7 的指示灯代表当前寻址的字的内容。标签为 A0 到 A15 的指示灯表示当前的地址。地址指示灯下的 16 个开关可以用来设置新地址；当 “EXAMINE” 开关被向上推动时，数据指示灯才会更新以显示新地址上的内容。用这个功能，你便能“观察”到内存中所有的信息了。你也可以将 “EXAMINE” 推下来“EXAMINE NEXT”位置，以自动检查下一个位置上的信息，这使得查看连续的信息更容易了。 + +要将位组合方式保存到内存信息中，请使用最右边的 8 个标签为 0 到 7 的开关。然后，请向上推动 “DEPOSIT” 按钮。 + +在《大众电子》 的 [1975 年 2 月刊][9] 中，Roberts 和 Yates 引导用户输入一小段程序来确保他们的 Altair 正常工作。这个程序从内存中读取两个整型数据并相加之后将和存回内存中。这个小程序仅由 6 条指令组成，但是这 6 条指令涉及了 14 个字的内存，所以要正确地输入它们需要一点时间。这个示例程序也被写入了 Altair 的说明书，原文如下： + +| Address | Mnemonic | Bit Pattern | Octal Equivalent | +| :------: | :------: | :------: | :------: | +| 0 | LDA | 00 111 010 | 0 7 2 | +| 1 | (address) | 10 000 000 | 2 0 0 | +| 2 | (address) | 00 000 000 | 0 0 0 | +| 3 | MOV B, A | 01 000 111 | 1 0 7 | +| 4 | LDA | 00 111 010 | 0 7 2 | +| 5 | (address) | 10 000 001 | 2 0 1 | +| 6 | (address) | 00 000 000 | 0 0 0 | +| 7 | ADD B | 10 000 000 | 2 0 0 | +| 8 | STA | 00 110 010 | 0 6 2 | +| 9 | (address) | 10 000 010 | 2 0 2 | +| 10 | (address) | 00 000 000 | 0 0 0 | +| 11 | JMP | 11 000 011 | 3 0 3 | +| 12 | (address) | 00 000 000 | 0 0 0 | +| 13 | (address) | 00 000 000 | 0 0 0 | + +如果你通过开关来将上表的这些值输入到 Altair，最终会得到一个程序，它会读取内存 128 中的值，并将其与 129 中的值相加，最终将其保存至 130 中。伴随每条取一个地址的指令的地址，它们最开始会给出最低有效位，这便是第二个字节总会被清零的原因了（没有高于 255 的地址）。在输入这个程序并在 128 和 129 中输入了一些值之后，你可以向下短暂推动 “RUN” ，之后再将它推到 “STOP” 位置。因为程序循环执行，以一秒内执行上千次的速度反复地添加并保存那些值。并且最后得到的值总是相同的，如果你停止该程序并查看 130 的内容，你应该能找到正确答案。 + +我不知道普通的 Altair 用户是否使用过汇编程序，不过 z80pack 包括了一个：`z80asm`，意思是适用于 Z80 的汇编程序Z80 assembly，所以它使用了一组不同的助记符。不过因为 Z80 是被设计来兼容为 Intel 8080 写的软件的，所以即使助记符不一样，它们的操作码也是相同的。你可以直接将 `z80asm` 汇编码装载进 Altair： + +``` + ORG 0000H +START: LD A,(80H) ;Load from address 128. + LD B,A ;Move loaded value from accumulator (A) to reg B. + LD A,(81H) ;Load from address 129. + ADD A,B ;Add A and B. + LD (82H),A ;Store A at address 130. + JP START ;Jump to start. +``` + +编译之后，你可以调用汇编程序来将其转换为 Intel HEX 文件： + +```shell +$ ./z80asm -fh -oadd.hex add.asm +``` + +我们用带有 `h` 参数的 `-f` 标识来定义输出的 HEX 文件。你可以用 `-x` 标识来传递 HEX 文件，从而使得 Altair 能够加载该程序： + +```shell +$ ./altairsim -x add.hex +``` + +这会在内存中自动设置前 14 个字，就和你通过开关手动输入这些值一样。你可以直接使用 “RUN” 按钮来替代以前那些繁琐的步骤，这是如此的简单！ + +我不觉得有很多 Altair 用户以这种方式来编写软件。Altair BASIC 发布后，使得 BASIC 成为了 Altair 编程最简单的方法。z80pack 同时也包括了一些不同版本 Altair BASIC 的 HEX 文件；在模拟器中，你可以用这个方式加载 4.0 版本的 4K BASIC： + +```shell +$ ./altairsim -x basic4k40.hex +``` + +当你开启模拟器并按下 “RUN” 按钮之后，你就会看到 BASIC 开始执行了，同时它会在终端中与你交互。它首先会提示你输入你的内存可用量，我们输入 4000 字节。随后，在显示 “OK” 提示符之前，它会问你几个问题，Gates 和 Allen 用这个“OK”来代替标准的 “READY” 并以此节省内存。在这之后，你便可以使用 BASIC 了： + +``` +OK +PRINT 3 + 4 + 7 +``` + +虽然运行 BASIC 只有 4kb 的内存并没有给你足够的空间，但你可以看到它是如何从使用前面板迈出了重要的一步。 + +很显然，Altair 远不及如今的家用电脑和笔记本电脑，并且比它晚十多年发布的 Mac 电脑看上去也是对 这个简朴的 Altair 电脑的巨大飞跃。但是对第一批购买并亲手组装了 Altair 的《大众电子》的读者们来说，Altair 才是他们拥有的第一个真正的全功能电脑，而这一切只用了 400 美金低价和一半的书柜空间。对那时只能用 [一叠卡片][10] 或一卷磁带来与计算机交互的人们来说，Altair 是个令人眼前一亮的玩意。这之后的微型计算机基本都是在对 Altair 改进，使得它更易用。从某种意义上来说，它们只是更复杂的 Altair。Altair，一个野兽派的极简作品，却为之后的许多微型计算机打下了铺垫。 + +如果你觉得这篇文章写的不错，你可以在推特上关注 [@TwoBitHistory][11] 或订阅 [RSS feed][12] 来获得我们文章的更新提醒。文章每两周就会更新一次！ + +[^1]: Paul E. Ceruzzi, A History of Modern Computing (Cambridge, Mass: MIT Press, 2003), 226. +[^2]: “Mark-8 Minicomputer,” Byran’s Old Computers, accessed July 21, 2018, http://bytecollector.com/mark_8.htm. +[^3]: Paul E. Ceruzzi, A History of Modern Computing (Cambridge, Mass: MIT Press, 2003), 226. + +-------------------------------------------------------------------------------- + +via: https://twobithistory.org/2018/07/22/dawn-of-the-microcomputer.html + +作者：[Sinclair Target][a] +选题：[lujun9972][b] +译者：[zhs852](https://github.com/zhs852) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://twobithistory.org +[b]: https://github.com/lujun9972 +[1]: https://www.americanradiohistory.com/Archive-Poptronics/70s/1974/Poptronics-1974-12.pdf +[2]: https://www.americanradiohistory.com/Archive-Poptronics/70s/1975/Poptronics-1975-01.pdf +[3]: https://twobithistory.org/images/jan1975-altair.jpg +[4]: https://linux.cn/article-10181-1.html +[5]: https://www.youtube.com/watch?v=qv5b1Xowxdk +[6]: https://www.autometer.de/unix4fun/z80pack/altair.png +[7]: http://www.classiccmp.org/dunfield/altair/d/88opman.pdf +[8]: https://www.youtube.com/watch?v=suyiMfzmZKs +[9]: https://www.americanradiohistory.com/Archive-Poptronics/70s/1975/Poptronics-1975-02.pdf +[10]: https://linux.cn/article-10382-1.html +[11]: https://twitter.com/TwoBitHistory +[12]: https://twobithistory.org/feed.xml +[13]: https://twitter.com/TwoBitHistory/status/1015647820353867776?ref_src=twsrc%5Etfw diff --git a/published/20180725 Build an interactive CLI with Node.js.md b/published/201901/20180725 Build an interactive CLI with Node.js.md similarity index 100% rename from published/20180725 Build an interactive CLI with Node.js.md rename to published/201901/20180725 Build an interactive CLI with Node.js.md diff --git a/published/20180731 How to be the lazy sysadmin.md b/published/201901/20180731 How to be the lazy sysadmin.md similarity index 100% rename from published/20180731 How to be the lazy sysadmin.md rename to published/201901/20180731 How to be the lazy sysadmin.md diff --git a/published/201901/20180809 Perform robust unit tests with PyHamcrest.md b/published/201901/20180809 Perform robust unit tests with PyHamcrest.md new file mode 100644 index 0000000000..4911aec938 --- /dev/null +++ b/published/201901/20180809 Perform robust unit tests with PyHamcrest.md @@ -0,0 +1,137 @@ +使用 PyHamcrest 执行健壮的单元测试 +====== +> 使用此框架编写断言，提高开发测试的准确性。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/web_browser_desktop_devlopment_design_system_computer.jpg?itok=pfqRrJgh) + +在[测试金字塔][1]的底部是单元测试。单元测试每次只测试一个代码单元，通常是一个函数或方法。 + +通常，设计单个单元测试是为了测试通过一个函数或特定分支的特定执行流程，这使得将失败的单元测试和导致失败的 bug 对应起来变得容易。 + +理想情况下，单元测试很少使用或不使用外部资源，从而隔离它们并使它们更快。 + +单元测试套件通过在开发过程的早期发现问题来帮助维护高质量的产品。有效的单元测试可以在代码离开开发人员机器之前捕获 bug，或者至少可以在特定分支上的持续集成环境中捕获 bug。这标志着好的和坏的单元测试之间的区别：*好的*测试通过尽早捕获 bug 并使测试更快来提高开发人员的生产力。*坏的*测试降低了开发人员的工作效率。 + +当测试*附带的特性*时，生产率通常会降低。当代码更改时测试会失败，即使它仍然是正确的。发生这种情况是因为输出的不同，但在某种程度上是因为它不是函数契约function's contract的一部分。 + +因此，一个好的单元测试可以帮助执行函数所提交的契约。 + +如果单元测试中断，那意味着该契约被违反了，应该（通过更改文档和测试）明确修改，或者（通过修复代码并保持测试不变）来修复。 + +虽然将测试限制为只执行公共契约是一项需要学习的复杂技能，但有一些工具可以提供帮助。 + +其中一个工具是 [Hamcrest][2]，这是一个用于编写断言的框架。最初是为基于 Java 的单元测试而发明的，但它现在支持多种语言，包括 [Python][3]。 + +Hamcrest 旨在使测试断言更容易编写和更精确。 + +``` +def add(a, b): +    return a + b + +from hamcrest import assert_that, equal_to + +def test_add(): +    assert_that(add(2, 2), equal_to(4))   +``` + +这是一个用于简单函数的断言。如果我们想要断言更复杂的函数怎么办？ + +``` +def test_set_removal(): +    my_set = {1, 2, 3, 4} +    my_set.remove(3) +    assert_that(my_set, contains_inanyorder([1, 2, 4])) +    assert_that(my_set, is_not(has_item(3))) +``` + +注意，我们可以简单地断言其结果是任何顺序的 `1`、`2` 和 `4`，因为集合不保证顺序。 + +我们也可以很容易用 `is_not` 来否定断言。这有助于我们编写*精确的断言*，使我们能够把自己限制在执行函数的公共契约方面。 + +然而，有时候，内置的功能都不是我们*真正*需要的。在这些情况下，Hamcrest 允许我们编写自己的匹配器matchers。 + +想象一下以下功能： + +``` +def scale_one(a, b): +    scale = random.randint(0, 5) +    pick = random.choice([a,b]) +    return scale * pick +``` + +我们可以自信地断言其结果均匀地分配到至少一个输入。 + +匹配器继承自 `hamcrest.core.base_matcher.BaseMatcher`，重写两个方法： + +``` +class DivisibleBy(hamcrest.core.base_matcher.BaseMatcher): +    def __init__(self, factor): +        self.factor = factor + +    def _matches(self, item): +        return (item % self.factor) == 0 + +    def describe_to(self, description): +        description.append_text('number divisible by') +        description.append_text(repr(self.factor)) +``` + +编写高质量的 `describe_to` 方法很重要，因为这是测试失败时显示的消息的一部分。 + +``` +def divisible_by(num): +    return DivisibleBy(num) +``` + +按照惯例，我们将匹配器包装在一个函数中。有时这给了我们进一步处理输入的机会，但在这种情况下，我们不需要进一步处理。 + +``` +def test_scale(): +    result = scale_one(3, 7) +    assert_that(result, +                any_of(divisible_by(3), +                divisible_by(7))) +``` + +请注意，我们将 `divisible_by` 匹配器与内置的 `any_of` 匹配器结合起来，以确保我们只测试函数提交的内容。 + +在编辑这篇文章时，我听到一个传言，取 “Hamcrest” 这个名字是因为它是 “matches” 字母组成的字谜。嗯... + +``` +>>> assert_that("matches", contains_inanyorder(*"hamcrest") +Traceback (most recent call last): +  File "", line 1, in +  File "/home/moshez/src/devops-python/build/devops/lib/python3.6/site-packages/hamcrest/core/assert_that.py", line 43, in assert_that +    _assert_match(actual=arg1, matcher=arg2, reason=arg3) +  File "/home/moshez/src/devops-python/build/devops/lib/python3.6/site-packages/hamcrest/core/assert_that.py", line 57, in _assert_match +    raise AssertionError(description) +AssertionError: +Expected: a sequence over ['h', 'a', 'm', 'c', 'r', 'e', 's', 't'] in any order +      but: no item matches: 'r' in ['m', 'a', 't', 'c', 'h', 'e', 's'] +``` + +经过进一步的研究，我找到了传言的来源：它是 “matchers” 字母组成的字谜。 + +``` +>>> assert_that("matchers", contains_inanyorder(*"hamcrest")) +>>> +``` + +如果你还没有为你的 Python 代码编写单元测试，那么现在是开始的好时机。如果你正在为你的 Python 代码编写单元测试，那么使用 Hamcrest 将允许你使你的断言更加*精确*，既不会比你想要测试的多也不会少。这将在修改代码时减少误报，并减少修改工作代码的测试所花费的时间。 + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/8/robust-unit-tests-hamcrest + +作者：[Moshe Zadka][a] +选题：[lujun9972](https://github.com/lujun9972) +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/moshez +[1]:https://martinfowler.com/bliki/TestPyramid.html +[2]:http://hamcrest.org/ +[3]:https://www.python.org/ diff --git a/published/201901/20180814 5 open source strategy and simulation games for Linux.md b/published/201901/20180814 5 open source strategy and simulation games for Linux.md new file mode 100644 index 0000000000..9666e74c0f --- /dev/null +++ b/published/201901/20180814 5 open source strategy and simulation games for Linux.md @@ -0,0 +1,103 @@ +5 款开源的 Linux 策略模拟游戏 +====== + +> 用这些开源游戏来挑战你的战略技能，探索新世界。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/arcade_game_gaming.jpg?itok=84Rjk_32) + +长久以来，游戏都是 Linux 的软肋。近些年，Steam、GOG 等游戏发布平台上不少商业游戏都开始支持 Linux，这对于 Linux 的游戏生态来说是件好事，但是我们能在这些平台上玩到的游戏通常是不开源的商业作品。当然，这些游戏在一个开源的操作系统上运行，但对于一个开源提倡者来说这似乎还不够纯粹。 + +那么，我们能找到既自由开源又能给玩家带来完整游戏体验的优质游戏吗？当然！虽然绝大多数的开源游戏很难和 3A 商业游戏大作竞争，但仍然有不少各种类型的开源游戏，不仅内容有趣而且直接可以通过几大 Linux 发行版本库中直接安装。就算某个游戏在不在某个发行版本的库中，我们也可以在这个游戏项目的网站上找到直接的安装方法。 + +本篇文章将会介绍策略和模拟类游戏。我已经写了[街机游戏][1]、[桌面卡牌游戏][2]、[解谜游戏][3]、[竞速飞行游戏][4]以及[角色扮演游戏][5]。 + +### 开源版“文明”（Freeciv） + +![](https://opensource.com/sites/default/files/uploads/freeciv.png) + +[Freeciv][6] 可以被视为是[文明系列][7]游戏的开源版本。游戏玩法和文明系列最早期的游戏十分类似，Freeciv 可以让玩家选择选用文明 1 或者文明 2 中的游戏规则设置。Freeciv 中包含了很多元素，例如建造城市、探索世界地图、发展科技以及和其他扩张中的文明竞争。胜利条件包括打败所有其他的文明或建立一个外星殖民地，如果在前两者都没有达成的话，在游戏时间期限前存活下来也可以算作胜利。这个游戏可以和其他玩家联机也可以和 AI 对战，不同的地图集可以改变游戏的外观。 + +安装 Freeciv，你只需要在终端下运行以下指令。 + + * Fedora 用户： `dnf install freeciv` + * Debian/Ubuntu 用户：`apt install freeciv` + +### MegaGlest + +![](https://opensource.com/sites/default/files/uploads/megaglest.png) + +[MegaGlest][8] 是一个开源的实时战略游戏，类似暴雪公司制作的游戏[魔兽世界][9]和[星际争霸][10]。玩家控制不同派别的人员、建造新建筑、招募士兵、拓展领土并与敌人作战。在游戏比赛的最开始，玩家仅能建造最基础的建筑和招募最基础的士兵。为了建造更高级的建筑并招募级别更高的人员，玩家必须通过增加建筑和人员从而一路提高科技树、解锁更加高级的选项。当敌人进入国土领域之中，战斗单元将会迎战。但是最好的应对策略是，通过控制战斗单元直接操控每一场战斗。在管理新建筑的建立，新人员的招募的同时控制战斗局势听上去十分困难，但是这就是 RTS（实时战略游戏）游戏的精华所在。MegaGlest 这个游戏提供了大量的人员派别，玩家可以不断尝试这些不同的技巧。 + +安装 MegaGlest，你只需要在终端下运行以下指令： + + * Fedora 用户： `dnf install megaglest` + * Debian/Ubuntu 用户：`apt install megaglest` + +### 开源版“运输大亨”（OpenTTD） + +![](https://opensource.com/sites/default/files/uploads/openttd.png) + +[OpenTTD][11]（见我们的 [评测][12] ）是一个开源实现的 [运输大亨][13] 。该游戏的目的在于创建一个交通运输网络并获得金钱，从而建立更加复杂的运输网络。这个运输网络包括了船只、巴士、火车、货车和飞机。默认的游戏时间在 1950 和 2050 之间，玩家的目标就是在规定时间内拿到最高的游戏分数。游戏的最终分数基于很多因素，例如货物运输的数量、玩家所拥有的汽车数量以及他们赚到的钱。 + +安装 OpenTTD，你只需要在终端运行以下指令： + + * Fedora 用户： `dnf install openttd` + * Debian/Ubuntu 用户 `apt install openttd` + +### 韦诺之战The Battle for Wesnoth + +![](https://opensource.com/sites/default/files/uploads/the_battle_for_wesnoth.png) + +[韦诺之战][14] 是目前最完善的开源游戏之一。这个回合制游戏在一个奇幻的故事设定下。游戏在一个六角形网格中进行，各个单元可以互相操作进行战斗。每个类型的单元都有它独特的能力和弱点，因此玩家需要根据这些特点来设计不同的行动。韦诺之战中有很多不同的行动分支，每个行动分支都有它特别的故事线和目标。韦诺之战同时也有一个地图编辑器，感兴趣的玩家可以创作自己的地图以及行动分支。 + +安装韦诺之战，你只需要在终端运行以下指令： + + * Fedora 用户： `dnf install wesnoth` + * Debian/Ubuntu 用户： `apt install wesnoth` + +### UFO：外星入侵UFO: Alien Invasion + +![](https://opensource.com/sites/default/files/uploads/ufo_alien_invasion.png) + +[UFO: Alien Invasion][15] 是一个开源策略游戏，基于 [幽浮系列][20]X-COM。 有两个不同的游戏模式： geoscape 和 tactical。在 geoscape 模式下，玩家控制大局、管理基地、开发新技术以及掌控整体策略。 在 tactical 游戏模式下，玩家控制一群士兵并且以回合制的形式直接迎战外星侵略者。两个游戏模式提供了不同的游戏玩法，两者都需要相当复杂的策略和战术。 + +安装这个游戏，你只需要在终端下运行以下指令： + + * Debian/Ubuntu 用户： `apt install ufoai` + +遗憾的是，UFO: 外星入寝不支持 Fedora 发行版。 + +如果你知道除了这些以外的开源策略模拟游戏的话，欢迎在评论中分享。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/8/strategy-simulation-games-linux + +作者：[Joshua Allen Holm][a] +选题：[lujun9972](https://github.com/lujun9972) +译者：[Scoutydren](https://github.com/Scoutydren) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://opensource.com/users/holmja +[1]:https://linux.cn/article-10433-1.html +[2]:https://opensource.com/article/18/3/card-board-games-linux +[3]:https://opensource.com/article/18/6/puzzle-games-linux +[4]:https://opensource.com/article/18/7/racing-flying-games-linux +[5]:https://opensource.com/article/18/8/role-playing-games-linux +[6]:http://www.freeciv.org/ +[7]:https://en.wikipedia.org/wiki/Civilization_(series) +[8]:https://megaglest.org/ +[9]:https://en.wikipedia.org/wiki/Warcraft +[10]:https://en.wikipedia.org/wiki/StarCraft +[11]:https://www.openttd.org/ +[12]:https://opensource.com/life/15/7/linux-game-review-openttd +[13]:https://en.wikipedia.org/wiki/Transport_Tycoon#Transport_Tycoon_Deluxe +[14]:https://www.wesnoth.org/ +[15]:https://ufoai.org/ +[16]:https://opensource.com/downloads/cheat-sheets?intcmp=7016000000127cYAAQ +[17]:https://opensource.com/alternatives?intcmp=7016000000127cYAAQ +[18]:https://opensource.com/tags/linux?intcmp=7016000000127cYAAQ +[19]:https://developers.redhat.com/cheat-sheets/advanced-linux-commands/?intcmp=7016000000127cYAAQ +[20]:https://en.wikipedia.org/wiki/X-COM diff --git a/translated/talk/20180919 5 ways DevSecOps changes security.md b/published/201901/20180919 5 ways DevSecOps changes security.md similarity index 54% rename from translated/talk/20180919 5 ways DevSecOps changes security.md rename to published/201901/20180919 5 ways DevSecOps changes security.md index 92f295ed04..cfa0bb07e4 100644 --- a/translated/talk/20180919 5 ways DevSecOps changes security.md +++ b/published/201901/20180919 5 ways DevSecOps changes security.md @@ -1,40 +1,42 @@ -五种 DevSecOps 提升安全性 +DevSecOps 提升安全性的五种方式 ====== +> 安全必须进化以跟上当今的应用开发和部署方式。 + ![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/security-lock-password.jpg?itok=KJMdkKum) -对于我们是否需要扩展 DevOps 以确实提升安全性，我们一直都有争议。毕竟，我们的想法是，DevOps 一直是一系列的新实践的简写，使用新工具（通常是开源的）并且在这之上构建更多的协作文化。为什么 DevBizOps 不能更好地满足商业的需求？或者说 DevChatOps 强调的是更快更好的沟通？ +对于我们是否需要扩展 DevOps 以确实提升安全性，我们一直都有争议。毕竟，我们认为，DevOps 一直是一系列的新实践的简写，使用新工具（通常是开源的）并且在这之上构建更多的协作文化。为什么 [DevBizOps][3] 不能更好地满足商业的需求？或者说 DevChatOps 强调的是更快更好的沟通？ -在今年（译者注：此处是2018年）的早些时候写的关于他理解的 DevSecOps 术语，“我希望，有一天在世界范围内，我们能不再使用 DevSecOps 这个词，安全会是所有的服务交付讨论中理所应当的部分。直到那一天到来为止，在这一点上，我的一般性结论是，这个词只有三个新的特性。更重要的是，我们作为一个产业，在信息安全方面并没有做的很好，而这个名称切实地区分出了问题的状况” +然而，如 [John Willis][4] 在今年（LCTT 译注：此处是 2018 年）的早些时候写的关于他对 [DevSecOps][5] 术语的理解，“我希望，有一天我们能在任何地方都不再使用 DevSecOps 这个词，安全会是所有关于服务交付的讨论中理所应当的部分。在那一天到来前，在这一点上，我的一般性结论是，这个词只是三个新的特性而已。更重要的是，我们作为一个产业，在信息安全方面并没有做的很好，而这个名称切实地区分出了问题的状况。” -所以，为什么我们在信息安全方面做的不好，在 DevSecOps 的语境下安全做的好又是什么意思呢？ +所以，为什么我们在[信息安全][6]方面做的不好，在 DevSecOps 的语境下安全做的好又是什么意思呢？ -我们大概从未做好过信息安全，尽管（也可能是因为）复杂的工业点产品地址拥挤问题。我们仍然可以在这个时代把工作做得足够好，以此来防范威胁，这些威胁主要集中在一个范围内，网络的连接是有限的，而且大多数的用户都是公司的员工，使用的是公司提供的设备。 +尽管（也可能是因为）庞大的复杂行业的单点产品解决了特定方面的问题，但我们可以说是从未做好过信息安全。我们仍然可以在这个时代把工作做得足够好，以此来防范威胁，这些威胁主要集中在一个范围内，网络的连接是受限的，而且大多数的用户都是公司的员工，使用的是公司提供的设备。 -这些年来，这些情况并没有能准确地描述出大多数组织的真实现状。但在现在这个时代，不止引入了 DevSecOps，也同时引入了新的应用架构模型，开发实践，和越来越多的安全威胁，这些一起定义了一个需要更快迭代的新常态。还没有应用得很多的 DevSecOps 在独立改变安全，但是 2018 年的信息安全需要新的方法。 +这些年来，这些情况并没有能准确地描述出大多数组织的真实现状。但在现在这个时代，不止引入了 DevSecOps，也同时引入了新的应用架构模型、开发实践，和越来越多的安全威胁，这些一起定义了一个需要更快迭代的新常态。与其说 DevSecOps 孤立地改变了安全，不如说信息安全公司在 2018 年需要新的方法。 请仔细思考下面这五个领域。 ### 自动化 -大量的自动化通常是 DevOps 的标志，这部分是关于速度的，如果你要快速移动（并且不会打坏东西），你需要有可重复的过程，而且这个过程不需要太多的人工干预。实际上，自动化是 DevOps 最好的切入点之一，甚至是在仍然主要工作在单片机电路程序的组织里也是如此。使用像 Ansible 这样易于使用的工具来自动化地处理相关的配置或者是测试，这是快速开始 DevOps 之路的常用方法。 +大量的自动化通常是 DevOps 的标志，这部分是关于速度的，如果你要快速变化（并且不会造成破坏），你需要有可重复的过程，而且这个过程不需要太多的人工干预。实际上，自动化是 DevOps 最好的切入点之一，甚至是在仍然主要使用老式的独石应用monolithic app的组织里也是如此。使用像 Ansible 这样易于使用的工具来自动化地处理相关的配置或者是测试，这是快速开始 DevOps 之路的常用方法。 -DevSecOps 也不例外，在今天，安全已经变成了一个持续性的过程，而不是在应用的生命周期里进行不定期的检查，甚至是每周、每月的检查。当漏洞被厂商发现并修复的时候，这些漏洞能被快速地应用是很重要的，因为利用这些漏洞的利用程序很快就会被淘汰。 +DevSecOps 也不例外，在今天，安全已经变成了一个持续性的过程，而不是在应用的生命周期里进行不定期的检查，甚至是每周、每月的检查。当漏洞被厂商发现并修复的时候，这些修复能被快速地应用是很重要的，这样对这些漏洞的利用程序很快就会被淘汰。 -### "左转" +### “左移” -在开发流程结束时，传统安全通常被视作一个守门人。检查所有的部分确保没有问题，然后这个应用程序就可以投入生产了。否则，就要再来一次。所以安全团队的声誉并不高。 +在开发流程结束时，传统的安全通常被视作一个守门人。检查所有的部分确保没有问题，然后这个应用程序就可以投入生产了。否则，就要再来一次。安全小组以说“不”而闻名。 -因此，我们想的是，没什么不把安全这个部分提到前面呢（左边是一个典型的从左到右的开发流程图）？安全性可能仍然不行，但在开发的早期进行重构的影响要远远小于开发已经完成并且准备上线时进行重构的影响。 +因此，我们想的是，为什么不把安全这个部分提到前面呢（在一个典型的从左到右的开发流程图的“左边”）？安全团队仍然可以说“不”，但在开发的早期进行重构的影响要远远小于开发已经完成并且准备上线时进行重构的影响。 不过，我不喜欢“左移”这个词，这意味着安全仍然是一个只不过提前进行的一次性工作。在应用程序的整个生命周期里，从供应链到开发，再到测试，直到上线部署，安全都需要进行大量的自动化处理。 ### 管理依赖 -我们在现代应用程序开发过程中看到的一个最大的改变，就是你通常不需要去编写这个程序的大部分代码。使用开源的函数库和框架就是一个明显的例子。但是你也可以从公共的云服务商或其他来源那里获得额外的服务。在许多情况下，这些额外的代码和服务比你给自己写的要好得多。 +我们在现代应用程序开发过程中看到的一个最大的改变，就是你通常不需要去编写这个程序的大部分代码。使用开源的函数库和框架就是一个明显的例子。而且你也可以从公共的云服务商或其他来源那里获得额外的服务。在许多情况下，这些额外的代码和服务比你给自己写的要好得多。 -因此，DevSecOps 需要你把重点放在你的软件供应链上，你是从可信的来源那里获取你的软件的吗？这些软件是最新的吗？它们已经集成到了你为自己的代码使用的安全流程中了吗？对于这些你能使用的代码和 API 你有哪些策略？你为自己的产品代码使用的组件是否有可用的商业支持？ +因此，DevSecOps 需要你把重点放在你的[软件供应链][8]上，你是从可信的来源那里获取你的软件的吗？这些软件是最新的吗？它们已经集成到了你为自己的代码所使用的安全流程中了吗？对于这些你能使用的代码和 API 你有哪些策略？你为自己的产品代码使用的组件是否有可用的商业支持？ 没有一套标准答案可以应对所有的情况。对于概念验证和大规模的生产，它们可能会有所不同。但是，正如制造业长期存在的情况（DevSecOps 和制造业的发展方面有许多相似之处），供应链的可信是至关重要的。 @@ -42,7 +44,7 @@ DevSecOps 也不例外，在今天，安全已经变成了一个持续性的过 关于贯穿应用程序整个生命周期里所有阶段的自动化的需求，我已经谈过很多了。这里假设我们能看见每个阶段里发生的情况。 -有效的 DevSecOps 需要有效的检测，以便于自动化程序知道要做什么。这个检测分了很多类别。一些长期的和高级别的指标能帮助我们了解整个 DevSecOps 流程是否工作良好。严重威胁级别的警报需要立刻有人进行处理（安全扫描系统已经关闭！）。有一些警报，比如扫描失败，需要进行修复。我们记录了大量的参数来生成日志，以便事后进行分析（随着时间的推移，哪些发生了改变？导致失败的原因是什么？）。 +有效的 DevSecOps 需要有效的检测，以便于自动化程序知道要做什么。这个检测分了很多类别。一些长期的和高级别的指标能帮助我们了解整个 DevSecOps 流程是否工作良好。严重威胁级别的警报需要立刻有人进行处理（安全扫描系统已经关闭！）。有一些警报，比如扫描失败，需要进行修复。我们记录了许多参数的志以便事后进行分析（随着时间的推移，哪些发生了改变？导致失败的原因是什么？）。 ### 分散服务 vs 一体化解决方案 @@ -50,7 +52,7 @@ DevSecOps 也不例外，在今天，安全已经变成了一个持续性的过 这种方法确实带来了一些新的安全挑战，组件之间的交互可能会很复杂，总的攻击面会更大，因为现在应用程序通过网络有了更多的切入点。 -另一方面，这种类型的架构还意味着自动化的安全和监视可以更加精细地查看应用程序的组件，因为它们不再深埋在一整个应用程序之中。 +另一方面，这种类型的架构还意味着自动化的安全和监视可以更加精细地查看应用程序的组件，因为它们不再深埋在一个独石应用程序之中。 不要过多地关注 DevSecOps 这个术语，但要提醒一下，安全正在不断地演变，因为我们编写和部署程序的方式也在不断地演变。 @@ -61,7 +63,7 @@ via: https://opensource.com/article/18/9/devsecops-changes-security 作者：[Gordon Haff][a] 选题：[lujun9972](https://github.com/lujun9972) 译者：[hopefully2333](https://github.com/hopefully2333) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/20181005 Dbxfs - Mount Dropbox Folder Locally As Virtual File System In Linux.md b/published/201901/20181005 Dbxfs - Mount Dropbox Folder Locally As Virtual File System In Linux.md similarity index 100% rename from published/20181005 Dbxfs - Mount Dropbox Folder Locally As Virtual File System In Linux.md rename to published/201901/20181005 Dbxfs - Mount Dropbox Folder Locally As Virtual File System In Linux.md diff --git a/translated/tech/20181016 Final JOS project.md b/published/201901/20181016 Final JOS project.md similarity index 76% rename from translated/tech/20181016 Final JOS project.md rename to published/201901/20181016 Final JOS project.md index eda24d1d5a..93358e622a 100644 --- a/translated/tech/20181016 Final JOS project.md +++ b/published/201901/20181016 Final JOS project.md @@ -1,12 +1,12 @@ -最终的 JOS 项目 +Caffeinated 6.828：实验 7：最终的 JOS 项目 ====== + ### 简介 对于最后的项目，你有两个选择： * 继续使用你自己的 JOS 内核并做 [实验 6][1]，包括实验 6 中的一个挑战问题。（你可以随意地、以任何有趣的方式去扩展实验 6 或者 JOS 的任何部分，当然了，这不是课程规定的。） - -* 在一个、二个或三个人组成的团队中，你选择去做一个涉及了你的 JOS 的项目。这个项目必须是涉及到与实验 6 相同或更大的（如果你是团队中的一员）领域。 +* 在一个、二个或三个人组成的团队中，你选择去做一个涉及了你的 JOS 的项目。这个项目必须是涉及到与实验 6 相同或更大的领域（如果你是团队中的一员）。 目标是为了获得乐趣或探索更高级的 O/S 的话题；你不需要做最新的研究。 @@ -16,70 +16,48 @@ ### 交付期限 -``` -11 月 3 日：Piazza 讨论和 1、2、或 3 年级组选择（根据你的最终选择来定）。使用在 Piazza 上的 lab7 标记/目录。在 Piazza 上的文章评论区与其它人计论想法。使用这些文章帮你去找到有类似想法的其它学生一起组建一个小组。课程的教学人员将在 Piazza 上为你的项目想法给出反馈；如果你想得到更详细的反馈，可以与我们单独讨论。 -``` +> 11 月 3 日：Piazza 讨论和 1、2、或 3 年级组选择（根据你的最终选择来定）。使用在 Piazza 上的 lab7 标记/目录。在 Piazza 上的文章评论区与其它人计论想法。使用这些文章帮你去找到有类似想法的其它学生一起组建一个小组。课程的教学人员将在 Piazza 上为你的项目想法给出反馈；如果你想得到更详细的反馈，可以与我们单独讨论。 -```markdown -11 月 9 日：在 [提交网站][19] 上提交一个提议，只需要一到两个段落就可以。提议要包括你的小组成员列表、你的计划、以及明确的设计和实现打算。（如果你做实验 6，就不用做这个了） -``` +. -```markdown -12 月 7 日：和你的简短报告一起提交源代码。将你的报告放在与名为 "README.pdf" 的文件相同的目录下。由于你只是这个实验任务小组中的一员，你可能需要去使用 git 在小组成员之间共享你的项目代码。因此你需要去决定哪些源代码将作为你的小组项目的共享起始点。一定要为你的最终项目去创建一个分支，并且命名为 `lab7`。（如果你做了实验 6，就按实验 6 的提交要求做即可。） -``` +> 11 月 9 日：在 [提交网站][19] 上提交一个提议，只需要一到两个段落就可以。提议要包括你的小组成员列表、你的计划、以及明确的设计和实现打算。（如果你做实验 6，就不用做这个了） -``` -12 月 11 日这一周：简短的课堂演示。为你的 JOS 项目准备一个简短的课堂演示。为了你的项目演示，我们将提供一个投影仪。根据小组数量和每个小组选择的项目类型，我们可能会限制总的演讲数，并且有些小组可能最终没有机会上台演示。 -``` +. -``` -12 月 11 日这一周：助教们验收。向助教演示你的项目，因此我们可能会提问一些问题，去了解你所做的一些细节。 -``` +> 12 月 7 日：和你的简短报告一起提交源代码。将你的报告放在与名为 “README.pdf” 的文件相同的目录下。由于你只是这个实验任务小组中的一员，你可能需要去使用 git 在小组成员之间共享你的项目代码。因此你需要去决定哪些源代码将作为你的小组项目的共享起始点。一定要为你的最终项目去创建一个分支，并且命名为 `lab7`。（如果你做了实验 6，就按实验 6 的提交要求做即可。） + +. + +> 12 月 11 日这一周：简短的课堂演示。为你的 JOS 项目准备一个简短的课堂演示。为了你的项目演示，我们将提供一个投影仪。根据小组数量和每个小组选择的项目类型，我们可能会限制总的演讲数，并且有些小组可能最终没有机会上台演示。 + +. + +> 12 月 11 日这一周：助教们验收。向助教演示你的项目，因此我们可能会提问一些问题，去了解你所做的一些细节。 ### 项目想法 如果你不做实验 6，下面是一个启迪你的想法列表。但是，你应该大胆地去实现你自己的想法。其中一些想法只是一个开端，并且本身不在实验 6 的领域内，并且其它的可能是在更大的领域中。 * 使用 [x86 虚拟机支持][2] 去构建一个能够运行多个访客系统（比如，多个 JOS 实例）的虚拟机监视器。 - * 使用 Intel SGX 硬件保护机制做一些有用的事情。[这是使用 Intel SGX 的最新的论文][3]。 - * 让 JOS 文件系统支持写入、文件创建、为持久性使用日志、等等。或许你可以从 Linux EXT3 上找到一些启示。 - * 从 [软更新][4]、[WAFL][5]、ZFS、或其它较高级的文件系统上找到一些使用文件系统的想法。 - * 给一个文件系统添加快照功能，以便于用户能够查看过去的多个时间点上的文件系统。为了降低空间使用量，你或许要使用一些写时复制技术。 - * 使用分页去提供实时共享的内存，来构建一个 [分布式的共享内存][6]（DSM）系统，以便于你在一个机器集群上运行多线程的共享内存的并行程序。当一个线程尝试去访问位于另外一个机器上的页时，页故障将给 DSM 系统提供一个机会，让它基于网络去从当前存储这个页的任意一台机器上获取这个页。 - * 允许进程在机器之间基于网络进行迁移。你将需要做一些关于一个进程状态的多个片段方面的事情，但是由于在 JOS 中许多状态是在用户空间中，它或许从 Linux 上的进程迁移要容易一些。 - * 在 JOS 中实现 [分页][7] 到磁盘，这样那个进程使用的内存就可以大于真实的内存。使用交换空间去扩展你的内存。 - * 为 JOS 实现文件的 [mmap()][8]。 - * 使用 [xfi][9] 将一个进程的代码沙箱化。 - * 支持 x86 的 [2MB 或 4MB 的页大小][10]。 - * 修改 JOS 让内核支持进程内的线程。从查看 [课堂上的 uthread 任务][11] 去开始。实现调度器触发将是实现这个项目的一种方式。 - * 在 JOS 的内核中或文件系统中（实现多线程之后），使用细粒度锁或无锁并发。Linux 内核使用 [读复制更新][12] 去执行无需上锁的读取操作。通过在 JOS 中实现它来探索 RCU，并使用它去支持无锁读取的名称缓存。 - * 实现 [外内核论文][13] 中的想法。例如包过滤器。 - * 使 JOS 拥有软实时行为。用它来辨识一些应用程序时非常有用。 - * 使 JOS 运行在 64 位 CPU 上。这包括重设计虚拟内存让它使用 4 级页表。有关这方面的文档，请查看 [参考页][14]。 - * 移植 JOS 到一个不同的微处理器。这个 [osdev wiki][15] 或许对你有帮助。 - * 为 JOS 系统增加一个“窗口”系统，包括图形驱动和鼠标。有关这方面的文档，请查看 [参考页][16]。[sqrt(x)][17] 就是一个 JOS “窗口” 系统的示例。 - * 在 JOS 中实现 [dune][18]，以提供特权硬件指令给用户空间应用程序。 - * 写一个用户级调试器，添加类似跟踪的功能；硬件寄存器概要（即：Oprofile）；调用跟踪等等。 - * 为（静态的）Linux 可运行程序做一个二进制仿真。 -------------------------------------------------------------------------------- @@ -89,7 +67,7 @@ via: https://pdos.csail.mit.edu/6.828/2018/labs/lab7/ 作者：[csail.mit][a] 选题：[lujun9972][b] 译者：[qhwdw](https://github.com/qhwdw) -校对：[校对者ID](https://github.com/校对者ID) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/20181016 Lab 6- Network Driver.md b/published/201901/20181016 Lab 6- Network Driver.md similarity index 100% rename from published/20181016 Lab 6- Network Driver.md rename to published/201901/20181016 Lab 6- Network Driver.md diff --git a/published/20181029 How I organize my knowledge as a Software Engineer.md b/published/201901/20181029 How I organize my knowledge as a Software Engineer.md similarity index 100% rename from published/20181029 How I organize my knowledge as a Software Engineer.md rename to published/201901/20181029 How I organize my knowledge as a Software Engineer.md diff --git a/published/201901/20181128 Arch-Audit - A Tool To Check Vulnerable Packages In Arch Linux.md b/published/201901/20181128 Arch-Audit - A Tool To Check Vulnerable Packages In Arch Linux.md new file mode 100644 index 0000000000..e31694679f --- /dev/null +++ b/published/201901/20181128 Arch-Audit - A Tool To Check Vulnerable Packages In Arch Linux.md @@ -0,0 +1,122 @@ +[#]: collector: "lujun9972" +[#]: translator: "Auk7F7" +[#]: reviewer: "wxy" +[#]: publisher: "wxy" +[#]: subject: "Arch-Audit : A Tool To Check Vulnerable Packages In Arch Linux" +[#]: via: "https://www.2daygeek.com/arch-audit-a-tool-to-check-vulnerable-packages-in-arch-linux/" +[#]: author: "Prakash Subramanian https://www.2daygeek.com/author/prakash/" +[#]: url: "https://linux.cn/article-10473-1.html" + +Arch-Audit：一款在 Arch Linux 上检查易受攻击的软件包的工具 +====== + +我们必须经常更新我们的系统以减少宕机时间和问题。每月给系统打一次补丁，60 天一次或者最多 90 天一次，这是 Linux 管理员的例行任务之一。这是忙碌的工作计划，我们不能在不到一个月内做到这一点，因为它涉及到多种活动和环境。 + +基本上，基础设施会一同提供测试、开发、 QA 环境（即各个分段和产品）。 + +最初，我们会在测试环境中部署补丁，相应的团队将监视系统一周，然后他们将给出一份或好或坏的状态的报告。如果成功的话，我们将会在其他环境中继续测试，若正常运行，那么最后我们会给生产服务器打上补丁。 + +许多组织会对整个系统打上补丁，我的意思是全系统更新，对于典型基础设施这是一种常规修补计划。 + +某些基础设施中可能只有生产环境，因此，我们不应该做全系统更新，而是应该使用安全修补程序来使系统更加稳定和安全。 + +由于 Arch Linux 及其衍生的发行版属于滚动更新版本，因此可以认为它们始终是最新的，因为它使用上游软件包的最新版本。 + +在某些情况下，如果要单独更新安全修补程序，则必须使用 arch-audit 工具来标识和修复安全修补程序。 + +### 漏洞是什么? + +漏洞是软件程序或硬件组件（固件）中的安全漏洞。这是一个可以让它容易受到攻击的缺陷。 + +为了缓解这种情况，我们需要相应地修补漏洞，就像应用程序/硬件一样，它可能是代码更改或配置更改或参数更改。 + +### Arch-Audit 工具是什么？ + +[Arch-audit][1] 是一个类似于 Arch Linux 的 pkg-audit 工具。它使用了令人称赞的 Arch 安全小组收集的数据。它不会扫描以发现系统中易受攻击的包（就像 `yum –security check-update & yum updateinfo` 一样列出可用的软件包），它只需解析 页面并在终端中显示结果，因此，它将显示准确的数据。（LCTT 译注：此处原作者叙述不清晰。该功能虽然不会像病毒扫描软件一样扫描系统上的文件，但是会读取已安装的软件列表，并据此查询上述网址列出风险报告。） + +Arch 安全小组是一群以跟踪 Arch Linux 软件包的安全问题为目的的志愿者。所有问题都在 Arch 安全追踪者的监视下。 + +该小组以前被称为 Arch CVE 监测小组，Arch 安全小组的使命是为提高 Arch Linux 的安全性做出贡献。 + +### 如何在 Arch Linux 上安装 Arch-Audit 工具 + +Arch-audit 工具已经存在社区的仓库中，所以你可以使用 Pacman 包管理器来安装它。 + +``` +$ sudo pacman -S arch-audit +``` + +运行 `arch-audit` 工具以查找在基于 Arch 的发行版本上的存在缺陷的包。 + +``` +$ arch-audit +Package cairo is affected by CVE-2017-7475. Low risk! +Package exiv2 is affected by CVE-2017-11592, CVE-2017-11591, CVE-2017-11553, CVE-2017-17725, CVE-2017-17724, CVE-2017-17723, CVE-2017-17722. Medium risk! +Package libtiff is affected by CVE-2018-18661, CVE-2018-18557, CVE-2017-9935, CVE-2017-11613. High risk!. Update to 4.0.10-1! +Package openssl is affected by CVE-2018-0735, CVE-2018-0734. Low risk! +Package openssl-1.0 is affected by CVE-2018-5407, CVE-2018-0734. Low risk! +Package patch is affected by CVE-2018-6952, CVE-2018-1000156. High risk!. Update to 2.7.6-7! +Package pcre is affected by CVE-2017-11164. Low risk! +Package systemd is affected by CVE-2018-6954, CVE-2018-15688, CVE-2018-15687, CVE-2018-15686. Critical risk!. Update to 239.300-1! +Package unzip is affected by CVE-2018-1000035. Medium risk! +Package webkit2gtk is affected by CVE-2018-4372. Critical risk!. Update to 2.22.4-1! +``` + +上述结果显示了系统的脆弱性风险状况，比如：低、中和严重三种情况。 + +若要仅显示易受攻击的包及其版本，请执行以下操作。 + +``` +$ arch-audit -q +cairo +exiv2 +libtiff>=4.0.10-1 +openssl +openssl-1.0 +patch>=2.7.6-7 +pcre +systemd>=239.300-1 +unzip +webkit2gtk>=2.22.4-1 +``` + +仅显示已修复的包。 + +``` +$ arch-audit --upgradable --quiet +libtiff>=4.0.10-1 +patch>=2.7.6-7 +systemd>=239.300-1 +webkit2gtk>=2.22.4-1 +``` + +为了交叉检查上述结果，我将测试在 列出的一个包以确认漏洞是否仍处于开放状态或已修复。是的，它已经被修复了，并于昨天在社区仓库中发布了更新后的包。 + +![][3] + +仅打印包名称和其相关的 CVE。 + +``` +$ arch-audit -uf "%n|%c" +libtiff|CVE-2018-18661,CVE-2018-18557,CVE-2017-9935,CVE-2017-11613 +patch|CVE-2018-6952,CVE-2018-1000156 +systemd|CVE-2018-6954,CVE-2018-15688,CVE-2018-15687,CVE-2018-15686 +webkit2gtk|CVE-2018-4372 +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/arch-audit-a-tool-to-check-vulnerable-packages-in-arch-linux/ + +作者：[Prakash Subramanian][a] +选题：[lujun9972][b] +译者：[Auk7F7](https://github.com/Auk7F7) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/prakash/ +[b]: https://github.com/lujun9972 +[1]: https://github.com/ilpianista/arch-audit +[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[3]: https://www.2daygeek.com/wp-content/uploads/2018/11/A-Tool-To-Check-Vulnerable-Packages-In-Arch-Linux.png diff --git a/published/20181128 Turn an old Linux desktop into a home media center.md b/published/201901/20181128 Turn an old Linux desktop into a home media center.md similarity index 100% rename from published/20181128 Turn an old Linux desktop into a home media center.md rename to published/201901/20181128 Turn an old Linux desktop into a home media center.md diff --git a/published/201901/20181203 How to bring good fortune to your Linux terminal.md b/published/201901/20181203 How to bring good fortune to your Linux terminal.md new file mode 100644 index 0000000000..816ead368e --- /dev/null +++ b/published/201901/20181203 How to bring good fortune to your Linux terminal.md @@ -0,0 +1,88 @@ +[#]: collector: (lujun9972) +[#]: translator: (MjSeven) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: subject: (How to bring good fortune to your Linux terminal) +[#]: via: (https://opensource.com/article/18/12/linux-toy-fortune) +[#]: author: (Jason Baker https://opensource.com/users/jason-baker) +[#]: url: (https://linux.cn/article-10486-1.html) + +如何为你的 Linux 终端带来好运 +====== +> 使用 fortune 实用程序将名言和俏皮话带到命令行。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-fortune.png?itok=5PVVZVer) + +这是 12 月，如果你还没有找到一款能激发你灵感的[科技降临节日历][1]，那么，也许这个系列可以。从现在到 24 日，每天我们都会为你带来一个不同的 Linux 命令行玩具。你可能会问，什么是命令行玩具？它可能是一个游戏或任何简单的娱乐程序，为你的终端带来一点点快乐。 + +你可能之前已经看过其中的一些，我们希望你也能发现一些新的东西。不管怎样，我们都希望你在关注时保有乐趣。 + +今天的玩具是 `fortune`，它很古老。它的版本可以追溯到 1980 年，当时它包含在 Unix 中。我在 Fedora 中安装的版本是在 BSD 许可下提供的，我可以使用以下命令获取它。（LCTT 译注：fortune 这个命令得名于 fortune cookies，是流行于西方的中餐馆的一种脆饼干，里面包含格言、幸运数字等。） + +``` +$ sudo dnf install fortune-mod -y +``` + +你的发行版可能会有所不同。在某些情况下，你可能需要在 `fortune` 命令之外单独安装那些“幸运饼干”（尝试在你的包管理器中搜索 “fortunes”）。你还可以在 [GitHub][2] 上查看它的源代码，然后，只需运行 `fortune` 即可获得好运。 + +``` +$ fortune +"Time is an illusion.  Lunchtime doubly so." +-- Ford Prefect, _Hitchhiker's Guide to the Galaxy_ +``` + +那么，你为什么会在终端上需要 `fortune` 呢？当然是为了好玩啦。也许你想将它们添加到系统上的每天消息（motd）中？ + +就我个人而言，当我使用终端来解析文本时，我喜欢使用 `fortune` 命令作为一段内置的虚拟数据，特别是使用[正则表达式][3]时，我想要一些简单的东西来尝试一下。 + +例如，假设我使用 `tr` 命令来测试转换，用数字 3 替换字母 e。 + +``` +$ fortune | tr 'eE' '3' +Unix 3xpr3ss: +All pass3ng3r bring a pi3c3 of th3 a3roplan3 and a box of tools with th3m to +th3 airport. Th3y gath3r on th3 tarmac, arguing constantly about what kind +of plan3 th3y want to build and how to put it tog3th3r. 3v3ntually, th3 +pass3ng3rs split into groups and build s3v3ral diff3r3nt aircraft, but giv3 +th3m all th3 sam3 nam3. Som3 pass3ng3rs actually r3ach th3ir d3stinations. +All pass3ng3rs b3li3v3 th3y got th3r3. +``` + +那么你的发行版带来了什么幸运饼干呢？看看你的 `/usr/share/games/fortune` 目录，找到它们。以下我最喜欢的几个。 + +``` +Never laugh at live dragons. +                -- Bilbo Baggins [J.R.R. Tolkien, "The Hobbit"] + +I dunno, I dream in Perl sometimes... +             -- Larry Wall in  <8538@jpl-devvax.JPL.NASA.GOV> + +I have an existential map.  It has "You are here" written all over it. +                -- Steven Wright +``` + +关于 `fortune` 想要了解更多？当然，你可以经常查看 man 页来了解更多选项，或者在[维基百科][4]上阅读更多关于此命令的历史信息。 + +你有特别喜欢的命令行小玩具需要我介绍的吗？这个系列要介绍的小玩具大部分已经有了落实，但还预留了几个空位置。请在评论区留言，我会查看的。如果还有空位置，我会考虑介绍它的。如果没有，但如果我得到了一些很好的意见，我会在最后做一些有价值的提及。 + +看看昨天的玩具：[驾驶火车头通过你的 Linux 终端][5]。记得明天再来！ + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/12/linux-toy-fortune + +作者：[Jason Baker][a] +选题：[lujun9972][b] +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/jason-baker +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/article/16/11/7-tech-advent-calendars-holiday-season +[2]: https://github.com/shlomif/fortune-mod +[3]: https://opensource.com/article/18/5/getting-started-regular-expressions +[4]: https://en.wikipedia.org/wiki/Fortune_%28Unix%29 +[5]: https://opensource.com/article/18/12/linux-toy-sl diff --git a/published/20181206 How To Boot Into Rescue Mode Or Emergency Mode In Ubuntu 18.04.md b/published/201901/20181206 How To Boot Into Rescue Mode Or Emergency Mode In Ubuntu 18.04.md similarity index 100% rename from published/20181206 How To Boot Into Rescue Mode Or Emergency Mode In Ubuntu 18.04.md rename to published/201901/20181206 How To Boot Into Rescue Mode Or Emergency Mode In Ubuntu 18.04.md diff --git a/sources/tech/20181207 Plan your own holiday calendar at the Linux command line.md b/published/201901/20181207 Plan your own holiday calendar at the Linux command line.md similarity index 60% rename from sources/tech/20181207 Plan your own holiday calendar at the Linux command line.md rename to published/201901/20181207 Plan your own holiday calendar at the Linux command line.md index b4d6f58b32..0a216f0d7b 100644 --- a/sources/tech/20181207 Plan your own holiday calendar at the Linux command line.md +++ b/published/201901/20181207 Plan your own holiday calendar at the Linux command line.md @@ -1,24 +1,26 @@ [#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) +[#]: translator: (MjSeven) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10495-1.html) [#]: subject: (Plan your own holiday calendar at the Linux command line) [#]: via: (https://opensource.com/article/18/12/linux-toy-cal) [#]: author: (Jason Baker https://opensource.com/users/jason-baker) -Plan your own holiday calendar at the Linux command line +在 Linux 命令行中规划你的假期日历 ====== -Link commands together to build a colorful calendar, and then whisk it away in a snowstorm. + +> 将命令链接在一起，构建一个彩色日历，然后在暴风雪中将其拂去。 + ![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-cal.png?itok=S0F8RY9k) -Welcome to today's installment of the Linux command-line toys advent calendar. If this is your first visit to the series, you might be asking yourself, what’s a command-line toy. Even I'm not quite sure, but generally, it could be a game or any simple diversion that helps you have fun at the terminal. +欢迎阅读今天推出的 Linux 命令行玩具降临日历。如果这是你第一次访问本系列，你可能会问：什么是命令行玩具。即使我不太确定，但一般来说，它可以是一个游戏或任何简单的娱乐，可以帮助你在终端玩得开心。 -It's quite possible that some of you will have seen various selections from our calendar before, but we hope there’s at least one new thing for everyone. +很可能你们中的一些人之前已经看过我们日历上的各种选择，但我们希望给每个人至少一件新东西。 -We've somehow made it to the seventh day of our series without creating an actual calendar to celebrate with, so let's use a command-line tool to do that today: **cal**. By itself, **cal** is perhaps not the most amazing of tools, but we can use a few other utilities to spice it up a bit. +我们在没有创建实际日历的情况下完成了本系列的第 7 天，所以今天让我们使用命令行工具来做到这一点：`cal`。就其本身而言，`cal` 可能不是最令人惊奇的工具，但我们可以使用其它一些实用程序来为它增添一些趣味。 -Chances are, **cal** is installed on your system already. To use it in this instance, just type **cal**. +很可能，你的系统上已经安装了 `cal`。要使用它，只需要输入 `cal` 即可。 ``` $ cal @@ -32,9 +34,10 @@ Su Mo Tu We Th Fr Sa 30 31           ``` -We aren't going to go into advanced usage in this article, so if you want to learn more about **cal** , go check out Opensource.com Community Moderator Don Watkin's excellent [overview of the date and cal commands][1]. +我们不打算在本文中深入介绍高级用法，因此如果你想了解有关 `cal` 的更多信息，查看 Opensouce.com 社区版主 Don Watkin 的优秀文章 [date 和 cal 命令概述][1]。 + +现在，让我们用一个漂亮的盒子来为它增添趣味，就像我们在上一篇 Linux 玩具文章中介绍的那样。我将使用钻石块，用一点内边距来对齐。 -Now, let's spice it up with a pretty box, as we covered in our previous Linux toy article. I'll use the diamonds box, and use a little bit of padding to get it nicely aligned. ``` $ cal | boxes -d diamonds -p a1l4t2  @@ -60,7 +63,7 @@ $ cal | boxes -d diamonds -p a1l4t2         \/          \/          \/ ``` -That looks nice, but for good measure, let's put the whole thing in a second box, just for fun. We'll use the scoll design this time. +看起来很不错，但是为了更规整，让我们把整个东西放到另一个盒子里，为了好玩，这次我们将使用卷轴式设计。 ``` cal | boxes -d diamonds -p a1t2l3 | boxes -a c -d scroll         @@ -92,25 +95,25 @@ cal | boxes -d diamonds -p a1t2l3 | boxes -a c -d scroll            ~~~                                                ~~~ ``` -Perfect. Now, here's where things get a little crazy. I like our design, but, I'd like to go all out. So I'm going to colorize it. But here in the Raleigh, NC office where Opensource.com's staff are based, there's a good chance for snow this weekend. So let's enjoy our colorized advent calendar, and then wipe it out with snow. +完美。现在，这事有点小激动了。我喜欢我们的设计，但我想更妙一些，所以我要给它上色。但是 Opensource.com 员工所在的北卡罗来版纳州罗利办公室，本周末很有可能下雪。所以，让我们享受彩色降临日历，然后用雪擦掉它。 -For the snow, I'm grabbing a nifty [snippet][2] of Bash and Gawk goodness I found over on CLIMagic. If you're not familiar with CLIMagic, go check out their [website][3] and follow them on [Twitter][4]. You'll be glad you did. +关于雪，我抓取了一些 Bash 和 Gawk 的漂亮[代码片段][2]，幸亏我发现了 CLIMagic。如果你不熟悉 CLIMagic，去查看他们的[网站][3]，在 [Twitter][4] 上关注他们。你会满意的。 -So here we go. Let's clear the screen, throw up our boxy calendar, colorize it, wait a few seconds, then snowstorm it away. All here at the terminal, in one line. +我们开始吧。让我们清除屏幕，扔掉四四方方的日历，给它上色，等几秒钟，然后用暴风雪把它吹走。这些在终端可以用一行命令完成。 ``` $ clear;cal|boxes -d diamonds -p a1t2l3|boxes -a c -d scroll|lolcat;sleep 3;while :;do echo $LINES $COLUMNS $(($RANDOM%$COLUMNS)) $(printf "\u2744\n");sleep 0.1;done|gawk '{a[$3]=0;for(x in a) {o=a[x];a[x]=a[x]+1;printf "\033[%s;%sH ",o,x;printf "\033[%s;%sH%s \033[0;0H",a[x],x,$4;}}' ``` -And there we go. +大功告成。 ![](https://opensource.com/sites/default/files/uploads/linux-toy-cal-animated.gif) -For this to work on your system, you'll need all of the referenced utilities (boxes, lolcat, cal, gawk, etc.), and you'll need to use a terminal emulator that supports Unicode. +要使它在你的系统上工作，你需要所有它引用的实用程序（`box`、`lolcat`、`gawk` 等），还需要使用支持 Unicode 的终端仿真器。 -Do you have a favorite command-line toy that you think I ought to profile? The calendar for this series is mostly filled out but I've got a few spots left. Let me know in the comments below, and I'll check it out. If there's space, I'll try to include it. If not, but I get some good submissions, I'll do a round-up of honorable mentions at the end. +你有特别喜欢的命令行小玩具需要我介绍的吗？这个系列要介绍的小玩具大部分已经有了落实，但还预留了几个空位置。请在评论区留言，我会查看的。如果还有空位置，我会考虑介绍它的。如果没有，但如果我得到了一些很好的意见，我会在最后做一些有价值的提及。 -Check out yesterday's toy, [Take a break at the Linux command line with Nyan Cat][5], and check back tomorrow for another! +看看昨天的玩具：[使用 Nyan Cat 在 Linux 命令行休息][5]。记得明天再来！ -------------------------------------------------------------------------------- @@ -118,8 +121,8 @@ via: https://opensource.com/article/18/12/linux-toy-cal 作者：[Jason Baker][a] 选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/published/20181209 Powers of two, powers of Linux- 2048 at the command line.md b/published/201901/20181209 Powers of two, powers of Linux- 2048 at the command line.md similarity index 100% rename from published/20181209 Powers of two, powers of Linux- 2048 at the command line.md rename to published/201901/20181209 Powers of two, powers of Linux- 2048 at the command line.md diff --git a/published/20181210 How to Update Ubuntu -Terminal - GUI Methods- It-s FOSS.md b/published/201901/20181210 How to Update Ubuntu -Terminal - GUI Methods- It-s FOSS.md similarity index 100% rename from published/20181210 How to Update Ubuntu -Terminal - GUI Methods- It-s FOSS.md rename to published/201901/20181210 How to Update Ubuntu -Terminal - GUI Methods- It-s FOSS.md diff --git a/published/20181210 McFly - A Replacement To ‘Ctrl-R- Bash History Search Feature.md b/published/201901/20181210 McFly - A Replacement To ‘Ctrl-R- Bash History Search Feature.md similarity index 100% rename from published/20181210 McFly - A Replacement To ‘Ctrl-R- Bash History Search Feature.md rename to published/201901/20181210 McFly - A Replacement To ‘Ctrl-R- Bash History Search Feature.md diff --git a/published/20181210 Snake your way across your Linux terminal.md b/published/201901/20181210 Snake your way across your Linux terminal.md similarity index 100% rename from published/20181210 Snake your way across your Linux terminal.md rename to published/201901/20181210 Snake your way across your Linux terminal.md diff --git a/published/20181211 Winterize your Bash prompt in Linux.md b/published/201901/20181211 Winterize your Bash prompt in Linux.md similarity index 100% rename from published/20181211 Winterize your Bash prompt in Linux.md rename to published/201901/20181211 Winterize your Bash prompt in Linux.md diff --git a/published/20181212 5 resolutions for open source project maintainers.md b/published/201901/20181212 5 resolutions for open source project maintainers.md similarity index 100% rename from published/20181212 5 resolutions for open source project maintainers.md rename to published/201901/20181212 5 resolutions for open source project maintainers.md diff --git a/published/20181213 What is PPA- Everything You Need to Know About PPA in Linux.md b/published/201901/20181213 What is PPA- Everything You Need to Know About PPA in Linux.md similarity index 100% rename from published/20181213 What is PPA- Everything You Need to Know About PPA in Linux.md rename to published/201901/20181213 What is PPA- Everything You Need to Know About PPA in Linux.md diff --git a/published/201901/20181214 The Linux terminal is no one-trick pony.md b/published/201901/20181214 The Linux terminal is no one-trick pony.md new file mode 100644 index 0000000000..f7c76392f9 --- /dev/null +++ b/published/201901/20181214 The Linux terminal is no one-trick pony.md @@ -0,0 +1,68 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10488-1.html) +[#]: subject: (The Linux terminal is no one-trick pony) +[#]: via: (https://opensource.com/article/18/12/linux-toy-ponysay) +[#]: author: (Jason Baker https://opensource.com/users/jason-baker) + +Linux 终端上的漂亮小马 +====== + +> 将小马宝莉的魔力带到终端 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-ponysay.png?itok=ehl6pTr_) + +欢迎再次来到 Linux 命令行玩具日历。如果这是你第一次访问该系列，你甚至可能会问自己什么是命令行玩具。我们正在思考中，但一般来说，它可能是一个游戏，或任何简单的消遣，可以帮助你在终端玩得开心。 + +很可能你们中的一些人之前已经看过我们日历中的各种玩具，但我们希望每个人至少见到一件新事物。 + +读者 [Lori][1] 在我之前关于 [cowsay][2] 的文章的评论中提出了今天玩具的建议： + +“嗯，我一直在玩一个叫 ponysay 的东西，它似乎是你的 cowsay 的彩色变种。” + +我对此感到好奇，并去看了一下，发现没有让我失望。 + +简而言之，[ponysay][3] 的 cowsay 的重写，它包括了来自[小马宝莉][4]中的许多全彩色人物，你可以用它在 Linux 命令行输出短句。它实际上是一个非常完善的项目，拥有超过 400 个字符和字符组合，它还有让人难以置信的的 [78 页的 PDF 文档][5]涵盖了所有的用法。 + +要安装 `ponysay`，你需要查看项目的 [README][6] 来选择最适合你的发行版和情况的安装方法。由于 `ponysay` 似乎没有为我的 Fedora 发行版打包，我选择试用 Docker 容器镜像，但你可以选择最适合你的方法。从源码安装可能也适合你。 + +作为一个业余容器用户，我很想试试 [podman][7] 来代替 docker。至少对于我而言，它可以正常工作。 + +``` +$ podman run -ti --rm mpepping/ponysay 'Ponytastic' +``` + +输出很神奇，我建议你也试下，然后告诉我你最喜欢的。这是我其中一个： + +![](https://opensource.com/sites/default/files/uploads/linux-toy-ponysay-output.png) + +它的开发人员选择用 [Pony][8] 来编写代码。（更新：很遗憾我写错了。虽然 Gihutb 根据它的文件扩展名认为它是 Pony，但是它是用 Python 写的。）Ponysay 使用 GPLv3 许可，你可以在 [GitHub][3] 中获取它的源码。 + +你有特别喜欢的命令行小玩具需要我介绍的吗？这个系列要介绍的小玩具大部分已经有了落实，但还预留了几个空位置。如果你有特别想了解的可以评论留言，我会查看的。如果还有空位置，我会考虑介绍它的。如果没有，但如果我得到了一些很好的意见，我会在最后做一些有价值的提及。 + +查看昨天的玩具，[在 Linux 终端中用火焰放松][9]，记得明天再来！ + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/12/linux-toy-ponysay + +作者：[Jason Baker][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/jason-baker +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/users/n8chz +[2]: https://opensource.com/article/18/12/linux-toy-cowsay +[3]: https://github.com/erkin/ponysay +[4]: https://en.wikipedia.org/wiki/My_Little_Pony +[5]: https://github.com/erkin/ponysay/blob/master/ponysay.pdf?raw=true +[6]: https://github.com/erkin/ponysay/blob/master/README.md +[7]: https://opensource.com/article/18/10/podman-more-secure-way-run-containers +[8]: https://opensource.com/article/18/5/pony +[9]: https://opensource.com/article/18/12/linux-toy-aafire diff --git a/published/201901/20181215 Head to the arcade in your Linux terminal with this Pac-man clone.md b/published/201901/20181215 Head to the arcade in your Linux terminal with this Pac-man clone.md new file mode 100644 index 0000000000..f7e411d88a --- /dev/null +++ b/published/201901/20181215 Head to the arcade in your Linux terminal with this Pac-man clone.md @@ -0,0 +1,55 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10474-1.html) +[#]: subject: (Head to the arcade in your Linux terminal with this Pac-man clone) +[#]: via: (https://opensource.com/article/18/12/linux-toy-myman) +[#]: author: (Jason Baker https://opensource.com/users/jason-baker) + +用这个吃豆人游戏在你的终端中玩街机 +====== + +> 想要重现你最喜欢的街机游戏的魔力么？今天的命令行玩具将带你回到过去。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-myman.png?itok=9j1DFgH0) + +欢迎来到今天的 Linux 命令行玩具日历。如果这是你第一次访问该系列，你会问什么是命令行玩具。基本上，它们是游戏和简单的消遣，可以帮助你在终端玩得开心。 + +有些是新的，有些是古老的经典。我们希望你喜欢。 + +今天的玩具，MyMan，是经典街机游戏[吃豆人][1]Pac-Man（你不会认为这是[类似命名的][2] Linux 包管理器对吧？）的有趣克隆。 如果你和我一样，为了在吃豆人游戏中取得高分，你过去在其中花费了很多时间，那么有机会的话，你应该试试这个。 + +MyMan 并不是 Linux 终端上唯一的吃豆人克隆版，但是我选择介绍它，因为 1）我喜欢它与原版一致的视觉风格，2）它为我的 Linux 发行版打包了，因此安装很容易。但是你也应该看看其他的克隆。这是[另一个][3]看起来可能不错的，但我没有尝试过。 + +由于 MyMan 已为 Fedora 打包，因此安装非常简单： + +``` +$ dnf install myman +``` + +MyMan 在 MIT 许可下可用，你可以在 [SourceForge][4] 上查看源代码。 + +![](https://opensource.com/sites/default/files/uploads/linux-toy-myman-animated.gif) + +你有特别喜欢的命令行小玩具需要我介绍的吗？这个系列要介绍的小玩具大部分已经有了落实，但还预留了几个空位置。如果你有特别想了解的可以评论留言，我会查看的。如果还有空位置，我会考虑介绍它的。如果没有，但如果我得到了一些很好的意见，我会在最后做一些有价值的提及。 + +了解一下昨天的玩具，[Linux 终端能做其他事][5]，还有记得明天再来！ + +-------------------------------------------------------------------------------- +via: https://opensource.com/article/18/12/linux-toy-myman + +作者：[Jason Baker][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/jason-baker +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Pac-Man +[2]: https://wiki.archlinux.org/index.php/pacman +[3]: https://github.com/YoctoForBeaglebone/pacman4console +[4]: https://myman.sourceforge.io/ +[5]: https://opensource.com/article/18/12/linux-toy-ponysay diff --git a/published/20181217 4 cool new projects to try in COPR for December 2018.md b/published/201901/20181217 4 cool new projects to try in COPR for December 2018.md similarity index 100% rename from published/20181217 4 cool new projects to try in COPR for December 2018.md rename to published/201901/20181217 4 cool new projects to try in COPR for December 2018.md diff --git a/published/20181217 Working with tarballs on Linux.md b/published/201901/20181217 Working with tarballs on Linux.md similarity index 100% rename from published/20181217 Working with tarballs on Linux.md rename to published/201901/20181217 Working with tarballs on Linux.md diff --git a/published/20181218 Termtosvg - Record Your Terminal Sessions As SVG Animations In Linux.md b/published/201901/20181218 Termtosvg - Record Your Terminal Sessions As SVG Animations In Linux.md similarity index 100% rename from published/20181218 Termtosvg - Record Your Terminal Sessions As SVG Animations In Linux.md rename to published/201901/20181218 Termtosvg - Record Your Terminal Sessions As SVG Animations In Linux.md diff --git a/published/20181218 Use your Linux terminal to celebrate a banner year.md b/published/201901/20181218 Use your Linux terminal to celebrate a banner year.md similarity index 100% rename from published/20181218 Use your Linux terminal to celebrate a banner year.md rename to published/201901/20181218 Use your Linux terminal to celebrate a banner year.md diff --git a/published/201901/20181219 How to open source your Python library.md b/published/201901/20181219 How to open source your Python library.md new file mode 100644 index 0000000000..e21eaeedb8 --- /dev/null +++ b/published/201901/20181219 How to open source your Python library.md @@ -0,0 +1,114 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10491-1.html) +[#]: subject: (How to open source your Python library) +[#]: via: (https://opensource.com/article/18/12/tips-open-sourcing-python-libraries) +[#]: author: (Moshe Zadka https://opensource.com/users/moshez) + +如何开源你的 Python 库 +====== + +> 这 12 个步骤能确保成功发布。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/button_push_open_keyboard_file_organize.png?itok=KlAsk1gx) + +你写了一个 Python 库。自己觉着这太棒了！如果让人们能够轻松使用它不是很优雅么？这有一个需要考虑的清单，以及在开源 Python 库时要采取的具体步骤。 + +### 1、源码 + +将代码放在 [GitHub][1] 上，这里有很多开源项目，并且人们很容易提交拉取请求。 + +### 2、许可证 + +选择一个开源许可证。一般来说 [MIT 许可证][2]是一个挺好的宽容许可证。如果你有特定要求，Creative Common 的[选择许可证][3]可以指导你完成其它选择。最重要的是，在选择许可证时要记住三条规则： + + * 不要创建自己的许可证。 + * 不要创建自己的许可证。 + * 不要创建自己的许可证。 + +### 3、README + +将一个名为 `README.rst` 的文件（使用 ReStructured Text 格式化）放在项目树的顶层。 + +GitHub 将像 Markdown 一样渲染 ReStructured Text，而 ReST 在 Python 的文档生态系统中的表现更好。 + +### 4、测试 + +写测试。这对你来说没有用处。但对于想要编写避免破坏相关功能的补丁的人来说，它非常有用。 + +测试可帮助协作者进行协作。 + +通常情况下，如果可以用 [pytest][4] 运行就最好了。还有其他测试工具 —— 但很少有理由去使用它们。 + +### 5、样式 + +使用 linter 制定样式：PyLint、Flake8 或者带上 `--check` 的 Black 。除非你使用 Black，否则请确保在一个文件中指定配置选项，并签入到版本控制系统中。 + +### 6、API 文档 + +使用 docstrings 来记录模块、函数、类和方法。 + +你可以使用几种样式。我更喜欢 [Google 风格的 docstrings][5]，但 [ReST docstrings][6] 也是一种选择。 + +Sphinx 可以同时处理 Google 风格和 ReST 的 docstrings，以将零散的文档集成为 API 文档。 + +### 7、零散文档 + +使用 [Sphinx][7]。（阅读[我们这篇文章][8]。）教程很有用，但同样重要的是要指明这是什么、它有什么好处、它有什么坏处、以及任何特殊的考虑因素。 + +### 8、构建 + +使用 tox 或 nox 自动运行测试和 linter，并构建文档。这些工具支持“依赖矩阵”。这些矩阵往往会快速增长，但你可以尝试针对合理的样本进行测试，例如 Python 版本、依赖项版本以及可能安装的可选依赖项。 + +### 9、打包 + +使用 [setuptools][9] 工具。写一个 `setup.py` 和一个 `setup.cfg`。如果同时支持 Python 2 和 3，请在 `setup.cfg` 中指定 universal 格式的 wheel。 + +tox 或 nox 应该做的一件事是构建 wheel 并对已安装的 wheel 进行测试。 + +避免使用 C 扩展。如果出于性能或绑定的原因一定需要它们，请将它们放在单独的包中。正确打包 C 扩展可以写一篇新的文章。这里有很多问题！ + +### 10、持续集成 + +使用公共持续工具。[TravisCI][10] 和 [CircleCI][11] 为开源项目提供免费套餐。将 GitHub 或其他仓库配置为在合并拉请求之前需要先通过检查，那么你就不必担心在代码评审中告知用户修复测试或样式。 + +### 11、版本 + +使用 [SemVer][12] 或 [CalVer][13]。有许多工具可以帮助你管理版本：[incremental][14]、[bumpversion][15] 和 [setuptools_scm][16] 等都是 PyPI 上的包，都可以帮助你管理版本。 + +### 12、发布 + +通过运行 tox 或 nox 并使用 twine 将文件上传到 PyPI 上发布。你可以通过在 [DevPI][17] 中“测试上传”。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/12/tips-open-sourcing-python-libraries + +作者：[Moshe Zadka][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/moshez +[b]: https://github.com/lujun9972 +[1]: https://github.com/ +[2]: https://en.wikipedia.org/wiki/MIT_License +[3]: https://choosealicense.com/ +[4]: https://docs.pytest.org/en/latest/ +[5]: https://github.com/google/styleguide/blob/gh-pages/pyguide.md +[6]: https://www.python.org/dev/peps/pep-0287/ +[7]: http://www.sphinx-doc.org/en/master/ +[8]: https://opensource.com/article/18/11/building-custom-workflows-sphinx +[9]: https://pypi.org/project/setuptools/ +[10]: https://travis-ci.org/ +[11]: https://circleci.com/ +[12]: https://semver.org/ +[13]: https://calver.org/ +[14]: https://pypi.org/project/incremental/ +[15]: https://pypi.org/project/bumpversion/ +[16]: https://pypi.org/project/setuptools_scm/ +[17]: https://opensource.com/article/18/7/setting-devpi diff --git a/published/20181219 Solve a puzzle at the Linux command line with nudoku.md b/published/201901/20181219 Solve a puzzle at the Linux command line with nudoku.md similarity index 100% rename from published/20181219 Solve a puzzle at the Linux command line with nudoku.md rename to published/201901/20181219 Solve a puzzle at the Linux command line with nudoku.md diff --git a/published/20181220 How To Install Microsoft .NET Core SDK On Linux.md b/published/201901/20181220 How To Install Microsoft .NET Core SDK On Linux.md similarity index 100% rename from published/20181220 How To Install Microsoft .NET Core SDK On Linux.md rename to published/201901/20181220 How To Install Microsoft .NET Core SDK On Linux.md diff --git a/published/20181220 Let your Linux terminal speak its mind.md b/published/201901/20181220 Let your Linux terminal speak its mind.md similarity index 100% rename from published/20181220 Let your Linux terminal speak its mind.md rename to published/201901/20181220 Let your Linux terminal speak its mind.md diff --git a/published/20181221 An Easy Way To Remove Programs Installed From Source In Linux.md b/published/201901/20181221 An Easy Way To Remove Programs Installed From Source In Linux.md similarity index 100% rename from published/20181221 An Easy Way To Remove Programs Installed From Source In Linux.md rename to published/201901/20181221 An Easy Way To Remove Programs Installed From Source In Linux.md diff --git a/published/20181221 How to Build a Netboot Server, Part 3.md b/published/201901/20181221 How to Build a Netboot Server, Part 3.md similarity index 100% rename from published/20181221 How to Build a Netboot Server, Part 3.md rename to published/201901/20181221 How to Build a Netboot Server, Part 3.md diff --git a/published/20181222 A Tale of HTTP-2.md b/published/201901/20181222 A Tale of HTTP-2.md similarity index 100% rename from published/20181222 A Tale of HTTP-2.md rename to published/201901/20181222 A Tale of HTTP-2.md diff --git a/published/20181222 Top 11 best Image Viewer for Ubuntu and other Linux.md b/published/201901/20181222 Top 11 best Image Viewer for Ubuntu and other Linux.md similarity index 100% rename from published/20181222 Top 11 best Image Viewer for Ubuntu and other Linux.md rename to published/201901/20181222 Top 11 best Image Viewer for Ubuntu and other Linux.md diff --git a/published/20181222 Watch YouTube videos at the Linux terminal.md b/published/201901/20181222 Watch YouTube videos at the Linux terminal.md similarity index 100% rename from published/20181222 Watch YouTube videos at the Linux terminal.md rename to published/201901/20181222 Watch YouTube videos at the Linux terminal.md diff --git a/published/20181223 The Linux command line can fetch fun from afar.md b/published/201901/20181223 The Linux command line can fetch fun from afar.md similarity index 100% rename from published/20181223 The Linux command line can fetch fun from afar.md rename to published/201901/20181223 The Linux command line can fetch fun from afar.md diff --git a/published/20190103 How to create presentations with Beamer.md b/published/201901/20190103 How to create presentations with Beamer.md similarity index 100% rename from published/20190103 How to create presentations with Beamer.md rename to published/201901/20190103 How to create presentations with Beamer.md diff --git a/published/201901/20190103 s-tui- A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux.md b/published/201901/20190103 s-tui- A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux.md new file mode 100644 index 0000000000..e1effb5acc --- /dev/null +++ b/published/201901/20190103 s-tui- A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux.md @@ -0,0 +1,120 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (https://linux.cn/article-10467-1.html) +[#]: url: (wxy) +[#]: subject: (s-tui: A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux) +[#]: via: (https://www.2daygeek.com/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency/) +[#]: author: (Prakash Subramanian https://www.2daygeek.com/author/prakash/) + +s-tui：在 Linux 中监控 CPU 温度、频率、功率和使用率的终端工具 +====== + +一般每个 Linux 管理员都会使用 [lm_sensors 监控 CPU 温度][1]。lm_sensors （Linux 监控传感器）是一个自由开源程序，它提供了监控温度、电压和风扇的驱动和工具。 + +如果你正在找替代的 CLI 工具，我会建议你尝试 s-tui。 + +它其实是一个压力测试的终端 UI，可以帮助管理员通过颜色查看 CPU 温度。 + +### s-tui 是什么 + +s-tui 是一个用于监控计算机的终端 UI。s-tui 可以在终端以图形方式监控 CPU 温度、频率、功率和使用率。此外，它还显示由发热量限制引起的性能下降，它需要很少的资源并且不需要 X 服务器。它是用 Python 编写的，需要 root 权限才能使用它。 + +s-tui 是一个独立的程序，可以开箱即用，并且不需要配置文件就可以使用其基本功能。 + +s-tui 使用 psutil 来探测你的一些硬件信息。如果不支持你的一些硬件，你可能看不到所有信息。 + +以 root 身份运行 s-tui 时，当压测所有 CPU 核心时，可以将 CPU 发挥到最大睿频频率。它在后台使用 Stress 压力测试工具，通过对系统施加某些类型的计算压力来检查其组件的温度是否超过其可接受的范围。只要计算机稳定并且其组件的温度不超过其可接受的范围，PC 超频就没问题。有几个程序可以通过压力测试得到系统的稳定性，从而评估超频水平。 + +### 如何在 Linux 中安装 s-tui + +它是用 Python 写的，`pip` 是在 Linux 上安装 s-tui 的推荐方法。确保你在系统上安装了 python-pip 软件包。如果还没有，请使用以下命令进行安装。 + +对于 Debian/Ubuntu 用户，使用 [apt 命令][2] 或 [apt-get 命令][3] 来安装 `pip`。 + +``` +$ sudo apt install python-pip stress +``` + +对于 Archlinux 用户，使用 [pacman 命令][4] 来安装 `pip`。 + +``` +$ sudo pacman -S python-pip stress +``` + +对于 Fedora 用户，使用 [dnf 命令][5] 来安装 `pip`。 + +``` +$ sudo dnf install python-pip stress +``` + +对于 CentOS/RHEL 用户，使用 [yum 命令][5] 来安装 `pip`。 + +``` +$ sudo yum install python-pip stress +``` + +对于 openSUSE 用户，使用 [zypper 命令][5] 来安装 `pip`。 + +``` +$ sudo zypper install python-pip stress +``` + +最后运行下面的 [pip 命令][8] 在 Linux 中安装 s-tui 工具。 + +对于 Python 2.x： + +``` +$ sudo pip install s-tui +``` + +对于Python 3.x： + +``` +$ sudo pip3 install s-tui +``` + +### 如何使用 s-tui + +正如我在文章开头所说的那样。它需要 root 权限才能从系统获取所有信息。只需运行以下命令即可启动 s-tui。 + +``` +$ sudo s-tui +``` + +![][10] + +默认情况下，它启用硬件监控并选择 “Stress” 选项以对系统执行压力测试。 + +![][11] + +要查看其他选项，请到帮助页面查看。 + +``` +$ s-tui --help +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency/ + +作者：[Prakash Subramanian][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/prakash/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/view-check-cpu-hard-disk-temperature-linux/ +[2]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/ +[3]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/ +[4]: https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/ +[5]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ +[6]: https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/ +[7]: https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/ +[8]: https://www.2daygeek.com/install-pip-manage-python-packages-linux/ +[9]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[10]: https://www.2daygeek.com/wp-content/uploads/2018/12/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency-1.jpg +[11]: https://www.2daygeek.com/wp-content/uploads/2018/12/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency-2.jpg diff --git a/published/201901/20190104 Managing dotfiles with rcm.md b/published/201901/20190104 Managing dotfiles with rcm.md new file mode 100644 index 0000000000..ae1169f84e --- /dev/null +++ b/published/201901/20190104 Managing dotfiles with rcm.md @@ -0,0 +1,113 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10466-1.html) +[#]: subject: (Managing dotfiles with rcm) +[#]: via: (https://fedoramagazine.org/managing-dotfiles-rcm/) +[#]: author: (Link Dupont https://fedoramagazine.org/author/linkdupont/) + +用 rcm 管理隐藏文件 +====== + +![](https://fedoramagazine.org/wp-content/uploads/2018/12/dotfiles-816x345.jpg) + +许多 GNU/Linux 程序的一个特点是有个易于编辑的配置文件。几乎所有常见的自由软件都将配置设置保存在纯文本文件中，通常采用结构化格式，如 JSON、YAML 或[“类似 ini”][1] 的文件中。这些配置文件经常隐藏在用户的主目录中。但是，基本的 `ls` 不会显示它们。UNIX 标准要求以点开头的任何文件或目录名称都被视为“隐藏”，除非用户特意要求，否则不会列在目录列表中。例如，要使用 `ls` 列出所有文件，要传递 `-a` 选项。 + +随着时间的推移，这些配置文件会有很多定制配置，管理它们变得越来越具有挑战性。不仅如此，在多台计算机之间保持同步是大型组织所面临的共同挑战。最后，许多用户也对其独特的配置感到自豪，并希望以简单的方式与朋友分享。这就是用到 rcm 介入的地方。 + +rcm 是一个 “rc” 文件管理套件（“rc” 是命名配置文件的另一种约定，它已被某些 GNU/Linux 程序采用，如 `screen` 或 `bash`）。 rcm 提供了一套命令来管理和列出它跟踪的文件。使用 `dnf` 安装 rcm。 + +### 开始使用 + +默认情况下，rcm 使用 `~/.dotfiles` 来存储它管理的所有隐藏文件。一个被管理的隐藏文件实际保存在 `~/.dotfiles` 目录中，而它的符号链接会放在文件原本的位置。例如，如果 `~/.bashrc` 由 rcm 所管理，那么详细列表将如下所示。 + +``` +[link@localhost ~]$ ls -l ~/.bashrc +lrwxrwxrwx. 1 link link 27 Dec 16 05:19 .bashrc -> /home/link/.dotfiles/bashrc +[link@localhost ~]$ +``` + +rcm 包含 4 个命令： + + * `mkrc` – 将文件转换为由 rcm 管理的隐藏文件 + * `lsrc` – 列出由 rcm 管理的文件 + * `rcup` – 同步由 rcm 管理的隐藏文件 + * `rcdn` – 删除 rcm 管理的所有符号链接 + +### 在两台计算机上共享 bashrc + +如今用户在多台计算机上拥有 shell 帐户并不罕见。在这些计算机之间同步隐藏文件可能是一个挑战。这里将提供一种可能的解决方案，仅使用 rcm 和 git。 + +首先使用 `mkrc` 将文件转换成由 rcm 管理的文件。 + +``` +[link@localhost ~]$ mkrc -v ~/.bashrc +Moving... +'/home/link/.bashrc' -> '/home/link/.dotfiles/bashrc' +Linking... +'/home/link/.dotfiles/bashrc' -> '/home/link/.bashrc' +[link@localhost ~]$ +``` + +接下来使用 `lsrc` 验证列表是否正确。 + +``` +[link@localhost ~]$ lsrc +/home/link/.bashrc:/home/link/.dotfiles/bashrc +[link@localhost ~]$ +``` + +现在在 `~/.dotfiles` 中创建一个 git 仓库，并使用你选择的 git 仓库托管设置一个远程仓库。提交 `bashrc` 文件并推送一个新分支。 + +``` +[link@localhost ~]$ cd ~/.dotfiles +[link@localhost .dotfiles]$ git init +Initialized empty Git repository in /home/link/.dotfiles/.git/ +[link@localhost .dotfiles]$ git remote add origin git@github.com:linkdupont/dotfiles.git +[link@localhost .dotfiles]$ git add bashrc +[link@localhost .dotfiles]$ git commit -m "initial commit" +[master (root-commit) b54406b] initial commit +1 file changed, 15 insertions(+) +create mode 100644 bashrc +[link@localhost .dotfiles]$ git push -u origin master +... +[link@localhost .dotfiles]$ +``` + +在第二台机器上，克隆这个仓库到 `~/.dotfiles` 中。 + +``` +[link@remotehost ~]$ git clone git@github.com:linkdupont/dotfiles.git ~/.dotfiles +... +[link@remotehost ~]$ +``` + +现在使用 `rcup` 更新受 rcm 管理的符号链接。 + +``` +[link@remotehost ~]$ rcup -v +replacing identical but unlinked /home/link/.bashrc +removed '/home/link/.bashrc' +'/home/link/.dotfiles/bashrc' -> '/home/link/.bashrc' +[link@remotehost ~]$ +``` + +覆盖现有的 `~/.bashrc`（如果存在）并重启 shell。 + +就是这些了！指定主机选项 （`-o`） 是对上面这种情况的有用补充。如往常一样，请阅读手册页。它们包含了很多示例命令。 + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/managing-dotfiles-rcm/ + +作者：[Link Dupont][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/author/linkdupont/ +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/INI_file diff --git a/published/201901/20190107 Getting started with Pelican- A Python-based static site generator.md b/published/201901/20190107 Getting started with Pelican- A Python-based static site generator.md new file mode 100644 index 0000000000..061effbde3 --- /dev/null +++ b/published/201901/20190107 Getting started with Pelican- A Python-based static site generator.md @@ -0,0 +1,222 @@ +[#]: collector: (lujun9972) +[#]: translator: (MjSeven) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10471-1.html) +[#]: subject: (Getting started with Pelican: A Python-based static site generator) +[#]: via: (https://opensource.com/article/19/1/getting-started-pelican) +[#]: author: (Craig Sebenik https://opensource.com/users/craig5) + +Pelican 入门：一个 Python 静态网站生成器 +====== + +> Pelican 是那些想要自我托管简单网站或博客的 Python 用户的绝佳选择。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/web-design-monitor-website.png?itok=yUK7_qR0) + +如果你想创建一个自定义网站或博客，有很多选择。许多提供商可以托管你的网站并为你完成大部分工作。（WordPress 是一个非常受欢迎的选项。）但是使用托管方式，你会失去一些灵活性。作为一名软件开发人员，我更喜欢管理我自己的服务器，并在我的网站如何运行方面保持更多的自由。 + +然而，管理 Web 服务器需要大量的工作。安装它并获得一个简单的应用程序来提供内容是非常容易的。但是，维护安全补丁和更新是非常耗时得。如果你只想提供静态网页，那么拥有一个 Web 服务器和一系列应用程序可能会得不偿失。手动创建 HTML 页面也不是一个好选择。 + +这是静态网站生成器的用武之地。这些应用程序使用模板来创建所需的静态页面，并将它们与关联的元数据交叉链接。（例如，所有显示的页面都带有公共标签或关键词。）静态网站生成器可以帮助你使用导航区域、页眉和页脚等元素创建一个具有公共外观的网站。 + +我使用 [Pyhton][1] 已经很多年了，所以，当我第一次开始寻找生成静态 HTML 页面的东西时，我想要用 Python 编写的东西。主要原因是我经常想要了解应用程序如何工作的内部细节，而使用一种我已经了解的语言使这一点更容易。（如果这对你不重要或者你不使用 Python，那么还有一些其他很棒的[静态网站生成器][2]，它们使用 Ruby、JavaScript 和其它语言。） + +我决定试试 [Pelican][3]。它是一个用 Python 编写的常用静态网站生成器。它支持 [reStructuredText][4]（LCTT 译注：这是一种用于文本数据的文件格式，主要用于 Python 社区的技术文档），并且也支持 [Markdown][5]，这需要通过安装必需的包来完成。所有任务都是通过命令行界面（CLI）工具执行的，这使得熟悉命令行的任何人都可以轻松完成。它简单的 quickstart CLI 工具使得创建一个网站非常容易。 + +在本文中，我将介绍如何安装 Pelican 4，添加一篇文章以及更改默认主题。（注意：我是在 MacOS 上开发的，使用其它 Unix/Linux 实验结果都将相同，但我没有 Windows 主机可以测试。） + +### 安装和配置 + +第一步是创建一个[虚拟环境][6]，在虚拟环境中安装 Pelican。 + +``` +$ mkdir test-site +$ cd test-site +$ python3 -m venv venv +$ ./venv/bin/pip install --upgrade pip +... +Successfully installed pip-18.1 +$ ./venv/bin/pip install pelican +Collecting pelican +... +Successfully installed MarkupSafe-1.1.0 blinker-1.4 docutils-0.14 feedgenerator-1.9 jinja2-2.10 pelican-4.0.1 pygments-2.3.1 python-dateutil-2.7.5 pytz-2018.7 six-1.12.0 unidecode-1.0.23 +``` + +Pelican 的 quickstart CLI 工具将创建基本布局和一些文件来帮助你开始，运行 `pelican-quickstart` 命令。为了简单起见，我输入了**网站标题**和**作者**的名字，并对 URL 前缀和文章分页选择了 “N”。（对于其它选项，我使用了默认值。）稍后在配置文件中更改这些设置非常容易。 + +``` +$ ./venv/bin/pelicanquickstart +Welcome to pelicanquickstart v4.0.1. + +This script will help you create a new Pelican-based website. + +Please answer the following questions so this script can generate the files needed by Pelican. + +> Where do you want to create your new web site? [.] +> What will be the title of this web site? My Test Blog +> Who will be the author of this web site? Craig +> What will be the default language of this web site? [en] +> Do you want to specify a URL prefix? e.g., https://example.com (Y/n) n +> Do you want to enable article pagination? (Y/n) n +> What is your time zone? [Europe/Paris] +> Do you want to generate a tasks.py/Makefile to automate generation and publishing? (Y/n) +> Do you want to upload your website using FTP? (y/N) +> Do you want to upload your website using SSH? (y/N) +> Do you want to upload your website using Dropbox? (y/N) +> Do you want to upload your website using S3? (y/N) +> Do you want to upload your website using Rackspace Cloud Files? (y/N) +> Do you want to upload your website using GitHub Pages? (y/N) +Done. Your new project is available at /Users/craig/tmp/pelican/test-site +``` + +你需要启动的所有文件都准备好了。 + +quickstart 默认为欧洲/巴黎时区，所以在继续之前更改一下。在你喜欢的文本编辑器中打开 `pelicanconf.py` 文件，寻找 `TIMEZONE` 变量。 + +``` +TIMEZONE = 'Europe/Paris' +``` + +将其改为 `UTC`。 + +``` +TIMEZONE = 'UTC' +``` + +要更新公共设置，在 `pelicanconf.py` 中查找 `SOCIAL` 变量。 + +``` +SOCIAL = (('You can add links in your config file', '#'), +          ('Another social link', '#'),) +``` + +我将添加一个我的 Twitter 账户链接。 + +``` +SOCIAL = (('Twitter (#craigs55)', 'https://twitter.com/craigs55'),) +``` + +注意末尾的逗号，它很重要。这个逗号将帮助 Python 识别变量实际上是一个集合。确保你没有删除这个逗号。 + +现在你已经有了网站的基本知识。quickstart 创建了一个包含许多目标的 `Makefile`。将 `devserver` 传给 `make` 命令将在你的计算机上启动一个开发服务器，以便你可以预览所有内容。`Makefile` 中使用的 CLI 命令假定放在 `PATH` 搜索路径中，因此你需要首先激活该虚拟环境。 + +``` +$ source ./venv/bin/activate +$ make devserver +pelican -lr /Users/craig/tmp/pelican/test-site/content o +/Users/craig/tmp/pelican/test-site/output -s /Users/craig/tmp/pelican/test-site/pelicanconf.py + +-> Modified: theme, settings. regenerating... +WARNING: No valid files found in content for the active readers: +   | BaseReader (static) +   | HTMLReader (htm, html) +   | RstReader (rst) +Done: Processed 0 articles, 0 drafts, 0 pages, 0 hidden pages and 0 draft pages in 0.18 seconds. +``` + +在你最喜欢的浏览器中打开 来查看你的简单测试博客。 + +![](https://opensource.com/sites/default/files/uploads/pelican_test-site1.png) + +你可以在右侧看到 Twitter 链接，左侧有 Pelican、Python 和 Jinja 的一些链接。（Jinja 是 Pelican 可以使用的一种很棒的模板语言。你可以在 [Jinja 的文档][7]中了解更多相关信息。） + +### 添加内容 + +现在你又了一个基本的网站，试着添加一些内容。首先，将名为 `welcome.rst` 的文件添加到网站的 `content` 目录中。在你喜欢的文本编辑器中，使用以下文本创建一个文件： + +``` +$ pwd +/Users/craig/tmp/pelican/test-site +$ cat content/welcome.rst + +Welcome to my blog! +################### + +:date: 20181216 08:30 +:tags: welcome +:category: Intro +:slug: welcome +:author: Craig +:summary: Welcome document + +Welcome to my blog. +This is a short page just to show how to put up a static page. +``` + +Pelican 会自动解析元数据行，包括日期、标签等。 + +编写完文件后，开发服务器应该输出以下内容： + +``` +-> Modified: content. regenerating... +Done: Processed 1 article, 0 drafts, 0 pages, 0 hidden pages and 0 draft pages in 0.10 seconds. +``` + +在浏览器中刷新你的测试网站来查看更改。 + +![](https://opensource.com/sites/default/files/uploads/pelican_test-site2.png) + +元数据（例如日期和标签）会自动添加到页面中。此外，Pelican 会自动检测到 intro 栏目，并将该部分添加到顶部导航中。 + +### 更改主题 + +使用像 Pelican 这样流行的开源软件的好处之一是，非常多的用户会做出更改并将其贡献给项目。许多都是以主题形式贡献的。 + +网站的主题会设置颜色、布局选项等。尝试一个新主题非常容易，你可以在 [Pelican 主题][8]中预览其中的许多内容。 + +首先，克隆 GitHub 仓库: + +``` +$ cd .. +$ git clone --recursive https://github.com/getpelican/pelicanthemes +Cloning into 'pelicanthemes'... +``` + +我喜欢蓝色，那么试试 [blueidea][9]。 + +编辑 `pelicanconf.py`，添加以下行： + +``` +THEME = '/Users/craig/tmp/pelican/pelican-themes/blueidea/' +``` + +开发服务器将重新生成你的输出。在浏览器中刷新网页来查看新主题。 + +![](https://opensource.com/sites/default/files/uploads/pelican_test-site3.png) + +主题控制布局的方方面面。例如，在默认主题中，你可以看到文章旁边带有元标记的栏目（Intro），但这个栏目并未显示在 blueidea 主题中。 + +### 其他考虑因素 + +本文是对 Pelican 的快速介绍，所以我并没有涉及一些重要的主题。 + +首先，我对迁移到静态站点犹豫不决的一个原因是它无法对文章评论。幸运的是，有一些第三方服务商将为你提供评论功能。我目前正在关注的是 [Disqus][10]。 + +接下来，上面的所有内容都是在我的本地机器上完成的。如果我希望其他人查看我的网站，我将不得不将预先生成的 HTML 文件上传到某个地方。如果你查看 `pelican-quickstart` 输出，你将看到使用 FTP、 SSH、S3 甚至 GitHub 页面的选项，每个选项都有其优点和缺点。但是，如果我必须选择一个，那么我可能会选择发布到 GitHub 页面。 + +Pelican 还有许多其他功能，我每天都在学习它。如果你想自托管一个网站或博客，内容简单并且是静态内容，同时你想使用 Python，那么 Pelican 是一个很好的选择。它有一个活跃的用户社区，可以修复 bug，添加特性，而且还会创建新的和有趣的主题。试试看吧！ + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/getting-started-pelican + +作者：[Craig Sebenik][a] +选题：[lujun9972][b] +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/craig5 +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/resources/python +[2]: https://opensource.com/sitewide-search?search_api_views_fulltext=static%20site%20generator +[3]: http://docs.getpelican.com/en/stable/ +[4]: http://docutils.sourceforge.net/rst.html +[5]: https://daringfireball.net/projects/markdown/ +[6]: https://virtualenv.pypa.io/en/latest/ +[7]: http://jinja.pocoo.org/docs/2.10/ +[8]: http://www.pelicanthemes.com/ +[9]: https://github.com/nasskach/pelican-blueidea/tree/58fb13112a2707baa7d65075517c40439ab95c0a +[10]: https://disqus.com/ diff --git a/published/201901/20190109 Bash 5.0 Released with New Features.md b/published/201901/20190109 Bash 5.0 Released with New Features.md new file mode 100644 index 0000000000..92aaedc8fc --- /dev/null +++ b/published/201901/20190109 Bash 5.0 Released with New Features.md @@ -0,0 +1,78 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10477-1.html) +[#]: subject: (Bash 5.0 Released with New Features) +[#]: via: (https://itsfoss.com/bash-5-release) +[#]: author: (Ankush Das https://itsfoss.com/author/ankush/) + +Bash 5.0 发布及其新功能 +====== + +[邮件列表][1]证实最近发布了 Bash-5.0。而且，令人兴奋的是它还有新的功能和变量。 + +如果你一直在使用 Bash 4.4.XX，那么你一定会喜欢 [Bash][2] 的第五个主要版本。 + +第五个版本侧重于新的 shell 变量和许多重大漏洞修复。它还引入了一些新功能，以及一些与 bash-4.4 不兼容的更改。 + +![Bash logo][3] + +### 新功能怎么样？ + +在邮件列表解释了此版本中修复的 bug： + +> 此版本修复了 bash-4.4 中的几个主要错误，并引入了几个新功能。最重要的 bug 修复是对 nameref 变量的解析以及通过模糊测试发现的许多潜在的内存越界错误。在为了符合 Posix 标准解释而不进行单词拆分的上下文中，对 `$@` 和 `$*` 的展开做了许多改变，另外还有解决极端情况中 Posix 一致性的修改。 + +它还引入了一些新功能。根据其发布说明，最值得注意的新功能是几个新的 shell 变量： + +> `BASH_ARGV0`、`EPOCHSECONDS` 和 `EPOCHREALTIME`。内置命令 `history` 可以删除指定范围的条目，并能将负数理解为从历史末端开始的偏移量。有一个选项允许局部变量继承前一个范围内具有相同名称的变量的值。有一个新的 shell 选项，在启用它时，会导致 shell 只尝试一次扩展关联数组下标（这在算术表达式中使用时会出现问题）。`globasciiranges` 这个 shell 选项现在默认启用。可以在配置时默认关闭它。 + +### Bash-4.4 和 Bash-5.0 之间有哪些变化？ + +其更新日志提到了不兼容的更改和所支持的 readline 版本历史记录。它是这么说的： + +> bash-4.4 和 bash-5.0 之间存在一些不兼容的变化。尽管我已经尽量最小化兼容性问题，但是对 `nameref` 变量解析的更改意味着对变量名引用的某些使用会有不同的行为。默认情况下，如果启用了扩展调试模式，shell 仅在启动时设置 `BASH_ARGC` 和 `BASH_ARGV`。它被无条件地设置是一个疏忽，并且在脚本传递大量参数时会导致性能问题。 +> +> 如果需要，可以将 Bash 链接到已安装的 Readline 库，而不是 `lib/readline` 中的私有版本。只有 readline-8.0 及更高版本能够提供 bash-5.0 所需的所有符号。早期版本的 Readline 库无法正常工作。 + +我相信一些添加的功能/变量非常有用。我最喜欢的一些是： + + * 有一个新的（默认情况下禁用，文档中没有说明）shell 选项，用于在运行时启用/禁用向 syslog 发送历史记录。 + * 正如文档一直所说的那样，除非 shell 处于调试模式，否则它不会在启动时自动设置 `BASH_ARGC` 和 `BASH_ARGV`，但如果脚本在上层引用它们且没有启用调试模式，那么 shell 将动态创建它们。 + * 现在可以使用 `-d start-end` 删除指定范围的 `history` 条目。 + * 如果启用了作业控制的非交互式 shell 检测到前台作业因 SIGINT 而死亡，则其行为就像接收到 SIGINT 一样。 + * `BASH_ARGV0`：一个新变量，扩展为 `$0`，并在赋值时设置为 `$0`。 + +要查看完整的更改和功能列表，请参阅[邮件列表文章][1]。 + +### 总结 + +你可以使用下面的命令检查你当前的 Bash 版本： + +``` +bash --version +``` + +你很可能安装了 Bash 4.4。如果你想获得新版本，我建议等待你的发行版提供它。 + +你怎么看待 Bash-5.0 发布？你在使用其他 bash 的替代品么？如果有的话，这个更新会改变你的想法么？ + +请在下面的评论中告诉我们你的想法。 + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/bash-5-release + +作者：[Ankush Das][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/ankush/ +[b]: https://github.com/lujun9972 +[1]: https://lists.gnu.org/archive/html/bug-bash/2019-01/msg00063.html +[2]: https://www.gnu.org/software/bash/ +[3]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/bash-logo.jpg?resize=800%2C450&ssl=1 diff --git a/published/20190109 Understanding -etc-services file in Linux.md b/published/201901/20190109 Understanding -etc-services file in Linux.md similarity index 100% rename from published/20190109 Understanding -etc-services file in Linux.md rename to published/201901/20190109 Understanding -etc-services file in Linux.md diff --git a/published/201901/20190113 Get started with Joplin, a note-taking app.md b/published/201901/20190113 Get started with Joplin, a note-taking app.md new file mode 100644 index 0000000000..e287e143f8 --- /dev/null +++ b/published/201901/20190113 Get started with Joplin, a note-taking app.md @@ -0,0 +1,67 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10476-1.html) +[#]: subject: (Get started with Joplin, a note-taking app) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-joplin) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +开始使用 Joplin 吧，一款开源笔记应用 +====== + +> 了解开源工具如何帮助你在 2019 年提高工作效率。先从 Joplin 开始。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/programming-code-keyboard-laptop.png?itok=pGfEfu2S) + +每年年初似乎都有疯狂的冲动想提高工作效率。新年的决心，渴望开启新的一年，当然，“抛弃旧的，拥抱新的”的态度促成了这一切。通常这时的建议严重偏向闭源和专有软件，但事实上并不用这样。 + +这是我挑选出的 19 个新的（或者对你而言新的）开源项目来帮助你在 2019 年更有效率。 + +### Joplin + +在生产力工具领域，笔记应用**非常**方便。是的，你可以使用开源 [NixNote][1] 访问 [Evernote][2] 笔记，但它仍然与 Evernote 服务器相关联，并且仍然依赖于第三方的安全性。虽然你**可以**从 NixNote 导出 Evernote 笔记，但可选格式只有 NixNote XML 或 PDF。 + +![](https://opensource.com/sites/default/files/uploads/joplin-1.png) + +*Joplin 的图形界面* + +看看 [Joplin][3]。Joplin 是一个 NodeJS 应用，它在本地运行和存储笔记，它允许你加密笔记并支持多种同步方法。Joplin 可在 Windows、Mac 和 Linux 上作为控制台应用或图形应用运行。Joplin 还有适用于 Android 和 iOS 的移动应用，这意味着你可以随身携带笔记而不会有任何麻烦。Joplin 甚至允许你使用 Markdown、HTML 或纯文本格式笔记。 + +![](https://opensource.com/sites/default/files/uploads/joplin-3.png) + +*Joplin 的 Android 应用* + +关于 Joplin 很棒的一件事是它支持两种类型笔记：普通笔记和待办事项笔记。普通笔记是你所想的包含文本的文档。另一个，待办事项笔记在笔记列表中有一个复选框，允许你将其标记为“已完成”。由于待办事项仍然是一个笔记，因此你可以在待办事项中添加列表、文档和其他待办事项。 + +当使用图形界面时，你可以在纯文本、WYSIWYG 和同时显示源文本和渲染视图的分屏之间切换编辑器视图。你还可以在图形界面中指定外部编辑器，以便使用 Vim、Emacs 或任何其他能够处理文本文档的编辑器轻松更新笔记。 + +![Joplin console version][5] + +*控制台中的 Joplin* + +控制台界面非常棒。虽然它缺少 WYSIWYG 编辑器，但默认登录使用文本编辑器。它还有强大的命令模式，它允许执行在图形版本中几乎所有的操作。并且能够在视图中正确渲染 Markdown。 + +你可以将笔记本中的笔记分组，还能为笔记打上标记，以便于在笔记本中进行分组。它甚至还有内置的搜索功能，因此如果你忘了笔记在哪，你可以通过它找到它们。 + +总的来说，Joplin 是一款一流的笔记应用（[还是 Evernote 的一个很好的替代品][6]），它能帮助你在明年组织化并提高工作效率。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-joplin + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: http://nixnote.org/NixNote-Home/ +[2]: https://evernote.com/ +[3]: https://joplin.cozic.net/ +[4]: https://opensource.com/article/19/1/file/419776 +[5]: https://opensource.com/sites/default/files/uploads/joplin-2_0.png (Joplin console version) +[6]: https://opensource.com/article/17/12/joplin-open-source-evernote-alternative diff --git a/published/20190114 Get started with Wekan, an open source kanban board.md b/published/201901/20190114 Get started with Wekan, an open source kanban board.md similarity index 100% rename from published/20190114 Get started with Wekan, an open source kanban board.md rename to published/201901/20190114 Get started with Wekan, an open source kanban board.md diff --git a/published/201901/20190114 How To Move Multiple File Types Simultaneously From Commandline.md b/published/201901/20190114 How To Move Multiple File Types Simultaneously From Commandline.md new file mode 100644 index 0000000000..738306b94c --- /dev/null +++ b/published/201901/20190114 How To Move Multiple File Types Simultaneously From Commandline.md @@ -0,0 +1,94 @@ +[#]: collector: (lujun9972) +[#]: translator: (MjSeven) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10464-1.html) +[#]: subject: (How To Move Multiple File Types Simultaneously From Commandline) +[#]: via: (https://www.ostechnix.com/how-to-move-multiple-file-types-simultaneously-from-commandline/) +[#]: author: (SK https://www.ostechnix.com/author/sk/) + +如何从命令行同时移动多种文件类型 +====== + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/Move-Multiple-File-Types-720x340.png) + +前几天，我想知道如何将多个文件类型从一个目录移动（不复制）到另一个目录。我已经知道如何[查找并将某些类型的文件从一个目录复制到另一个目录][1]。但是，我不知道如何同时移动多种文件类型。如果你曾遇到这样的情况，我知道在类 Unix 系统中从命令行执行该操作的一个简单方法。 + +### 同时移动多种文件类型 + +想象一下这种场景，你在名为 `dir1` 的目录中有多种类型的文件，例如 .pdf、 .doc、 .mp3、 .mp4、 .txt 等等。我们来看看 `dir1` 的内容： + +``` +$ ls dir1 +file.txt image.jpg mydoc.doc personal.pdf song.mp3 video.mp4 +``` + +你希望将某些文件类型（不是所有文件类型）移动到另一个位置。例如，假设你想将 .doc、 .pdf 和 .txt 文件一次性移动到名为 `dir2` 的另一个目录中。 + +要同时将 .doc、 .pdf 和 .txt 文件从 `dir1` 移动到 `dir2`，命令是： + +``` +$ mv dir1/*.{doc,pdf,txt} dir2/ +``` + +很容易，不是吗？ + +现在让我们来查看一下 `dir2` 的内容： + +``` +$ ls dir2/ +file.txt mydoc.doc personal.pdf +``` + +看到了吗？只有 .doc、 .pdf 和 .txt 从 `dir1` 移到了 `dir2`。 + +![][3] + +在上面的命令中，你可以在花括号内添加任意数量的文件类型，以将它们移动到不同的目录中。它在 Bash 上非常适合我。 + +另一种移动多种文件类型的方法是转到源目录，在我们的例子中即为 `dir1`： + +``` +$ cd ~/dir1 +``` + +将你选择的文件类型移动到目的地（即 `dir2`），如下所示： + +``` +$ mv *.doc *.txt *.pdf /home/sk/dir2/ +``` + +要移动具有特定扩展名的所有文件，例如 .doc，运行： + +``` +$ mv dir1/*.doc dir2/ +``` + +更多细节，参考 man 页： + +``` +$ man mv +``` + +移动一些相同或不同的文件类型很容易！你可以在 GUI 模式下单击几下鼠标，或在 CLI 模式下使用一行命令来完成。但是，如果目录中有数千种不同的文件类型，并且希望一次将多种文件类型移动到不同的目录，这将是一项繁琐的任务。对我来说，上面的方法很容易完成工作！如果你知道任何其它一行命令可以一次移动多种文件类型，请在下面的评论部分与我们分享。我会核对并更新指南。 + +这些就是全部了，希望这很有用。更多好东西将要来了，敬请关注！ + +共勉！ + +-------------------------------------------------------------------------------- + +via: https://www.ostechnix.com/how-to-move-multiple-file-types-simultaneously-from-commandline/ + +作者：[SK][a] +选题：[lujun9972][b] +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.ostechnix.com/author/sk/ +[b]: https://github.com/lujun9972 +[1]: https://www.ostechnix.com/find-copy-certain-type-files-one-directory-another-linux/ +[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[3]: http://www.ostechnix.com/wp-content/uploads/2019/01/mv-command.gif diff --git a/published/201901/20190114 How to Build a Netboot Server, Part 4.md b/published/201901/20190114 How to Build a Netboot Server, Part 4.md new file mode 100644 index 0000000000..87eb7a25cd --- /dev/null +++ b/published/201901/20190114 How to Build a Netboot Server, Part 4.md @@ -0,0 +1,627 @@ +[#]: collector: "lujun9972" +[#]: translator: "qhwdw" +[#]: reviewer: "wxy" +[#]: publisher: "wxy" +[#]: url: "https://linux.cn/article-10470-1.html" +[#]: subject: "How to Build a Netboot Server, Part 4" +[#]: via: "https://fedoramagazine.org/how-to-build-a-netboot-server-part-4/" +[#]: author: "Gregory Bartholomew https://fedoramagazine.org/author/glb/" + +如何构建一台网络引导服务器（四） +====== +![](https://fedoramagazine.org/wp-content/uploads/2018/11/netboot4-816x345.jpg) + +在本系列教程中所构建的网络引导服务器有一个很重要的限制，那就是所提供的操作系统镜像是只读的。一些使用场景或许要求终端用户能够修改操作系统镜像。例如，一些教师或许希望学生能够安装和配置一些像 MariaDB 和 Node.js 这样的包来做为他们课程练习的一部分。 + +可写镜像的另外的好处是，终端用户“私人定制”的操作系统，在下次不同的工作站上使用时能够“跟着”他们。 + +### 修改 Bootmenu 应用程序以使用 HTTPS + +为 bootmenu 应用程序创建一个自签名的证书： + +``` +$ sudo -i +# MY_NAME=$( .*#listen => ['https://$MY_NAME:443?cert=$MY_TLSD/$MY_NAME.pem\&key=$MY_TLSD/$MY_NAME.key\&ciphers=AES256-SHA256:AES128-SHA256:AES256-SHA:AES128-SHA'],#" /opt/bootmenu/bootmenu.conf +``` + +注意 [iPXE 当前支持的][1] 加密算法是有限制的。 + +GnuTLS 要求 “CAP_DAC_READ_SEARCH” 能力，因此将它添加到 bootmenu 应用程序的 systemd 服务： + +``` +# sed -i '/^AmbientCapabilities=/ s/$/ CAP_DAC_READ_SEARCH/' /etc/systemd/system/bootmenu.service +# sed -i 's/Serves iPXE Menus over HTTP/Serves iPXE Menus over HTTPS/' /etc/systemd/system/bootmenu.service +# systemctl daemon-reload +``` + +现在，在防火墙中为 bootmenu 服务添加一个例外规则并重启动该服务： + +``` +# MY_SUBNET=192.0.2.0 +# MY_PREFIX=24 +# firewall-cmd --add-rich-rule="rule family='ipv4' source address='$MY_SUBNET/$MY_PREFIX' service name='https' accept" +# firewall-cmd --runtime-to-permanent +# systemctl restart bootmenu.service +``` + +使用 `wget` 去验证是否工作正常： + +``` +$ MY_NAME=server-01.example.edu +$ MY_TLSD=/opt/bootmenu/tls +$ wget -q --ca-certificate=$MY_TLSD/$MY_NAME.pem -O - https://$MY_NAME/menu +``` + +### 添加 HTTPS 到 iPXE + +更新 `init.ipxe` 去使用 HTTPS。接着使用选项重新编译 ipxe 引导加载器，以便它包含和信任你为 bootmenu 应用程序创建的自签名证书： + +``` +$ echo '#define DOWNLOAD_PROTO_HTTPS' >> $HOME/ipxe/src/config/local/general.h +$ sed -i 's/^chain http:/chain https:/' $HOME/ipxe/init.ipxe +$ cp $MY_TLSD/$MY_NAME.pem $HOME/ipxe +$ cd $HOME/ipxe/src +$ make clean +$ make bin-x86_64-efi/ipxe.efi EMBED=../init.ipxe CERT="../$MY_NAME.pem" TRUST="../$MY_NAME.pem" +``` + +你现在可以将启用了 HTTPS 的 iPXE 引导加载器复制到你的客户端上，并测试它能否正常工作： + +``` +$ cp $HOME/ipxe/src/bin-x86_64-efi/ipxe.efi $HOME/esp/efi/boot/bootx64.efi +``` + +### 添加用户验证到 Mojolicious 中 + +为 bootmenu 应用程序创建一个 PAM 服务定义： + +``` +# dnf install -y pam_krb5 +# echo 'auth required pam_krb5.so' > /etc/pam.d/bootmenu +``` + +添加一个库到 bootmenu 应用程序中，它使用 Authen-PAM 的 Perl 模块去执行用户验证： + +``` +# dnf install -y perl-Authen-PAM; +# MY_MOJO=/opt/bootmenu +# mkdir $MY_MOJO/lib +# cat << 'END' > $MY_MOJO/lib/PAM.pm +package PAM; + +use Authen::PAM; + +sub auth { + my $success = 0; + + my $username = shift; + my $password = shift; + + my $callback = sub { + my @res; + while (@_) { + my $code = shift; + my $msg = shift; + my $ans = ""; + + $ans = $username if ($code == PAM_PROMPT_ECHO_ON()); + $ans = $password if ($code == PAM_PROMPT_ECHO_OFF()); + + push @res, (PAM_SUCCESS(), $ans); + } + push @res, PAM_SUCCESS(); + + return @res; + }; + + my $pamh = new Authen::PAM('bootmenu', $username, $callback); + + { + last unless ref $pamh; + last unless $pamh->pam_authenticate() == PAM_SUCCESS; + $success = 1; + } + + return $success; +} + +return 1; +END +``` + +以上的代码是一字不差是从 Authen::PAM::FAQ 的 man 页面中复制来的。 + +重定义 bootmenu 应用程序，以使它仅当提供了有效的用户名和密码之后返回一个网络引导模板： + +``` +# cat << 'END' > $MY_MOJO/bootmenu.pl +#!/usr/bin/env perl + +use lib 'lib'; + +use PAM; +use Mojolicious::Lite; +use Mojolicious::Plugins; +use Mojo::Util ('url_unescape'); + +plugin 'Config'; + +get '/menu'; +get '/boot' => sub { + my $c = shift; + + my $instance = $c->param('instance'); + my $username = $c->param('username'); + my $password = $c->param('password'); + + my $template = 'menu'; + + { + last unless $instance =~ /^fc[[:digit:]]{2}$/; + last unless $username =~ /^[[:alnum:]]+$/; + last unless PAM::auth($username, url_unescape($password)); + $template = $instance; + } + + return $c->render(template => $template); +}; + +app->start; +END +``` + +bootmenu 应用程序现在查找 `lib` 命令去找到相应的 `WorkingDirectory`。但是，默认情况下，对于 systemd 单元它的工作目录设置为服务器的 root 目录。因此，你必须更新 systemd 单元去设置 `WorkingDirectory` 为 bootmenu 应用程序的根目录： + +``` +# sed -i "/^RuntimeDirectory=/ a WorkingDirectory=$MY_MOJO" /etc/systemd/system/bootmenu.service +# systemctl daemon-reload +``` + +更新模块去使用重定义后的 bootmenu 应用程序： + +``` +# cd $MY_MOJO/templates +# MY_BOOTMENU_SERVER=$( fc$i.html.ep; grep "^kernel\|initrd" menu.html.ep | grep "fc$i" >> fc$i.html.ep; echo "boot || chain https://$MY_BOOTMENU_SERVER/menu" >> fc$i.html.ep; sed -i "/^:f$i$/,/^boot /c :f$i\nlogin\nchain https://$MY_BOOTMENU_SERVER/boot?instance=fc$i\&username=\${username}\&password=\${password:uristring} || goto failed" menu.html.ep; done +``` + +上面的最后的命令将生成类似下面的三个文件： + +`menu.html.ep`： + +``` +#!ipxe + +set timeout 5000 + +:menu +menu iPXE Boot Menu +item --key 1 lcl 1. Microsoft Windows 10 +item --key 2 f29 2. RedHat Fedora 29 +item --key 3 f28 3. RedHat Fedora 28 +choose --timeout ${timeout} --default lcl selected || goto shell +set timeout 0 +goto ${selected} + +:failed +echo boot failed, dropping to shell... +goto shell + +:shell +echo type 'exit' to get the back to the menu +set timeout 0 +shell +goto menu + +:lcl +exit + +:f29 +login +chain https://server-01.example.edu/boot?instance=fc29&username=${username}&password=${password:uristring} || goto failed + +:f28 +login +chain https://server-01.example.edu/boot?instance=fc28&username=${username}&password=${password:uristring} || goto failed +``` + +`fc29.html.ep`： + +``` +#!ipxe +kernel --name kernel.efi ${prefix}/vmlinuz-4.19.5-300.fc29.x86_64 initrd=initrd.img ro ip=dhcp rd.peerdns=0 nameserver=192.0.2.91 nameserver=192.0.2.92 root=/dev/disk/by-path/ip-192.0.2.158:3260-iscsi-iqn.edu.example.server-01:fc29-lun-1 netroot=iscsi:192.0.2.158::::iqn.edu.example.server-01:fc29 console=tty0 console=ttyS0,115200n8 audit=0 selinux=0 quiet +initrd --name initrd.img ${prefix}/initramfs-4.19.5-300.fc29.x86_64.img +boot || chain https://server-01.example.edu/menu +``` + +`fc28.html.ep`： + +``` +#!ipxe +kernel --name kernel.efi ${prefix}/vmlinuz-4.19.3-200.fc28.x86_64 initrd=initrd.img ro ip=dhcp rd.peerdns=0 nameserver=192.0.2.91 nameserver=192.0.2.92 root=/dev/disk/by-path/ip-192.0.2.158:3260-iscsi-iqn.edu.example.server-01:fc28-lun-1 netroot=iscsi:192.0.2.158::::iqn.edu.example.server-01:fc28 console=tty0 console=ttyS0,115200n8 audit=0 selinux=0 quiet +initrd --name initrd.img ${prefix}/initramfs-4.19.3-200.fc28.x86_64.img +boot || chain https://server-01.example.edu/menu +``` + +现在，重启动 bootmenu 应用程序，并验证用户认证是否正常工作： + +``` +# systemctl restart bootmenu.service +``` + +### 使得 iSCSI Target 可写 + +现在，用户验证通过 iPXE 可以正常工作，在用户连接时，你可以按需在只读镜像的上面创建每用户可写的overlay叠加层。使用一个 [写时复制][2] 的叠加层与简单地为每个用户复制原始镜像相比有三个好处： + + 1. 副本创建非常快。这样就可以按需创建。 + 2. 副本并不增加服务器上的磁盘使用。除了原始镜像之外，仅存储用户写入个人镜像的内容。 + 3. 由于每个副本的扇区大多都是服务器的存储器上的相同扇区，在随后的用户访问这些操作系统的副本时，它们可能已经加载到内存中，这样就提升了服务器的性能，因为对内存的访问速度要比磁盘 I/O 快得多。 + +使用写时复制的一个潜在隐患是，一旦叠加层创建后，叠加层之下的镜像就不能再改变。如果它们改变，所有它们之上的叠加层将出错。因此，叠加层必须被删除并用新的、空白的进行替换。即便只是简单地以读写模式加载的镜像，也可能因为某些文件系统更新导致叠加层出错。 + +由于这个隐患，如果原始镜像被修改将导致叠加层出错，因此运行下列的命令，将原始镜像标记为不可改变： + +``` +# chattr +i +``` + +你可以使用 `lsattr ` 去查看不可改变标志，并可以使用 `chattr -i ` 取消设置不可改变标志。在设置了不可改变标志之后，即便是 root 用户或以 root 运行的系统进程也不修改或删除这个文件。 + +停止 tgtd.service 之后，你就可以改变镜像文件： + +``` +# systemctl stop tgtd.service +``` + +当仍有连接打开的时候，运行这个命令一般需要一分钟或更长的时间。 + +现在，移除只读的 iSCSI 出口。然后更新模板中的 `readonly-root` 配置文件，以使镜像不再是只读的： + +``` +# MY_FC=fc29 +# rm -f /etc/tgt/conf.d/$MY_FC.conf +# TEMP_MNT=$(mktemp -d) +# mount /$MY_FC.img $TEMP_MNT +# sed -i 's/^READONLY=yes$/READONLY=no/' $TEMP_MNT/etc/sysconfig/readonly-root +# sed -i 's/^Storage=volatile$/#Storage=auto/' $TEMP_MNT/etc/systemd/journald.conf +# umount $TEMP_MNT +``` + +将 journald 日志从发送到内存修改回缺省值（如果 `/var/log/journal` 存在的话记录到磁盘），因为一个用户报告说，他的客户端由于应用程序生成了大量的系统日志而产生内存溢出错误，导致它的客户端被卡住。而将日志记录到磁盘的负面影响是客户端产生了额外的写入流量，这将在你的网络引导服务器上可能增加一些没有必要的 I/O。你应该去决定到底使用哪个选择 —— 记录到内存还是记录到硬盘 —— 哪个更合适取决于你的环境。 + +因为你的模板镜像在以后不能做任何的更改，因此在它上面设置不可更改标志，然后重启动 tgtd.service： + +``` +# chattr +i /$MY_FC.img +# systemctl start tgtd.service +``` + +现在，更新 bootmenu 应用程序： + +``` +# cat << 'END' > $MY_MOJO/bootmenu.pl +#!/usr/bin/env perl + +use lib 'lib'; + +use PAM; +use Mojolicious::Lite; +use Mojolicious::Plugins; +use Mojo::Util ('url_unescape'); + +plugin 'Config'; + +get '/menu'; +get '/boot' => sub { + my $c = shift; + + my $instance = $c->param('instance'); + my $username = $c->param('username'); + my $password = $c->param('password'); + + my $chapscrt; + my $template = 'menu'; + + { + last unless $instance =~ /^fc[[:digit:]]{2}$/; + last unless $username =~ /^[[:alnum:]]+$/; + last unless PAM::auth($username, url_unescape($password)); + last unless $chapscrt = `sudo scripts/mktgt $instance $username`; + $template = $instance; + } + + return $c->render(template => $template, username => $username, chapscrt => $chapscrt); +}; + +app->start; +END +``` + +新版本的 bootmenu 应用程序调用一个定制的 `mktgt` 脚本，如果成功，它将为每个它自己创建的新的 iSCSI 目标返回一个随机的 [CHAP][3] 密码。这个 CHAP 密码可以防止其它用户的 iSCSI 目标以间接方式挂载这个用户的目标。这个应用程序只有在用户密码认证成功之后才返回一个正确的 iSCSI 目标密码。 + +`mktgt` 脚本要加 `sudo` 前缀来运行，因为它需要 root 权限去创建目标。 + +`$username` 和 `$chapscrt` 变量也传递给 `render` 命令，因此在需要的时候，它们也能够被纳入到模板中返回给用户。 + +接下来，更新我们的引导模板，以便于它们能够读取用户名和 `chapscrt` 变量，并传递它们到所属的终端用户。也要更新模板以 rw（读写）模式加载根文件系统： + +``` +# cd $MY_MOJO/templates +# sed -i "s/:$MY_FC/:$MY_FC-<%= \$username %>/g" $MY_FC.html.ep +# sed -i "s/ netroot=iscsi:/ netroot=iscsi:<%= \$username %>:<%= \$chapscrt %>@/" $MY_FC.html.ep +# sed -i "s/ ro / rw /" $MY_FC.html.ep +``` + +运行上面的命令后，你应该会看到如下的引导模板： + +``` +#!ipxe +kernel --name kernel.efi ${prefix}/vmlinuz-4.19.5-300.fc29.x86_64 initrd=initrd.img rw ip=dhcp rd.peerdns=0 nameserver=192.0.2.91 nameserver=192.0.2.92 root=/dev/disk/by-path/ip-192.0.2.158:3260-iscsi-iqn.edu.example.server-01:fc29-<%= $username %>-lun-1 netroot=iscsi:<%= $username %>:<%= $chapscrt %>@192.0.2.158::::iqn.edu.example.server-01:fc29-<%= $username %> console=tty0 console=ttyS0,115200n8 audit=0 selinux=0 quiet +initrd --name initrd.img ${prefix}/initramfs-4.19.5-300.fc29.x86_64.img +boot || chain https://server-01.example.edu/menu +``` + +注意：如果在 [插入][4] 变量后需要查看引导模板，你可以在 `boot` 命令之前，在它自己的行中插入 `shell` 命令。然后在你网络引导你的客户端时，iPXE 将在那里给你提供一个用于交互的 shell，你可以在 shell 中输入 `imgstat` 去查看传递到内核的参数。如果一切正确，你可以输入 `exit` 去退出 shell 并继续引导过程。 + +现在，通过 `sudo` 允许 bootmenu 用户以 root 权限去运行 `mktgt` 脚本（仅这个脚本）： + +``` +# echo "bootmenu ALL = NOPASSWD: $MY_MOJO/scripts/mktgt *" > /etc/sudoers.d/bootmenu +``` + +bootmenu 用户不应该写访问 `mktgt` 脚本或在它的家目录下的任何其它文件。在 `/opt/bootmenu` 目录下的所有文件的属主应该是 root，并且不应该被其它任何 root 以外的用户可写。 + +`sudo` 在使用 systemd 的 `DynamicUser` 选项下不能正常工作，因此创建一个普通用户帐户，并设置 systemd 服务以那个用户运行： + +``` +# useradd -r -c 'iPXE Boot Menu Service' -d /opt/bootmenu -s /sbin/nologin bootmenu +# sed -i 's/^DynamicUser=true$/User=bootmenu/' /etc/systemd/system/bootmenu.service +# systemctl daemon-reload +``` + +最后，为写时复制覆盖创建一个目录，并创建管理 iSCSI 目标的 `mktgt` 脚本和它们的覆盖支持存储： + +``` +# mkdir /$MY_FC.cow +# mkdir $MY_MOJO/scripts +# cat << 'END' > $MY_MOJO/scripts/mktgt +#!/usr/bin/env perl + +# if another instance of this script is running, wait for it to finish +"$ENV{FLOCKER}" eq 'MKTGT' or exec "env FLOCKER=MKTGT flock /tmp $0 @ARGV"; + +# use "RETURN" to print to STDOUT; everything else goes to STDERR by default +open(RETURN, '>&', STDOUT); +open(STDOUT, '>&', STDERR); + +my $instance = shift or die "instance not provided"; +my $username = shift or die "username not provided"; + +my $img = "/$instance.img"; +my $dir = "/$instance.cow"; +my $top = "$dir/$username"; + +-f "$img" or die "'$img' is not a file"; +-d "$dir" or die "'$dir' is not a directory"; + +my $base; +die unless $base = `losetup --show --read-only --nooverlap --find $img`; +chomp $base; + +my $size; +die unless $size = `blockdev --getsz $base`; +chomp $size; + +# create the per-user sparse file if it does not exist +if (! -e "$top") { + die unless system("dd if=/dev/zero of=$top status=none bs=512 count=0 seek=$size") == 0; +} + +# create the copy-on-write overlay if it does not exist +my $cow="$instance-$username"; +my $dev="/dev/mapper/$cow"; +if (! -e "$dev") { + my $over; + die unless $over = `losetup --show --nooverlap --find $top`; + chomp $over; + die unless system("echo 0 $size snapshot $base $over p 8 | dmsetup create $cow") == 0; +} + +my $tgtadm = '/usr/sbin/tgtadm --lld iscsi'; + +# get textual representations of the iscsi targets +my $text = `$tgtadm --op show --mode target`; +my @targets = $text =~ /(?:^T.*\n)(?:^ .*\n)*/mg; + +# convert the textual representations into a hash table +my $targets = {}; +foreach (@targets) { + my $tgt; + my $sid; + + foreach (split /\n/) { + /^Target (\d+)(?{ $tgt = $targets->{$^N} = [] })/; + /I_T nexus: (\d+)(?{ $sid = $^N })/; + /Connection: (\d+)(?{ push @{$tgt}, [ $sid, $^N ] })/; + } +} + +my $hostname; +die unless $hostname = `hostname`; +chomp $hostname; + +my $target = 'iqn.' . join('.', reverse split('\.', $hostname)) . ":$cow"; + +# find the target id corresponding to the provided target name and +# close any existing connections to it +my $tid = 0; +foreach (@targets) { + next unless /^Target (\d+)(?{ $tid = $^N }): $target$/m; + foreach (@{$targets->{$tid}}) { + die unless system("$tgtadm --op delete --mode conn --tid $tid --sid $_->[0] --cid $_->[1]") == 0; + } +} + +# create a new target if an existing one was not found +if ($tid == 0) { + # find an available target id + my @ids = (0, sort keys %{$targets}); + $tid = 1; while ($ids[$tid]==$tid) { $tid++ } + + # create the target + die unless -e "$dev"; + die unless system("$tgtadm --op new --mode target --tid $tid --targetname $target") == 0; + die unless system("$tgtadm --op new --mode logicalunit --tid $tid --lun 1 --backing-store $dev") == 0; + die unless system("$tgtadm --op bind --mode target --tid $tid --initiator-address ALL") == 0; +} + +# (re)set the provided target's chap password +my $password = join('', map(chr(int(rand(26))+65), 1..8)); +my $accounts = `$tgtadm --op show --mode account`; +if ($accounts =~ / $username$/m) { + die unless system("$tgtadm --op delete --mode account --user $username") == 0; +} +die unless system("$tgtadm --op new --mode account --user $username --password $password") == 0; +die unless system("$tgtadm --op bind --mode account --tid $tid --user $username") == 0; + +# return the new password to the iscsi target on stdout +print RETURN $password; +END +# chmod +x $MY_MOJO/scripts/mktgt +``` + +上面的脚本将做以下五件事情： + + 1. 创建 `/.cow/` 稀疏文件（如果不存在的话）。 + 2. 创建 `/dev/mapper/-` 设备节点作为 iSCSI 目标的写时复制支持存储（如果不存在的话）。 + 3. 创建 `iqn.:-` iSCSI 目标（如果不存在的话）。或者，如果已存在了，它将关闭任何已存在的连接，因为在任何时刻，镜像只能以只读模式从一个地方打开。 + 4. 它在 `iqn.:-` iSCSI 目标上（重新）设置 chap 密码为一个新的随机值。 + 5. （如果前面的所有任务都成功的话）它在 [标准输出][5] 上显示新的 chap 密码。 + +你应该可以在命令行上通过使用有效的测试参数来运行它，以测试 `mktgt` 脚本能否正常工作。例如： + +``` +# echo `$MY_MOJO/scripts/mktgt fc29 jsmith` +``` + +当你从命令行上运行时，`mktgt` 脚本应该会输出 iSCSI 目标的一个随意的八字符随机密码（如果成功的话）或者是出错位置的行号（如果失败的话）。 + +有时候，你可能需要在不停止整个服务的情况下删除一个 iSCSI 目标。例如，一个用户可能无意中损坏了他的个人镜像，在那种情况下，你可能需要按步骤撤销上面的 `mktgt` 脚本所做的事情，以便于他下次登入时他将得到一个原始镜像。 + +下面是用于撤销的 `rmtgt` 脚本，它以相反的顺序做了上面 `mktgt` 脚本所做的事情： + +``` +# mkdir $HOME/bin +# cat << 'END' > $HOME/bin/rmtgt +#!/usr/bin/env perl + +@ARGV >= 2 or die "usage: $0 [+d|+f]\n"; + +my $instance = shift; +my $username = shift; + +my $rmd = ($ARGV[0] eq '+d'); #remove device node if +d flag is set +my $rmf = ($ARGV[0] eq '+f'); #remove sparse file if +f flag is set +my $cow = "$instance-$username"; + +my $hostname; +die unless $hostname = `hostname`; +chomp $hostname; + +my $tgtadm = '/usr/sbin/tgtadm'; +my $target = 'iqn.' . join('.', reverse split('\.', $hostname)) . ":$cow"; + +my $text = `$tgtadm --op show --mode target`; +my @targets = $text =~ /(?:^T.*\n)(?:^ .*\n)*/mg; + +my $targets = {}; +foreach (@targets) { + my $tgt; + my $sid; + + foreach (split /\n/) { + /^Target (\d+)(?{ $tgt = $targets->{$^N} = [] })/; + /I_T nexus: (\d+)(?{ $sid = $^N })/; + /Connection: (\d+)(?{ push @{$tgt}, [ $sid, $^N ] })/; + } +} + +my $tid = 0; +foreach (@targets) { + next unless /^Target (\d+)(?{ $tid = $^N }): $target$/m; + foreach (@{$targets->{$tid}}) { + die unless system("$tgtadm --op delete --mode conn --tid $tid --sid $_->[0] --cid $_->[1]") == 0; + } + die unless system("$tgtadm --op delete --mode target --tid $tid") == 0; + print "target $tid deleted\n"; + sleep 1; +} + +my $dev = "/dev/mapper/$cow"; +if ($rmd or ($rmf and -e $dev)) { + die unless system("dmsetup remove $cow") == 0; + print "device node $dev deleted\n"; +} + +if ($rmf) { + my $sf = "/$instance.cow/$username"; + die "sparse file $sf not found" unless -e "$sf"; + die unless system("rm -f $sf") == 0; + die unless not -e "$sf"; + print "sparse file $sf deleted\n"; +} +END +# chmod +x $HOME/bin/rmtgt +``` + +例如，使用上面的脚本去完全删除 fc29-jsmith 目标，包含它的支持存储设备节点和稀疏文件，可以按下列方式运行命令： + +``` +# rmtgt fc29 jsmith +f +``` + +一旦你验证 `mktgt` 脚本工作正常，你可以重启动 bootmenu 服务。下次有人从网络引导时，他们应该能够接收到一个他们可以写入的、可”私人定制“的网络引导镜像的副本： + +``` +# systemctl restart bootmenu.service +``` + +现在，就像下面的截屏示范的那样，用户应该可以修改根文件系统了： + +![][6] + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/how-to-build-a-netboot-server-part-4/ + +作者：[Gregory Bartholomew][a] +选题：[lujun9972][b] +译者：[qhwdw](https://github.com/qhwdw) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/author/glb/ +[b]: https://github.com/lujun9972 +[1]: http://ipxe.org/crypto +[2]: https://en.wikipedia.org/wiki/Copy-on-write +[3]: https://en.wikipedia.org/wiki/Challenge-Handshake_Authentication_Protocol +[4]: https://en.wikipedia.org/wiki/String_interpolation +[5]: https://en.wikipedia.org/wiki/Standard_streams +[6]: https://fedoramagazine.org/wp-content/uploads/2018/11/netboot-fix-pam_mount-1024x819.png diff --git a/published/201901/20190114 Turn a Raspberry Pi 3B- into a PriTunl VPN.md b/published/201901/20190114 Turn a Raspberry Pi 3B- into a PriTunl VPN.md new file mode 100644 index 0000000000..9baed49a1e --- /dev/null +++ b/published/201901/20190114 Turn a Raspberry Pi 3B- into a PriTunl VPN.md @@ -0,0 +1,114 @@ +[#]: collector: (lujun9972) +[#]: translator: (jrglinux) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10493-1.html) +[#]: subject: (Turn a Raspberry Pi 3B+ into a PriTunl VPN) +[#]: via: (https://opensource.com/article/19/1/pritunl-vpn-raspberry-pi) +[#]: author: (Stephen Bancroft https://opensource.com/users/stevereaver) + +将树莓派 3B+ 变为 PriTunl VPN +====== + +> PriTunl 是一种 VPN 解决方案，适用于希望私密的访问其网络的小型企业和个人。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/life-raspberrypi_0.png?itok=Kczz87J2) + +[PriTunl][1] 是一款出色的 VPN 终端解决方案，非常适合希望以简单快捷的方式私密的访问网络的小型企业和个人。它是开源的，基本的免费版本涵盖最通用的简单的实例，足以让你快速入门。也有集成了活动目录等高级功能的付费企业版。 + +### 有关树莓派 3B+ 的特别注意事项 + +PriTunl 的安装通常也很简单，但要在树莓派 3B+ 上安装 PriTunl 有点小复杂。比如，PriTunl 只提供了 AMD64 和 i386 架构的二进制文件，但树莓派 3B+ 是 ARM 架构的，这意味着需要从源码自行编译可用于树莓派 3B+ 的 PriTunl 可执行文件。不过，无需担心，编译过程很简单，只需花一点时间执行几行命令即可。 + +另一个问题：PriTunl 好像必须要是 64 位处理器架构，当我在 32 位操作系统上尝试编译的时候报错了。但幸运的是，用于 ARM64 架构的 Ubuntu 18.04 测试版本可以安装在树莓派 3B+ 上。 + +同样，树莓派 3B+ 需要和其他树莓派不同的引导程序。需要一组小复杂的命令来安装更新树莓派 3B+ 上必要的组件。 + +### 安装 PriTunl + +你可以先在树莓派 3B+ 上安装 64 位的操作系统来避免下面这些问题。此处需要一些必要的基础知识如在树莓派上执行命令行。 + +打开终端，用如下命令下载 Ubuntu 18.04 用于 ARM64 架构的测试版： + +``` +$ wget http://cdimage.ubuntu.com/releases/18.04/beta/ubuntu-18.04-beta-preinstalled-server-arm64+raspi3.img.xz +``` + +将下载的固件解压： + +``` +$ xz -d ubuntu-18.04-beta-preinstalled-server-arm64+raspi3.xz +``` + +将准备好的 SD 卡插入电脑读卡槽，电脑会为 SD 卡分配一个驱动分配器号，例如 `/dev/sda` 或者 `/dev/sdb`。 输入命令 `dmesg` 然后观察屏幕上的最后几行找到 SD 卡的驱动分配器。 + +**下一步小心操作，如果搞错了驱动分配器号，可能会破坏你的系统。** + +用如下命令往 SD 卡中写入数据，将其中的 `` 替换成你的 SD 驱动器号。 + +``` +$ dd if=ubuntu-18.04-beta-preinstalled-server-arm64+raspi3.img of= bs=8M +``` + +完成上一步之后，将 SD 卡插入树莓派 3B+ ，并启动它。确保树莓派 3B+ 是连网的，然后登录系统，用户名/密码：`ubuntu` / `ubuntu`。 + +在树莓派上输入以下命令以安装一些编译 PriTunl 所需的包： + +``` +$ sudo apt-get -y install build-essential git bzr python python-dev python-pip net-tools openvpn bridge-utils psmisc golang-go libffi-dev mongodb +``` + +和 PriTunl 标准源码上的 [安装说明][2] 有一点不一样。确保已经登录进树莓派然后切换到管理员账户： + +``` +$ sudo su - +``` + +现在你应该在管理员账户的目录下，按如下命令来安装 PriTunl 1.29.1914.98 版本： + +``` +export VERSION=1.29.1914.98 +tee -a ~/.bashrc << EOF +export GOPATH=\$HOME/go +export PATH=/usr/local/go/bin:\$PATH +EOF +source ~/.bashrc +mkdir pritunl && cd pritunl +go get -u github.com/pritunl/pritunl-dns +go get -u github.com/pritunl/pritunl-web +sudo ln -s ~/go/bin/pritunl-dns /usr/bin/pritunl-dns +sudo ln -s ~/go/bin/pritunl-web /usr/bin/pritunl-web +wget https://github.com/pritunl/pritunl/archive/$VERSION.tar.gz +tar -xf $VERSION.tar.gz +cd pritunl-$VERSION +python2 setup.py build +pip install -r requirements.txt +python2 setup.py install --prefix=/usr/local +``` + +现在，不出意外的话应该可以启动 MongoDB 和 PriTunl 的 systemd 单元了。假如现在还是以管理员账户登录的话，输入： + +``` +systemctl daemon-reload +systemctl start mongodb pritunl +systemctl enable mongodb pritunl +``` + +大功告成！你现在可以登录 PriTunl 的用户界面并按照官网上的 [安装和配置手册][3] 来配置它了。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/pritunl-vpn-raspberry-pi + +作者：[Stephen Bancroft][a] +选题：[lujun9972][b] +译者：[jrg](https://github.com/jrglinux) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/stevereaver +[b]: https://github.com/lujun9972 +[1]: https://pritunl.com/ +[2]: https://github.com/pritunl/pritunl +[3]: https://docs.pritunl.com/docs/configuration-5 diff --git a/published/201901/20190114 You (probably) don-t need Kubernetes.md b/published/201901/20190114 You (probably) don-t need Kubernetes.md new file mode 100644 index 0000000000..458bfe51f1 --- /dev/null +++ b/published/201901/20190114 You (probably) don-t need Kubernetes.md @@ -0,0 +1,82 @@ +[#]: collector: (lujun9972) +[#]: translator: (beamrolling) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10469-1.html) +[#]: subject: (You (probably) don't need Kubernetes) +[#]: via: (https://arp242.net/weblog/dont-need-k8s.html) +[#]: author: (Martin Tournoij https://arp242.net/) + +你（多半）不需要 Kubernetes +====== + +这也许是一个不太受欢迎的观点，但大多数主流公司最好不要再使用 k8s 了。 + +你知道那个古老的“以程序员技能写 Hello world ”笑话吗？—— 从一个新手程序员的 `printf("hello, world\n")` 语句开始，最后结束于高级软件架构工程师令人费解的 Java OOP 模式设计。使用 k8s 就有点像这样。 + +* 新手系统管理员： + + `./binary` +* 有经验的系统管理员： + + 在 EC2 上的 `./binary` +* DevOp： + + 在 EC2 上自部署的 CI 管道运行 `./binary` +* 高级云编排工程师： + + 在 EC2 上通过 k8s 编排的自部署 CI 管道运行 `./binary` + +`¯\\_(ツ)_/¯` + +这不意味着 Kubernetes 或者任何这样的东西本身都是*坏的*，就像 Java 或者 OOP 设计本身并不是坏的一样，但是，在很多情况下，它们被严重地误用，就像在一个 hello world 的程序中可怕地误用 Java 面向对象设计模式一样。对大多数公司而言，系统运维从根本上来说并不十分复杂，此时在这上面应用 k8s 起效甚微。 + +复杂性本质上来说创造了工作，我十分怀疑使用 k8s 对大多数使用者来说是省时的这一说法。这就好像花一天时间来写一个脚本，用来自动完成一些你一个月进行一次，每次只花 10 分钟完成的工作。这不是一个好的时间投资（特别是你可能会在未来由于扩展或调试这个脚本而进一步投入的更多时间）。 + +你的部署大概应该*需要*自动化 – 以免你 [最终像 Knightmare][1] 那样 —— 但 k8s 通常可以被一个简单的 shell 脚本所替代。 + +在我们公司，系统运维团队用了很多时间来设置 k8s 。他们还不得不用了很大一部分时间来更新到新一点的版本（1.6 ➙ 1.8）。结果是如果没有真正深入理解 k8s ，有些东西就没人会真的明白，甚至连深入理解 k8s 这一点也很难（那些 YAML 文件，哦呦！） + +在我能自己调试和修复部署问题之前 —— 现在这更难了，我理解基本概念，但在真正调试实际问题的时候，它们并不是那么有用。我不经常用 k8s 足以证明这点。 + +--- + +k8s 真的很难这点并不是什么新看法，这也是为什么现在会有这么多 “k8s 简单用”的解决方案。在 k8s 上再添一层来“让它更简单”的方法让我觉得，呃，不明智。复杂性并没有消失，你只是把它藏起来了。 + +以前我说过很多次：在确定一样东西是否“简单”时，我最关心的不是写东西的时候有多简单，而是当失败的时候调试起来有多容易。包装 k8s 并不会让调试更加简单，恰恰相反，它让事情更加困难了。 + +--- + +Blaise Pascal 有一句名言： + +> 几乎所有的痛苦都来自于我们不善于在房间里独处。 + +k8s —— 略微拓展一下，Docker —— 似乎就是这样的例子。许多人似乎迷失在当下的兴奋中，觉得 “k8s 就是这么回事！”，就像有些人迷失在 Java OOP 刚出来时的兴奋中一样，所以一切都必须从“旧”方法转为“新”方法，即使“旧”方法依然可行。 + +有时候 IT 产业挺蠢的。 + +或者用 [一条推特][2] 来总结: + +> - 2014 - 我们必须采用 #微服务 来解决独石应用的所有问题 +> - 2016 - 我们必须采用 #docker 来解决微服务的所有问题 +> - 2018 - 我们必须采用 #kubernetes 来解决 docker 的所有问题 + +你可以通过 [martin@arp242.net][3] 给我发邮件或者 [创建 GitHub issue][4] 来给我反馈或提出问题等。 + +-------------------------------------------------------------------------------- + +via: https://arp242.net/weblog/dont-need-k8s.html + +作者：[Martin Tournoij][a] +选题：[lujun9972][b] +译者：[beamrolling](https://github.com/beamrolling) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://arp242.net/ +[b]: https://github.com/lujun9972 +[1]: https://dougseven.com/2014/04/17/knightmare-a-devops-cautionary-tale/ +[2]: https://twitter.com/sahrizv/status/1018184792611827712 +[3]: mailto:martin@arp242.net +[4]: https://github.com/Carpetsmoker/arp242.net/issues/new diff --git a/published/201901/20190115 Linux Tools- The Meaning of Dot.md b/published/201901/20190115 Linux Tools- The Meaning of Dot.md new file mode 100644 index 0000000000..6c5cfe5032 --- /dev/null +++ b/published/201901/20190115 Linux Tools- The Meaning of Dot.md @@ -0,0 +1,185 @@ +[#]: collector: (lujun9972) +[#]: translator: (asche910) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10465-1.html) +[#]: subject: (Linux Tools: The Meaning of Dot) +[#]: via: (https://www.linux.com/blog/learn/2019/1/linux-tools-meaning-dot) +[#]: author: (Paul Brown https://www.linux.com/users/bro66) + +Linux 工具：点的含义 +====== + +> Paul Brown 解释了 Linux shell 命令中那个不起眼的“点”的各种意思和用法。 + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/psychedelic-dot.jpg?itok=giKEHvwQ) + +在现实情况中，使用 shell 命令编写的单行命令或脚本可能会令人很困惑。你使用的很多工具的名称与它们的实际功能相差甚远（`grep`、`tee` 和 `awk`，还有吗？），而当你将两个或更多个组合起来时，所组成的 “句子” 看起来更像某种外星人的天书。 + +因此，上面说的这些对于你并无帮助，因为你用来编写一连串的指令所使用的符号根据你使用的场景有着不同的意义。 + +### 位置、位置、位置 + +就拿这个不起眼的点（`.`）来说吧。当它放在一个需要一个目录名称的命令的参数处时，表示“当前目录”： + +``` +find . -name "*.jpg" +``` + +意思就是“在当前目录（包括子目录）中寻找以 `.jpg` 结尾的文件”。 + +`ls .` 和 `cd .` 结果也如你想的那样，它们分别列举和“进入”到当前目录，虽然在这两种情况下这个点都是多余的。 + +而一个紧接着另一个的两个点呢，在同样的场景下（即当你的命令期望一个文件目录的时候）表示“当前目录的父目录”。如果你当前在 `/home/your_directory` 下并且运行： + +``` +cd .. +``` + +你就会进入到 `/home`。所以，你可能认为这仍然适合“点代表附近目录”的叙述，并且毫不复杂，对吧？ + +那下面这样会怎样呢？如果你在一个文件或目录的开头加上点，它表示这个文件或目录会被隐藏： + +``` +$ touch somedir/file01.txt somedir/file02.txt somedir/.secretfile.txt +$ ls -l somedir/ +total 0 +-rw-r--r-- 1 paul paul 0 Jan 13 19:57 file01.txt +-rw-r--r-- 1 paul paul 0 Jan 13 19:57 file02.txt +$ # 注意上面列举的文件中没有 .secretfile.txt +$ ls -la somedir/ +total 8 +drwxr-xr-x 2 paul paul 4096 Jan 13 19:57 . +drwx------ 48 paul paul 4096 Jan 13 19:57 .. +-rw-r--r-- 1 paul paul 0 Jan 13 19:57 file01.txt +-rw-r--r-- 1 paul paul 0 Jan 13 19:57 file02.txt +-rw-r--r-- 1 paul paul 0 Jan 13 19:57 .secretfile.txt +$ # 这个 -a 选项告诉 ls 去展示“all”文件，包括那些隐藏的 +``` + +然后就是你可以将 `.` 当作命令。是的，你听我说：`.` 是个真真正正的命令。它是 `source` 命令的代名词，所以你可以用它在当前 shell 中执行一个文件，而不是以某种其它的方式去运行一个脚本文件（这通常指的是 Bash 会产生一个新的 shell 去运行它） + +很困惑？别担心 —— 试试这个：创建一个名为 `myscript` 的脚本，内容包含下面一行： + +``` +myvar="Hello" +``` + +然后通过常规的方法执行它，也就是用 `sh myscript`（或者通过 `chmod a+x myscript` 命令让它可执行，然后运行 `./myscript`）。现在尝试并且观察 `myvar` 的内容，通过 `echo $myvar`（理所当然你什么也得不到）。那是因为，当你的脚本赋值 `"Hello"` 给 `myvar` 时，它是在一个隔离的bash shell 实例中进行的。当脚本运行结束时，这个新产生的实例会消失并且将控制权转交给原来的shell，而原来的 shell 里甚至都不存在 `myvar` 变量。 + +然而，如果你这样运行 `myscript`： + +``` +. myscript +``` + +`echo $myvar` 就会打印 `Hello` 到命令行上。 + +当你的 `.bashrc` 文件发生变化后，你经常会用到 `.`（或 `source`）命令，[就像当你要扩展 `PATH` 变量那样][1]。在你的当前 shell 实例中，你可以使用 `.` 来让变化立即生效。 + +### 双重麻烦 + +就像看似无关紧要的一个点有多个含义一样，两个点也是如此。除了指向当前目录的父级之外，两个点（`..`）也用于构建序列。 + +尝试下这个： + +``` +echo {1..10} +``` + +它会打印出从 1 到 10 的序列。在这种场景下，`..` 表示 “从左边的值开始，计数到右边的值”。 + +现在试下这个： + +``` +echo {1..10..2} +``` + +你会得到 `1 3 5 7 9`。`..2` 这部分命令告诉 Bash 输出这个序列，不过不是每个相差 1，而是相差 2。换句话说，就是你会得到从 1 到 10 之间的奇数。 + +它反着也仍然有效： + +``` +echo {10..1..2} +``` + +你也可以用多个 0 填充你的数字。这样： + +``` +echo {000..121..2} +``` + +会这样打印出从 0 到 121 之间的偶数（填充了前置 0）： + +``` +000 002 004 006 ... 050 052 054 ... 116 118 120 +``` + +不过这样的序列发生器有啥用呢？当然，假设您的新年决心之一是更加谨慎控制您的帐户花销。作为决心的一部分，您需要创建目录，以便对过去 10 年的数字发票进行分类： + +``` +mkdir {2009..2019}_Invoices +``` + +工作完成。 + +或者你可能有数百个带编号的文件，比如从视频剪辑中提取的帧，或许因为某种原因，你只想从第 43 帧到第 61 帧每隔三帧删除一帧： + +``` +rm frame_{043..61..3} +``` + +很可能，如果你有超过 100 个帧，它们将以填充 0 命名，如下所示： + +``` +frame_000 frame_001 frame_002 ... +``` + +那就是为什么你在命令中要用 `043`，而不是`43` 的原因。 + +### 花括号花招 + +说实话，序列的神奇之处不在于双点，而是花括号（`{}`）的巫术。看看它对于字母是如何工作的。这样做： + +``` +touch file_{a..z}.txt +``` + +它创建了从 `file_a.txt` 到 `file_z.txt` 的文件。 + +但是，你必须小心。使用像 `{Z..a}` 这样的序列将产生一大堆大写字母和小写字母之间的非字母、数字的字符（既不是数字或字母的字形）。其中一些字形是不可打印的或具有自己的特殊含义。使用它们来生成文件名称可能会导致一系列意外和可能令人不快的影响。 + +最后一件值得指出的事：包围在 `{...}` 的序列，它们也可以包含字符串列表： + +``` +touch {blahg, splurg, mmmf}_file.txt +``` + +将创建了 `blahg_file.txt`、`splurg_file.txt` 和 `mmmf_file.txt`。 + +当然，在别的场景中，大括号也有不同的含义（惊喜吗！）。不过那是别的文章的内容了。 + +### 总结 + +Bash 以及运行于其中的各种工具已经被寻求解决各种特定问题的系统管理员们把玩了数十年。要说这种有自己之道的系统管理员是一种特殊物种的话，那是有点轻描淡写。总而言之，与其他语言相反，Bash 的设计目标并不是为了用户友好、简单、甚至合乎逻辑。 + +但这并不意味着它不强大 —— 恰恰相反。Bash 的语法和 shell 工具可能不一致且很庞大，但它们也提供了一系列令人眼花缭乱的方法来完成您可能想象到的一切。就像有一个工具箱，你可以从中找到从电钻到勺子的所有东西，以及橡皮鸭、一卷胶带和一些指甲钳。 + +除了引人入胜之外，探明你可以直接在 shell 中达成的所有能力也很有趣，所以下次我们将深入探讨如何构建更大更好的 Bash 命令行。 + +在那之前，玩得开心！ + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/blog/learn/2019/1/linux-tools-meaning-dot + +作者：[Paul Brown][a] +选题：[lujun9972][b] +译者：[asche910](https://github.com/asche910) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/users/bro66 +[b]: https://github.com/lujun9972 +[1]: https://www.linux.com/blog/learn/2018/12/bash-variables-environmental-and-otherwise diff --git a/published/201901/20190118 Get started with WTF, a dashboard for the terminal.md b/published/201901/20190118 Get started with WTF, a dashboard for the terminal.md new file mode 100644 index 0000000000..c7da18b982 --- /dev/null +++ b/published/201901/20190118 Get started with WTF, a dashboard for the terminal.md @@ -0,0 +1,91 @@ +[#]: collector: (lujun9972) +[#]: translator: (wxy) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10484-1.html) +[#]: subject: (Get started with WTF, a dashboard for the terminal) +[#]: via: (https://opensource.com/article/19/1/wtf-information-dashboard) +[#]: author: (Kevein Sonney https://opensource.com/users/ksonney) + +开始使用 WTF 吧，一款终端仪表板 +====== + +> 使用 WTF 将关键信息置于视野之中，这个系列中第六个开源工具可使你在 2019 年更有工作效率。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/data_metrics_analytics_desktop_laptop.png?itok=9QXd7AUr) + +每年年初似乎都有疯狂的冲动想提高工作效率。新年的决心，渴望开启新的一年，当然，“抛弃旧的，拥抱新的”的态度促成了这一切。通常这时的建议严重偏向闭源和专有软件，但事实上并不用这样。 + +这是我挑选出的 19 个新的（或者对你而言新的）开源项目来帮助你在 2019 年更有效率。 + +### WTF + +曾几何时，我在一家使用[彭博终端][1]的公司做咨询。我的反应是，“哇，在一个屏幕上显示的信息太多了。” 然而，现在，当我正在工作并且打开多个网页、仪表板和控制台应用程序以试图跟踪事物时，我似乎无法在屏幕上获得足够的信息。 + +虽然 [tmux][2] 和 [Screen][3] 可以进行分屏和打开多个窗口，但它们很难设置，并且它们的键绑定可能需要一段时间才能学会（还经常与其他应用程序冲突）。 + +[WTF][4] 是一个简单的、易于配置的终端信息仪表板。它是用 [Go][5] 语言编写的，使用 YAML 配置文件，可以从几个不同的源提取数据。所有的数据源都包含在[模块][6]中，包括天气、问题跟踪器、日期和时间、Google 表格以及更多内容。有些窗格是交互式的，有些窗格只是使用最新的信息进行更新。 + +安装它就像下载适用于您的操作系统的最新版本并运行命令一样简单。因为它是用 Go 编写的，所以它的移植性很好，应该可以在任何可以编译它的地方运行（尽管开发人员目前只为 Linux 和 MacOS 做了构建）。 + +![](https://opensource.com/sites/default/files/uploads/wtf-1.png) + +当您第一次运行 WTF 时，您将看到如上图的默认屏幕。 + +![](https://opensource.com/sites/default/files/uploads/wtf-2.png) + +其默认配置文件在 `~/.wtf/config.yml`，您可以编辑该文件以满足您的需要。网格布局的配置在文件的顶部。 + +``` +grid: +  columns: [45, 45] +  rows: [7, 7, 7, 4] +``` + +网格设置中的数字表示每个块的字符尺寸。默认配置是两列，每列 40 个字符，两行 13 个字符高，一行 4 个字符高。在上面的代码中，我使列更宽（`45,45`），行更小，并添加了第四行，所以我可以放更多的小部件。 + +![](https://opensource.com/sites/default/files/uploads/wtf-3.png) + +我喜欢在仪表板上看到当天的天气。有两个天气模块可供选择：[Weather][7]，它只显示文本信息；[Pretty Weather][8] 则色彩丰富，并使用基于文本的图形显示。 + +``` +prettyweather: +  enabled: true +  position: +    top: 0 +    left: 1 +    height: 2 +    width: 1 +``` + +此代码创建了一个窗格，高为两个块（`height: 2`），宽为一个块（`width: 1`），位于顶行（`top: 0`）的第二列（`left: 1`）上，包含 Pretty Weather 模块. + +一些模块是交互式的，如 Jira、GitHub 和 Todo，您可以在其中滚动、更新和保存信息。您可以使用 Tab 键在交互式窗格之间移动。`\` 键会显示活动窗格的帮助屏幕，以便您可以查看可以执行的操作以及操作方式。Todo 模块允许您添加、编辑和删除待办事项，并在完成后勾掉它们。 + +![](https://opensource.com/sites/default/files/uploads/wtf-4.png) + +还有一些模块可以执行命令并显示输出、监视文本文件，以及监视构建和集成服务器的输出。所有文档都做得很好。 + +对于需要在不同来源的一个屏幕上查看大量数据的人来说，WTF 是一个有价值的工具。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/wtf-information-dashboard + +作者：[Kevein Sonney][a] +选题：[lujun9972][b] +译者：[wxy](https://github.com/wxy) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Bloomberg_Terminal +[2]: https://github.com/tmux/tmux +[3]: https://www.gnu.org/software/screen/ +[4]: https://wtfutil.com/ +[5]: https://golang.org/ +[6]: https://wtfutil.com/posts/modules/ +[7]: https://wtfutil.com/posts/modules/weather/ +[8]: https://wtfutil.com/posts/modules/prettyweather/ diff --git a/published/201901/20190118 Top 5 Linux Server Distributions.md b/published/201901/20190118 Top 5 Linux Server Distributions.md new file mode 100644 index 0000000000..e1515510a3 --- /dev/null +++ b/published/201901/20190118 Top 5 Linux Server Distributions.md @@ -0,0 +1,190 @@ +[#]: collector: (lujun9972) +[#]: translator: (wxy) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10490-1.html) +[#]: subject: (Top 5 Linux Server Distributions) +[#]: via: (https://www.linux.com/blog/learn/2019/1/top-5-linux-server-distributions) +[#]: author: (Jack Wallen https://www.linux.com/users/jlwallen) + +5 个用于 SOHO 的 Linux 服务器发行版 +====== + +> Jack Wallen 为 Linux 服务器发行版提供了一些可靠的选择，绝对值回票价。 + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/rockstor-main.jpg?itok=VNvfEIlf) + +啊，这个古老的问题：哪种 Linux 发行版最适合做服务器？通常，问这种问题时，所浮现出来的标准的答复就是： + + * RHEL + * SUSE + * Ubuntu 服务器 + * Debian + * CentOS + +然而，假如你将眼界放得更宽（不将服务器只看做是 IDC 托管的那种互联网服务器时），可能答案会有点不同。我准备稍微来点不同的。我想做出一个满足入选标准的发行版列表，这些发行版不仅是优秀的候选者，而且易于使用，可以为你的业务中的许多功能提供服务。在某些情况下，我选择的是一些替代品，可以取代其它需要一些工作才能达成要求的操作系统。 + +我的一些选择是企业级服务器的社区版本，它们可以被视为购买更强大平台的入门级产品。你甚至可以在这里找到一两个作为特定任务平台的候选者。然而，最重要的是，你在此列表中找到的并非寻常的泛泛之辈。 + +### ClearOS + +什么是 ClearOS？对于家庭和小型企业用途，你可能找不到比它更好的解决方案。ClearOS 开箱即用，包括了入侵检测、强大的防火墙、带宽管理工具、邮件服务器、域控制器等工具。其目的是将服务器作为一个简单的家庭和 SOHO 服务器，并具有用户友好的基于 Web 的图形化界面，这使得 ClearOS 在某些评比中脱颖而出。从其界面中，你可以找到一个应用程序市场（图 1），其中包含数百个应用程序（其中一些是免费的，而另一些则具有相关费用），这使得扩展 ClearOS 功能集非常容易。换句话说，你可以将 ClearOS 作为你的家庭和小型企业所需的平台。最重要的是，与许多其他替代方案不同，你只需支付所需的软件和支持。 + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/clearos.jpg?itok=knQkn5ch) + +*图 1：ClearOS 应用程序市场* + +有三种版本的 ClearOS： + + * [ClearOS Community][1] - 免费版 ClearOS + * [ClearOS Home][2] - 适于家庭办公 + * [ClearOS Business][3] - 适于小型企业，包括了付费支持。 + +为了使软件安装更加容易，ClearOS 应用市场允许你通过以下方式进行选择软件： + +   * 按功能（根据任务显示应用程序） +   * 按类别（显示相关应用程序组） +   * 快速选择文件（允许你按预先配置的模板选择，以帮助你快速启动和运行） + +换句话说，如果你正在寻找 Linux 的家庭、SOHO 或 SMB 服务器，ClearOS 是一个出色的选择（特别是如果你没有启动和运行标准的 Linux 服务器的能力时）。 + +### Fedora 服务器 + +你肯定听说过 Fedora Linux。它是市场上最好的前沿发行版之一。但是你知道这个出色的 Fedora 桌面发行版的开发者们也开发了服务器版吗？Fedora 服务器平台是一个短生命周期的、社区支持的服务器操作系统。这使得经验丰富的、或对任何类型的 Linux（或任何操作系统）有经验的系统管理员，可以使用开源社区中提供的最新技术。在这段描述中有三个关键词： + + * 经验丰富 + * 系统 + * 管理员 + +换言之，新用户就不要考虑了。虽然 Fedora 服务器完全能够处理你抛出的任何任务，但它需要一些拥有更多的 Linux 功夫的人来使它工作并且运行良好。Fedora 服务器非常好的一点是，开箱即用，它包括了市场上用于服务器的开源的基于 Web 的最好的界面之一。通过 Cockpit（图 2），你可以快速浏览系统资源、日志、存储、网络以及拥有管理帐户、服务、应用程序和更新的能力。 + +![Fedora Server][5] + +*图 2：运行在 Fedora 服务器上的 Cockpit* + +如果你可以使用最前沿的软件，并想要一个出色的管理仪表板，Fedora 服务器可能就是你要的平台。 + +### NethServer + +正如你所发现的那样，NethServer 是每个人都知道的简单 SMB Linux 服务器。通过 NethServer 的最新版本，你的小型企业将得到： + + * 内置 Samba 活动目录控制器 +   * 与 Nextcloud 的无缝集成 +   * 证书管理 +   * HTTPS 透明代理 +   * 防火墙 +   * 邮件服务器和过滤器 +   * Web 服务器和过滤器 +   * 群件 +   * IPS / IDS 或 VPN + +所有包含的功能都可以通过用户友好的基于 Web 的界面轻松配置，包括单击安装模块以扩展 NethServer 功能集（图 3）。NethServer 与 ClearOS 的区别在于它的设计目的是使管理工作更轻松。换句话说，这个平台提供了更多的灵活性和功能。与面向家庭办公室和 SOHO 部署的 ClearOS 不同，NethServer 在小型商业环境中用起来就像在家庭里使用一样方便。 + +![NethServer][8] + +*图 3：给 NethServer 添加模块* + +### Rockstor + +Rockstor 是采用 Linux 和 Btfrs 的高级网络附加存储（NAS）和云存储服务器，可部署用于家庭、SOHO 以及中小型企业。借助 Rockstor，你可以获得一个完整的 NAS /云解决方案，其中包含一个用户友好的基于 Web 的 GUI 工具，管理员可以像普通用户一样轻松使用它来设置。一旦部署好了 Rockstor，你就可以创建存储池、共享、快照、管理复制和用户、共享文件（借助 Samba、NFS、SFTP 和 AFP），甚至扩展它的功能集，这要归功于附加组件（称为 Rock-ons）。Rock-ons 列表包括： + + * CouchPotato（Usenet 和 BitTorrent 用户的下载器） + * Deluge（BitTorrent 用户的电影下载器） + * EmbyServer（Emby 媒体服务器） + * Ghost（专业博主的发布平台） + * GitLab CE（Git 仓库托管和协作） + * Gogs Go Git Service（轻量级 Git 版本控制服务器和前端） + * Headphones（NZB 和 Torrent 的音乐自动下载器） + * 用于 Squeezebox 设备的罗技 Squeezebox 服务器 + * MariaDB（关系型数据管理系统） + * NZBGet（高效的 usenet 下载器） + * OwnCloud-Official（安全的文件共享和托管） + * Plexpy（基于 Python 的 Plex 用量跟踪器） + * Rocket.Chat（开源聊天平台） + * SaBnzbd（Usenet 下载器） + * Sickbeard（用于电视节目的互联网个人视频录像机） + * Sickrage（电视节目的自动视频库管理器） + * Sonarr（Usenet 和 BitTorrent 用户的个人视频录像机） + * Symform（备份设备） + +Rockstor 还包括了一目了然的仪表板，使管理员可以快速访问他们所需的有关其服务器的所有信息（图 4）。 + +![Rockstor][10] + +*图 4： Rockstor 面板* + +### Zentyal + +Zentyal 是另一个小型企业服务器，可以很好地处理多个任务。如果你正在寻找可以处理以下内容的 Linux 发行版： + + * 目录和域服务器 + * 邮件服务器 + * 网关 + * DHCP、DNS 和 NTP 服务器 + * 认证机构（CA） + * VPN + * 实时消息（IM） + * FTP 服务器 + * 反病毒 + * SSO 认证 + * 文件共享 + * RADIUS 认证 + * 虚拟化管理 + * 等等 + +Zentyal 可能是你的新选择。从 2004 年 Zentyal 就存在了，它基于 Ubuntu Server，因此它拥有坚实的基础和丰富的应用程序。在 Zentyal 仪表板的帮助下（图 5），管理员可以轻松管理： + + * 系统 + * 网络 + * 日志 + * 软件更新和安装 + * 用户/组 + * 域 + * 文件共享 + * 邮件 + * DNS + * 防火墙 + * 证书 + * 等等 + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/zentyal.jpg?itok=Un9lpgh6) + +*图 5：Zentyal 仪表板* + +向 Zentyal 服务器添加新组件只需要打开仪表板，单击“软件管理” -> “Zentyal 组件”，选择要添加的组件，然后单击安装。Zentyal 可能会遇到的一个问题是，它提供不了与 Nethserver 和 ClearOS 一样多的插件。但它提供的服务，则做得非常好。 + +### 更多来自于 + +这个 Linux 服务器列表显然不是详尽无遗的。然而，这是一种对你可能没有听说过的五大服务器发行版的独特视角。当然，如果你更愿意使用更传统的 Linux 服务器发行版，你可以随时坚持使用 [CentOS][11]、[Ubuntu 服务器][12]、[SUSE][13]、[RHEL][14] 或 [Debian][15]……它们大多都出现在市场上最好的服务器发行版列表中。但是，如果你正在寻找一些不同的东西，那么试试这五个发行版中的一个。 + +通过 Linux 基金会和 edX 的免费[“Linux 简介”][16]课程了解有关 Linux 的更多信息。 + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/blog/learn/2019/1/top-5-linux-server-distributions + +作者：[Jack Wallen][a] +选题：[lujun9972][b] +译者：[wxy](https://github.com/wxy) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/users/jlwallen +[b]: https://github.com/lujun9972 +[1]: https://www.clearos.com/clearfoundation/software/clearos-7-community +[2]: https://www.clearos.com/products/clearos-editions/clearos-7-home +[3]: https://www.clearos.com/products/clearos-editions/clearos-7-business +[4]: https://www.linux.com/files/images/fedoraserverjpg +[5]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/fedoraserver.jpg?itok=phaAIRXW (Fedora Server) +[6]: https://www.linux.com/licenses/category/used-permission +[7]: https://www.linux.com/files/images/nethserverjpg +[8]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/nethserver.jpg?itok=HO-CRbOV (NethServer) +[9]: https://www.linux.com/files/images/rockstorejpg +[10]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/rockstore.jpg?itok=EN_5oFxQ (Rockstor) +[11]: https://www.centos.org/ +[12]: https://www.ubuntu.com/download/server +[13]: https://www.suse.com/ +[14]: https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux +[15]: https://www.debian.org/ +[16]: https://training.linuxfoundation.org/linux-courses/system-administration-training/introduction-to-linux diff --git a/published/201901/20190123 Getting started with Isotope, an open source webmail client.md b/published/201901/20190123 Getting started with Isotope, an open source webmail client.md new file mode 100644 index 0000000000..5397aad573 --- /dev/null +++ b/published/201901/20190123 Getting started with Isotope, an open source webmail client.md @@ -0,0 +1,61 @@ +[#]: collector: (lujun9972) +[#]: translator: (MjSeven) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10494-1.html) +[#]: subject: (Getting started with Isotope, an open source webmail client) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-isotope) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +开始使用 Isotope 吧，一款开源的 Web 邮件客户端 +====== + +> 使用轻量级的电子邮件客户端 Isotope 阅读富文本电子邮件，这个开源工具系列的第十一个工具将使你在 2019 年更高效。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/newsletter_email_mail_web_browser.jpg?itok=Lo91H9UH) + +在每年的年初，似乎都有一股疯狂的寻找提高工作效率方法的冲动。新年决心，渴望以正确的方式开始新的一年。当然，“旧不去的，新的不来”的态度都会导致这种情况。一般的建议都偏向于闭源和专有软件，然而并不是必须这样。 + +以下是我挑选的 19 个新的（或者对你来说是新的）开源工具中的第 11 个，它将帮助你在 2019 年提高工作效率。 + +### Isotope + +正如我们在[本系列的第四篇文章][1]（Cypht）中所讨论的那样，我们花了很多时间来处理电子邮件。有很多方法可以解决它，我已经花了很多时间来寻找最适合我的电子邮件客户端。我认为这是一个重要的区别：对我有效的方法并不总是对其它人有效。有时对我有用的是像 [Thunderbird][2] 这样的完整客户端，有时是像 [Mutt][3] 这样的控制台客户端，有时是像 [Gmail][4] 和 [RoundCube][5] 这样基于 Web 的界面。 + +![](https://opensource.com/sites/default/files/uploads/isotope_1.png) + +[Isotope][6] 是一个本地托管的、基于 Web 的电子邮件客户端。它非常轻巧，只使用 IMAP 协议，占用的磁盘空间非常小。与 Cypht 不同，Isotope 具有完整的 HTML 邮件支持，这意味着显示富文本电子邮件没有问题。 + +![](https://opensource.com/sites/default/files/uploads/isotope_2_0.png) + +如果你安装了 [Docker][7]，那么安装 Isotope 非常容易。你只需将文档中的命令复制到控制台中，然后按下回车键。在浏览器中输入 `localhost` 来访问 Isotope 登录界面，输入你的 IMAP 服务器，登录名和密码将打开收件箱视图。 + +![](https://opensource.com/sites/default/files/uploads/isotope_3.png) + +在这一点上，Isotope 的功能和你想象的差不多。单击消息进行查看，单击铅笔图标以创建新邮件等。你会注意到用户界面（UI）非常简单，没有“移动到文件夹”、“复制到文件夹”和“存档”等常规按钮。你可以通过拖动来移动消息，因此其实你并不太需要这些按钮。 + +![](https://opensource.com/sites/default/files/uploads/isotope_4.png) + +总的来说，Isotope 干净、速度快、工作得非常好。更棒的是，它正在积极开发中（最近一次的提交是在我撰写本文的两小时之前），所以它正在不断得到改进。你可以查看代码并在 [GitHub][8] 上为它做出贡献。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-isotope + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[MjSeven](https://github.com/MjSeven) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/article/19/1/productivity-tool-cypht-email +[2]: https://www.thunderbird.net/ +[3]: http://www.mutt.org/ +[4]: https://mail.google.com/ +[5]: https://roundcube.net/ +[6]: https://blog.marcnuri.com/isotope-mail-client-introduction/ +[7]: https://www.docker.com/ +[8]: https://github.com/manusa/isotope-mail diff --git a/published/20190114 Hegemon - A Modular System And Hardware Monitoring Tool For Linux.md b/published/20190114 Hegemon - A Modular System And Hardware Monitoring Tool For Linux.md new file mode 100644 index 0000000000..873ecb8cbb --- /dev/null +++ b/published/20190114 Hegemon - A Modular System And Hardware Monitoring Tool For Linux.md @@ -0,0 +1,129 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10503-1.html) +[#]: subject: (Hegemon – A Modular System And Hardware Monitoring Tool For Linux) +[#]: via: (https://www.2daygeek.com/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux/) +[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) + +Hegemon：一个 Linux 的模块化系统和硬件监控工具 +====== + +我知道每个人都更喜欢使用 [top 命令][1]来监控系统利用率。这是被 Linux 系统管理员大量使用的原生命令之一。 + +在 Linux 中，每个包都有一个替代品。Linux 中有许多可用于此的工具，我更喜欢 [htop 命令][2]。 + +如果你想了解其他替代方案，我建议你浏览每个链接了解更多信息。它们有 htop、CorFreq、glances、atop、Dstat、Gtop、Linux Dash、Netdata、Monit 等。 + +所有这些只允许我们监控系统利用率而不能监控系统硬件。但是 Hegemon 允许我们在单个仪表板中监控两者。 + +如果你正在寻找系统硬件监控软件，那么我建议你看下 [lm_sensors][3] 和 [s-tui 压力终端 UI][4]。 + +### Hegemon 是什么？ + +Hegemon 是一个正在开发中的模块化系统监视器，以安全的 Rust 编写。 + +它允许用户在单个仪表板中监控两种使用情况。分别是系统利用率和硬件温度。 + +### Hegemon 目前的特性 + + * 监控 CPU 和内存使用情况、温度和风扇速度 + * 展开任何数据流以显示更详细的图表和其他信息 + * 可调整的更新间隔 + * 干净的 MVC 架构，具有良好的代码质量 + * 单元测试 + +### 计划的特性包括 + + * macOS 和 BSD 支持（目前仅支持 Linux） +  * 监控磁盘和网络 I/O、GPU 使用情况（可能）等 +  * 选择并重新排序数据流 +  * 鼠标控制 + +### 如何在 Linux 中安装 Hegemon？ + +Hegemon 需要 Rust 1.26 或更高版本以及 libsensors 的开发文件。因此，请确保在安装 Hegemon 之前安装了这些软件包。 + +libsensors 库在大多数发行版官方仓库中都有，因此，使用以下命令进行安装。 + +对于 Debian/Ubuntu 系统，使用 [apt-get 命令][5] 或 [apt 命令][6] 在你的系统上安装 libsensors。 + +``` +# apt install lm_sensors-devel +``` + +对于 Fedora 系统，使用 [dnf 包管理器][7]在你的系统上安装 libsensors。 + +``` +# dnf install libsensors4-dev +``` + +运行以下命令安装 Rust 语言，并按照指示来做。如果你想要看 [Rust 安装][8]的方便教程，请进入该 URL。 + +``` +$ curl https://sh.rustup.rs -sSf | sh +``` + +如果你已成功安装 Rust。运行以下命令安装 Hegemon。 + +``` +$ cargo install hegemon +``` + +### 如何在 Linux 中启动 Hegemon？ + +成功安装 Hegemon 包后，运行下面的命令启动。 + +``` +$ hegemon +``` + +![][10] + +由于 libsensors.so.4 库的问题，我在启动 Hegemon 时遇到了一个问题。 + +``` +$ hegemon +error while loading shared libraries: libsensors.so.4: cannot open shared object file: No such file or directory manjaro +``` + +我使用的是 Manjaro 18.04。它存在 libsensors.so 和 libsensors.so.5 共享库，而没有 libsensors.so.4。所以，我刚刚创建了以下符号链接来解决问题。 + +``` +$ sudo ln -s /usr/lib/libsensors.so /usr/lib/libsensors.so.4 +``` + +这是从我的 Lenovo-Y700 笔记本中截取的示例 gif。 + +![][11] + +默认它仅显示总体摘要，如果你想查看详细输出，则需要展开每个部分。如下是 Hegemon 的展开视图。 + +![][12] + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux/ + +作者：[Magesh Maruthamuthu][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/magesh/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/top-command-examples-to-monitor-server-performance/ +[2]: https://www.2daygeek.com/linux-htop-command-linux-system-performance-resource-monitoring-tool/ +[3]: https://www.2daygeek.com/view-check-cpu-hard-disk-temperature-linux/ +[4]: https://www.2daygeek.com/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency/ +[5]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/ +[6]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/ +[7]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ +[8]: https://www.2daygeek.com/how-to-install-rust-programming-language-in-linux/ +[9]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[10]: https://www.2daygeek.com/wp-content/uploads/2019/01/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux-1.png +[11]: https://www.2daygeek.com/wp-content/uploads/2019/01/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux-2a.gif +[12]: https://www.2daygeek.com/wp-content/uploads/2019/01/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux-3.png diff --git a/published/20190119 Get started with Roland, a random selection tool for the command line.md b/published/20190119 Get started with Roland, a random selection tool for the command line.md new file mode 100644 index 0000000000..5cba8db837 --- /dev/null +++ b/published/20190119 Get started with Roland, a random selection tool for the command line.md @@ -0,0 +1,90 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10507-1.html) +[#]: subject: (Get started with Roland, a random selection tool for the command line) +[#]: via: (https://opensource.com/article/19/1/productivity-tools-roland) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +开始使用 Roland 吧，一款命令行随机选择工具 +====== + +> Roland 可以帮你做出艰难的决定，它是我们在开源工具系列中的第七个工具，将帮助你在 2019 年提高工作效率。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/dice_tabletop_board_gaming_game.jpg?itok=y93eW7HN) + +每年年初似乎都有疯狂的冲动想提高工作效率。新年的决心，渴望开启新的一年，当然，“抛弃旧的，拥抱新的”的态度促成了这一切。通常这时的建议严重偏向闭源和专有软件，但事实上并不用这样。 + +这是我挑选出的 19 个新的（或者对你而言新的）开源工具中的第七个工具来帮助你在 2019 年更有效率。 + +### Roland + +当一周的工作结束后，我唯一想做的就是躺到沙发上打一个周末的游戏。但即使我的职业义务在工作日结束后停止了，但我仍然需要管理我的家庭。洗衣、宠物护理、确保我孩子有他所需要的东西，以及最重要的是：决定晚餐吃什么。 + +像许多人一样，我经常受到[决策疲劳][1]的困扰，根据速度、准备难易程度以及（坦白地说）任何让我压力最小的方式都会导致不太健康的晚餐选择。 + +![](https://opensource.com/sites/default/files/uploads/roland-1.png) + +[Roland][2] 让我计划饭菜变得容易。Roland 是一款专为桌面角色扮演游戏设计的 Perl 应用。它从怪物和雇佣者等项目列表中随机挑选。从本质上讲，Roland 在命令行做的事情就像游戏管理员在桌子上掷骰子，以便在《要对玩家做的坏事全书》中找个东西一样。 + +通过微小的修改，Roland 可以做得更多。例如，只需添加一张表，我就可以让 Roland 帮我选择晚餐。 + +第一步是安装 Roland 及其依赖项。 + +``` +git clone git@github.com:rjbs/Roland.git +cpan install Getopt::Long::Descriptive Moose \ +   namespace::autoclean List:AllUtils Games::Dice \ +   Sort::ByExample Data::Bucketeer Text::Autoformat \ +   YAML::XS +cd oland +``` + +接下来，创建一个名为 `dinner` 的 YAML 文档，并输入我们所有的用餐选项。 + +``` +type: list +pick: 1 +items: + - "frozen pizza" +  - "chipotle black beans" +  - "huevos rancheros" +  - "nachos" +  - "pork roast" +  - "15 bean soup" +  - "roast chicken" +  - "pot roast" +  - "grilled cheese sandwiches" +``` + +运行命令 `bin/roland dinner` 将读取文件并选择其中一项。 + +![](https://opensource.com/sites/default/files/uploads/roland-2.png) + +我想提前计划一周，这样我可以提前购买所有食材。 `pick` 命令确定列表中要选择的物品数量，现在，`pick` 设置为 1。如果我想计划一周的晚餐菜单，我可以将 `pick: 1` 变成 `pick: 7`，它会提供一周的菜单。你还可以使用 `-m` 选项手动输入选择。 + +![](https://opensource.com/sites/default/files/uploads/roland-3.png) + +你也可以用 Roland 做些有趣的事情，比如用经典短语添加一个名为 `8ball` 的文件。 + +![](https://opensource.com/sites/default/files/uploads/roland-4.png) + +你可以创建各种文件来帮助做出长时间工作后看起来非常难做的常见决策。即使你不用来做这个，你仍然可以用它来为今晚的游戏设置哪个狡猾的陷阱做个决定。 + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tools-roland + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Decision_fatigue +[2]: https://github.com/rjbs/Roland diff --git a/published/20190120 Get started with HomeBank, an open source personal finance app.md b/published/20190120 Get started with HomeBank, an open source personal finance app.md new file mode 100644 index 0000000000..602477dd01 --- /dev/null +++ b/published/20190120 Get started with HomeBank, an open source personal finance app.md @@ -0,0 +1,62 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10500-1.html) +[#]: subject: (Get started with HomeBank, an open source personal finance app) +[#]: via: (https://opensource.com/article/19/1/productivity-tools-homebank) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +开始使用 HomeBank 吧，一款开源个人财务应用 +====== +> 使用 HomeBank 跟踪你的资金流向，这是我们开源工具系列中的第八个工具，它将在 2019 年提高你的工作效率。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/math_money_financial_calculator_colors.jpg?itok=_yEVTST1) + +每年年初似乎都有疯狂的冲动想提高工作效率。新年的决心，渴望开启新的一年，当然，“抛弃旧的，拥抱新的”的态度促成了这一切。通常这时的建议严重偏向闭源和专有软件，但事实上并不用这样。 + +这是我挑选出的 19 个新的（或者对你而言新的）开源项目来帮助你在 2019 年更有效率。 + +### HomeBank + +管理我的财务可能会很有压力。我不会每天查看我的银行余额，有时也很难跟踪我的钱流向哪里。我经常会花更多的时间来管理我的财务，挖掘账户和付款历史并找出我的钱去了哪里。了解我的财务状况可以帮助我保持冷静，并让我专注于其他事情。 + +![](https://opensource.com/sites/default/files/uploads/homebank-1.png) + +[HomeBank][1] 是一款个人财务桌面应用，帮助你轻松跟踪你的财务状况，来帮助减少此类压力。它有很好的报告可以帮助你找出你花钱的地方，允许你设置导入交易的规则，并支持大多数现代格式。 + +HomeBank 默认可在大多数发行版上可用，因此安装它非常简单。当你第一次启动它时，它将引导你完成设置并让你创建一个帐户。之后，你可以导入任意一种支持的文件格式或开始输入交易。交易簿本身就是一个交易列表。[与其他一些应用不同][2]，你不必学习[复式记账法][3]来使用 HomeBank。 + +![](https://opensource.com/sites/default/files/uploads/homebank-2.png) + +从银行导入文件将使用另一个分步向导进行处理，该向导提供了创建新帐户或填充现有帐户的选项。导入新帐户可节省一点时间，因为你无需在开始导入之前预先创建所有帐户。你还可以一次将多个文件导入帐户，因此不需要对每个帐户中的每个文件重复相同的步骤。 + +![](https://opensource.com/sites/default/files/uploads/homebank-3.png) + +我在导入和管理帐户时遇到的一个痛点是指定类别。一般而言，类别可以让你分解你的支出，看看你花钱的方式。HomeBank 与一些商业服务（以及一些商业程序）不同，它要求你手动设置所有类别。但这通常是一次性的事情，它可以在添加/导入交易时自动添加类别。还有一个按钮来分析帐户并跳过已存在的内容，这样可以加快对大量导入的分类（就像我第一次做的那样）。HomeBank 提供了大量可用的类别，你也可以添加自己的类别。 + +HomeBank 还有预算功能，允许你计划未来几个月的开销。 + +![](https://opensource.com/sites/default/files/uploads/homebank-4.png) + +对我来说，最棒的功能是 HomeBank 的报告。主页面上不仅有一个图表显示你花钱的地方，而且还有许多其他报告可供你查看。如果你使用预算功能，还会有一份报告会根据预算跟踪你的支出情况。你还可以以饼图和条形图的方式查看报告。它还有趋势报告和余额报告，因此你可以回顾并查看一段时间内的变化或模式。 + +总的来说，HomeBank 是一个非常友好，有用的程序，可以帮助你保持良好的财务状况。如果跟踪你的钱是你生活中的一件麻烦事，它使用起来很简单并且非常有用。 + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tools-homebank + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: http://homebank.free.fr/en/index.php +[2]: https://www.gnucash.org/ +[3]: https://en.wikipedia.org/wiki/Double-entry_bookkeeping_system diff --git a/published/20190123 Commands to help you monitor activity on your Linux server.md b/published/20190123 Commands to help you monitor activity on your Linux server.md new file mode 100644 index 0000000000..4900629eaf --- /dev/null +++ b/published/20190123 Commands to help you monitor activity on your Linux server.md @@ -0,0 +1,157 @@ +[#]: collector: (lujun9972) +[#]: translator: (dianbanjiu) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10498-1.html) +[#]: subject: (Commands to help you monitor activity on your Linux server) +[#]: via: (https://www.networkworld.com/article/3335200/linux/how-to-monitor-activity-on-your-linux-server.html) +[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/) + +监控 Linux 服务器活动的几个命令 +====== + +> `watch`、`top` 和 `ac` 命令为我们监视 Linux 服务器上的活动提供了一些十分高效的途径。 + +![](https://images.idgesg.net/images/article/2019/01/owl-face-100785829-large.jpg) + +为了在获取系统活动时更加轻松，Linux 系统提供了一系列相关的命令。在这篇文章中，我们就一起来看看这些对我们很有帮助的命令吧。 + +### watch 命令 + +`watch` 是一个用来轻松地重复检测 Linux 系统中一系列数据命令，例如用户活动、正在运行进程、登录、内存使用等。这个命令实际上是重复地运行一个特定的命令，每次都会重写之前显示的输出，它提供了一个比较方便的方式用以监测在你的系统中发生的活动。 + +首先以一个基础且不是特别有用的命令开始，你可以运行 `watch -n 5 date`，然后你可以看到在终端中显示了当前的日期和时间，这些数据会每五秒更新一次。你可能已经猜到了，`-n 5` 选项指定了运行接下来一次命令需要等待的秒数。默认是 2 秒。这个命令将会一直运行并按照指定的时间更新显示，直到你使用 `^C` 停下它。 + +``` +Every 5.0s: date butterfly: Wed Jan 23 15:59:14 2019 + +Wed Jan 23 15:59:14 EST 2019 +``` + +下面是一个更有趣的命令实例，你可以监控一个在服务器中登录用户的列表，该列表会按照指定的时间定时更新。就像下面写到的，这个命令会每 10 秒更新一次这个列表。登出的用户将会从当前显示的列表中消失，那些新登录的将会被添加到这个表格当中。如果没有用户再登录或者登出，这个表格跟之前显示的将不会有任何不同。 + +``` +$ watch -n 10 who + +Every 10.0s: who butterfly: Tue Jan 23 16:02:03 2019 + +shs :0 2019-01-23 09:45 (:0) +dory pts/0 2019-01-23 15:50 (192.168.0.5) +nemo pts/1 2019-01-23 16:01 (192.168.0.15) +shark pts/3 2019-01-23 11:11 (192.168.0.27) +``` + +如果你只是想看有多少用户登录进来，可以通过 `watch` 调用 `uptime` 命令获取用户数和负载的平均水平，以及系统的工作状况。 + +``` +$ watch uptime + +Every 2.0s: uptime butterfly: Tue Jan 23 16:25:48 2019 + + 16:25:48 up 22 days, 4:38, 3 users, load average: 1.15, 0.89, 1.02 +``` + +如果你想使用 `watch` 重复一个包含了管道的命令，就需要将该命令用引号括起来，就比如下面这个每五秒显示一次有多少进程正在运行的命令。 + +``` +$ watch -n 5 'ps -ef | wc -l' + +Every 5.0s: ps -ef | wc -l butterfly: Tue Jan 23 16:11:54 2019 + +245 +``` + +要查看内存使用，你也许会想要试一下下面的这个命令组合： + +``` +$ watch -n 5 free -m + +Every 5.0s: free -m butterfly: Tue Jan 23 16:34:09 2019 + +Every 5.0s: free -m butterfly: Tue Jan 23 16:34:09 2019 + + total used free shared buff/cache available +Mem: 5959 776 3276 12 1906 4878 +Swap: 2047 0 2047 +``` + +你可以在 `watch` 后添加一些选项查看某个特定用户下运行的进程，不过 `top` 为此提供了更好的选择。 + +### top 命令 + +如果你想查看某个特定用户下的进程，`top` 命令的 `-u` 选项可以很轻松地帮你达到这个目的。 + +``` +$ top -u nemo +top - 16:14:33 up 2 days, 4:27, 3 users, load average: 0.00, 0.01, 0.02 +Tasks: 199 total, 1 running, 198 sleeping, 0 stopped, 0 zombie +%Cpu(s): 0.0 us, 0.2 sy, 0.0 ni, 99.8 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st +MiB Mem : 5959.4 total, 3277.3 free, 776.4 used, 1905.8 buff/cache +MiB Swap: 2048.0 total, 2048.0 free, 0.0 used. 4878.4 avail Mem + + PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND +23026 nemo 20 0 46340 7820 6504 S 0.0 0.1 0:00.05 systemd +23033 nemo 20 0 149660 3140 72 S 0.0 0.1 0:00.00 (sd-pam) +23125 nemo 20 0 63396 5100 4092 S 0.0 0.1 0:00.00 sshd +23128 nemo 20 0 16836 5636 4284 S 0.0 0.1 0:00.03 zsh +``` + +你可能不仅可以看到某个用户下的进程，还可以查看每个进程所占用的资源，以及系统总的工作状况。 + +### ac 命令 + +如果你想查看系统中每个用户登录的时长，可以使用 `ac` 命令。运行该命令之前首先需要安装 `acct`（Debian 等）或者 `psacct`（RHEL、Centos 等）包。 + +`ac` 命令有一系列的选项，该命令从 `wtmp` 文件中拉取数据。这个例子展示的是最近用户登录的总小时数。 + +``` +$ ac + total 1261.72 +``` + +这个命令显示了用户登录的总的小时数： + +``` +$ ac -p + shark 5.24 + nemo 5.52 + shs 1251.00 + total 1261.76 +``` + +这个命令显示了每天登录的用户小时数： + +``` +$ ac -d | tail -10 + +Jan 11 total 0.05 +Jan 12 total 1.36 +Jan 13 total 16.39 +Jan 15 total 55.33 +Jan 16 total 38.02 +Jan 17 total 28.51 +Jan 19 total 48.66 +Jan 20 total 1.37 +Jan 22 total 23.48 +Today total 9.83 +``` + +### 总结 + +Linux 系统上有很多命令可以用于检查系统活动。`watch` 命令允许你以重复的方式运行任何命令，并观察输出有何变化。`top` 命令是一个专注于用户进程的最佳选项，以及允许你以动态方式查看进程的变化，还可以使用 `ac` 命令检查用户连接到系统的时间。 + +-------------------------------------------------------------------------------- + +via: https://www.networkworld.com/article/3335200/linux/how-to-monitor-activity-on-your-linux-server.html + +作者：[Sandra Henry-Stocker][a] +选题：[lujun9972][b] +译者：[dianbanjiu](https://github.com/dianbanjiu) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/ +[b]: https://github.com/lujun9972 +[1]: https://www.facebook.com/NetworkWorld/ +[2]: https://www.linkedin.com/company/network-world diff --git a/published/20190124 Understanding Angle Brackets in Bash.md b/published/20190124 Understanding Angle Brackets in Bash.md new file mode 100644 index 0000000000..1c8f4ffe7c --- /dev/null +++ b/published/20190124 Understanding Angle Brackets in Bash.md @@ -0,0 +1,154 @@ +[#]: collector: (lujun9972) +[#]: translator: (HankChow) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10502-1.html) +[#]: subject: (Understanding Angle Brackets in Bash) +[#]: via: (https://www.linux.com/blog/learn/2019/1/understanding-angle-brackets-bash) +[#]: author: (Paul Brown https://www.linux.com/users/bro66) + +理解 Bash 中的尖括号 +====== + +> 为初学者介绍尖括号。 + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/architecture-1839450_1920.jpg?itok=ra6XonD3) + +[Bash][1] 内置了很多诸如 `ls`、`cd`、`mv` 这样的重要的命令，也有很多诸如 `grep`、`awk`、`sed` 这些有用的工具。但除此之外，其实 [Bash][1] 中还有很多可以[起到胶水作用][2]的标点符号，例如点号（`.`）、逗号（`,`）、括号（`<>`）、引号（`"`）之类。下面我们就来看一下可以用来进行数据转换和转移的尖括号（`<>`）。 + +### 转移数据 + +如果你对其它编程语言有所了解，你会知道尖括号 `<` 和 `>` 一般是作为逻辑运算符，用来比较两个值之间的大小关系。如果你还编写 HTML，尖括号作为各种标签的一部分，就更不会让你感到陌生了。 + +在 shell 脚本语言中，尖括号可以将数据从一个地方转移到另一个地方。例如可以这样把数据存放到一个文件当中： + +``` +ls > dir_content.txt +``` + +在上面的例子中，`>` 符号让 shell 将 `ls` 命令的输出结果写入到 `dir_content.txt` 里，而不是直接显示在命令行中。需要注意的是，如果 `dir_content.txt` 这个文件不存在，Bash 会为你创建；但是如果 `dir_content.txt` 是一个已有的非空文件，它的内容就会被覆盖掉。所以执行类似的操作之前务必谨慎。 + +你也可以不使用 `>` 而使用 `>>`，这样就可以把新的数据追加到文件的末端而不会覆盖掉文件中已有的数据了。例如： + +``` +ls $HOME > dir_content.txt; wc -l dir_content.txt >> dir_content.txt +``` + +在这串命令里，首先将家目录的内容写入到 `dir_content.txt` 文件中，然后使用 `wc -l` 计算出 `dir_content.txt` 文件的行数（也就是家目录中的文件数）并追加到 `dir_content.txt` 的末尾。 + +在我的机器上执行上述命令之后，`dir_content.txt` 的内容会是以下这样： + +``` +Applications +bin +cloud +Desktop +Documents +Downloads +Games +ISOs +lib +logs +Music +OpenSCAD +Pictures +Public +Templates +test_dir +Videos +17 dir_content.txt +``` + +你可以将 `>` 和 `>>` 作为箭头来理解。当然，这个箭头的指向也可以反过来。例如，Coen brothers +（LCTT 译注：科恩兄弟，一个美国电影导演组合）的一些演员以及他们出演电影的次数保存在 `CBActors` 文件中，就像这样： + +``` +John Goodman 5 +John Turturro 3 +George Clooney 2 +Frances McDormand 6 +Steve Buscemi 5 +Jon Polito 4 +Tony Shalhoub 3 +James Gandolfini 1 +``` + +你可以执行这样的命令： + +``` +sort < CBActors +Frances McDormand 6 # 你会得到这样的输出 +George Clooney 2 +James Gandolfini 1 +John Goodman 5 +John Turturro 3 +Jon Polito 4 +Steve Buscemi 5 +Tony Shalhoub 3 +``` + +就可以使用 [sort][4] 命令将这个列表按照字母顺序输出。但是，`sort` 命令本来就可以接受传入一个文件，因此在这里使用 `<` 会略显多余，直接执行 `sort CBActors` 就可以得到期望的结果。 + +如果你想知道 Coens 最喜欢的演员是谁，你可以这样操作。首先： + +``` +while read name surname films; do echo $films $name $surname > filmsfirst.txt; done < CBActors +``` + +上面这串命令写在多行中可能会比较易读： + +``` +while read name surname films;\ + do + echo $films $name $surname >> filmsfirst;\ + done < CBActors +``` + +下面来分析一下这些命令做了什么： + + * [while ...; do ... done][5] 是一个循环结构。当 `while` 后面的条件成立时，`do` 和 `done` 之间的部分会一直重复执行； + * [read][6] 语句会按行读入内容。`read` 会从标准输入中持续读入，直到没有内容可读入； + * `CBActors` 文件的内容会通过 `<` 从标准输入中读入，因此 `while` 循环会将 `CBActors` 文件逐行完整读入； + * `read` 命令可以按照空格将每一行内容划分为三个字段，然后分别将这三个字段赋值给 `name`、`surname` 和 `films` 三个变量，这样就可以很方便地通过 `echo $films $name $surname >> filmsfirst;\` 来重新排列几个字段的放置顺序并存放到 `filmfirst` 文件里面了。 + +执行完以后，查看 `filmsfirst` 文件，内容会是这样的： + +``` +5 John Goodman +3 John Turturro +2 George Clooney +6 Frances McDormand +5 Steve Buscemi +4 Jon Polito +3 Tony Shalhoub +1 James Gandolfini +``` + +这时候再使用 `sort` 命令： + +``` +sort -r filmsfirst +``` + +就可以看到 Coens 最喜欢的演员是 Frances McDormand 了。（`-r` 参数表示降序排列，因此 McDormand 会排在最前面） + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/blog/learn/2019/1/understanding-angle-brackets-bash + +作者：[Paul Brown][a] +选题：[lujun9972][b] +译者：[HankChow](https://github.com/HankChow) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/users/bro66 +[b]: https://github.com/lujun9972 +[1]: https://www.linux.com/blog/2019/1/bash-shell-utility-reaches-50-milestone +[2]: https://www.linux.com/blog/learn/2019/1/linux-tools-meaning-dot +[3]: https://linux.die.net/man/1/wc +[4]: https://linux.die.net/man/1/sort +[5]: http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-7.html +[6]: https://linux.die.net/man/2/read + diff --git a/published/20190128 fdisk - Easy Way To Manage Disk Partitions In Linux.md b/published/20190128 fdisk - Easy Way To Manage Disk Partitions In Linux.md new file mode 100644 index 0000000000..5ebe7d556c --- /dev/null +++ b/published/20190128 fdisk - Easy Way To Manage Disk Partitions In Linux.md @@ -0,0 +1,495 @@ +[#]: collector: (lujun9972) +[#]: translator: (zhs852) +[#]: reviewer: (wxy) +[#]: publisher: (wxy) +[#]: url: (https://linux.cn/article-10508-1.html) +[#]: subject: (fdisk – Easy Way To Manage Disk Partitions In Linux) +[#]: via: (https://www.2daygeek.com/linux-fdisk-command-to-manage-disk-partitions/) +[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) + +fdisk：Linux 下管理磁盘分区的利器 +====== + +一块硬盘可以被划分成一个或多个逻辑磁盘，我们将其称作分区。我们对硬盘进行的划分信息被储存于建立在扇区 0 的分区表（MBR 或 GPT）中。 + +Linux 需要至少一个分区来当作根文件系统，所以我们不能在没有分区的情况下安装 Linux 系统。当我们创建一个分区时，我们必须将它格式化为一个适合的文件系统，否则我们就没办法往里面储存文件了。 + +要在 Linux 中完成分区的相关工作，我们需要一些工具。Linux 下有很多可用的相关工具，我们曾介绍过 [Parted 命令][1]。不过，今天我们的主角是 `fdisk`。 + +人人都喜欢用 `fdisk`，它是 Linux 下管理磁盘分区的最佳利器之一。它可以操作最大 2TB 的分区。大量 Linux 管理员都喜欢使用这个工具，因为当下 LVM 和 SAN 的原因，并没有多少人会用到 2TB 以上的分区。并且这个工具被世界上许多的基础设施所使用。如果你还是想创建比 2TB 更大的分区，请使用 `parted` 命令 或 `cfdisk` 命令。 + +对磁盘进行分区和创建文件系统是 Linux 管理员的日常。如果你在许多不同的环境中工作，你一定每天都会重复几次这项操作。 + +### Linux 内核是如何理解硬盘的？ + +作为人类，我们可以很轻松地理解一些事情；但是电脑就不是这样了，它们需要合适的命名才能理解这些。 + +在 Linux 中，外围设备都位于 `/dev` 挂载点，内核通过以下的方式理解硬盘： + + * `/dev/hdX[a-z]:` IDE 硬盘被命名为 hdX + * `/dev/sdX[a-z]:` SCSI 硬盘被命名为 sdX + * `/dev/xdX[a-z]:` XT 硬盘被命名为 xdX + * `/dev/vdX[a-z]:` 虚拟硬盘被命名为 vdX + * `/dev/fdN:` 软盘被命名为 fdN + * `/dev/scdN or /dev/srN:` CD-ROM 被命名为 `/dev/scdN` 或 `/dev/srN` + +### 什么是 fdisk 命令？ + +`fdisk` 的意思是 固定磁盘Fixed Disk 或 格式化磁盘Format Disk，它是命令行下允许用户对分区进行查看、创建、调整大小、删除、移动和复制的工具。它支持 MBR、Sun、SGI、BSD 分区表，但是它不支持 GUID 分区表（GPT）。它不是为操作大分区设计的。 + +`fdisk` 允许我们在每块硬盘上创建最多四个主分区。它们中的其中一个可以作为扩展分区，并下设多个逻辑分区。1-4 扇区作为主分区被保留，逻辑分区从扇区 5 开始。 + +![磁盘分区结构图][3] + +### 如何在 Linux 下安装 fdisk？ + +`fdisk` 作为核心组件内置于 Linux 中，所以你不必手动安装它。 + +### 如何用 fdisk 列出可用磁盘？ + +在执行操作之前，我们必须知道的是哪些磁盘被加入了系统。要想列出所有可用的磁盘，请执行下文的命令。这个命令将会列出磁盘名称、分区数量、分区表类型、磁盘识别代号、分区 ID 和分区类型。 + +```shell +$ sudo fdisk -l +Disk /dev/sda: 30 GiB, 32212254720 bytes, 62914560 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +Disklabel type: dos +Disk identifier: 0xeab59449 + +Device Boot Start End Sectors Size Id Type +/dev/sda1 * 20973568 62914559 41940992 20G 83 Linux + + +Disk /dev/sdb: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes + + +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes + + +Disk /dev/sdd: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes + + +Disk /dev/sde: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +``` + +### 如何使用 fdisk 列出特定分区信息？ + +如果你希望查看指定分区的信息，请使用以下命令： + +```shell +$ sudo fdisk -l /dev/sda +Disk /dev/sda: 30 GiB, 32212254720 bytes, 62914560 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +Disklabel type: dos +Disk identifier: 0xeab59449 + +Device Boot Start End Sectors Size Id Type +/dev/sda1 * 20973568 62914559 41940992 20G 83 Linux +``` + +### 如何列出 fdisk 所有的可用操作？ + +在 `fdisk` 中敲击 `m`，它便会列出所有可用操作： + +```shell +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + +Device does not contain a recognized partition table. +Created a new DOS disklabel with disk identifier 0xe944b373. + +Command (m for help): m + +Help: + + DOS (MBR) + a toggle a bootable flag + b edit nested BSD disklabel + c toggle the dos compatibility flag + + Generic + d delete a partition + F list free unpartitioned space + l list known partition types + n add a new partition + p print the partition table + t change a partition type + v verify the partition table + i print information about a partition + + Misc + m print this menu + u change display/entry units + x extra functionality (experts only) + + Script + I load disk layout from sfdisk script file + O dump disk layout to sfdisk script file + + Save & Exit + w write table to disk and exit + q quit without saving changes + + Create a new label + g create a new empty GPT partition table + G create a new empty SGI (IRIX) partition table + o create a new empty DOS partition table + s create a new empty Sun partition table +``` + +### 如何使用 fdisk 列出分区类型？ + +在 `fdisk` 中敲击 `l`，它便会列出所有可用分区的类型： + +```shell +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + +Device does not contain a recognized partition table. +Created a new DOS disklabel with disk identifier 0x9ffd00db. + +Command (m for help): l + + 0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris + 1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT- + 2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT- + 3 XENIX usr 3c PartitionMagic 84 OS/2 hidden or c6 DRDOS/sec (FAT- + 4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx + 5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data + 6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / . + 7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility + 8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt + 9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access + a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O + b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor + c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi ea Rufus alignment + e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD eb BeOS fs + f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ee GPT +10 OPUS 55 EZ-Drive a7 NeXTSTEP ef EFI (FAT-12/16/ +11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f0 Linux/PA-RISC b +12 Compaq diagnost 5c Priam Edisk a9 NetBSD f1 SpeedStor +14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f4 SpeedStor +16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ f2 DOS secondary +17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fb VMware VMFS +18 AST SmartSleep 65 Novell Netware b8 BSDI swap fc VMware VMKCORE +1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fd Linux raid auto +1c Hidden W95 FAT3 75 PC/IX bc Acronis FAT32 L fe LANstep +1e Hidden W95 FAT1 80 Old Minix be Solaris boot ff BBT +``` +### 如何使用 fdisk 创建一个磁盘分区？ + +如果你希望新建磁盘分区，请参考下面的步骤。比如我希望在 `/dev/sdc` 中新建四个分区（三个主分区和一个扩展分区），只需要执行下文的命令。 + +首先，请在操作 “First sector” 的时候先按下回车，然后在 “Last sector” 中输入你希望创建分区的大小（可以在数字后面加 KB、MB、G 和 TB）。例如，你希望为这个分区扩容 1GB，就应该在 “Last sector” 中输入 `+1G`。当你创建三个分区之后，`fdisk` 默认会将分区类型设为扩展分区，如果你希望创建第四个主分区，请输入 `p` 来替代它的默认值 `e`。 + +```shell +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): n +Partition type + p primary (0 primary, 0 extended, 4 free) + e extended (container for logical partitions) +Select (default p): Enter + +Using default response p. +Partition number (1-4, default 1): Enter +First sector (2048-20971519, default 2048): Enter +Last sector, +sectors or +size{K,M,G,T,P} (2048-20971519, default 20971519): +1G + +Created a new partition 1 of type 'Linux' and of size 1 GiB. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +Disklabel type: dos +Disk identifier: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### 如何使用 fdisk 创建扩展分区？ + +请注意，创建扩展分区时，你应该使用剩下的所有空间，以便之后在扩展分区下创建逻辑分区。 + +```shell +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): n +Partition type + p primary (3 primary, 0 extended, 1 free) + e extended (container for logical partitions) +Select (default e): Enter + +Using default response e. +Selected partition 4 +First sector (6293504-20971519, default 6293504): Enter +Last sector, +sectors or +size{K,M,G,T,P} (6293504-20971519, default 20971519): Enter + +Created a new partition 4 of type 'Extended' and of size 7 GiB. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +Disklabel type: dos +Disk identifier: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux +/dev/sdc2 2099200 4196351 2097152 1G 83 Linux +/dev/sdc3 4196352 6293503 2097152 1G 83 Linux +/dev/sdc4 6293504 20971519 14678016 7G 5 Extended + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### 如何用 fdisk 查看未分配空间？ + +上文中，我们总共创建了四个分区（三个主分区和一个扩展分区）。在创建逻辑分区之前，扩展分区的容量将会以未分配空间显示。 + +使用以下命令来显示磁盘上的未分配空间，下面的示例中显示的是 7GB： + +```shell +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): F +Unpartitioned space /dev/sdc: 7 GiB, 7515144192 bytes, 14678016 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes + + Start End Sectors Size +6293504 20971519 14678016 7G + +Command (m for help): q +``` + +### 如何使用 fdisk 创建逻辑分区？ + +创建扩展分区后，请按照之前的步骤创建逻辑分区。在这里，我创建了位于 `/dev/sdc5` 的 `1GB` 逻辑分区。你可以查看分区表值来确认这点。 + +```shell +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + +Command (m for help): n +All primary partitions are in use. +Adding logical partition 5 +First sector (6295552-20971519, default 6295552): Enter +Last sector, +sectors or +size{K,M,G,T,P} (6295552-20971519, default 20971519): +1G + +Created a new partition 5 of type 'Linux' and of size 1 GiB. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +Disklabel type: dos +Disk identifier: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux +/dev/sdc2 2099200 4196351 2097152 1G 83 Linux +/dev/sdc3 4196352 6293503 2097152 1G 83 Linux +/dev/sdc4 6293504 20971519 14678016 7G 5 Extended +/dev/sdc5 6295552 8392703 2097152 1G 83 Linux + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### 如何使用 fdisk 命令删除分区？ + +如果我们不再使用某个分区，请按照下面的步骤删除它。 + +请确保你输入了正确的分区号。在这里，我准备删除 `/dev/sdc2` 分区： + +```shell +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): d +Partition number (1-5, default 5): 2 + +Partition 2 has been deleted. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +Disklabel type: dos +Disk identifier: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux +/dev/sdc3 4196352 6293503 2097152 1G 83 Linux +/dev/sdc4 6293504 20971519 14678016 7G 5 Extended +/dev/sdc5 6295552 8392703 2097152 1G 83 Linux + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### 如何在 Linux 下格式化分区或建立文件系统？ + +在计算时，文件系统控制了数据的储存方式，并通过 索引节点Inode Tables 来检索数据。如果没有文件系统，操作系统是无法找到信息储存的位置的。 + +在此，我准备在 `/dev/sdc1` 上创建分区。有三种方式创建文件系统： + +```shell +$ sudo mkfs.ext4 /dev/sdc1 +或 +$ sudo mkfs -t ext4 /dev/sdc1 +或 +$ sudo mke2fs /dev/sdc1 + +mke2fs 1.43.5 (04-Aug-2017) +Creating filesystem with 262144 4k blocks and 65536 inodes +Filesystem UUID: c0a99b51-2b61-4f6a-b960-eb60915faab0 +Superblock backups stored on blocks: + 32768, 98304, 163840, 229376 + +Allocating group tables: done +Writing inode tables: done +Creating journal (8192 blocks): done +Writing superblocks and filesystem accounting information: done +``` + +当你在分区上建立文件系统时，以下重要信息会同时被创建： + + * `Filesystem UUID:` UUID 代表了通用且独一无二的识别符，UUID 在 Linux 中通常用来识别设备。它 128 位长的数字代表了 32 个十六进制数。 + * `Superblock:` 超级块储存了文件系统的元数据。如果某个文件系统的超级块被破坏，我们就无法挂载它了（也就是说无法访问其中的文件了）。 + * `Inode:` Inode 是类 Unix 系统中文件系统的数据结构，它储存了所有除名称以外的文件信息和数据。 + * `Journal:` 日志式文件系统包含了用来修复电脑意外关机产生下错误信息的日志。 + +### 如何在 Linux 中挂载分区？ + +在你创建完分区和文件系统之后，我们需要挂载它们以便使用。我们需要创建一个挂载点来挂载分区，使用 `mkdir` 来创建一个挂载点。 + +```shell +$ sudo mkdir -p /mnt/2g-new +``` + +如果你希望进行临时挂载，请使用下面的命令。在计算机重启之后，你会丢失这个挂载点。 + +```shell +$ sudo mount /dev/sdc1 /mnt/2g-new +``` + +如果你希望永久挂载某个分区，请将分区详情加入 `fstab` 文件。我们既可以输入设备名称，也可以输入 UUID。 + +使用设备名称来进行永久挂载： + +``` +# vi /etc/fstab + +/dev/sdc1 /mnt/2g-new ext4 defaults 0 0 +``` + +使用 UUID 来进行永久挂载（请使用 `blkid` 来获取 UUID）： + +``` +$ sudo blkid +/dev/sdc1: UUID="d17e3c31-e2c9-4f11-809c-94a549bc43b7" TYPE="ext2" PARTUUID="8cc8f9e5-01" +/dev/sda1: UUID="d92fa769-e00f-4fd7-b6ed-ecf7224af7fa" TYPE="ext4" PARTUUID="eab59449-01" +/dev/sdc3: UUID="ca307aa4-0866-49b1-8184-004025789e63" TYPE="ext4" PARTUUID="8cc8f9e5-03" +/dev/sdc5: PARTUUID="8cc8f9e5-05" + +# vi /etc/fstab + +UUID=d17e3c31-e2c9-4f11-809c-94a549bc43b7 /mnt/2g-new ext4 defaults 0 0 +``` + +使用 `df` 命令亦可： + +``` +$ df -h +Filesystem Size Used Avail Use% Mounted on +udev 969M 0 969M 0% /dev +tmpfs 200M 7.0M 193M 4% /run +/dev/sda1 20G 16G 3.0G 85% / +tmpfs 997M 0 997M 0% /dev/shm +tmpfs 5.0M 4.0K 5.0M 1% /run/lock +tmpfs 997M 0 997M 0% /sys/fs/cgroup +tmpfs 200M 28K 200M 1% /run/user/121 +tmpfs 200M 25M 176M 13% /run/user/1000 +/dev/sdc1 1008M 1.3M 956M 1% /mnt/2g-new +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/linux-fdisk-command-to-manage-disk-partitions/ + +作者：[Magesh Maruthamuthu][a] +选题：[lujun9972][b] +译者：[zhs852](https://github.com/zhs852) +校对：[wxy](https://github.com/wxy) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/magesh/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/how-to-manage-disk-partitions-using-parted-command/ +[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[3]: https://www.2daygeek.com/wp-content/uploads/2019/01/linux-fdisk-command-to-manage-disk-partitions-1a.png diff --git a/sources/talk/20171222 10 keys to quick game development.md b/sources/talk/20171222 10 keys to quick game development.md deleted file mode 100644 index 50c8164ae0..0000000000 --- a/sources/talk/20171222 10 keys to quick game development.md +++ /dev/null @@ -1,100 +0,0 @@ -XYenChi is translating -10 keys to quick game development -====== -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/computer_keyboard_laptop_development_code_woman.png?itok=vbYz6jjb) - -In early October, the inaugural [Open Jam][1] sponsored by Opensource.com drew 45 entries from teams located around the world. The teams had just three days to create a game using open source software to enter into the competition, and [three teams came out on top][2]. - -We hosted our own Open Jam event at our university for anyone who wanted to participate. We reserved a computer lab for the weekend and taught people how to use open source software--[Godot][3] for the game engine, [LMMS][4] for music creation, [GIMP][5] for 2D art, and [Blender][6] for 3D art--to create games and game art assets. Three games were submitted from our event: [Loathsome][7], [Lost Artist][8], and [Paint Rider][9] (which I created). - -From my experience with game jams and game development in general, here are 10 lessons I've learned about game engines, coding, and rapid game development. - -## 1\. Narrow your scope - -It's easy to get carried away with ideas to make an expansive adventure game or something that compares to your favorite game. Pursuing that outside of a game jam can be awesome, once you have some experience, but don't overestimate what you have time for. What I love about game jams is they force you to focus on getting a game from the conceptual stage to a final product quickly, since you have such a limited amount of time. This is why narrowing your scope is so important. - -The theme for Open Jam was "Leave a Mark." As soon as it was announced, my friends and I started brainstorming games that could fit that theme. One idea was a 3D boxing game where the player left bruises on their enemy. I had very little experience making 3D games and, while I would have loved to get better at them, I probably would have spent too much time learning how to get all the textures situated and hit boxes working before I could even start to figure out what would make a fun game. - -## 2\. Have something playable very early - -This is my favorite advice for game jams. Try to come up with the core mechanics and code them to a working state quickly so you can test them and decide whether it's worthy of making a full game. You shouldn't be hours away from the deadline and still trying to get your game playable. For a three-day jam like Open Jam, it shouldn't take more than a few hours to have some sort of demo running. - -## 3\. Keep it simple - -Every feature that you want to include extends your total development time. You never know if committing to a feature will lead to a major time sink because you just can't quite get it to work. Arcade-style high-score games typically work well for game jams because they're usually simple by nature. Once you've finished the core, you can start adding features and polish without having to worry whether you'll have a functioning game in the end. - -## 4\. Take inspiration from other games - -You may be tempted to create something totally original, but having models to base your work on is extremely helpful. It will decrease the time it takes to come up with the mechanics, since you'll already have an idea of what is fun. Remind yourself that the more experience you have under your belt, the easier it is to create that massive game you have so many ideas for, so you might as well practice by trying to recreate things other people have done. - -Considering Open Jam's "Leave a Mark" theme, I thought it would be fun to create a game where you leave a trail of paint as you played, so you could see the mark you left. I remembered the old Flash game [Line Rider 2 Beta][10] (hence the name Paint Rider), and about the secret feature where you could draw a track if you held the Control button down while you played. I simplified that concept even more by requiring only one button for vertical movement (much like old helicopter games). About an hour or two into the jam, I had a basic demo where you could move up or down with one button and leave a trail of little black circles. - -## 5\. Don't overlook accessibility - -Make sure as many people as possible can play your game. One of the games submitted to Open Jam was a virtual-reality game. As cool as that was, hardly anyone was able to play it, because not many people have a VR device. Luckily, its developer didn't expect it would do well in the ratings, and instead considered it practice. But, if you want to share your game with lots of people (or win game jams), it's important to pay attention to accessibility. - -Godot (and most other game engines) allow you to export your game to all major platforms. When submitting a game specifically to [Itch.io][11], having an in-browser version will allow most people to play it. But always look into exporting to as many platforms and operating systems as you can. I even tried exporting Paint Rider to mobile, but technical difficulties got in the way. - -## 6\. Don't make it too difficult - -If your game takes too much effort to learn or play, you'll lose a portion of your audience. This aligns nicely with keeping your game simple and within scope, and it puts even more importance on the game planning phase. Again, it's easy to come up with an epic game idea you could spend weeks or months developing; it's harder to come up with a good, simple game. - -I showed Paint Rider to my Mom and she was able to play it immediately. I don't think I need to say anything more about that. - -## 7\. Don't be too neat - -If you're used to taking your time applying design patterns everywhere and making sure that your code will be reusable and readable, try to loosen up a bit. If you spend too much time worrying about design, when you finally get to the point when you can play your game, you may find out it's not very fun. By then, it's too late to make changes. - -This process is also used for prototyping more serious games: You quickly code up messy proof-of-concept demos until you find one that's worth making into a full game, then you dive into building a perfect code base to support it. Creating a game for a game jam is like quickly coding up a proof of concept. - -## 8\. But don't be too messy, either - -On the other hand, [spaghetti code][12] can easily get out of control, even if there's not a ton of code in a game. Luckily, most game engines are built with design patterns in mind. Take Godot's [Signals][13] functionality, which allows nodes to send messages with data to nodes they've been "connected" with--it's the [observer pattern][14] automatically baked into your design. As long as you know how to take advantage of the game engine's features, you should be able to code quickly without making your code too painful to look at. - -## 9\. Get feedback - -Show people what you're working on. Have them try it out and see what they say about it. Watch how they play your game and see if they find something you didn't expect. If the game jam has a [Discord][15] channel or something similar, post your game there, or bounce your ideas off people. One of Paint Rider's defining features is that the canvas loops, so you see the paint you left before. I hadn't even considered that mechanic until someone asked me why the game didn't have it. - -Working on a team will ensure that there are other people built into the process who can pass feedback around. - -And don't forget to help other people out in the same way; it's a win-win if you realize something that could help your game while you're playing someone else's game. - -## 10\. Know where to find resources - -Creating all your own assets can really slow you down. During Open Jam, I noticed that Loathsome's developer was spending multiple hours drawing the main character while I was busy incorporating new features and fixing bugs. You could simplify your art style for the game and still come up with something that looks and sounds good, but there are other options. Try looking for assets in [Creative Commons][16] or on free music sites like [Anttis Instrumentals][17]. Or, if possible, form a team with a dedicated artist, writer, or musician. - -Other software you might find useful includes [Krita][18], an open source 2D image creator that's nice for digital painting, especially if you have a drawing tablet, and [sfxr][19], a game sound-effect creator that has a lot of parameters to play with, but as its creator says: "Basic usage involves hitting the randomize button." (All sound effects in Paint Rider were made with Sfxr.) You can also check out [Calinou][20]'s large and neatly organized list of open source game development software. - -Have you participated in Open Jam or another a game jam and have other advice? Or do you have questions I didn't address? If so, please share them in the comments. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/17/12/10-keys-rapid-open-source-game-development - -作者：[Ryan Estes][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/figytuna -[1]:https://itch.io/jam/open-jam-1 -[2]:https://opensource.com/article/17/11/open-jam -[3]:https://godotengine.org/ -[4]:https://lmms.io/ -[5]:https://www.gimp.org/ -[6]:https://www.blender.org/ -[7]:https://astropippin.itch.io/loathsome -[8]:https://masonraus.itch.io/lost-artist -[9]:https://figytuna.itch.io/paint-rider -[10]:http://www.andkon.com/arcade/racing/lineriderbeta2/ -[11]:https://itch.io/ -[12]:https://en.wikipedia.org/wiki/Spaghetti_code -[13]:http://kidscancode.org/blog/2017/03/godot_101_07/ -[14]:https://en.wikipedia.org/wiki/Observer_pattern -[15]:https://discordapp.com/ -[16]:https://creativecommons.org/ -[17]:http://www.soundclick.com/bands/default.cfm?bandID=1277008 -[18]:https://krita.org/en/ -[19]:http://www.drpetter.se/project_sfxr.html -[20]:https://notabug.org/Calinou/awesome-gamedev/src/master/README.md diff --git a/sources/talk/20180206 Building Slack for the Linux community and adopting snaps.md b/sources/talk/20180206 Building Slack for the Linux community and adopting snaps.md deleted file mode 100644 index 3f4774ba74..0000000000 --- a/sources/talk/20180206 Building Slack for the Linux community and adopting snaps.md +++ /dev/null @@ -1,75 +0,0 @@ -Building Slack for the Linux community and adopting snaps -====== -![][1] - -Used by millions around the world, [Slack][2] is an enterprise software platform that allows teams and businesses of all sizes to communicate effectively. Slack works seamlessly with other software tools within a single integrated environment, providing an accessible archive of an organisation’s communications, information and projects. Although Slack has grown at a rapid rate in the 4 years since their inception, their desktop engineering team who work across Windows, MacOS and Linux consists of just 4 people currently. We spoke to Felix Rieseberg, Staff Software Engineer, who works on this team following the release of Slack’s first [snap last month][3] to discover more about the company’s attitude to the Linux community and why they decided to build a snap. - -[Install Slack snap][4] - -### Can you tell us about the Slack snap which has been published? - -We launched our first snap last month as a new way to distribute to our Linux community. In the enterprise space, we find that people tend to adopt new technology at a slower pace than consumers, so we will continue to offer a .deb package. - -### What level of interest do you see for Slack from the Linux community? - -I’m excited that interest for Slack is growing across all platforms, so it is hard for us to say whether the interest coming out of the Linux community is different from the one we’re generally seeing. However, it is important for us to meet users wherever they do their work. We have a dedicated QA engineer focusing entirely on Linux and we really do try hard to deliver the best possible experience. - -We generally find it is a little harder to build for Linux, than say Windows, as there is a less predictable base to work from – and this is an area where the Linux community truly shines. We have a fairly large number of users that are quite helpful when it comes to reporting bugs and hunting root causes down. - -### How did you find out about snaps? - -Martin Wimpress at Canonical reached out to me and explained the concept of snaps. Honestly, initially I was hesitant – even though I use Ubuntu – because it seemed like another standard to build and maintain. However, once understanding the benefits I was convinced it was a worthwhile investment. - -### What was the appeal of snaps that made you decide to invest in them? - -Without doubt, the biggest reason we decided to build the snap is the updating feature. We at Slack make heavy use of web technologies, which in turn allows us to offer a wide variety of features – like the integration of YouTube videos or Spotify playlists. Much like a browser, that means that we frequently need to update the application. - -On macOS and Windows, we already had a dedicated auto-updater that doesn’t require the user to even think about updates. We have found that any sort of interruption, even for an update, is an annoyance that we’d like to avoid. Therefore, the automatic updates via snaps seemed far more seamless and easy. - -### How does building snaps compare to other forms of packaging you produce? How easy was it to integrate with your existing infrastructure and process? - -As far as Linux is concerned, we have not tried other “new” packaging formats, but we’ll never say never. Snaps were an easy choice given that the majority of our Linux customers do use Ubuntu. The fact that snaps also run on other distributions was a decent bonus. I think it is really neat how Canonical is making snaps cross-distro rather than focusing on just Ubuntu. - -Building it was surprisingly easy: We have one unified build process that creates installers and packages – and our snap creation simply takes the .deb package and churns out a snap. For other technologies, we sometimes had to build in-house tools to support our buildchain, but the `snapcraft` tool turned out to be just the right thing. The team at Canonical were incredibly helpful to push it through as we did experience a few problems along the way. - -### How do you see the store changing the way users find and install your software? - -What is really unique about Slack is that people don’t just stumble upon it – they know about it from elsewhere and actively try to find it. Therefore, our levels of awareness are already high but having the snap available in the store, I hope, will make installation a lot easier for our users. - -We always try to do the best for our users. The more convinced we become that it is better than other installation options, the more we will recommend the snap to our users. - -### What are your expectations or already seen savings by using snaps instead of having to package for other distros? - -We expect the snap to offer more convenience for our users and ensure they enjoy using Slack more. From our side, the snap will save time on customer support as users won’t be stuck on previous versions which will naturally resolve a lot of issues. Having the snap is an additional bonus for us and something to build on, rather than displacing anything we already have. - -### What release channels (edge/beta/candidate/stable) in the store are you using or plan to use, if any? - -We used the edge channel exclusively in the development to share with the team at Canonical. Slack for Linux as a whole is still in beta, but long-term, having the options for channels is interesting and being able to release versions to interested customers a little earlier will certainly be beneficial. - -### How do you think packaging your software as a snap helps your users? Did you get any feedback from them? - -Installation and updating generally being easier will be the big benefit to our users. Long-term, the question is “Will users that installed the snap experience less problems than other customers?” I have a decent amount of hope that the built-in dependencies in snaps make it likely. - -### What advice or knowledge would you share with developers who are new to snaps? - -I would recommend starting with the Debian package to build your snap – that was shockingly easy. It also starts the scope smaller to avoid being overwhelmed. It is a fairly small time investment and probably worth it. Also if you can, try to find someone at Canonical to work with – they have amazing engineers. - -### Where do you see the biggest opportunity for development? - -We are taking it step by step currently – first get people on the snap, and build from there. People using it will already be more secure as they will benefit from the latest updates. - --------------------------------------------------------------------------------- - -via: https://insights.ubuntu.com/2018/02/06/building-slack-for-the-linux-community-and-adopting-snaps/ - -作者：[Sarah][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://insights.ubuntu.com/author/sarahfd/ -[1]:https://insights.ubuntu.com/wp-content/uploads/a115/Slack_linux_screenshot@2x-2.png -[2]:https://slack.com/ -[3]:https://insights.ubuntu.com/2018/01/18/canonical-brings-slack-to-the-snap-ecosystem/ -[4]:https://snapcraft.io/slack/ diff --git a/sources/talk/20180319 6 common questions about agile development practices for teams.md b/sources/talk/20180319 6 common questions about agile development practices for teams.md deleted file mode 100644 index ef472374b4..0000000000 --- a/sources/talk/20180319 6 common questions about agile development practices for teams.md +++ /dev/null @@ -1,60 +0,0 @@ -translated by lixinyuxx -6 common questions about agile development practices for teams -====== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/collab-team-pair-programming-code-keyboard.png?itok=kBeRTFL1) -"Any questions?" - -You’ve probably heard a speaker ask this question at the end of their presentation. This is the most important part of the presentation—after all, you didn't attend just to hear a lecture but to participate in a conversation and a community. - -Recently I had the opportunity to hear my fellow Red Hatters present a session called "[Agile in Practice][1]" to a group of technical students at a local university. During the session, software engineer Tomas Tomecek and agile practitioners Fernando Colleone and Pavel Najman collaborated to explain the foundations of agile methodology and showcase best practices for day-to-day activities. - -### 1\. What is the perfect team size? - -Knowing that students attended this session to learn what agile practice is and how to apply it to projects, I wondered how the students' questions would compare to those I hear every day as an agile practitioner at Red Hat. It turns out that the students asked the same questions as my colleagues. These questions drive straight into the core of agile in practice. - -Students wanted to know the size of a small team versus a large team. This issue is relevant to anyone who has ever teamed up to work on a project. Based on Tomas's experience as a tech leader, 12 people working on a project would be considered a large team. In the real world, team size is not often directly correlated to productivity. In some cases, a smaller team located in a single location or time zone might be more productive than a larger team that's spread around the world. Ultimately, the presenters suggested that the ideal team size is probably five people (which aligns with scrum 7, +-2). - -### 2\. What operational challenges do teams face? - -The presenters compared projects supported by local teams (teams with all members in one office or within close proximity to each other) with distributed teams (teams located in different time zones). Engineers prefer local teams when the project requires close cooperation among team members because delays caused by time differences can destroy the "flow" of writing software. At the same time, distributed teams can bring together skill sets that may not be available locally and are great for certain development use cases. Also, there are various best practices to improve cooperation in distributed teams. - -### 3\. How much time is needed to groom the backlog? - -Because this was an introductory talk targeting students who were new to agile, the speakers focused on [Scrum][2] and [Kanban][3] as ways to make agile specific for them. They used the Scrum framework to illustrate a method of writing software and Kanban for a communication and work planning system. On the question of time needed to groom a project's backlog, the speakers explained that there is no fixed rule. Rather, practice makes perfect: During the early stages of development, when a project is new—and especially if some members of the team are new to agile—grooming can consume several hours per week. Over time and with practice, it becomes more efficient. - -### 4\. Is a product owner necessary? What is their role? - -Product owners help facilitate scaling; however, what matters is not the job title, but that you have someone on your team who represents the customer's voice and goals. In many teams, especially those that are part of a larger group of engineering teams working on a single output, a lead engineer can serve as the product owner. - -### 5\. What agile tools do you suggest using? Is specific software necessary to implement Scrum or Kanban in practice? - -Although using proprietary software such as Jira or Trello can be helpful, especially when working with large numbers of contributors working on big enterprise projects, they are not required. Scrum and Kanban can be done with tools as simple as paper cards. The key is to have a clear source of information and strong communication across the entire team. That said, two excellent open source kanban tools are [Taiga][4] and [Wekan][5]. For more information, see [5 open source alternatives to Trello][6] and [Top 7 open source project management tools for agile teams][7]. - -### 6\. How can students use agile techniques for school projects? - -The presenters encouraged students to use kanban to visualize and outline tasks to be completed before the end of the project. The key is to create a common board so the entire team can see the status of the project. By using kanban or a similar high-visibility strategy, students won’t get to the end of the project and discover that any particular team member has not been keeping up. - -Scrum practices such as sprints and daily standups are also excellent ways to ensure that everyone is making progress and that the various parts of the project will work together at the end. Regular check-ins and information-sharing are also essential. To learn more about Scrum, see [What is scrum?][8]. - -Remember that Kanban and Scrum are just two of many tools and frameworks that make up agile. They may not be the best approach for every situation. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/3/agile-mindset - -作者：[Dominika Bula][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/dominika -[1]:http://zijemeit.cz/sessions/agile-in-practice/ -[2]:https://www.scrum.org/resources/what-is-scrum -[3]:https://en.wikipedia.org/wiki/Kanban -[4]:https://taiga.io/ -[5]:https://wekan.github.io/ -[6]:https://opensource.com/alternatives/trello -[7]:https://opensource.com/article/18/2/agile-project-management-tools -[8]:https://opensource.com/resources/scrum diff --git a/sources/talk/20180809 Two Years With Emacs as a CEO (and now CTO).md b/sources/talk/20180809 Two Years With Emacs as a CEO (and now CTO).md deleted file mode 100644 index 3e1f5d1eb2..0000000000 --- a/sources/talk/20180809 Two Years With Emacs as a CEO (and now CTO).md +++ /dev/null @@ -1,86 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Two Years With Emacs as a CEO (and now CTO)) -[#]: via: (https://www.fugue.co/blog/2018-08-09-two-years-with-emacs-as-a-cto.html) -[#]: author: (Josh Stella https://www.fugue.co/blog/author/josh-stella) - -Two Years With Emacs as a CEO (and now CTO) -====== - -Two years ago, I wrote [a blog post][1] that got some notice, which surprised me. It was a piece about going back to Emacs as my primary content creation tool, first as a CEO, and now as a CTO. A brief recap is that I spent most of my career as a programmer and a software architect, and preferred Emacs as my code editor for much of that time. Reconsidering Emacs was an experiment that I was excited about, but wasn't sure how it would work out. On the Internet, the post was met with roughly equal parts disdain and appreciation, but tens of thousands of people read it, so it seems that I touched on something interesting. Some of the more challenging and funny posts on [Reddit][2] and [HackerNews][3] predicted that I'd have hands shaped like claws or that I'd have lost my eyesight because I use white backgrounds. I'm pleased to report that no dire consequences resulted, and in fact my wrists are thanking me for the decision. Some folks worried that using Emacs would be a cognitive drain on a CEO. Having taken Fugue from an idea in my backyard to a powerful product with great and enthusiastic customers, I find Emacs to be a solace from things that are actually difficult. I still use white backgrounds. - -Recently, the post was rediscovered and posted to [HackerNews][4]. I got a number of requests to follow up with a post on how things have gone since, so this is that report. In this post, I will also focus on why Emacs and functional programming are highly relevant now; and how Emacs works with our product, Fugue, that uses functional programming to automate cloud computing. I received a lot of feedback that the level of detail and color commentary were useful, so this post is also fairly verbose and I do spend some effort on explaining my thinking. I've recently moved from the CEO to CTO role here at Fugue, but the content of this post reflects the work I have been doing as CEO. I expect to do more work in code with Emacs going forward, so I have some yak shaving ahead. As always, YMMV, caveat emptor, etc. - -### It worked out better than I suspected it would - -My time is filled with nearly constant communication outside of and within the company. Communication is how things get done in the world, and the enemy of reflection and real contemplation of difficult or complex problems. The rarest commodity for me as a startup CEO is time to focus without distraction. Emacs is particularly good for this, once you've invested the time to learn a handful of commands. Other applications call out to be noticed, but a well configured Emacs gets out of the way both visually and mentally. It doesn't change unless you want it to, and there is no cleaner interface than a blank screen and beautiful typography. In my world of constant interruption, this simplicity allows me to focus solely on what I am thinking rather than the computer. The best programs provide access to the computer without demanding attention. - -A few folks pointed out that the original post was as much a criticism of modern computer interfaces as a recommendation of Emacs. I agree and disagree. Modern interfaces, and particularly their application-centric approach (vs. content-centric), are not user focused or task oriented. Emacs avoids this fallacy, which is part of why I like it so much, but it brings other merits to the table as well. Emacs is a portal into the power of the computer itself, and that is a rabbit hole worth descending. Its idioms are paths to discovering and creating your own, and that for me is the definition of creativity. One of the sad things about modern computing is that it is largely made up of black boxes with shiny interfaces that provide momentary gratification rather than real satisfaction. This makes us into consumers rather than creators/makers of technology. I don't care who you are or what your background is; you can understand your computer, and you can make things with it. It's fun, satisfying, and not as hard as you think to get started! - -We often underappreciate the effects of our environments on our psychology. Emacs imparts a feeling of calm and freedom, rather than of urgency, annoyance, or excitement - the latter of which are enemies of thought and contemplation. I like things that last, get out of the way, and provide insight when I do take the time to pay attention to them. Emacs meets all these criteria for me. I use Emacs every day for content creation, and I'm very pleased with how little I think about it. Emacs does have a learning curve, but it's no steeper than a bicycle, and has a similar payoff in that once you are through it, you don't have to think about it anymore, and it imparts a feeling of freedom that other tools don't. It's an elegant tool, from a more civilized age. I'm happy that we seem to be entering another civilized age in computing, and so Emacs is gaining in popularity. - -### I gave up on using Org-mode for schedules and to-do lists - -I spent some words in the original post on using Org-mode for schedules. I gave up on using Org-mode for to dos and the like, as I have to coordinate many meetings and calls every day with dozens of people, and I cannot ask the rest of the world to adapt to my choice of tools, nor do I have the time to transcribe or automate moving things to Org. We are primarily a Mac shop, use Google Calendar etc., and the native Mac OS/iOS tools do a good job for collaboration. I also use a plain old pen for note-taking during meetings, as I find laptop/keyboard use in meetings to be rude and limiting to my ability to listen and think. Therefore I've largely abandoned the idea that Emacs/org can help me with my schedule or organizing my life. Org-mode is great for lots of other things too though, and is my go-to for writing documents, including this one. In other words, I use it largely in ways the author didn't intend, and it's great at them. I hope someone says the same of our work at Fugue someday. - -### Emacs use has spread at Fugue - -I started the original post with an admonition that you may love Emacs, but will probably hate it. I was therefore a little concerned when the documentation team at Fugue picked it as their standard tool, as I thought perhaps they were influenced by my appreciation for it. A couple years later, I'm pretty sure that it was a good call for them. The leader of the team at the time was a very bright programmer, but the two writers we hired to make the Fugue documentation had less technical backgrounds. I figured that if it was a case of a manager imposing the wrong tool, I'd hear about it and it would resolve itself, as Fugue has an anti-authoritarian culture where people are unafraid to call bullshit on anything or anyone, including me. The original manager left Fugue last year, but the docs team now has a slick, integrated CI/CD toolchain for [docs.fugue.co][5], and they've become enthusiastic Emacs users. There is a learning curve for Emacs, but it's not that tall even if it is steep, and climbing it has real benefits in productivity and general happiness. It was also a reminder that liberal arts focused people are every bit as smart and capable with technology as programmers, and perhaps less prone to technology religions and tribalism. - -### My wrists are thanking me - -I've been spending 12 hours a day or so at a computer since the mid-eighties, and it has taken a toll on my wrists (as well as my back, for which I unreservedly recommend the Tag Capisco chair). The combination of Emacs and an ergonomic keyboard has made the RSI wrist issues go away to the point that I haven't thought about it in over a year. Prior to that, I was having daily pain, particularly in my right wrist, and if you've had this issue, you know it can be very distracting and worrying. A few folks asked about keyboards and mice, so if you're interested I'm currently using a [keyboard.io][6] though I've mainly used a Truly Ergonomic keyboard over the last couple years. I'm a few weeks into using the keyboard.io, and I absolutely love it. The shaped key caps are amazing for knowing where you are without looking, and the thumb keys seem obvious in retrospect, particularly for Emacs, where Control and Meta are your constant companions. No more using the pinkie for highly repetitive tasks! - -The amount of mousing I do is much lower than when using Office and IDEs, and that has helped a lot, but I do still need a mouse. I've been using the rather dated looking but highly functional and ergonomic Clearly Superior trackball, which lives up to its name. - -Specific tools aside, the main point is that a great keyboard combined with mouse avoidance has proved very effective at reducing wear and tear on my body. Emacs is central to this because I don't have to mouse around menus to get things done, and the navigation keys are right under my fingers. I'm pretty convinced now that hand movement away from the standard typing position causes a lot of tendon stress for me. YMMV, I'm not a doctor, etc. - -### I haven't done much to my config... - -Some predicted that I'd spend a lot of time yak shaving my configuration. I wondered if they were right, so I paid attention. Not only have I left my config largely alone, paying attention to the issue has made me realize just how much the other tools I use demand my attention and time. Emacs is easily the lowest maintenance piece of software I use. Mac OS and Windows are constantly demanding that I update them, but that's far less intrusive than Adobe Suite and Office's update intrusions in my world. I do occasionally update my Emacs, but it still works the same way, so it's largely a near zero cost operation for me, and one I can choose to do when I please. - -I'm sorry to disappoint, as a number of folks wanted to know what I've done to keep up with a renewed Emacs community and its output, but I've only added a few things to my config over the last two years. I consider this a success, as Emacs is a tool, not a hobby for me. That said, I'd love to hear about new things if you want to share. - -### ...Except for controlling the cloud - -We have a lot of Emacs fans at Fugue, so we've had a [Ludwig-mode][7] for a while now. Ludwig is our declarative, functional DSL for automating cloud infrastructure and services. Recently, Alex Schoof took some flight and evening hours to build fugue-mode, which acts as an Emacs console over the Fugue CLI. If you aren't familiar with Fugue, we make a cloud automation and governance tool that leverages functional programming to give users a great experience of interacting with cloud APIs. Well, it does a lot more than that, but it does that too. Fugue-mode is cool for a number of reasons. It allows me to have a buffer that is constantly reporting on the status of my cloud infrastructure, and since I often modify that infrastructure, I can quickly see the effects of my coding. Fugue organizes cloud workloads into processes, and Fugue-mode is a lot like top for cloud workloads. It also allows me to perform operations like creating new infrastructure or deleting stuff that isn't needed anymore, without much typing. Fugue-mode is a prototype, but it's pretty handy and I now use it regularly. - -![fugue-mode-edited.gif][8] - -### Modes and monitors - -I have added a few modes and integrations, but not really for work/CEO functions. I've been hacking around in Haskell and Scheme on the weekends for fun, so I've added haskell-mode and geiser. Emacs is great for languages that have a REPL, as you can divide up your screen into different "windows" that are running different modes, including REPLs or shells. Geiser is great for Scheme, and if you've not done so, working through SICP is a joy and possibly a revelation in an age that has lots of examples of cargo cult programming. Install MIT Scheme and geiser and you've got something that feels a bit like the Symbolics environments of lore. - -This brings up another topic I didn't cover in the 2015 post: screen management. I like to use a single portrait mode monitor for writing, and I have this configuration at my home and at my primary office. For programming or mixed use, I like the new ultra-wide monitors that we provide to all Fuguers. For these, I prefer to divide my screen into three columns, with the center having my main editing buffer, the left side having a shell and a fugue-mode buffer divided horizontally, and the right having either a documentation buffer or another editing buffer or two. This is easily done by first using 'Ctl-x 3' twice, then 'Ctl-x =' to make the windows equal in width. This will give you three equal columns that you can further subdivide as you like with 'Ctl-x 2' for horizontal divisions. Here's a screenshot of what this looks like. - -![Emacs Screen Shot][9] - -### This will be my last CEO/Emacs post... - -The first reason for this is that I'm now the CTO of Fugue, but also because there are so many topics I'm looking forward to blogging about and now I should have time to do so. I'm planning on doing some deeper dive posts on topics like functional programming, type safety for infrastructure-as-code, and as we roll out some awesome new Fugue capabilities, some posts on what is achievable on the cloud using Fugue. - --------------------------------------------------------------------------------- - -via: https://www.fugue.co/blog/2018-08-09-two-years-with-emacs-as-a-cto.html - -作者：[Josh Stella][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.fugue.co/blog/author/josh-stella -[b]: https://github.com/lujun9972 -[1]: https://blog.fugue.co/2015-11-11-guide-to-emacs.html -[2]: https://www.reddit.com/r/emacs/comments/7efpkt/a_ceos_guide_to_emacs/ -[3]: https://news.ycombinator.com/item?id=10642088 -[4]: https://news.ycombinator.com/item?id=15753150 -[5]: https://docs.fugue.co/ -[6]: https://shop.keyboard.io/ -[7]: https://github.com/fugue/ludwig-mode -[8]: https://www.fugue.co/hubfs/Imported_Blog_Media/fugue-mode-edited-1.gif -[9]: https://www.fugue.co/hs-fs/hubfs/Emacs%20Screen%20Shot.png?width=929&name=Emacs%20Screen%20Shot.png diff --git a/sources/talk/20190108 Hacking math education with Python.md b/sources/talk/20190108 Hacking math education with Python.md deleted file mode 100644 index 111b306c7a..0000000000 --- a/sources/talk/20190108 Hacking math education with Python.md +++ /dev/null @@ -1,84 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Hacking math education with Python) -[#]: via: (https://opensource.com/article/19/1/hacking-math) -[#]: author: (Don Watkins https://opensource.com/users/don-watkins) - -Hacking math education with Python -====== -Teacher, programmer, and author Peter Farrell explains why teaching math with Python works better than the traditional approach. -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/getting_started_with_python.png?itok=MFEKm3gl) - -Mathematics instruction has a bad reputation, especially with people (like me) who've had trouble with the traditional approach, which emphasizes rote memorization and theory that seems far removed from students' real world. - -While teaching a student who was baffled by his math lessons, [Peter Farrell][1], a Python developer and mathematics teacher, decided to try using Python to teach the boy the math concepts he was having trouble learning. - -Peter was inspired by the work of [Seymour Papert][2], the father of the Logo programming language, which lives on in Python's [Turtle module][3]. The Turtle metaphor hooked Peter on Python and using it to teach math, much like [I was drawn to Python][4]. - -Peter shares his approach in his new book, [Math Adventures with Python][5]: An Illustrated Guide to Exploring Math with Code. And, I recently interviewed him to learn more about it. - -**Don Watkins:** What is your background? - -**Peter Farrell:** I was a math teacher for eight years, and I tutored math for 10 years after that. When I was a teacher, I read Papert's [Mindstorms][6] and was inspired to introduce all my math classes to Logo and Turtles. - -**DW:** Why did you start using Python? - -**PF:** I was working with a homeschooled boy on a very dry, textbook-driven math curriculum, which at the time seemed like a curse to me. But I found ways to sneak in the Logo Turtles, and he was a programming fan, so he liked that. Once we got into functions and real programming, he asked if we could continue in Python. I didn't know any Python but it didn't seem that different from Logo, so I agreed. And I never looked back! - -I was also looking for a 3D graphics package I could use to model a solar system and lead students through making planets move and get pulled by the force of attraction between the bodies, according to Newton's formula. Many graphics packages required programming in C or something hard, but I found an excellent package called Visual Python that was very easy to use. I used [VPython][7] for years after that. - -So, I was introduced to Python in the context of working with a student on math. For some time after that, he was my programming tutor while I was his math tutor! - -**DW:** What got you interested in math? - -**PF:** I learned it the old-fashioned way: by hand, on paper and blackboards. I was good at manipulating symbols, so algebra was never a problem, and I liked drawing and graphing, so geometry and trig could be fun, too. I did some programming in BASIC and Fortran in college, but it never inspired me. Later on, programming inspired me greatly! I'm still tickled by the way programming makes easy work of the laborious stuff you have to do in math class, freeing you up to do the more fun of exploring, graphing, tweaking, and discovering. - -**DW:** What inspired you to consider your Python approach to math? - -**PF:** When I was teaching the homeschooled student, I was amazed at what we could do by writing a simple function and then calling it a bunch of times with different values using a loop. That would take a half an hour by hand, but the computer spit it out instantly! Then we could look for patterns (which is what a math student should be doing), express the pattern as a function, and extend it further. - -**DW:** How does your approach to teaching help students—especially those who struggle with math? How does it make math more relevant? - -**PF:** Students, especially high-schoolers, question the need to be doing all this calculating, graphing, and solving by hand in the 21st century, and I don't disagree with them. Learning to use Excel, for example, to crunch numbers should be seen as a basic necessity to work in an office. Learning to code, in any language, is becoming a very valuable skill to companies. So, there's a real-world appeal to me. - -But the idea of making art with code can revolutionize math class. Just putting a shape on a screen requires math—the position (x-y coordinates), the dimensions, and even the color are all numbers. If you want something to move or change, you'll need to use variables, and not the "guess what x equals" kind of variable. You'll vary the position using a variable or, more efficiently, using a vector. [This makes] math topics like vectors and matrices seen as helpful tools you can use, rather than required information you'll never use. - -Students who struggle with math might just be turned off to "school math," which is heavy on memorization and following rules and light on creativity and real applications. They might find they're actually good at math, just not the way it was taught in school. I've had parents see the cool graphics their kids have created with code and say, "I never knew that's what sines and cosines were used for!" - -**DW:** How do you see your approach to math and programming encouraging STEM in schools? - -**PF:** I love the idea of combining previously separated topics into an idea like STEM or STEAM! Unfortunately for us math folks, the "M" is very often neglected. I see lots of fun projects being done in STEM labs, even by very young children, and they're obviously getting an education in technology, engineering, and science. But I see precious little math material in the projects. STEM/[mechatronics][8] teacher extraordinaire Ken Hawthorn and I are creating projects to try to remedy that. - -Hopefully, my book helps encourage students, girls and boys, to get creative with technology, real and virtual. There are a lot of beautiful graphics in the book, which I hope will inspire people to go through the coding adventure and make them. All the software I use ([Python Processing][9]) is available for free and can be easily installed, or is already installed, on the Raspberry Pi. Entry into the STEM world should not be cost-prohibitive to schools or individuals. - -**DW:** What would you like to share with other math teachers? - -**PF:** If the math establishment is really serious about teaching students the standards they have agreed upon, like numerical reasoning, logic, analysis, modeling, geometry, interpreting data, and so on, they're going to have to admit that coding can help with every single one of those goals. My approach was born, as I said before, from just trying to enrich a dry, traditional approach, and I think any teacher can do that. They just need somebody who can show them how to do everything they're already doing, just using code to automate the laborious stuff. - -My graphics-heavy approach is made possible by the availability of free graphics software. Folks might need to be shown where to find these packages and how to get started. But a math teacher can soon be leading students through solving problems using 21st-century technology and visualizing progress or results and finding more patterns to pursue. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/19/1/hacking-math - -作者：[Don Watkins][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/don-watkins -[b]: https://github.com/lujun9972 -[1]: https://twitter.com/hackingmath -[2]: https://en.wikipedia.org/wiki/Seymour_Papert -[3]: https://en.wikipedia.org/wiki/Turtle_graphics -[4]: https://opensource.com/life/15/8/python-turtle-graphics -[5]: https://nostarch.com/mathadventures -[6]: https://en.wikipedia.org/wiki/Mindstorms_(book) -[7]: http://vpython.org/ -[8]: https://en.wikipedia.org/wiki/Mechatronics -[9]: https://processing.org/ diff --git a/sources/talk/20190114 Remote Working Survival Guide.md b/sources/talk/20190114 Remote Working Survival Guide.md deleted file mode 100644 index 42b151f4cb..0000000000 --- a/sources/talk/20190114 Remote Working Survival Guide.md +++ /dev/null @@ -1,130 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Remote Working Survival Guide) -[#]: via: (https://www.jonobacon.com/2019/01/14/remote-working-survival/) -[#]: author: (Jono Bacon https://www.jonobacon.com/author/admin/) - -Remote Working Survival Guide -====== -![](https://www.jonobacon.com/wp-content/uploads/2019/01/5b5471d7eadb585ec8b8a0c3_featureimage-remotejob-1080x675.jpg) - -Remote working seems to be all the buzz. Apparently, [70% of professionals work from home at least once a week][1]. Similarly, [77% of people work more productively][2] and [68% of millennials would consider a company more if they offered remote working][3]. It seems to make sense: technology, connectivity, and culture seem to be setting the world up more and more for remote working. Oh, and home-brewed coffee is better than ever too. - -Now, I am going to write another piece for how companies should optimize for remote working (so make sure you [Join As a Member][4] to stay tuned — it is free). - -Today though I want to **share recommendations for how individuals can do remote working well themselves**. Whether you are a full-time remote worker or have the option of working from home a few days a week, this article should hopefully be helpful. - -Now, you need to know that **remote working is not a panacea**. Sure, it seems like hanging around at home in your jimjams, listening to your antisocial music, and sipping on buckets of coffee is perfect, but it isn’t for everyone. - -Some people need the structure of an office. Some people need the social element of an office. Some people need to get out the house. Some people lack the discipline to stay focused at home. Some people are avoiding the government coming and knocking on the door due to years of unpaid back taxes. - -**Remote working is like a muscle: it can bring enormous strength and capabilities IF you train and maintain it**. If you don’t, your results are going to vary. - -I have worked from home for the vast majority of my career. I love it. I am more productive, happier, and empowered when I work from home. I don’t dislike working in an office, and I enjoy the social element, but I am more in my “zone” when I work from home. I also love blisteringly heavy metal, which can pose a problem when the office don’t want to listen to [After The Burial][5]. - -![][6] -“Squirrel.” -[Credit][7] - -I have learned how I need to manage remote work, using the right balance of work routine, travel, and other elements, and here are some of my recommendations. Be sure to **share yours in the comments**. - -### 1\. You need discipline and routine (and to understand your “waves”) - -Remote work really is a muscle that needs to be trained. Just like building actual muscle, there needs to be a clear routine and a healthy dollop of discipline mixed in. - -Always get dressed (no jimjams). Set your start and end time for your day (I work 9am – 6pm most days). Choose your lunch break (mine is 12pm). Choose your morning ritual (mine is email followed by a full review of my client needs). Decide where your main workplace will be (mine is my home office). Decide when you will exercise each day (I do it at 5pm most days). - -**Design a realistic routine and do it for 66 days**. It takes this long to build a habit. Try not to deviate from the routine. The more you stick the routine, the less work it will seem further down the line. By the end of the 66 days it will feel natural and you won’t have to think about it. - -Here’s the deal though, we don’t live in a vacuum ([cleaner, or otherwise][8]). We all have waves. - -A wave is when you need a change of routine to mix things up. For example, in summertime I generally want more sunlight. I will often work outside in the garden. Near the holidays I get more distracted, so I need more structure in my day. Sometimes I just need more human contact, so I will work from coffee shops for a few weeks. Sometimes I just fancy working in the kitchen or on the couch. You need to learn your waves and listen to your body. **Build your habit first, and then modify it as you learn your waves**. - -### 2\. Set expectations with your management and colleagues - -Not everyone knows how to do remote working, and if your company is less familiar with remote working, you especially need to set expectations with colleagues. - -This can be pretty simple: **when you have designed your routine, communicate it clearly to your management and team**. Let them know how they can get hold of you, how to contact you in an emergency, and how you will be collaborating while at home. - -The communication component here is critical. There are some remote workers who are scared to leave their computer for fear that someone will send them a message while they are away (and they are worried people may think they are just eating Cheetos and watching Netflix). - -You need time away. You need to eat lunch without one eye on your computer. You are not a 911 emergency responder. **Set expectations that sometimes you may not be immediately responsive, but you will get back to them as soon as possible**. - -Similarly, set expectations on your general availability. For example, I set expectations with clients that I generally work from 9am – 6pm every day. Sure, if a client needs something urgently, I am more than happy to respond outside of those hours, but as a general rule I am usually working between those hours. This is necessary for a balanced life. - -### 3\. Distractions are your enemy and they need managing - -We all get distracted. It is human nature. It could be your young kid getting home and wanting to play Rescue Bots. It could be checking Facebook, Instagram, or Twitter to ensure you don’t miss any unwanted political opinions or photos of people’s lunches. It could be that there is something else going on your life that is taking your attention (such as an upcoming wedding, event, or big trip.) - -**You need to learn what distracts you and how to manage it**. For example, I know I get distracted by my email and Twitter. I check it religiously and every check gets me out of the zone of what I am working on. I also get distracted by grabbing coffee and water, which then may turn into a snack and a YouTube video. - -![][9] -My nemesis for distractions. - -The digital distractions have a simple solution: **lock them out**. Close down the tabs until you complete what you are doing. I do this all the time with big chunks of work: I lock out the distractions until I am done. It requires discipline, but all of this does. - -The human elements are tougher. If you have a family you need to make it clear that when you are work, you need to be generally left alone. This is why a home office is so important: you need to set boundaries that mum or dad is working. Come in if there is emergency, but otherwise they need to be left alone. - -There are all kinds of opportunities for locking these distractions out. Put your phone on silent. Set yourself as away. Move to a different room (or building) where the distraction isn’t there. Again, be honest in what distracts you and manage it. If you don’t, you will always be at their mercy. - -### 4\. Relationships need in-person attention - -Some roles are more attuned to remote working than others. For example, I have seen great work from engineering, quality assurance, support, security, and other teams (typically more focused on digital collaboration). Other teams such as design or marketing often struggle more in remote environments (as they are often more tactile.) - -With any team though, having strong relationship is critical, and in-person discussion, collaboration, and socializing is essential to this. So many of our senses (such as body language) are removed in a digital environment, and these play a key role in how we build trust and relationships. - -![][10] -Rockets also help. - -This is especially important if (a) you are new a company and need to build these relationships, (b) are new to a role and need to build relationships with your team, or (c) are in a leadership position where building buy-in and engagement is a key part of your job. - -**The solution? A sensible mix of remote and in-person time.** If your company is nearby, work from home part of the week and at the office part of the week. If your company is further a away, schedule regular trips to the office (and set expectations with your management that you need this). For example, when I worked at XPRIZE I flew to LA every few weeks for a few days. When I worked at Canonical (who were based in London), we had sprints every three months. - -### 5\. Stay focused, but cut yourself some slack - -The crux of everything in this article is about building a capability, and developing a remote working muscle. This is as simple as building a routine, sticking to it, and having an honest view of your “waves” and distractions and how to manage them. - -I see the world in a fairly specific way: **everything we do has the opportunity to be refined and improved**. For example, I have been public speaking now for over 15 years, but I am always discovering new ways to improve, and new mistakes to fix (speaking of which, see my [10 Ways To Up Your Public Speaking Game][11].) - -There is a thrill in the discovery of new ways to get better, and to see every stumbling block and mistake as an “aha!” moment to kick ass in new and different ways. It is no different with remote working: look for patterns that help to unlock ways in which you can make your remote working time more efficient, more comfortable, and more fun. - -![][12] -Get these books. They are fantastic for personal development. -See my [$150 Personal Development Kit][13] article - -…but don’t go crazy over it. There are some people who obsesses every minute of their day about how to get better. They beat themselves up constantly for “not doing well enough”, “not getting more done”, and not meeting their internal unrealistic view of perfection. - -We are humans. We are animals, and we are not robots. Always strive to improve, but be realistic that not everything will be perfect. You are going to have some off-days or off-weeks. You are going to struggle at times with stress and burnout. You are going to handle a situation poorly remotely that would have been easier in the office. Learn from these moments but don’t obsess over them. Life is too damn short. - -**What are your tips, tricks, and recommendations? How do you manage remote working? What is missing from my recommendations? Share them in the comments box!** - - --------------------------------------------------------------------------------- - -via: https://www.jonobacon.com/2019/01/14/remote-working-survival/ - -作者：[Jono Bacon][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.jonobacon.com/author/admin/ -[b]: https://github.com/lujun9972 -[1]: https://www.cnbc.com/2018/05/30/70-percent-of-people-globally-work-remotely-at-least-once-a-week-iwg-study.html -[2]: http://www.cosocloud.com/press-release/connectsolutions-survey-shows-working-remotely-benefits-employers-and-employees -[3]: https://www.aftercollege.com/cf/2015-annual-survey -[4]: https://www.jonobacon.com/join/ -[5]: https://www.facebook.com/aftertheburial/ -[6]: https://www.jonobacon.com/wp-content/uploads/2019/01/aftertheburial2.jpg -[7]: https://skullsnbones.com/burial-live-photos-vans-warped-tour-denver-co/ -[8]: https://www.youtube.com/watch?v=wK1PNNEKZBY -[9]: https://www.jonobacon.com/wp-content/uploads/2019/01/IMG_20190114_102429-1024x768.jpg -[10]: https://www.jonobacon.com/wp-content/uploads/2019/01/15381733956_3325670fda_k-1024x576.jpg -[11]: https://www.jonobacon.com/2018/12/11/10-ways-to-up-your-public-speaking-game/ -[12]: https://www.jonobacon.com/wp-content/uploads/2019/01/DwVBxhjX4AgtJgV-1024x532.jpg -[13]: https://www.jonobacon.com/2017/11/13/150-dollar-personal-development-kit/ diff --git a/sources/talk/20190114 You (probably) don-t need Kubernetes.md b/sources/talk/20190114 You (probably) don-t need Kubernetes.md deleted file mode 100644 index a57f47959e..0000000000 --- a/sources/talk/20190114 You (probably) don-t need Kubernetes.md +++ /dev/null @@ -1,76 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (beamrolling) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (You (probably) don't need Kubernetes) -[#]: via: (https://arp242.net/weblog/dont-need-k8s.html) -[#]: author: (Martin Tournoij https://arp242.net/) - -You (probably) don't need Kubernetes -====== - -This may perhaps be an unpopular opinion, but the overwhelming majority of companies are probably better off not using k8s. - -You know those old “Hello world according to programmer skill” jokes that start with `printf("hello, world\n")` for a junior programmer and end with some convoluted Java OOP design pattern solution for senior software architect engineer? This is kind of like that. - -* Junior sysops - `./binary` -* Experienced sysops - `./binary` on EC2. -* devops - Self-deployed CI pipeline to run `./binary` on EC2. -* Senior cloud orchestration engineer - k8s orchestrated self-deployed CI pipeline to run `./binary` on E2C platform. - - - -¯\\_(ツ)_/¯ - -That doesn’t mean that Kubernetes or any of these things are bad per se, just as Java or OOP aren’t bad per se, but rather that they’re horribly misapplied in many cases, just as using several Java OOP design patterns are horribly misapplied to a hello world program. For most companies the sysops requirements are fundamentally not very complex, and applying k8s to them makes litle sense. - -Complexity creates work by its very nature, and I’m skeptical that using k8s is a time-saver for most users. It’s like spending a day on a script to automate some 10-minute task that you do once a month. That’s not a good time investment (especially since the chances are you’ll have to invest further time in the future by expanding or debugging that script at some point). - -Your deployments probably should be automated – lest you [end up like Knightmare][1] – but k8s can often be replaced by a simple shell script. - -In our own company the sysops team spent a lot of time setting up k8s. They also had to spend a lot of time on updating to a newer version a while ago (1.6 ➙ 1.8). And the result is something no one really understands without really diving in to k8s, and even then it’s hard (those YAML files, yikes!) - -Before I could debug and fix deploy issues myself. Now that’s a lot harder. I understand the basic concepts, but that’s not all that useful when actually debugging practical issues. I don’t deal with k8s often enough to justify learning this. - -That k8s is really hard is not a novel insight, which is why there are a host of “k8s made easy” solutions out there. The idea of adding another layer on top of k8s to “make it easier” strikes me as, ehh, unwise. It’s not like that complexity disappears; you’ve just hidden it. - -I have said this many times before: when determining if something is “easy” then my prime concern is not how easy something is to write, but how easy something is to debug when things fail. Wrapping k8s will not make things easier to debug, quite the opposite: it will make it even harder. - -There is a famous Blaise Pascal quote: - -> All human evil comes from a single cause, man’s inability to sit still in a room. - -k8s – and to lesser extent, Docker – seem to be an example of that. A lot of people seem lost in the excitement of the moment and are “k8s al the things!”, just as some people were lost in the excitement when Java OOP was new, so everything has to be converted from the “old” way to the “new” ones, even though the “old” ways still worked fine. - -Sometimes the IT industry is pretty silly. - -Or to summarize this post [with a Tweet][2]: - -> 2014 - We must adopt #microservices to solve all problems with monoliths -> 2016 - We must adopt #docker to solve all problems with microservices -> 2018 - We must adopt #kubernetes to solve all problems with docker - -You can mail me at [martin@arp242.net][3] or [create a GitHub issue][4] for feedback, questions, etc. - --------------------------------------------------------------------------------- - -via: https://arp242.net/weblog/dont-need-k8s.html - -作者：[Martin Tournoij][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://arp242.net/ -[b]: https://github.com/lujun9972 -[1]: https://dougseven.com/2014/04/17/knightmare-a-devops-cautionary-tale/ -[2]: https://twitter.com/sahrizv/status/1018184792611827712 -[3]: mailto:martin@arp242.net -[4]: https://github.com/Carpetsmoker/arp242.net/issues/new diff --git a/sources/talk/20190115 What happens when a veteran teacher goes to an open source conference.md b/sources/talk/20190115 What happens when a veteran teacher goes to an open source conference.md new file mode 100644 index 0000000000..e16505c36c --- /dev/null +++ b/sources/talk/20190115 What happens when a veteran teacher goes to an open source conference.md @@ -0,0 +1,68 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (What happens when a veteran teacher goes to an open source conference) +[#]: via: (https://opensource.com/open-organization/19/1/educator-at-open-source-conference) +[#]: author: (Ben Owens https://opensource.com/users/engineerteacher) + +What happens when a veteran teacher goes to an open source conference +====== +Sometimes feeling like a fish out of water is precisely what educators need. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/rh_003588_01_rd3os.combacktoschoolseriesgen_rh_032x_0.png?itok=cApG9aB4) + +"Change is going to be continual, and today is the slowest day society will ever move."—[Tony Fadell][1] + +If ever there was an experience that brought the above quotation home for me, it was my experience at the [All Things Open conference][2] in Raleigh, NC last October. Thousands of people from all over the world attended the conference, and many (if not most), worked as open source coders and developers. As one of the relatively few educators in attendance, I saw and heard things that were completely foreign to me—terms like as Istio, Stack Overflow, Ubuntu, Sidecar, HyperLedger, and Kubernetes tossed around for days. + +I felt like a fish out of water. But in the end, that was the perfect dose of reality I needed to truly understand how open principles can reshape our approach to education. + +### Not-so-strange attractors + +All Things Open attracted me to Raleigh for two reasons, both of which have to do with how our schools must do a better job of creating environments that truly prepare students for a rapidly changing world. + +The first is my belief that schools should embrace the ideals of the [open source way][3]. The second is that educators have to periodically force themselves out of their relatively isolated worlds of "doing school" in order to get a glimpse of what the world is actually doing. + +When I was an engineer for 20 years, I developed a deep sense of the power of an open exchange of ideas, of collaboration, and of the need for rapid prototyping of innovations. Although we didn't call these ideas "open source" at the time, my colleagues and I constantly worked together to identify and solve problems using tools such as [Design Thinking][4] so that our businesses remained competitive and met market demands. When I became a science and math teacher at a small [public school][5] in rural Appalachia, my goal was to adapt these ideas to my classrooms and to the school at large as a way to blur the lines between a traditional school environment and what routinely happens in the "real world." + +Through several years of hard work and many iterations, my fellow teachers and I were eventually able to develop a comprehensive, school-wide project-based learning model, where students worked in collaborative teams on projects that [made real connections][6] between required curriculum and community-based applications. Doing so gave these students the ability to develop skills they can use for a lifetime, rather than just on the next test—skills such as problem solving, critical thinking, oral and written communication, perseverance through setbacks, and adapting to changing conditions, as well as how to have routine conversations with adult mentors form the community. Only after reading [The Open Organization][7] did I realize that what we had been doing essentially embodied what Jim Whitehurst had described. In our case, of course, we applied open principles to an educational context (that model, called Open Way Learning, is the subject of a [book][8] published in December). + +I felt like a fish out of water. But in the end, that was the perfect dose of reality I needed to truly understand how open principles can reshape our approach to education. + +As good as this model is in terms of pushing students into a relevant, engaging, and often unpredictable learning environments, it can only go so far if we, as educators who facilitate this type of project-based learning, do not constantly stay abreast of changing technologies and their respective lexicon. Even this unconventional but proven approach will still leave students ill-prepared for a global, innovation economy if we aren't constantly pushing ourselves into areas outside our own comfort zones. My experience at the All Things Open conference was a perfect example. While humbling, it also forced me to confront what I didn't know so that I can learn from it to help the work I do with other teachers and schools. + +### A critical decision + +I made this point to others when I shared a picture of the All Things Open job board with dozens of colleagues all over the country. I shared it with the caption: "What did you do in your school today to prepare your students for this reality tomorrow?" The honest answer from many was, unfortunately, "not much." That has to change. + +![](https://opensource.com/sites/default/files/images/open-org/owens_1.jpg) +![](https://opensource.com/sites/default/files/images/open-org/owens_2.jpg) +(Images courtesy of Ben Owens, CC BY-SA) + +People in organizations everywhere have to make a critical decision: either embrace the rapid pace of change that is a fact of life in our world or face the hard reality of irrelevance. Our systems in education are at this same crossroads—even ones who think of themselves as being innovative. It involves admitting to students, "I don't know, but I'm willing to learn." That's the kind of teaching and learning experience our students deserve. + +It can happen, but it will take pioneering educators who are willing to move away from comfortable, back-of-the-book answers to help students as they work on difficult and messy challenges. You may very well be a veritable fish out of water. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/open-organization/19/1/educator-at-open-source-conference + +作者：[Ben Owens][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/engineerteacher +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Tony_Fadell +[2]: https://allthingsopen.org/ +[3]: https://opensource.com/open-source-way +[4]: https://dschool.stanford.edu/resources-collections/a-virtual-crash-course-in-design-thinking +[5]: https://www.tricountyearlycollege.org/ +[6]: https://www.bie.org/about/what_pbl +[7]: https://www.redhat.com/en/explore/the-open-organization-book +[8]: https://www.amazon.com/Open-Up-Education-Learning-Transform/dp/1475842007/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=&sr= diff --git a/sources/talk/20190121 Booting Linux faster.md b/sources/talk/20190121 Booting Linux faster.md new file mode 100644 index 0000000000..ef79351e0e --- /dev/null +++ b/sources/talk/20190121 Booting Linux faster.md @@ -0,0 +1,54 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Booting Linux faster) +[#]: via: (https://opensource.com/article/19/1/booting-linux-faster) +[#]: author: (Stewart Smith https://opensource.com/users/stewart-ibm) + +Booting Linux faster +====== +Doing Linux kernel and firmware development leads to lots of reboots and lots of wasted time. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/tux_linux_penguin_code_binary.jpg?itok=TxGxW0KY) +Of all the computers I've ever owned or used, the one that booted the quickest was from the 1980s; by the time your hand moved from the power switch to the keyboard, the BASIC interpreter was ready for your commands. Modern computers take anywhere from 15 seconds for a laptop to minutes for a small home server to boot. Why is there such a difference in boot times? + +A microcomputer from the 1980s that booted straight to a BASIC prompt had a very simple CPU that started fetching and executing instructions from a memory address immediately upon getting power. Since these systems had BASIC in ROM, there was no loading time—you got to the BASIC prompt really quickly. More complex systems of that same era, such as the IBM PC or Macintosh, took a significant time to boot (~30 seconds), although this was mostly due to having to read the operating system (OS) off a floppy disk. Only a handful of seconds were spent in firmware before being able to load an OS. + +Modern servers typically spend minutes, rather than seconds, in firmware before getting to the point of booting an OS from disk. This is largely due to modern systems' increased complexity. No longer can a CPU just come up and start executing instructions at full speed; we've become accustomed to CPU frequency scaling, idle states that save a lot of power, and multiple CPU cores. In fact, inside modern CPUs are a surprising number of simpler CPUs that help start the main CPU cores and provide runtime services such as throttling the frequency when it gets too hot. On most CPU architectures, the code running on these cores inside your CPU is provided as opaque binary blobs. + +On OpenPOWER systems, every instruction executed on every core inside the CPU is open source software. On machines with [OpenBMC][1] (such as IBM's AC922 system and Raptor's TALOS II and Blackbird systems), this extends to the code running on the Baseboard Management Controller as well. This means we can get a tremendous amount of insight into what takes so long from the time you plug in a power cable to the time a familiar login prompt is displayed. + +If you're part of a team that works on the Linux kernel, you probably boot a lot of kernels. If you're part of a team that works on firmware, you're probably going to boot a lot of different firmware images, followed by an OS to ensure your firmware still works. If we can reduce the hardware's boot time, these teams can become more productive, and end users may be grateful when they're setting up systems or rebooting to install firmware or OS updates. + +Over the years, many improvements have been made to Linux distributions' boot time. Modern init systems deal well with doing things concurrently and on-demand. On a modern system, once the kernel starts executing, it can take very few seconds to get to a login prompt. This handful of seconds are not the place to optimize boot time; we have to go earlier: before we get to the OS. + +On OpenPOWER systems, the firmware loads an OS by booting a Linux kernel stored in the firmware flash chip that runs a userspace program called [Petitboot][2] to find the disk that holds the OS the user wants to boot and [kexec][3][()][3] to it. This code reuse leverages the efforts that have gone into making Linux boot quicker. Even so, we found places in our kernel config and userspace where we could improve and easily shave seconds off boot time. With these optimizations, booting the Petitboot environment is a single-digit percentage of boot time, so we had to find more improvements elsewhere. + +Before the Petitboot environment starts, there's a prior bit of firmware called [Skiboot][4], and before that there's [Hostboot][5]. Prior to Hostboot is the [Self-Boot Engine][6], a separate core on the die that gets a single CPU core up and executing instructions out of Level 3 cache. These components are where we can make the most headway in reducing boot time, as they take up the overwhelming majority of it. Perhaps some of these components aren't optimized enough or doing as much in parallel as they could be? + +Another avenue of attack is reboot time rather than boot time. On a reboot, do we really need to reinitialize all the hardware? + +Like any modern system, the solutions to improving boot (and reboot) time have been a mixture of doing more in parallel, dealing with legacy, and (arguably) cheating. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/booting-linux-faster + +作者：[Stewart Smith][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/stewart-ibm +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/OpenBMC +[2]: https://github.com/open-power/petitboot +[3]: https://en.wikipedia.org/wiki/Kexec +[4]: https://github.com/open-power/skiboot +[5]: https://github.com/open-power/hostboot +[6]: https://github.com/open-power/sbe +[7]: https://linux.conf.au/schedule/presentation/105/ +[8]: https://linux.conf.au/ diff --git a/sources/talk/20190123 Book Review- Fundamentals of Linux.md b/sources/talk/20190123 Book Review- Fundamentals of Linux.md new file mode 100644 index 0000000000..5e0cffd9bc --- /dev/null +++ b/sources/talk/20190123 Book Review- Fundamentals of Linux.md @@ -0,0 +1,74 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Book Review: Fundamentals of Linux) +[#]: via: (https://itsfoss.com/fundamentals-of-linux-book-review) +[#]: author: (John Paul https://itsfoss.com/author/john/) + +Book Review: Fundamentals of Linux +====== + +There are many great books that cover the basics of what Linux is and how it works. Today, I will be taking a look at one such book. Today, the subject of our discussion is [Fundamentals of Linux][1] by Oliver Pelz and is published by [PacktPub][2]. + +[Oliver Pelz][3] has over ten years of experience as a software developer and a system administrator. He holds a degree in bioinformatics. + +### What is the book ‘Fundamentals of Linux’ about? + +![Fundamental of Linux books][4] + +As can be guessed from the title, the goal of Fundamentals of Linux is to give the reader a strong foundation from which to learn about the Linux command line. The book is a little over two hundred pages long, so it only focuses on teaching the everyday tasks and problems that users commonly encounter. The book is designed for readers who want to become Linux administrators. + +The first chapter starts out by giving an overview of virtualization. From there the author instructs how to create a virtual instance of [CentOS][5] in [VirtualBox][6], how to clone it, and how to use snapshots. You will also learn how to connect to the virtual machines via SSH. + +The second chapter covers the basics of the Linux command line. This includes shell globbing, shell expansion, how to work with file names that contain spaces or special characters. It also explains how to interpret a command’s manual page, as well as, how to use `sed`, `awk`, and to navigate the Linux file system. + +The third chapter takes a more in-depth look at the Linux file system. You will learn how files are linked in Linux and how to search for them. You will also be given an overview of users, groups and file permissions. Since the chapter focuses on interacting with files, it tells how to read text files from the command line, as well as, an overview of how to use the VIM editor. + +Chapter four focuses on using the command line. It covers important commands, such as `cat`, `sort`, `awk`. `tee`, `tar`, `rsync`, `nmap`, `htop` and more. You will learn what processes are and how they communicate with each other. This chapter also includes an introduction to Bash shell scripting. + +The fifth and final chapter covers networking on Linux and other advanced command line concepts. The author discusses how Linux handles networking and gives examples using multiple virtual machines. He also covers how to install new programs and how to set up a firewall. + +### Thoughts on the book + +Fundamentals of Linux might seem short at five chapters and a little over two hundred pages. However, quite a bit of information is covered. You are given everything that you need to get going on the command line. + +The book’s sole focus on the command line is one thing to keep in mind. You won’t get any information on how to use a graphical user interface. That is partially because Linux has so many different desktop environments and so many similar system applications that it would be hard to write a book that could cover all of the variables. It is also partially because the book is aimed at potential Linux administrators. + +I was kinda surprised to see that the author used [CentOS][7] to teach Linux. I would have expected him to use a more common Linux distro, like Ubuntu, Debian, or Fedora. However, because it is a distro designed for servers very little changes over time, so it is a very stable basis for a course on Linux basics. + +I’ve used Linux for over half a decade. I spent most of that time using desktop Linux. I dove into the terminal when I needed to, but didn’t spend lots of time there. I have performed many of the actions covered in this book using a mouse. Now, I know how to do the same things via the terminal. It won’t change the way I do my tasks, but it will help me understand what goes on behind the curtain. + +If you have either just started using Linux or are planning to do so in the future, I would not recommend this book. It might be a little overwhelming. If you have already spent some time with Linux or can quickly grasp the technical language, this book may very well be for you. + +If you think this book is apt for your learning needs, you can get the book from the link below: + +We will be trying to review more Linux books in coming months so stay tuned with us. + +What is your favorite introductory book on Linux? Let us know in the comments below. + +If you found this article interesting, please take a minute to share it on social media, Hacker News or [Reddit][8]. + + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/fundamentals-of-linux-book-review + +作者：[John Paul][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/john/ +[b]: https://github.com/lujun9972 +[1]: https://www.packtpub.com/networking-and-servers/fundamentals-linux +[2]: https://www.packtpub.com/ +[3]: http://www.oliverpelz.de/index.html +[4]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/fundamentals-of-linux-book-review.jpeg?resize=800%2C450&ssl=1 +[5]: https://centos.org/ +[6]: https://www.virtualbox.org/ +[7]: https://www.centos.org/ +[8]: http://reddit.com/r/linuxusersgroup diff --git a/sources/tech/20091104 Linux-Unix App For Prevention Of RSI (Repetitive Strain Injury).md b/sources/tech/20091104 Linux-Unix App For Prevention Of RSI (Repetitive Strain Injury).md deleted file mode 100644 index 989f54d45a..0000000000 --- a/sources/tech/20091104 Linux-Unix App For Prevention Of RSI (Repetitive Strain Injury).md +++ /dev/null @@ -1,142 +0,0 @@ -Translating By Guevaraya - -Linux/Unix App For Prevention Of RSI (Repetitive Strain Injury) -====== -![workrave-image][1] - -[A repetitive strain injury][2] (RSI) is occupational overuse syndrome, non-specific arm pain or work related upper limb disorder. RSI caused from overusing the hands to perform a repetitive task, such as typing, writing, or clicking a mouse. Unfortunately, most people do not understand what RSI is or how dangerous it can be. You can easily prevent RSI using open source software called Workrave. - - -### What are the symptoms of RSI? - -I'm quoting from this [page][3]. Do you experience: - - 1. Fatigue or lack of endurance? - 2. Weakness in the hands or forearms? - 3. Tingling, numbness, or loss of sensation? - 4. Heaviness: Do your hands feel like dead weight? - 5. Clumsiness: Do you keep dropping things? - 6. Lack of strength in your hands? Is it harder to open jars? Cut vegetables? - 7. Lack of control or coordination? - 8. Chronically cold hands? - 9. Heightened awareness? Just being slightly more aware of a body part can be a clue that something is wrong. - 10. Hypersensitivity? - 11. Frequent self-massage (subconsciously)? - 12. Sympathy pains? Do your hands hurt when someone else talks about their hand pain? - - - -### How to reduce your risk of Developing RSI - - * Take breaks, when using your computer, every 30 minutes or so. Use software such as workrave to prevent RSI. - * Regular exercise can prevent all sort of injuries including RSI. - * Use good posture. Adjust your computer desk and chair to support muscles necessary for good posture. - - - -### Workrave - -Workrave is a free open source software application intended to prevent computer users from developing RSI or myopia. The software periodically locks the screen while an animated character, "Miss Workrave," walks the user through various stretching exercises and urges them to take a coffee break. The program frequently alerts you to take micro-pauses, rest breaks and restricts you to your daily limit. The program works under MS-Windows and Linux, UNIX-like operating systems. - -#### Install workrave - -Type the following [apt command][4]/[apt-get command][5] under a Debian / Ubuntu Linux: -`$ sudo apt-get install workrave` -Fedora Linux user should type the following dnf command: -`$ sudo dnf install workrave` -RHEL/CentOS Linux user should enable EPEL repo and install it using [yum command][6]: -``` -### [ **tested on a CentOS/RHEL 7.x and clones** ] ### -$ sudo yum install epel-release -$ sudo yum install https://rpms.remirepo.net/enterprise/remi-release-7.rpm -$ sudo yum install workrave -``` -Arch Linux user type the following pacman command to install it: -`$ sudo pacman -S workrave` -FreeBSD user can install it using the following pkg command: -`# pkg install workrave` -OpenBSD user can install it using the following pkg_add command -``` -$ doas pkg_add workrave -``` - -#### How to configure workrave - -Workrave works as an applet which is a small application whose user interface resides within a panel. You need to add workrave to panel to control behavior and appearance of the software. - -##### Adding a New Workrave Object To Panel - - * Right-click on a vacant space on a panel to open the panel popup menu. - * Choose Add to Panel. - * The Add to Panel dialog opens.The available panel objects are listed alphabetically, with launchers at the top. Select workrave applet and click on Add button. - -![Fig.01: Adding an Object \(Workrave\) to a Panel][7] -Fig.01: Adding an Object (Workrave) to a Panel - -##### How Do I Modify Properties Of Workrave Software? - -To modify the properties of an object workrave, perform the following steps: - - * Right-click on the workrave object to open the panel object popup. - * Choose Preference. Use the Properties dialog to modify the properties as required. - -![](https://www.cyberciti.biz/media/new/tips/2009/11/linux-gnome-workwave-preferences-.png) -Fig.02: Modifying the Properties of The Workrave Software - -#### Workrave in Action - -The main window shows the time remaining until it suggests a pause. The windows can be closed and you will the time remaining on the panel itself: -![Fig.03: Time reaming counter ][8] -Fig.03: Time reaming counter - -![Fig.04: Miss Workrave - an animated character walks you through various stretching exercises][9] -Fig.04: Miss Workrave - an animated character walks you through various stretching exercises - -The break prelude window, bugging you to take a micro-pause: -![Fig.05: Time for a micro-pause remainder ][10] -Fig.05: Time for a micro-pause remainder - -![Fig.06: You can skip Micro-break ][11] -Fig.06: You can skip Micro-break - -##### References: - - 1. [Workrave project][12] home page. - 2. [pokoy][13] lightweight daemon that helps prevent RSI and other computer related stress. - 3. [A Pomodoro][14] timer for GNOME 3. - 4. [RSI][2] from the wikipedia. - - - -### about the author - -The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on [Twitter][15], [Facebook][16], [Google+][17]. - --------------------------------------------------------------------------------- - -via: https://www.cyberciti.biz/tips/repetitive-strain-injury-prevention-software.html - -作者：[Vivek Gite][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://www.cyberciti.biz/ -[1]:https://www.cyberciti.biz/media/new/tips/2009/11/workrave-image.jpg (workrave-image) -[2]:https://en.wikipedia.org/wiki/Repetitive_strain_injury -[3]:https://web.eecs.umich.edu/~cscott/rsi.html##symptoms -[4]:https://www.cyberciti.biz/faq/ubuntu-lts-debian-linux-apt-command-examples/ (See Linux/Unix apt command examples for more info) -[5]:https://www.cyberciti.biz/tips/linux-debian-package-management-cheat-sheet.html (See Linux/Unix apt-get command examples for more info) -[6]:https://www.cyberciti.biz/faq/rhel-centos-fedora-linux-yum-command-howto/ (See Linux/Unix yum command examples for more info) -[7]:https://www.cyberciti.biz/media/new/tips/2009/11/add-workwave-to-panel.png (Adding an Object (Workrave) to a Gnome Panel) -[8]:https://www.cyberciti.biz/media/new/tips/2009/11/screenshot-workrave.png (Workrave main window shows the time remaining until it suggests a pause.) -[9]:https://www.cyberciti.biz/media/new/tips/2009/11/miss-workrave.png (Miss Workrave Sofrware character walks you through various RSI stretching exercises ) -[10]:https://www.cyberciti.biz/media/new/tips/2009/11/time-for-micro-pause.gif (Workrave RSI Software Time for a micro-pause remainder ) -[11]:https://www.cyberciti.biz/media/new/tips/2009/11/Micro-break.png (Workrave RSI Software Micro-break ) -[12]:http://www.workrave.org/ -[13]:https://github.com/ttygde/pokoy -[14]:http://gnomepomodoro.org -[15]:https://twitter.com/nixcraft -[16]:https://facebook.com/nixcraft -[17]:https://plus.google.com/+CybercitiBiz diff --git a/sources/tech/20120203 Computer Laboratory - Raspberry Pi- Lesson 3 OK03.md b/sources/tech/20120203 Computer Laboratory - Raspberry Pi- Lesson 3 OK03.md deleted file mode 100644 index c6724ff672..0000000000 --- a/sources/tech/20120203 Computer Laboratory - Raspberry Pi- Lesson 3 OK03.md +++ /dev/null @@ -1,383 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 3 OK03) -[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html) -[#]: author: (Robert Mullins http://www.cl.cam.ac.uk/~rdm34) - -Computer Laboratory – Raspberry Pi: Lesson 3 OK03 -====== - -The OK03 lesson builds on OK02 by teaching how to use functions in assembly to make more reusable and rereadable code. It is assumed you have the code for the [Lesson 2: OK02][1] operating system as a basis. - -### 1 Reusable Code - -So far we've made code for our operating system by typing the things we want to happen in order. This is fine for such tiny programs, but if we wrote the whole system like this, the code would be completely unreadable. Instead we use functions. - -``` -A function is a piece of code that can be reused to compute a certain kind of answer, or perform a certain action. You may also hear them called procedures, routines or subroutines. Although these are all different, people rarely use the correct term. - -You should already be happy with the concept of a function from mathematics. For example the cosine function applied to a number gives another number between -1 and 1 which is the cosine of the angle. Notationally we write cos(x) to be the cosine function applied to the value x. - -In code, functions can take multiple inputs (including none), give multiple outputs (including none), and may cause side effects. For example a function might create a file on the file system, named after the first input, with length based on the second. -``` - -![Function as black boxes][2] - -``` -Functions are said to be 'black boxes'. We put inputs in, and outputs come out, but we don't need to know how they work. -``` - -In higher level code such as C or C++, functions are part of the language itself. In assembly code, functions are just ideas we have. - -Ideally we want to be able to set our registers to some input values, branch to an address, and expect that at some point the code will branch back to our code having set the registers to output values. This is what a function is in assembly code. The difficulty comes in what system we use for setting the registers. If we just used any system we felt like, each programmer may use a different system, and would find other programmers' work hard to understand. Further, compilers would not be able to work with assembly code as easily, as they would not know how to use the functions. To prevent confusion, a standard called the Application Binary Interface (ABI) was devised for each assembly language which is an agreement on how functions should be run. If everyone makes functions in the same way, then everyone will be able to use each others' functions. I will teach that standard here, and from now on I will code all of my functions to meet the standard. - -The standard says that r0,r1,r2 and r3 will be used as inputs to a function in order. If a function needs no inputs, then it doesn't matter what value it takes. If it needs only one it always goes in r0, if it needs two, the first goes in r0, and the second goes on r1, and so on. The output will always be in r0. If a function has no output, it doesn't matter what value r0 takes. - -Further, it also requires that after a function is run, r4 to r12 must have the same values as they had when the function started. This means that when you call a function, you can be sure the r4 to r12 will not change value, but you cannot be so sure about r0 to r3. - -When a function completes it has to branch back to the code that started it. This means it must know the address of the code that started it. To facilitate this, there is a special register called lr (link register) which always holds the address of the instruction after the one that called this function. - -Table 1.1 ARM ABI register usage -| Register | Brief | Preserved | Rules | -| -------- | ------------------- | --------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -| r0 | Argument and result | No | r0 and r1 are used for passing the first two arguments to functions, and returning the results of functions. If a function does not use them for a return value, they can take any value after a function. | -| r1 | Argument and result | No | | -| r2 | Argument | No | r2 and r3 are used for passing the second two arguments to functions. There values after a function is called can be anything. | -| r3 | Argument | No | | -| r4 | General purpose | Yes | r4 to r12 are used for working values, and their value after a function is called must be the same as before. | -| r5 | General purpose | Yes | | -| r6 | General purpose | Yes | | -| r7 | General purpose | Yes | | -| r8 | General purpose | Yes | | -| r9 | General purpose | Yes | | -| r10 | General purpose | Yes | | -| r11 | General purpose | Yes | | -| r12 | General purpose | Yes | | -| lr | Return address | No | lr is the address to branch back to when a function is finished, but this does have to contain the same address after the function has finished. | -| sp | Stack pointer | Yes | sp is the stack pointer, described below. Its value must be the same after the function has finished. | - -Often functions need to use more registers than just r0 to r3. But, since r4 to r12 must stay the same after the method has run, they must be saved somewhere. We save them on something called the stack. - - -![Stack diagram][3] -``` -A stack is a metaphor we use in computing for a method of storing values. Just like in a stack of plates, you can only remove items from the top of a stack, and only add items to the top of the stack. - -The stack is a brilliant idea for storing registers on when functions are running. For example if I have a function which needs to use registers r4 and r5, it could place the current values of those registers on a stack. At the end of the method it could take them back off again. What is most clever is that if my function had to run another function in order to complete and that function needed to save some registers, it could put those on the top of the stack while it ran, and then take them off again at the end. That wouldn't affect the values of r4 and r5 that my method had to save, as they would be added to the top of the stack, and then taken off again. - -The terminology we used to refer to the values put on the stack by a particular method is that methods 'stack frame'. Not every method needs a stack frame, some don't need to store values. -``` - -Because the stack is so useful, it has been implemented in the ARMv6 instruction set directly. A special register called sp (stack pointer) holds the address of the stack. When items are added to the stack, the sp register updates so that it always holds the address of the first item on the stack. push {r4,r5} would put the values in r4 and r5 onto the top of the stack and pop {r4,r5} would take them back off again (in the correct order). - -### 2 Our First Function - -Now that we have some idea about how functions work, let's try to make one. For a basic first example, we are going to make a function that takes no input, and gives an output of the GPIO address. In the last lesson, we just wrote in this value, but it would be better as a function, since it is something we might need to do often in a real operating system, and we might not always remember the address. - -Copy the following code into a new file called 'gpio.s'. Just make the new file in the 'source' directory with 'main.s'. We're going to put all functions related to the GPIO controller in one file to make them easier to find. - -``` -.globl GetGpioAddress -GetGpioAddress: -ldr r0,=0x20200000 -mov pc,lr -``` - -``` -.globl lbl makes the label lbl accessible from other files. - -mov reg1,reg2 copies the value in reg2 into reg1. -``` - -This is a very simple complete function. The .globl GetGpioAddress command is a message to the assembler to make the label GetGpioAddress accessible to all files. This means that in our main.s file we can branch to the label GetGpioAddress even though it is not defined in that file. - -You should recognise the ldr r0,=0x20200000 command, which stores the GPIO controller address in r0. Since this is a function, we have to give the output in r0, so we are not as free to use any register as we once were. - -mov pc,lr copies the value in lr to pc. As mentioned earlier lr always contains the address of the code that we have to go back to when a method finishes. pc is a special register which always contains the address of the next instruction to be run. A normal branch command just changes the value of this register. By copying the value in lr to pc we just change the next line to be run to be the one we were told to go back to. - -A reasonable question would now be, how would we actually run this code? A special type of branch bl does what we need. It branches to a label like a normal branch, but before it does it updates lr to contain the address of the line after the branch. That means that when the function finishes, the line it will go back to will be the one after the bl command. This makes a function running just look like any other command, it simply runs, does whatever it needs to do, and then carries on to the next line. This is a really useful way of thinking about functions. We treat them as 'black boxes' in that when we use them, we don't need to think about how they work, we just need to know what inputs they need, and what outputs they give. - -For now, don't worry about using the function, we will use it in the next section. - -### 3 A Big Function - -Now we're going to implement a bigger function. Our first job was to enable output on GPIO pin 16. It would be nice if this was a function. We could simply specify a pin and a function as the input, and the function would set the function of that pin to that value. That way, we could use the code to control any GPIO pin, not just the LED. - -Copy the following commands below the GetGpioAddress function in gpio.s. - -``` -.globl SetGpioFunction -SetGpioFunction: -cmp r0,#53 -cmpls r1,#7 -movhi pc,lr -``` - -``` -Suffix ls causes the command to be executed only if the last comparison determined that the first number was less than or the same as the second. Unsigned. - -Suffix hi causes the command to be executed only if the last comparison determined that the first number was higher than the second. Unsigned. -``` - -One of the first things we should always think about when writing functions is our inputs. What do we do if they are wrong? In this function, we have one input which is a GPIO pin number, and so must be a number between 0 and 53, since there are 54 pins. Each pin has 8 functions, numbered 0 to 7 and so the function code must be too. We could just assume that the inputs will be correct, but this is very dangerous when working with hardware, as incorrect values could cause very bad side effects. Therefore, in this case, we wish to make sure the inputs are in the right ranges. - -To do this we need to check that r0 <= 53 and r1 <= 7. First of all, we can use the comparison we've seen before to compare the value of r0 with 53. The next instruction, cmpls is a normal comparison instruction that will only be run if r0 was lower than or the same as 53. If that was the case, it compares r1 with 7, otherwise the result of the comparison is the same as before. Finally we go back to the code that ran the function if the result of the last comparison was that the register was higher than the number. - -The effect of this is exactly what we want. If r0 was bigger than 53, then the cmpls command doesn't run, but the movhi does. If r0 is <= 53, then the cmpls command does run, and so r1 is compared with 7, and then if it is higher than 7, movhi is run, and the function ends, otherwise movhi does not run, and we know for sure that r0 <= 53 and r1 <= 7. - -There is a subtle difference between the ls (lower or same) and le (less or equal) as well as between hi (higher) and gt (greater) suffixes, but I will cover this later. - -Copy these commands below the above. - -``` -push {lr} -mov r2,r0 -bl GetGpioAddress -``` - -``` -push {reg1,reg2,...} copies the registers in the list reg1,reg2,... onto the top of the stack. Only general purpose registers and lr can be pushed. - -bl lbl sets lr to the address of the next instruction and then branches to the label lbl. -``` - -These next three commands are focused on calling our first method. The push {lr} command copies the value in lr onto the top of the stack, so that we can retrieve it later. We must do this because when we call GetGpioAddress, we will need to use lr to store the address to come back to in our function. - -If we did not know anything about the GetGpioAddress function, we would have to assume it changes r0,r1,r2 and r3, and would have to move our values to r4 and r5 to keep them the same after it finishes. Fortunately, we do know about GetGpioAddress, and we know it only changes r0 to the address, it doesn't affect r1,r2 or r3. Thus, we only have to move the GPIO pin number out of r0 so it doesn't get overwritten, but we know we can safely move it to r2, as GetGpioAddress doesn't change r2. - -Finally we use the bl instruction to run GetGpioAddress. Normally we use the term 'call' for running a function, and I will from now. As discussed earlier bl calls a function by updating the lr to the next instruction's address, and then branching to the function. - -When a function ends we say it has 'returned'. When the call to GetGpioAddress returns, we now know that r0 contains the GPIO address, r1 contains the function code and r2 contains the GPIO pin number. I mentioned earlier that the GPIO functions are stored in blocks of 10, so first we need to determine which block of ten our pin number is in. This sounds like a job we would use a division for, but divisions are very slow indeed, so it is better for such small numbers to do repeated subtraction. - -Copy the following code below the above. - -``` -functionLoop$: - -cmp r2,#9 -subhi r2,#10 -addhi r0,#4 -bhi functionLoop$ -``` - -``` -add reg,#val adds the number val to the contents of the register reg. -``` - -This simple loop code compares the pin number to 9. If it is higher than 9, it subtracts 10 from the pin number, and adds 4 to the GPIO Controller address then runs the check again. - -The effect of this is that r2 will now contain a number from 0 to 9 which represents the remainder of dividing the pin number by 10. r0 will now contain the address in the GPIO controller of this pin's function settings. This would be the same as GPIO Controller Address + 4 × (GPIO Pin Number ÷ 10). - -Finally, copy the following code below the above. - -``` -add r2, r2,lsl #1 -lsl r1,r2 -str r1,[r0] -pop {pc} -``` - -``` -Argument shift reg,lsl #val shifts the binary representation of the number in reg left by val before using it in the operation before. - -lsl reg,amt shifts the binary representation of the number in reg left by the number in amt. - -str reg,[dst] is the same as str reg,[dst,#0]. - -pop {reg1,reg2,...} copies the values from the top of the stack into the register list reg1,reg2,.... Only general purpose registers and pc can be popped. -``` - -This code finishes off the method. The first line is actually a multiplication by 3 in disguise. Multiplication is a big and slow instruction in assembly code, as the circuit can take a long time to come up with the answer. It is much faster sometimes to use some instructions which can get the answer quicker. In this case, I know that r2 × 3 is the same as r2 × 2 + r2. It is very easy to multiply a register by 2 as this is conveniently the same as shifting the binary representation of the number left by one place. - -One of the very useful features of the ARMv6 assembly code language is the ability to shift an argument before using it. In this case, I add r2 to the result of shifting the binary representation of r2 to the left by one place. In assembly code, you often use tricks such as this to compute answers more easily, but if you're uncomfortable with this, you could also write something like mov r3,r2; add r2,r3; add r2,r3. - -Now we shift the function value left by a number of places equal to r2. Most instructions such as add and sub have a variant which uses a register rather than a number for the amount. We perform this shift because we want to set the bits that correspond to our pin number, and there are three bits per pin. - -We then store the the computed function value at the address in the GPIO controller. We already worked out the address in the loop, so we don't need to store it at an offset like we did in OK01 and OK02. - -Finally, we can return from this method call. Since we pushed lr onto the stack, if we pop pc, it will copy the value that was in lr at the time we pushed it into pc. This would be the same as having used mov pc,lr and so the function call will return when this line is run. - -The very keen may notice that this function doesn't actually work correctly. Although it sets the function of the GPIO pin to the requested value, it causes all the pins in the same block of 10's functions to go back to 0! This would likely be quite annoying in a system which made heavy use of the GPIO pins. I leave it as a challenge to the interested to fix this function so that it does not overwrite other pins values by ensuring that all bits other than the 3 that must be set remain the same. A solution to this can be found on the downloads page for this lesson. Functions that you may find useful are and which computes the Boolean and function of two registers, mvns which computes the Boolean not and orr which computes the Boolean or. - -### 4 Another Function - -So, we now have a function which takes care of the GPIO pin function setting. We now need to make a function to turn a GPIO pin on or off. Rather than having one function for off and one function for on, it would be handy to have a single function which does either. - -We will make a function called SetGpio which takes a GPIO pin number as its first input in r0, and a value as its second in r1. If the value is 0 we will turn the pin off, and if it is not zero we will turn it on. - -Copy and paste the following code at the end of 'gpio.s'. - -``` -.globl SetGpio -SetGpio: -pinNum .req r0 -pinVal .req r1 -``` - -``` -alias .req reg sets alias to mean the register reg. -``` - -Once again we need the .globl command and the label to make the function accessible from other files. This time we're going to use register aliases. Register aliases allow us to use a name other than just r0 or r1 for registers. This may not be so important now, but it will prove invaluable when writing big methods later, and you should try to use aliases from now on. pinNum .req r0 means that pinNum now means r0 when used in instructions. - -Copy and paste the following code after the above. - -``` -cmp pinNum,#53 -movhi pc,lr -push {lr} -mov r2,pinNum -.unreq pinNum -pinNum .req r2 -bl GetGpioAddress -gpioAddr .req r0 -``` - -``` -.unreq alias removes the alias alias. -``` - -Like in SetGpioFunction the first thing we must do is check that we were actually given a valid pin number. We do this in exactly the same way by comparing pinNum (r0) with 53, and returning immediately if it is higher. Once again we wish to call GetGpioAddress, so we have to preserve lr by pushing it onto the stack, and to move pinNum to r2. We then use the .unreq statement to remove our alias from r0. Since the pin number is now stored in r2 we want our alias to reflect this, so we remove the alias from r0 and remake it on r2. You should always .unreq every alias as soon as it is done with, so that you cannot make the mistake of using it further down the code when it no longer exists. - -We then call GetGpioAddress, and we create an alias for r0 to reflect this. - -Copy and paste the following code after the above. - -``` -pinBank .req r3 -lsr pinBank,pinNum,#5 -lsl pinBank,#2 -add gpioAddr,pinBank -.unreq pinBank -``` - -``` -lsr dst,src,#val shifts the binary representation of the number in src right by val, but stores the result in dst. -``` - -The GPIO controller has two sets of 4 bytes each for turning pins on and off. The first set in each case controls the first 32 pins, and the second set controls the remaining 22. In order to determine which set it is in, we need to divide the pin number by 32. Fortunately this is very easy, at is the same as shifting the binary representation of the pin number right by 5 places. Hence, in this case I've named r3 as pinBank and then computed pinNum ÷ 32. Since it is a set of 4 bytes, we then need to multiply the result of this by 4. This is the same as shifting the binary representation left by 2 places, which is the command that follows. You may wonder if we could just shift it right by 3 places, as we went right then left. This won't work however, as some of the answer may have been rounded away when we did ÷ 32 which may not be if we just ÷ 8. - -The result of this is that gpioAddr now contains either 2020000016 if the pin number is 0-31, and 2020000416 if the pin number is 32-53. This means if we add 2810 we get the address for turning the pin on, and if we add 4010 we get the address for turning the pin off. Since we are done with pinBank, I use .unreq immediately afterwards. - -Copy and paste the following code after the above. - -``` -and pinNum,#31 -setBit .req r3 -mov setBit,#1 -lsl setBit,pinNum -.unreq pinNum -``` - -``` -and reg,#val computes the Boolean and function of the number in reg with val. -``` - -This next part of the function is for generating a number with the correct bit set. For the GPIO controller to turn a pin on or off, we give it a number with a bit set in the place of the remainder of that pin's number divided by 32. For example, to set pin 16, we need a number with the 16th bit a 1. To set pin 45 we would need a number with the 13th bit 1 as 45 ÷ 32 = 1 remainder 13. - -The and command computes the remainder we need. How it does this is that the result of an and operation is a number with 1s in all binary digits which had 1s in both of the inputs, and 0s elsewhere. This is a fundamental binary operation, and is very quick. We have given it inputs of pinNum and 3110 = 111112. This means that the answer can only have 1 bits in the last 5 places, and so is definitely between 0 and 31. Specifically it only has 1s where there were 1s in pinNum's last 5 places. This is the same as the remainder of a division by 32. It is no coincidence that 31 = 32 - 1. - -![binary division example][4] - -The rest of this code simply uses this value to shift the number 1 left. This has the effect of creating the binary number we need. - -Copy and paste the following code after the above. - -``` -teq pinVal,#0 -.unreq pinVal -streq setBit,[gpioAddr,#40] -strne setBit,[gpioAddr,#28] -.unreq setBit -.unreq gpioAddr -pop {pc} -``` - -``` -teq reg,#val checks if the number in reg is equal to val. -``` - -This code ends the method. As stated before, we turn the pin off if pinVal is zero, and on otherwise. teq (test equal) is another comparison operation that can only be used to test for equality. It is similar to cmp but it does not work out which number is bigger. If all you wish to do is test if to numbers are the same, you can use teq. - -If pinVal is zero, we store the setBit at 40 away from the GPIO address, which we already know turns the pin off. Otherwise we store it at 28, which turns the pin on. Finally, we return by popping the pc, which sets it to the value that we stored when we pushed the link register. - -### 5 A New Beginning - -Finally, after all that work we have our GPIO functions. We now need to alter 'main.s' to use them. Since 'main.s' is now getting a lot bigger and more complicated, it is better design to split it into two sections. The '.init' we've been using so far is best kept as small as possible. We can change the code to reflect this easily. - -Insert the following just after _start: in main.s: - -``` -b main - -.section .text -main: -mov sp,#0x8000 -``` - -The key change we have made here is to introduce the .text section. I have designed the makefile and linker scripts such that code in the .text section (which is the default section) is placed after the .init section which is placed at address 800016. This is the default load address and gives us some space to store the stack. As the stack exists in memory, it has to have an address. The stack grows down memory, so that each new value is at a lower address, thus making the 'top' of the stack, the lowest address. - -``` -The 'ATAGs' section in the diagram is a place where information about the Raspberry Pi is stored such as how much memory it has, and what its default screen resolution is. -``` - -![Layout diagram of operating system][5] - -Replace all the code that set the function of the GPIO pin with the following: - -``` -pinNum .req r0 -pinFunc .req r1 -mov pinNum,#16 -mov pinFunc,#1 -bl SetGpioFunction -.unreq pinNum -.unreq pinFunc -``` - -This code calls SetGpioFunction with the pin number 16 and the pin function code 1. This has the effect of enabling output to the OK LED. - -Replace any code which turns the OK LED on with the following: - -``` -pinNum .req r0 -pinVal .req r1 -mov pinNum,#16 -mov pinVal,#0 -bl SetGpio -.unreq pinNum -.unreq pinVal -``` - -This code uses SetGpio to turn off GPIO pin 16, thus turning on the OK LED. If we instead used mov pinVal,#1, it would turn the LED off. Replace your old code to turn the LED off with that. - -### 6 Onwards - -Hopefully now, you should be able to test what you have made on the Raspberry Pi. We've done a large amount of code this time, so there is a lot that can go wrong. If it does, head to the troubleshooting page. - -When you get it working, congratulations. Although our operating system does nothing more than it did in [Lesson 2: OK02][1], we've learned a lot about functions and formatting, and we can now code new features much more quickly. It would be very simple now to make an Operating System that alters any GPIO register, which could be used to control hardware! - -In [Lesson 4: OK04][6], we will address our wait function, which is currently imprecise, so that we can gain better control over our LED, and ultimately over all of the GPIO pins. - --------------------------------------------------------------------------------- - -via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html - -作者：[Robert Mullins][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.cl.cam.ac.uk/~rdm34 -[b]: https://github.com/lujun9972 -[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok02.html -[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/functions.png -[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/stack.png -[4]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/binary3.png -[5]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/osLayout.png -[6]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok04.html diff --git a/sources/tech/20120204 Computer Laboratory - Raspberry Pi- Lesson 4 OK04.md b/sources/tech/20120204 Computer Laboratory - Raspberry Pi- Lesson 4 OK04.md deleted file mode 100644 index 00fe349914..0000000000 --- a/sources/tech/20120204 Computer Laboratory - Raspberry Pi- Lesson 4 OK04.md +++ /dev/null @@ -1,161 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 4 OK04) -[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok04.html) -[#]: author: (Robert Mullins http://www.cl.cam.ac.uk/~rdm34) - -Computer Laboratory – Raspberry Pi: Lesson 4 OK04 -====== - -The OK04 lesson builds on OK03 by teaching how to use the timer to flash the 'OK' or 'ACT' LED at precise intervals. It is assumed you have the code for the [Lesson 3: OK03][1] operating system as a basis. - -### 1 A New Device - -The timer is the only way the Pi can keep time. Most computers have a battery powered clock to keep time when off. - -So far, we've only looked at one piece of hardware on the Raspberry Pi, namely the GPIO Controller. I've simply told you what to do, and it happened. Now we're going to look at the timer, and I'm going to lead you through understanding how it works. - -Just like the GPIO Controller, the timer has an address. In this case, the timer is based at 2000300016. Reading the manual, we find the following table: - -Table 1.1 GPIO Controller Registers -| Address | Size / Bytes | Name | Description | Read or Write | -| -------- | ------------ | ---------------- | ---------------------------------------------------------- | ---------------- | -| 20003000 | 4 | Control / Status | Register used to control and clear timer channel comparator matches. | RW | -| 20003004 | 8 | Counter | A counter that increments at 1MHz. | R | -| 2000300C | 4 | Compare 0 | 0th Comparison register. | RW | -| 20003010 | 4 | Compare 1 | 1st Comparison register. | RW | -| 20003014 | 4 | Compare 2 | 2nd Comparison register. | RW | -| 20003018 | 4 | Compare 3 | 3rd Comparison register. | RW | - -![Flowchart of the system timer's operation][2] - -This table tells us a lot, but the descriptions in the manual of the various fields tell us the most. The manual explains that the timer fundamentally just increments the value in Counter by 1 every 1 micro second. Each time it does so, it compares the lowest 32 bits (4 bytes) of the counter's value with the 4 comparison registers, and if it matches any of them, it updates Control / Status to reflect which ones matched. - -For more information about bits, bytes, bit fields, and data sizes expand the box below. - -``` -A bit is a name for a single binary digit. As you may recall, a single binary digit is either a 1 or a 0. - -A byte is the name we give for a collection of 8 bits. Since each bit can be one of two values, there are 28 = 256 different possible values for a byte. We normally interpret a byte as a binary number between 0 and 255 inclusive. - -![Diagram of GPIO function select controller register 0.][3] - -A bit field is another way of interpreting binary. Rather than interpreting it as a number, binary can be interpreted as many different things. A bit field treats binary as a series of switches which are either on (1) or off (0). If we have a meaning for each of these little switches, we can use them to control things. We have actually already met bitfields with the GPIO controller, with the setting a pin on or off. The bit that was a 1 was the GPIO pin to actually turn on or off. Sometimes we need more options than just on or off, so we group several of the switches together, such as with the GPIO controller function settings (pictured), in which every group of 3 bits controls one GPIO pin function. -``` - -Our goal is to implement a function that we can call with an amount of time as an input that will wait for that amount of time and then return. Think for a moment about how we could do this, given what we have. - -I see there being two options: - - 1. Read a value from the counter, and then keep branching back into the same code until the counter is the amount of time to wait more than it was. - 2. Read a value from the counter, add the amount of time to wait, store this in one of the comparison registers and then keep branching back into the same code until the Control / Status register updates. - - -``` -Issues like these are called concurrency problems, and can be almost impossible to fix. -``` - -Both of these strategies would work fine, but in this tutorial we will only implement the first. The reason is because the comparison registers are more likely to go wrong, as during the time it takes to add the wait time and store it in the comparison register, the counter may have increased, and so it would not match. This could lead to very long unintentional delays if a 1 micro second wait is requested (or worse, a 0 microsecond wait). - -### 2 Implementation - -``` -Large Operating Systems normally use the Wait function as an opportunity to perform background tasks. -``` - -I will largely leave the challenge of creating the ideal wait method to you. I suggest you put all code related to the timer in a file called 'systemTimer.s' (for hopefully obvious reasons). The complicated part about this method, is that the counter is an 8 byte value, but each register only holds 4 bytes. Thus, the counter value will span two registers. - -The following code blocks are examples. - -``` -ldrd r0,r1,[r2,#4] -``` - -``` -ldrd regLow,regHigh,[src,#val] loads 8 bytes from the address given by the number in src plus val into regLow and regHigh . -``` - -An instruction you may find useful is the ldrd instruction above. It loads 8 bytes of memory across 2 registers. In this case, the 8 bytes of memory starting at the address in r2 would be copied into r0 and r1. What is slightly complicated about this arrangement is that r1 actually holds the highest 4 bytes. In other words, if the counter had a value of 999,999,999,99910 = 11101000110101001010010100001111111111112, r1 would contain 111010002 and r0 would contain 110101001010010100001111111111112. - -The most sensible way to implement this would be to compute the difference between the current counter value and the one from when the method started, and then to compare this with the requested amount of time to wait. Conveniently, unless you wish to support wait times that were 8 bytes, the value in r1 in the example above could be discarded, and only the low 4 bytes of the counter need be used. - -When waiting you should always be sure to use higher comparisons not equality comparisons, as if you try to wait for the gap between the time the method started and the time it ends to be exactly the amount requested, you could miss the value, and wait forever. - -If you cannot figure out how to code the wait function, expand the box below for a guide. - -``` -Borrowing the idea from the GPIO controller, the first function we should write should be to get the address of this system timer. An example of this is shown below: - -.globl GetSystemTimerBase -GetSystemTimerBase: -ldr r0,=0x20003000 -mov pc,lr - -Another function that will prove useful would be one that returns the current counter value in registers r0 and r1: - -.globl GetTimeStamp -GetTimeStamp: -push {lr} -bl GetSystemTimerBase -ldrd r0,r1,[r0,#4] -pop {pc} - -This function simply uses the GetSystemTimerBase function and loads in the counter value using ldrd like we have just learned. - -Now we actually want to code our wait method. First of all, we need to know the counter value when the method started, which we can now get using GetTimeStamp. - -delay .req r2 -mov delay,r0 -push {lr} -bl GetTimeStamp -start .req r3 -mov start,r0 - -This code copies our method's input, the amount of time to delay, into r2, and then calls GetTimeStamp, which we know will return the current counter value in r0 and r1. It then copies the lower 4 bytes of the counter's value to r3. - -Next we need to compute the difference between the current counter value and the reading we just took, and then keep doing so until the gap between them is at least the size of delay. - -loop$: - -bl GetTimeStamp -elapsed .req r1 -sub elapsed,r0,start -cmp elapsed,delay -.unreq elapsed -bls loop$ - -This code will wait until the requested amount of time has passed. It takes a reading from the counter, subtracts the initial value from this reading and then compares that to the requested delay. If the amount of time that has elapsed is less than the requested delay, it branches back to loop$. - -.unreq delay -.unreq start -pop {pc} - -This code finishes off the function by returning. -``` - -### 3 Another Blinking Light - -Once you have what you believe to be a working wait function, change 'main.s' to use it. Alter everywhere you wait to set the value of r0 to some big number (remember it is in microseconds) and then test it on the Raspberry Pi. If it does not function correctly please see our troubleshooting page. - -Once it is working, congratulations you have now mastered another device, and with it, time itself. In the next and final lesson in the OK series, [Lesson 5: OK05][4] we shall use all we have learned to flash out a pattern on the LED. - --------------------------------------------------------------------------------- - -via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok04.html - -作者：[Robert Mullins][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.cl.cam.ac.uk/~rdm34 -[b]: https://github.com/lujun9972 -[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html -[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/systemTimer.png -[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/gpioControllerFunctionSelect.png -[4]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok05.html diff --git a/sources/tech/20120205 Computer Laboratory - Raspberry Pi- Lesson 5 OK05.md b/sources/tech/20120205 Computer Laboratory - Raspberry Pi- Lesson 5 OK05.md index 9eb5bf6f93..912d4c348c 100644 --- a/sources/tech/20120205 Computer Laboratory - Raspberry Pi- Lesson 5 OK05.md +++ b/sources/tech/20120205 Computer Laboratory - Raspberry Pi- Lesson 5 OK05.md @@ -1,5 +1,5 @@ [#]: collector: (lujun9972) -[#]: translator: ( ) +[#]: translator: (oska874) [#]: reviewer: ( ) [#]: publisher: ( ) [#]: url: ( ) @@ -7,88 +7,83 @@ [#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok05.html) [#]: author: (Robert Mullins http://www.cl.cam.ac.uk/~rdm34) -Computer Laboratory – Raspberry Pi: Lesson 5 OK05 +translating by ezio + +树莓派计算机实验室 课程 5 OK05 ====== -The OK05 lesson builds on OK04 using it to flash the SOS Morse Code pattern (...---...). It is assumed you have the code for the [Lesson 4: OK04][1] operating system as a basis. +OK05 课程构建于课程 OK04 的基础，使用更多代码方式烧、保存写莫尔斯码的 SOS 序列(`...---...`)。这里假设你已经有了 [课程 4: OK04][1] 操作系统的代码基础。 -### 1 Data +### 1 数据 -So far, all we've had to do with our operating system is provide instructions to be followed. Sometimes however, instructions are only half the story. Our operating systems may need data. +到目前为止，我们与操作系统有关的所有内容都提供了遵循的说明。然而有时候，说明只是一半。我们的操作系统可能需要数据 + +> 一些早期的操作系统确实只允许特定文件中的特定类型的数据，但是这通常被认为太严格了。现代方法确实使程序变得复杂的多。 + +通常，只是数据的值很重要。你可能经过训练，认为数据是指定类型，比如，一个文本文件包含文章，一个图像文件包含一幅图片，等等。说实话，这只是一个理想罢了。计算机上的全部数据都是二进制数字，重要的是我们选择用什么来解释这些数据。在这个例子中，我们会将一个闪灯序列作为数据保存下来。 + +在 `main.s` 结束处复制下面的代码： ``` -Some early Operating Systems did only allow certain types of data in certain files, but this was generally found to be too restrictive. The modern way does make programs a lot more complicated however. -``` - -In general data is just values that are important. You are probably trained to think of data as being of a specific type, e.g. a text file contains text, an image file contains an image, etc. This is, in truth, just an idea. All data on a computer is just binary numbers, how we choose to interpret them is what counts. In this example we're going to store a light flashing sequence as data. - -At the end of 'main.s' copy the following code: - -``` -.section .data -.align 2 -pattern: +.section .data %定义 .data 段 +.align 2 %对齐 +pattern: %定义整形变量 .int 0b11111111101010100010001000101010 ``` -``` -.align num ensures the address of the next line is a multiple of 2num . +>`.align num` 保证下一行代码的地址是 `2^num` 的整数倍。 -.int val outputs the number val . -``` +>`.int val` 输出数值 `val`。 -To differentiate between data and code, we put all the data in the .data. I've included this on the operating system memory layout diagram here. I've just chosen to put the data after the end of the code. The reason for keeping our data and instructions separate is so that if we eventually implement some security on our operating system, we need to know what parts of the code can be executed, and what parts can't. +要区分数据和代码，我们将数据都放在 `.data` 区域。我已经将该区域包含在操作系统的内存布局图。我已经选择将数据放到代码后面。将我们的指令和数据分开保存的原因是，如果最后我们在自己的操作系统上实现一些安全措施，我们就需要知道代码的那些部分是可以执行的，而那些部分是不行的。 -I've used two new commands here. .align and .int. .align ensures alignment of the following data to a specified power of 2. In this case I've used .align 2 which means that this data will definitely be placed at an address which is a multiple of 22 = 4. It is really important to do this, because the ldr instruction we used to read memory only works at addresses that are multiples of 4. +我在这里使用了两个新命令 `.align` 和 `.int`。`.align` 保证下来的数据是按照 2 的乘方对齐的。在这个里，我使用 `.align 2` ，意味着数据最终存放的地址是 `2^2=4` 的整数倍。这个操作是很重要的，因为我们用来读取内寸的指令 `ldr` 要求内存地址是 4 的倍数。 The .int command copies the constant after it into the output directly. That means that 111111111010101000100010001010102 will be placed into the output, and so the label pattern actually labels this piece of data as pattern. -``` -One challenge with data is finding an efficient and useful representation. This method of storing the sequence as on and off units of time is easy to run, but would be difficult to edit, as the concept of a Morse - or . is lost. -``` +命令 `.int` 直接复制它后面的常量到输出。这意味着 `11111111101010100010001000101010`(二进制数) 将会被存放到输出，所以标签模式实际将标记这段数据作为模式。 -As I mentioned, data can mean whatever you want. In this case I've encoded the Morse Code SOS sequence, which is ...---... for those unfamiliar. I've used a 0 to represent a unit of time with the LED off, and a 1 to represent a unit of time with the LED on. That way, we can write some code which just displays a sequence in data like this one, and then all we have to do to make it display a different sequence is change the data. This is a very simple example of what operating systems must do all the time; interpret and display data. +> 关于数据的一个挑战是寻找一个高效和有用的展示形式。这种保存一个开、关的时间单元的序列的方式，运行起来很容易，但是将很难编辑，因为摩尔斯的原理 `-` 或 `.` 丢失了。 -Copy the following lines before the loop$ label in 'main.s'. +如我提到的，数据可以意味这你想要的所有东西。在这里我编码了摩尔斯代码 SOS 序列，对于不熟悉的人，就是 `...---...`。我使用 0 表示一个时间单元的 LED 灭灯，而 1 表示一个时间单元的 LED 亮。这样，我们可以像这样编写一些代码在数据中显示一个序列，然后要显示不同序列，我们所有需要做的就是修改这段数据。下面是一个非常简单的例子，操作系统必须一直执行这段程序，解释和展示数据。 + +复制下面几行到 `main.s` 中的标记 `loop$` 之前。 ``` -ptrn .req r4 -ldr ptrn,=pattern -ldr ptrn,[ptrn] -seq .req r5 -mov seq,#0 +ptrn .req r4 %重命名 r4 为 ptrn +ldr ptrn,=pattern %加载 pattern 的地址到 ptrn +ldr ptrn,[ptrn] %加载地址 ptrn 所在内存的值 +seq .req r5 %重命名 r5 为 seq +mov seq,#0 %seq 赋值为 0 ``` -This code loads the pattern into r4, and loads 0 into r5. r5 will be our sequence position, so we can keep track of how much of the pattern we have displayed. +这段代码加载 `pattrern` 到寄存器 `r4`，并加载 0 到寄存器 `r5`。`r5` 将是我们的序列位置，所以我们可以追踪有多少 `pattern` 我们已经展示了。 -The following code puts a non-zero into r1 if and only if there is a 1 in the current part of the pattern. +下面的代码将非零值放入 `r1` ，如果仅仅是如果，这里有个 1 在当前位置的 `pattern`。 ``` -mov r1,#1 -lsl r1,seq -and r1,ptrn +mov r1,#1 %加载1到 r1 +lsl r1,seq %对r1 的值逻辑左移 seq 次 +and r1,ptrn %按位与 ``` -This code is useful for your calls to SetGpio, which must have a non-zero value to turn the LED off, and a value of zero to turn the LED on. +这段代码对你调用 `SetGpio` 很有用，它必须有一个非零值来关掉 LED，而一个0值会打开 LED。 -Now modify all of your code in 'main.s' so that each loop the code sets the LED based on the current sequence number, waits for 250000 micro seconds (or any other appropriate delay), and then increments the sequence number. When the sequence number reaches 32, it needs to go back to 0. See if you can implement this, and for an extra challenge, try to do it using only 1 instruction (solution in the download). +现在修改 `main.s` 中全部你的代码，这样代码中每次循环会根据当前的序列数设置 LED，等待 250000 毫秒（或者其他合适的延时），然后增加序列数。当这个序列数到达 32 就需要返回 0.看看你是否能实现这个功能，作为额外的挑战，也可以试着只使用一条指令。 -### 2 Time Flies When You're Having Fun... +### 2 Time Flies When You're Having Fun... 当你玩得开心时，过得很快 -You're now ready to test this on the Raspberry Pi. It should flash out a sequence of 3 short pulses, 3 long pulses and then 3 more short pulses. After a delay, the pattern should repeat. If it doesn't work please see our troubleshooting page. +你现在准备好在树莓派上实验。应该闪烁一串包含 3 个短脉冲，3 个长脉冲，然后 3 个更短脉冲的序列。在一次延时之后，这种模式应该重复。如果这部工作，请查看我们的问题页。 -Once it works, congratulations you have reached the end of the OK series of tutorials. +一旦它工作，祝贺你已经达到 OK 系列教程的结束。 -In this series we've learnt about assembly code, the GPIO controller and the System Timer. We've learnt about functions and the ABI, as well as several basic Operating System concepts, and also about data. +在这个谢列我们学习了汇编代码，GPIO 控制器和系统定时器。我们已经学习了函数和 ABI，以及几个基础的操作系统原理，和关于数据的知识。 -You're now ready to move onto one of the more advanced series. - - * The [Screen][2] series is next and teaches you how to use the screen with assembly code. - * The [Input][3] series teaches you how to use the keyboard and mouse. - - - -By now you already have enough information to make Operating Systems that interact with the GPIO in other ways. If you have any robot kits, you may want to try writing a robot operating system controlled with the GPIO pins! +你现在已经准备好下面几个更高级的课程的某一个。 + * [Screen][2] 系列是接下来的，会教你如何通过汇编代码使用屏幕。 + * [Input][3] 系列教授你如何使用键盘和鼠标。 + +到现在，你已经有了足够的信息来制作操作系统，用其它方法和 GPIO 交互。如果你有任何机器人工具，你可能会想尝试编写一个通过 GPIO 管教控制的机器人操作系统。 -------------------------------------------------------------------------------- @@ -96,7 +91,7 @@ via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok05.html 作者：[Robert Mullins][a] 选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) +译者：[ezio](https://github.com/oska874) 校对：[校对者ID](https://github.com/校对者ID) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/sources/tech/20140510 Managing Digital Files (e.g., Photographs) in Files and Folders.md b/sources/tech/20140510 Managing Digital Files (e.g., Photographs) in Files and Folders.md index 9a5c691e42..d1fd01ef0c 100644 --- a/sources/tech/20140510 Managing Digital Files (e.g., Photographs) in Files and Folders.md +++ b/sources/tech/20140510 Managing Digital Files (e.g., Photographs) in Files and Folders.md @@ -1,4 +1,3 @@ -Moelf translating Managing Digital Files (e.g., Photographs) in Files and Folders ====== Update 2014-05-14: added real world example diff --git a/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 10 Input01.md b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 10 Input01.md new file mode 100644 index 0000000000..beb7613b2f --- /dev/null +++ b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 10 Input01.md @@ -0,0 +1,494 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 10 Input01) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/input01.html) +[#]: author: (Alex Chadwick https://www.cl.cam.ac.uk) + +Computer Laboratory – Raspberry Pi: Lesson 10 Input01 +====== + +Welcome to the Input lesson series. In this series, you will learn how to receive inputs to the Raspberry Pi using the keyboard. We will start with just revealing the input, and then move to a more traditional text prompt. + +This first input lesson teaches some theory about drivers and linking, as well as about keyboards and ends up displaying text on the screen. + +### 1 Getting Started + +It is expected that you have completed the OK series, and it would be helpful to have completed the Screen series. Many of the files from that series will be called, without comment. If you do not have these files, or prefer to use a correct implementation, download the template for this lesson from the [Downloads][1] page. If you're using your own implementation, please remove everything after your call to SetGraphicsAddress. + +### 2 USB + +``` +The USB standard was designed to make simple hardware in exchange for complex software. +``` + +As you are no doubt aware, the Raspberry Pi model B has two USB ports, commonly used for connecting a mouse and keyboard. This was a very good design decision, USB is a very generic connector, and many different kinds of device use it. It's simple to build new devices for, simple to write device drivers for, and is highly extensible thanks to USB hubs. Could it get any better? Well, no, in fact for an Operating Systems developer this is our worst nightmare. The USB standard is huge. I really mean it this time, it is over 700 pages, before you've even thought about connecting a device. + +I spoke to a number of other hobbyist Operating Systems developers about this and they all say one thing: don't bother. "It will take too long to implement", "You won't be able to write a tutorial on it" and "It will be of little benefit". In many ways they are right, I'm not able to write a tutorial on the USB standard, as it would take weeks. I also can't teach how to write device drivers for all the different devices, so it is useless on its own. However, I can do the next best thing: Get a working USB driver, get a keyboard driver, and then teach how to use these in an Operating System. I set out searching for a free driver that would run in an operating system that doesn't even know what a file is yet, but I couldn't find one. They were all too high level. So, I attempted to write one. Everybody was right, this took weeks to do. However, I'm pleased to say I did get one that works with no external help from the Operating System, and can talk to a mouse and keyboard. It is by no means complete, efficient, or correct, but it does work. It has been written in C and the full source code can be found on the downloads page for those interested. + +So, this tutorial won't be a lesson on the USB standard (at all). Instead we'll look at how to work with other people's code. + +### 3 Linking + +``` +Linking allows us to make reusable code 'libraries' that anyone can use in their program. +``` + +Since we're about to incorporate external code into the Operating System, we need to talk about linking. Linking is a process which is applied to programs or Operating System to link in functions. What this means is that when a program is made, we don't necessarily code every function (almost certainly not in fact). Linking is what we do to make our program link to functions in other people's code. This has actually been going on all along in our Operating Systems, as the linker links together all of the different files, each of which is compiled separately. + +``` +Programs often just call libraries, which call other libraries and so on until eventually they call an Operating System library which we would write. +``` + +There are two types of linking: static and dynamic. Static linking is like what goes on when we make our Operating Systems. The linker finds all the addresses of the functions, and writes them into the code, before the program is finished. Dynamic linking is linking that occurs after the program is 'complete'. When it is loaded, the dynamic linker goes through the program and links any functions which are not in the program to libraries in the Operating System. This is one of the jobs our Operating System should eventually be capable of, but for now everything will be statically linked. + +The USB driver I have written is suitable for static linking. This means I give you the compiled code for each of my files, and then the linker finds functions in your code which are not defined in your code, and links them to functions in my code. On the [Downloads][1] page for this lesson is a makefile and my USB driver, which you will need to continue. Download them and replace the makefile in your code with this one, and also put the driver in the same folder as that makefile. + +### 4 Keyboards + +In order to get input into our Operating System, we need to understand at some level how keyboards actually work. Keyboards have two types of keys: Normal and Modifier keys. The normal keys are the letters, numbers, function keys, etc. They constitute almost every key on the keyboard. The modifiers are up to 8 special keys. These are left shift, right shift, left control, right control, left alt, right alt, left GUI and right GUI. The keyboard can detect any combination of the modifier keys being held, as well as up to 6 normal keys. Every time a key changes (i.e. is pushed or released), it reports this to the computer. Typically, keyboards also have three LEDs for Caps Lock, Num Lock and Scroll Lock, which are controlled by the computer, not the keyboard itself. Keyboards may have many more lights such as power, mute, etc. + +In order to help standardise USB keyboards, a table of values was produced, such that every keyboard key ever is given a unique number, as well as every conceivable LED. The table below lists the first 126 of values. + +Table 4.1 USB Keyboard Keys +| Number | Description | Number | Description | Number | Description | Number | Description | | +| ------ | ---------------- | ------- | ---------------------- | -------- | -------------- | --------------- | -------------------- | | +| 4 | a and A | 5 | b and B | 6 | c and C | 7 | d and D | | +| 8 | e and E | 9 | f and F | 10 | g and G | 11 | h and H | | +| 12 | i and I | 13 | j and J | 14 | k and K | 15 | l and L | | +| 16 | m and M | 17 | n and N | 18 | o and O | 19 | p and P | | +| 20 | q and Q | 21 | r and R | 22 | s and S | 23 | t and T | | +| 24 | u and U | 25 | v and V | 26 | w and W | 27 | x and X | | +| 28 | y and Y | 29 | z and Z | 30 | 1 and ! | 31 | 2 and @ | | +| 32 | 3 and # | 33 | 4 and $ | 34 | 5 and % | 35 | 6 and ^ | | +| 36 | 7 and & | 37 | 8 and * | 38 | 9 and ( | 39 | 0 and ) | | +| 40 | Return (Enter) | 41 | Escape | 42 | Delete (Backspace) | 43 | Tab | | +| 44 | Spacebar | 45 | - and _ | 46 | = and + | 47 | [ and { | | +| 48 | ] and } | 49 | \ and | | 50 | # and ~ | 51 | ; and : | +| 52 | ' and " | 53 | ` and ~ | 54 | , and < | 55 | . and > | | +| 56 | / and ? | 57 | Caps Lock | 58 | F1 | 59 | F2 | | +| 60 | F3 | 61 | F4 | 62 | F5 | 63 | F6 | | +| 64 | F7 | 65 | F8 | 66 | F9 | 67 | F10 | | +| 68 | F11 | 69 | F12 | 70 | Print Screen | 71 | Scroll Lock | | +| 72 | Pause | 73 | Insert | 74 | Home | 75 | Page Up | | +| 76 | Delete forward | 77 | End | 78 | Page Down | 79 | Right Arrow | | +| 80 | Left Arrow | 81 | Down Arrow | 82 | Up Arrow | 83 | Num Lock | | +| 84 | Keypad / | 85 | Keypad * | 86 | Keypad - | 87 | Keypad + | | +| 88 | Keypad Enter | 89 | Keypad 1 and End | 90 | Keypad 2 and Down Arrow | 91 | Keypad 3 and Page Down | | +| 92 | Keypad 4 and Left Arrow | 93 | Keypad 5 | 94 | Keypad 6 and Right Arrow | 95 | Keypad 7 and Home | | +| 96 | Keypad 8 and Up Arrow | 97 | Keypad 9 and Page Up | 98 | Keypad 0 and Insert | 99 | Keypad . and Delete | | +| 100 | \ and | | 101 | Application | 102 | Power | 103 | Keypad = | +| 104 | F13 | 105 | F14 | 106 | F15 | 107 | F16 | | +| 108 | F17 | 109 | F18 | 110 | F19 | 111 | F20 | | +| 112 | F21 | 113 | F22 | 114 | F23 | 115 | F24 | | +| 116 | Execute | 117 | Help | 118 | Menu | 119 | Select | | +| 120 | Stop | 121 | Again | 122 | Undo | 123 | Cut | | +| 124 | Copy | 125 | Paste | 126 | Find | 127 | Mute | | +| 128 | Volume Up | 129 | Volume Down | | | | | | + +The full list can be found in section 10, page 53 of [HID Usage Tables 1.12][2]. + +### 5 The Nut Behind the Wheel + +``` +These summaries and the code they describe form an API - Application Product Interface. +``` + +Normally, when you work with someone else's code, they provide a summary of their methods, what they do and roughly how they work, as well as how they can go wrong. Here is a table of the relevant instructions required to use my USB driver. + +Table 5.1 Keyboard related functions in CSUD +| Function | Arguments | Returns | Description | +| ----------------------- | ----------------------- | ----------------------- | ----------------------- | +| UsbInitialise | None | r0 is result code | This method is the all-in-one method that loads the USB driver, enumerates all devices and attempts to communicate with them. This method generally takes about a second to execute, though with a few USB hubs plugged in this can be significantly longer. After this method is completed methods in the keyboard driver become available, regardless of whether or not a keyboard is indeed inserted. Result code explained below. | +| UsbCheckForChange | None | None | Essentially provides the same effect as UsbInitialise, but does not provide the same one time initialisation. This method checks every port on every connected hub recursively, and adds new devices if they have been added. This should be very quick if there are no changes, but can take up to a few seconds if a hub with many devices is attached. | +| KeyboardCount | None | r0 is count | Returns the number of keyboards currently connected and detected. UsbCheckForChange may update this. Up to 4 keyboards are supported by default. Up to this many keyboards may be accessed through this driver. | +| KeyboardGetAddress | r0 is index | r0 is address | Retrieves the address of a given keyboard. All other functions take a keyboard address in order to know which keyboard to access. Thus, to communicate with a keyboard, first check the count, then retrieve the address, then use other methods. Note, the order of keyboards that this method returns may change after calls to UsbCheckForChange. | +| KeyboardPoll | r0 is address | r0 is result code | Reads in the current key state from the keyboard. This operates via polling the device directly, contrary to the best practice. This means that if this method is not called frequently enough, a key press could be missed. All reading methods simply return the value as of the last poll. | +| KeyboardGetModifiers | r0 is address | r0 is modifier state | Retrieves the status of the modifier keys as of the last poll. These are the shift, alt control and GUI keys on both sides. This is returned as a bit field, such that a 1 in the bit 0 means left control is held, bit 1 means left shift, bit 2 means left alt, bit 3 means left GUI and bits 4 to 7 mean the right versions of those previous. If there is a problem r0 contains 0. | +| KeyboardGetKeyDownCount | r0 is address | r0 is count | Retrieves the number of keys currently held down on the keyboard. This excludes modifier keys. Normally, this cannot go above 6. If there is an error this method returns 0. | +| KeyboardGetKeyDown | r0 is address, r1 is key number | r0 is scan code | Retrieves the scan code (see Table 4.1) of a particular held down key. Normally, to work out which keys are down, call KeyboardGetKeyDownCount and then call KeyboardGetKeyDown up to that many times with increasing values of r1 to determine which keys are down. Returns 0 if there is a problem. It is safe (but not recommended) to call this method without calling KeyboardGetKeyDownCount and interpret 0s as keys not held. Note, the order or scan codes can change randomly (some keyboards sort numerically, some sort temporally, no guarantees are made). | +| KeyboardGetKeyIsDown | r0 is address, r1 is scan code | r0 is status | Alternative to KeyboardGetKeyDown, checks if a particular scan code is among the held down keys. Returns 0 if not, or a non-zero value if so. Faster when detecting particular scan codes (e.g. looking for ctrl+c). On error, returns 0. | +| KeyboardGetLedSupport | r0 is address | r0 is LEDs | Checks which LEDs a particular keyboard supports. Bit 0 being 1 represents Number Lock, bit 1 represents Caps Lock, bit 2 represents Scroll Lock, bit 3 represents Compose, bit 4 represents Kana, bit 5 represents Power, bit 6 represents Mute and bit 7 represents Compose. As per the USB standard, none of these LEDs update automatically (e.g. Caps Lock must be set manually when the Caps Lock scan code is detected). | +| KeyboardSetLeds | r0 is address, r1 is LEDs | r0 is result code | Attempts to turn on/off the specified LEDs on the keyboard. See below for result code values. See KeyboardGetLedSupport for LEDs' values. | + +``` +Result codes are an easy way to handle errors, but often more elegant solutions exist in higher level code. +``` + +Several methods return 'result codes'. These are commonplace in C code, and are just numbers which represent what happened in a method call. By convention, 0 always indicates success. The following result codes are used by this driver. + +Table 5.2 - CSUD Result Codes +| Code | Description | +| ---- | ----------------------------------------------------------------------- | +| 0 | Method completed successfully. | +| -2 | Argument: A method was called with an invalid argument. | +| -4 | Device: The device did not respond correctly to the request. | +| -5 | Incompatible: The driver is not compatible with this request or device. | +| -6 | Compiler: The driver was compiled incorrectly, and is broken. | +| -7 | Memory: The driver ran out of memory. | +| -8 | Timeout: The device did not respond in the expected time. | +| -9 | Disconnect: The device requested has disconnected, and cannot be used. | + +The general usage of the driver is as follows: + + 1. Call UsbInitialise + 2. Call UsbCheckForChange + 3. Call KeyboardCount + 4. If this is 0, go to 2. + 5. For each keyboard you support: + 1. Call KeyboardGetAddress + 2. Call KeybordGetKeyDownCount + 3. For each key down: + 1. Check whether or not it has just been pushed + 2. Store that the key is down + 4. For each key stored: + 1. Check whether or not key is released + 2. Remove key if released + 6. Perform actions based on keys pushed/released + 7. Go to 2. + + + +Ultimately, you may do whatever you wish to with the keyboard, and these methods should allow you to access all of its functionality. Over the next 2 lessons, we shall look at completing the input side of a text terminal, similarly to most command line computers, and interpreting the commands. In order to do this, we're going to need to have keyboard inputs in a more useful form. You may notice that my driver is (deliberately) unhelpful, because it doesn't have methods to deduce whether or not a key has just been pushed down or released, it only has methods about what is currently held down. This means we'll need to write such methods ourselves. + +### 6 Updates Available + +Repeatedly checking for updates is called 'polling'. This is in contrast to interrupt driven IO, where the device sends a signal when data is ready. + +First of all, let's implement a method KeyboardUpdate which detects the first keyboard and uses its poll method to get the current input, as well as saving the last inputs for comparison. We can then use this data with other methods to translate scan codes to keys. The method should do precisely the following: + + 1. Retrieve a stored keyboard address (initially 0). + 2. If this is not 0, go to 9. + 3. Call UsbCheckForChange to detect new keyboards. + 4. Call KeyboardCount to detect how many keyboards are present. + 5. If this is 0 store the address as 0 and return; we can't do anything with no keyboard. + 6. Call KeyboardGetAddress with parameter 0 to get the first keyboard's address. + 7. Store this address. + 8. If this is 0, return; there is some problem. + 9. Call KeyboardGetKeyDown 6 times to get each key currently down and store them + 10. Call KeyboardPoll + 11. If the result is non-zero go to 3. There is some problem (such as disconnected keyboard). + + + +To store the values mentioned above, we will need the following values in the .data section. + +``` +.section .data +.align 2 +KeyboardAddress: +.int 0 +KeyboardOldDown: +.rept 6 +.hword 0 +.endr +``` + +``` +.hword num inserts the half word constant num into the file directly. +``` + +``` +.rept num [commands] .endr copies the commands commands to the output num times. +``` + +Try to implement the method yourself. My implementation for this is as follows: + +1. +``` +.section .text +.globl KeyboardUpdate +KeyboardUpdate: +push {r4,r5,lr} + +kbd .req r4 +ldr r0,=KeyboardAddress +ldr kbd,[r0] +``` +We load in the keyboard address. +2. +``` +teq kbd,#0 +bne haveKeyboard$ +``` +If the address is non-zero, we have a keyboard. Calling UsbCheckForChanges is slow, and so if everything works we avoid it. +3. +``` +getKeyboard$: +bl UsbCheckForChange +``` +If we don't have a keyboard, we have to check for new devices. +4. +``` +bl KeyboardCount +``` +Now we see if a new keyboard has been added. +5. +``` +teq r0,#0 +ldreq r1,=KeyboardAddress +streq r0,[r1] +beq return$ +``` +There are no keyboards, so we have no keyboard address. +6. +``` +mov r0,#0 +bl KeyboardGetAddress +``` +Let's just get the address of the first keyboard. You may want to allow more. +7. +``` +ldr r1,=KeyboardAddress +str r0,[r1] +``` +Store the keyboard's address. +8. +``` +teq r0,#0 +beq return$ +mov kbd,r0 +``` +If we have no address, there is nothing more to do. +9. +``` +saveKeys$: + mov r0,kbd + mov r1,r5 + bl KeyboardGetKeyDown + + ldr r1,=KeyboardOldDown + add r1,r5,lsl #1 + strh r0,[r1] + add r5,#1 + cmp r5,#6 + blt saveKeys$ +``` +Loop through all the keys, storing them in KeyboardOldDown. If we ask for too many, this returns 0 which is fine. + +10. +``` +mov r0,kbd +bl KeyboardPoll +``` +Now we get the new keys. + +11. +``` +teq r0,#0 +bne getKeyboard$ + +return$: +pop {r4,r5,pc} +.unreq kbd +``` +Finally we check if KeyboardPoll worked. If not, we probably disconnected. + + +With our new KeyboardUpdate method, checking for inputs becomes as simple as calling this method at regular intervals, and it will even check for disconnections etc. This is a useful method to have, as our actual key processing may differ based on the situation, and so being able to get the current input in its raw form with one method call is generally applicable. The next method we ideally want is KeyboardGetChar, a method that simply returns the next key pressed as an ASCII character, or returns 0 if no key has just been pressed. This could be extended to support typing a key multiple times if it is held for a certain duration, and to support the 'lock' keys as well as modifiers. + +To make this method it is useful if we have a method KeyWasDown, which simply returns 0 if a given scan code is not in the KeyboardOldDown values, and returns a non-zero value otherwise. Have a go at implementing this yourself. As always, a solution can be found on the downloads page. + +### 7 Look Up Tables + +``` +In many areas of programming, the larger the program, the faster it is. Look up tables are large, but are very fast. Some problems can be solved by a mixture of look up tables and normal functions. +``` + +The KeyboardGetChar method could be quite complex if we write it poorly. There are 100s of scan codes, each with different effects depending on the presence or absence of the shift key or other modifiers. Not all of the keys can be translated to a character. For some characters, multiple keys can produce the same character. A useful trick in situations with such vast arrays of possibilities is look up tables. A look up table, much like in the physical sense, is a table of values and their results. For some limited functions, the simplest way to deduce the answer is just to precompute every answer, and just return the correct one by retrieving it. In this case, we could build up a sequence of values in memory such that the nth value into the sequence is the ASCII character code for the scan code n. This means our method would simply have to detect if a key was pressed, and then retrieve its value from the table. Further, we could have a separate table for the values when shift is held, so that the shift key simply changes which table we're working with. + +After the .section .data command, copy the following tables: + +``` +.align 3 +KeysNormal: + .byte 0x0, 0x0, 0x0, 0x0, 'a', 'b', 'c', 'd' + .byte 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l' + .byte 'm', 'n', 'o', 'p', 'q', 'r', 's', 't' + .byte 'u', 'v', 'w', 'x', 'y', 'z', '1', '2' + .byte '3', '4', '5', '6', '7', '8', '9', '0' + .byte '\n', 0x0, '\b', '\t', ' ', '-', '=', '[' + .byte ']', '\\\', '#', ';', '\'', '`', ',', '.' + .byte '/', 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 + .byte 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 + .byte 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 + .byte 0x0, 0x0, 0x0, 0x0, '/', '*', '-', '+' + .byte '\n', '1', '2', '3', '4', '5', '6', '7' + .byte '8', '9', '0', '.', '\\\', 0x0, 0x0, '=' + +.align 3 +KeysShift: + .byte 0x0, 0x0, 0x0, 0x0, 'A', 'B', 'C', 'D' + .byte 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L' + .byte 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T' + .byte 'U', 'V', 'W', 'X', 'Y', 'Z', '!', '"' + .byte '£', '$', '%', '^', '&', '*', '(', ')' + .byte '\n', 0x0, '\b', '\t', ' ', '_', '+', '{' + .byte '}', '|', '~', ':', '@', '¬', '<', '>' + .byte '?', 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 + .byte 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 + .byte 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 + .byte 0x0, 0x0, 0x0, 0x0, '/', '*', '-', '+' + .byte '\n', '1', '2', '3', '4', '5', '6', '7' + .byte '8', '9', '0', '.', '|', 0x0, 0x0, '=' +``` + +``` +.byte num inserts the byte constant num into the file directly. +``` + +``` +Most assemblers and compilers recognise escape sequences; character sequences such as \t which insert special characters instead. +``` + +These tables map directly the first 104 scan codes onto the ASCII characters as a table of bytes. We also have a separate table describing the effects of the shift key on those scan codes. I've used the ASCII null character (0) for all keys without direct mappings in ASCII (such as the function keys). Backspace is mapped to the ASCII backspace character (8 denoted \b), enter is mapped to the ASCII new line character (10 denoted \n) and tab is mapped to the ASCII horizontal tab character (9 denoted \t). + +The KeyboardGetChar method will need to do the following: + + 1. Check if KeyboardAddress is 0. If so, return 0. + 2. Call KeyboardGetKeyDown up to 6 times. Each time: + 1. If key is 0, exit loop. + 2. Call KeyWasDown. If it was, go to the next key. + 3. If the scan code is more than 103, go to the next key. + 4. Call KeyboardGetModifiers + 5. If shift is held, load the address of KeysShift. Otherwise load KeysNormal. + 6. Read the ASCII value from the table. + 7. If it is 0, go to the next key otherwise return this ASCII code and exit. + 3. Return 0. + + + +Try to implement this yourself. My implementation is presented below: + +1. +``` +.globl KeyboardGetChar +KeyboardGetChar: +ldr r0,=KeyboardAddress +ldr r1,[r0] +teq r1,#0 +moveq r0,#0 +moveq pc,lr +``` +Simple check to see if we have a keyboard. + +2. +``` +push {r4,r5,r6,lr} +kbd .req r4 +key .req r6 +mov r4,r1 +mov r5,#0 +keyLoop$: + mov r0,kbd + mov r1,r5 + bl KeyboardGetKeyDown +``` +r5 will hold the index of the key, r4 holds the keyboard address. + + 1. + ``` + teq r0,#0 + beq keyLoopBreak$ + ``` + If a scan code is 0, it either means there is an error, or there are no more keys. + + 2. + ``` + mov key,r0 + bl KeyWasDown + teq r0,#0 + bne keyLoopContinue$ + ``` + If a key was already down it is uninteresting, we only want ot know about key presses. + + 3. + ``` + cmp key,#104 + bge keyLoopContinue$ + ``` + If a key has a scan code higher than 104, it will be outside our table, and so is not relevant. + + 4. + ``` + mov r0,kbd + bl KeyboardGetModifiers + ``` + We need to know about the modifier keys in order to deduce the character. + + 5. + ``` + tst r0,#0b00100010 + ldreq r0,=KeysNormal + ldrne r0,=KeysShift + ``` + We detect both a left and right shift key as changing the characters to their shift variants. Remember, a tst instruction computes the logical AND and then compares it to zero, so it will be equal to 0 if and only if both of the shift bits are zero. + + 6. + ``` + ldrb r0,[r0,key] + ``` + Now we can load in the key from the look up table. + + 7. + ``` + teq r0,#0 + bne keyboardGetCharReturn$ + keyLoopContinue$: + add r5,#1 + cmp r5,#6 + blt keyLoop$ + ``` + If the look up code contains a zero, we must continue. To continue, we increment the index, and check if we've reached 6. + +3. +``` +keyLoopBreak$: +mov r0,#0 +keyboardGetCharReturn$: +pop {r4,r5,r6,pc} +.unreq kbd +.unreq key +``` +We return our key here, if we reach keyLoopBreak$, then we know there is no key held, so return 0. + + + + +### 8 Notepad OS + +Now we have our KeyboardGetChar method, we can make an operating system that just types what the user writes to the screen. For simplicity we'll ignore all the unusual keys. In 'main.s' delete all code after bl SetGraphicsAddress. Call UsbInitialise, set r4 and r5 to 0, then loop forever over the following commands: + + 1. Call KeyboardUpdate + 2. Call KeyboardGetChar + 3. If it is 0, got to 1 + 4. Copy r4 and r5 to r1 and r2 then call DrawCharacter + 5. Add r0 to r4 + 6. If r4 is 1024, add r1 to r5 and set r4 to 0 + 7. If r5 is 768 set r5 to 0 + 8. Go to 1 + + + +Now compile this and test it on the Pi. You should almost immediately be able to start typing text to the screen when the Pi starts. If not, please see our troubleshooting page. + +When it works, congratulations, you've achieved an interface with the computer. You should now begin to realise that you've almost got a primitive operating system together. You can now interface with the computer, issuing it commands, and receive feedback on screen. In the next tutorial, [Input02][3] we will look at producing a full text terminal, in which the user types commands, and the computer executes them. + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/input01.html + +作者：[Alex Chadwick][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.cl.cam.ac.uk +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/downloads.html +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/downloads/hut1_12v2.pdf +[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/input02.html diff --git a/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 11 Input02.md b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 11 Input02.md new file mode 100644 index 0000000000..9040162a97 --- /dev/null +++ b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 11 Input02.md @@ -0,0 +1,911 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 11 Input02) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/input02.html) +[#]: author: (Alex Chadwick https://www.cl.cam.ac.uk) + +Computer Laboratory – Raspberry Pi: Lesson 11 Input02 +====== + +The Input02 lesson builds on Input01, by building a simple command line interface where the user can type commands and the computer interprets and displays them. It is assumed you have the code for the [Lesson 11: Input01][1] operating system as a basis. + +### 1 Terminal 1 + +``` +In the early days of computing, there would usually be one large computer in a building, and many 'terminals' which sent commands to it. The computer would take it in turns to execute different incoming commands. +``` + +Almost every operating system starts life out as a text terminal. This is typically a black screen with white writing, where you type commands for the computer to execute on the keyboard, and it explains how you've mistyped them, or very occasionally, does what you want. This approach has two main advantages: it provides a simple, robust control mechanism for the computer using only a keyboard and monitor, and it is done by almost every operating system, so is widely understood by system administrators. + +Let's analyse what we want to do precisely: + + 1. Computer turns on, displays some sort of welcome message + 2. Computer indicates its ready for input + 3. User types a command, with parameters, on the keyboard + 4. User presses return or enter to commit the command + 5. Computer interprets command and performs actions if command is acceptable + 6. Computer displays messages to indicate if command was successful, and also what happened + 7. Loop back to 2 + + + +One defining feature of such terminals is that they are unified for both input and output. The same screen is used to enter inputs as is used to print outputs. This means it is useful to build an abstraction of a character based display. In a character based display, the smallest unit is a character, not a pixel. The screen is divided into a fixed number of characters which have varying colours. We can build this on top of our existing screen code, by storing the characters and their colours, and then using the DrawCharacter method to push them to the screen. Once we have a character based display, drawing text becomes a matter of drawing a line of characters. + +In a new file called terminal.s copy the following code: +``` +.section .data +.align 4 +terminalStart: +.int terminalBuffer +terminalStop: +.int terminalBuffer +terminalView: +.int terminalBuffer +terminalColour: +.byte 0xf +.align 8 +terminalBuffer: +.rept 128*128 +.byte 0x7f +.byte 0x0 +.endr +terminalScreen: +.rept 1024/8 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 768/16 +.byte 0x7f +.byte 0x0 +.endr +``` +This sets up the data we need for the text terminal. We have two main storages: terminalBuffer and terminalScreen. terminalBuffer is storage for all of the text we have displayed. It stores up to 128 lines of text (each containing 128 characters). Each character consists of an ASCII character code and a colour, all of which are initially set to 0x7f (ASCII delete) and 0 (black on a black background). terminalScreen stores the characters that are currently displayed on the screen. It is 128 by 48 characters, similarly initialised. You may think that we only need this terminalScreen, not the terminalBuffer, but storing the buffer has 2 main advantages: + + 1. We can easily see which characters are different, so we only have to draw those. + 2. We can 'scroll' back through the terminal's history because it is stored (to a limit). + + + +You should always try to design systems that do the minimum amount of work, as they run much faster for things which don't often change. + +The differing trick is really common on low power Operating Systems. Drawing the screen is a slow operation, and so we only want to draw thing that we absolutely have to. In this system, we can freely alter the terminalBuffer, and then call a method which copies the bits that change to the screen. This means we don't have to draw each character as we go along, which may save time in the long run on very long sections of text that span many lines. + +The other values in the .data section are as follows: + + * terminalStart + The first character which has been written in terminalBuffer. + * terminalStop + The last character which has been written in terminalBuffer. + * terminalView + The first character on the screen at present. We can use this to scroll the screen. + * temrinalColour + The colour to draw new characters with. + + + +``` +Circular buffers are an example of an **data structure**. These are just ideas we have for organising data, that we sometimes implement in software. +``` + +![Diagram showing hellow world being inserted into a circular buffer of size 5.][2] +The reason why terminalStart needs to be stored is because termainlBuffer should be a circular buffer. This means that when the buffer is completely full, the end 'wraps' round to the start, and so the character after the very last one is the first one. Thus, we need to advance terminalStart so we know that we've done this. When wokring with the buffer this can easily be implemented by checking if the index goes beyond the end of the buffer, and setting it back to the beginning if it does. Circular buffers are a common and clever way of storing a lot of data, where only the most recent data is important. It allows us to keep writing indefinitely, while always being sure there is a certain amount of recent data available. They're often used in signal processing or compression algorithms. In this case, it allows us to store a 128 line history of the terminal, without any penalties for writing over 128 lines. If we didn't have this, we would have to copy 127 lines back a line very time we went beyond the 128th line, wasting valuable time. + +I've mentioned the terminalColour here a few times. You can implement this however you, wish, however there is something of a standard on text terminals to have only 16 colours for foreground, and 16 colours for background (meaning there are 162 = 256 combinations). The colours on a CGA terminal are defined as follows: + +Table 1.1 - CGA Colour Codes +| Number | Colour (R, G, B) | +| ------ | ------------------------| +| 0 | Black (0, 0, 0) | +| 1 | Blue (0, 0, ⅔) | +| 2 | Green (0, ⅔, 0) | +| 3 | Cyan (0, ⅔, ⅔) | +| 4 | Red (⅔, 0, 0) | +| 5 | Magenta (⅔, 0, ⅔) | +| 6 | Brown (⅔, ⅓, 0) | +| 7 | Light Grey (⅔, ⅔, ⅔) | +| 8 | Grey (⅓, ⅓, ⅓) | +| 9 | Light Blue (⅓, ⅓, 1) | +| 10 | Light Green (⅓, 1, ⅓) | +| 11 | Light Cyan (⅓, 1, 1) | +| 12 | Light Red (1, ⅓, ⅓) | +| 13 | Light Magenta (1, ⅓, 1) | +| 14 | Yellow (1, 1, ⅓) | +| 15 | White (1, 1, 1) | + +``` +Brown was used as the alternative (dark yellow) was unappealing and not useful. +``` + +We store the colour of each character by storing the fore colour in the low nibble of the colour byte, and the background colour in the high nibble. Apart from brown, all of these colours follow a pattern such that in binary, the top bit represents adding ⅓ to each component, and the other bits represent adding ⅔ to individual components. This makes it easy to convert to RGB colour values. + +We need a method, TerminalColour, to read these 4 bit colour codes, and then call SetForeColour with the 16 bit equivalent. Try to implement this on your own. If you get stuck, or have not completed the Screen series, my implementation is given below: + +``` +.section .text +TerminalColour: +teq r0,#6 +ldreq r0,=0x02B5 +beq SetForeColour + +tst r0,#0b1000 +ldrne r1,=0x52AA +moveq r1,#0 +tst r0,#0b0100 +addne r1,#0x15 +tst r0,#0b0010 +addne r1,#0x540 +tst r0,#0b0001 +addne r1,#0xA800 +mov r0,r1 +b SetForeColour +``` +### 2 Showing the Text + +The first method we really need for our terminal is TerminalDisplay, one that copies the current data from terminalBuffer to terminalScreen and the actual screen. As mentioned, this method should do a minimal amount of work, because we need to be able to call it often. It should compare the text in terminalBuffer with that in terminalDisplay, and copy it across if they're different. Remember, terminalBuffer is a circular buffer running, in this case, from terminalView to terminalStop or 128*48 characters, whichever comes sooner. If we hit terminalStop, we'll assume all characters after that point are 7f16 (ASCII delete), and have colour 0 (black on a black background). + +Let's look at what we have to do: + + 1. Load in terminalView, terminalStop and the address of terminalDisplay. + 2. For each row: + 1. For each column: + 1. If view is not equal to stop, load the current character and colour from view + 2. Otherwise load the character as 0x7f and the colour as 0 + 3. Load the current character from terminalDisplay + 4. If the character and colour are equal, go to 10 + 5. Store the character and colour to terminalDisplay + 6. Call TerminalColour with the background colour in r0 + 7. Call DrawCharacter with r0 = 0x7f (ASCII delete, a block), r1 = x, r2 = y + 8. Call TerminalColour with the foreground colour in r0 + 9. Call DrawCharacter with r0 = character, r1 = x, r2 = y + 10. Increment the position in terminalDisplay by 2 + 11. If view and stop are not equal, increment the view position by 2 + 12. If the view position is at the end of textBuffer, set it to the start + 13. Increment the x co-ordinate by 8 + 2. Increment the y co-ordinate by 16 + + + +Try to implement this yourself. If you get stuck, my solution is given below: + +1. +``` +.globl TerminalDisplay +TerminalDisplay: +push {r4,r5,r6,r7,r8,r9,r10,r11,lr} +x .req r4 +y .req r5 +char .req r6 +col .req r7 +screen .req r8 +taddr .req r9 +view .req r10 +stop .req r11 + +ldr taddr,=terminalStart +ldr view,[taddr,#terminalView - terminalStart] +ldr stop,[taddr,#terminalStop - terminalStart] +add taddr,#terminalBuffer - terminalStart +add taddr,#128*128*2 +mov screen,taddr +``` + +I go a little wild with variables here. I'm using taddr to store the location of the end of the textBuffer for ease. + +2. +``` +mov y,#0 +yLoop$: +``` +Start off the y loop. + + 1. + ``` + mov x,#0 + xLoop$: + ``` + Start off the x loop. + + 1. + ``` + teq view,stop + ldrneh char,[view] + ``` + I load both the character and the colour into char simultaneously for ease. + + 2. + ``` + moveq char,#0x7f + ``` + This line complements the one above by acting as though a black delete character was read. + + 3. + ``` + ldrh col,[screen] + ``` + For simplicity I load both the character and colour into col simultaneously. + + 4. + ``` + teq col,char + beq xLoopContinue$ + ``` + Now we can check if anything has changed with a teq. + + 5. + ``` + strh char,[screen] + ``` + We can also easily save the current value. + + 6. + ``` + lsr col,char,#8 + and char,#0x7f + lsr r0,col,#4 + bl TerminalColour + ``` + I split up char into the colour in col and the character in char with a bitshift and an and, then use a bitshift to get the background colour to call TerminalColour. + + 7. + ``` + mov r0,#0x7f + mov r1,x + mov r2,y + bl DrawCharacter + ``` + Write out a delete character which is a coloured block. + + 8. + ``` + and r0,col,#0xf + bl TerminalColour + ``` + Use an and to get the low nibble of col then call TerminalColour. + + 9. + ``` + mov r0,char + mov r1,x + mov r2,y + bl DrawCharacter + ``` + Write out the character we're supposed to write. + + 10. + ``` + xLoopContinue$: + add screen,#2 + ``` + Increment the screen pointer. + + 11. + ``` + teq view,stop + addne view,#2 + ``` + Increment the view pointer if necessary. + + 12. + ``` + teq view,taddr + subeq view,#128*128*2 + ``` + It's easy to check for view going past the end of the buffer because the end of the buffer's address is stored in taddr. + + 13. + ``` + add x,#8 + teq x,#1024 + bne xLoop$ + ``` + We increment x and then loop back if there are more characters to go. + + 2. + ``` + add y,#16 + teq y,#768 + bne yLoop$ + ``` + We increment y and then loop back if there are more characters to go. + +``` +pop {r4,r5,r6,r7,r8,r9,r10,r11,pc} +.unreq x +.unreq y +.unreq char +.unreq col +.unreq screen +.unreq taddr +.unreq view +.unreq stop +``` +Don't forget to clean up at the end! + + +### 3 Printing Lines + +Now we have our TerminalDisplay method, which will automatically display the contents of terminalBuffer to terminalScreen, so theoretically we can draw text. However, we don't actually have any drawing routines that work on a character based display. A quick method that will come in handy first of all is TerminalClear, which completely clears the terminal. This can actually very easily be achieved with no loops. Try to deduce why the following method suffices: + +``` +.globl TerminalClear +TerminalClear: +ldr r0,=terminalStart +add r1,r0,#terminalBuffer-terminalStart +str r1,[r0] +str r1,[r0,#terminalStop-terminalStart] +str r1,[r0,#terminalView-terminalStart] +mov pc,lr +``` + +Now we need to make a basic method for character based displays; the Print function. This takes in a string address in r0, and a length in r1, and simply writes it to the current location at the screen. There are a few special characters to be wary of, as well as special behaviour to ensure that terminalView is kept up to date. Let's analyse what it has to do: + + 1. Check if string length is 0, if so return + 2. Load in terminalStop and terminalView + 3. Deduce the x-coordinate of terminalStop + 4. For each character: + 1. Check if the character is a new line + 2. If so, increment bufferStop to the end of the line storing a black on black delete character. + 3. Otherwise, copy the character in the current terminalColour + 4. Check if we're at the end of a line + 5. If so, check if the number of characters between terminalView and terminalStop is more than one screen + 6. If so, increment terminalView by one line + 7. Check if terminalView is at the end of the buffer, replace it with the start if so + 8. Check if terminalStop is at the end of the buffer, replace it with the start if so + 9. Check if terminalStop equals terminalStart, increment terminalStart by one line if so + 10. Check if terminalStart is at the end of the buffer, replace it with the start if so + 5. Store back terminalStop and terminalView. + + + +See if you can implement this yourself. My solution is provided below: + +1. +``` +.globl Print +Print: +teq r1,#0 +moveq pc,lr +``` +This quick check at the beginning makes a call to Print with a string of length 0 almost instant. + +2. +``` +push {r4,r5,r6,r7,r8,r9,r10,r11,lr} +bufferStart .req r4 +taddr .req r5 +x .req r6 +string .req r7 +length .req r8 +char .req r9 +bufferStop .req r10 +view .req r11 + +mov string,r0 +mov length,r1 + +ldr taddr,=terminalStart +ldr bufferStop,[taddr,#terminalStop-terminalStart] +ldr view,[taddr,#terminalView-terminalStart] +ldr bufferStart,[taddr] +add taddr,#terminalBuffer-terminalStart +add taddr,#128*128*2 +``` +I do a lot of setup here. bufferStart contains terminalStart, bufferStop contains terminalStop, view contains terminalView, taddr is the address of the end of terminalBuffer. + +3. +``` +and x,bufferStop,#0xfe +lsr x,#1 +``` +As per usual, a sneaky alignment trick makes everything easier. Because of the aligment of terminalBuffer, the x-coordinate of any character address is simply the last 8 bits divided by 2. + + 4. + 1. + ``` + charLoop$: + ldrb char,[string] + and char,#0x7f + teq char,#'\n' + bne charNormal$ + ``` + We need to check for new lines. + + 2. + ``` + mov r0,#0x7f + clearLine$: + strh r0,[bufferStop] + add bufferStop,#2 + add x,#1 + teq x,#128 blt clearLine$ + + b charLoopContinue$ + ``` + Loop until the end of the line, writing out 0x7f; a delete character in black on a black background. + + 3. + ``` + charNormal$: + strb char,[bufferStop] + ldr r0,=terminalColour + ldrb r0,[r0] + strb r0,[bufferStop,#1] + add bufferStop,#2 + add x,#1 + ``` + Store the current character in the string and the terminalColour to the end of the terminalBuffer and then increment it and x. + + 4. + ``` + charLoopContinue$: + cmp x,#128 + blt noScroll$ + ``` + Check if x is at the end of a line; 128. + + 5. + ``` + mov x,#0 + subs r0,bufferStop,view + addlt r0,#128*128*2 + cmp r0,#128*(768/16)*2 + ``` + Set x back to 0 and check if we're currently showing more than one screen. Remember, we're using a circular buffer, so if the difference between bufferStop and view is negative, we're actually wrapping around the buffer. + + 6. + ``` + addge view,#128*2 + ``` + Add one lines worth of bytes to the view address. + + 7. + ``` + teq view,taddr + subeq view,taddr,#128*128*2 + ``` + If the view address is at the end of the buffer we subtract the buffer length from it to move it back to the start. I set taddr to the address of the end of the buffer at the beginning. + + 8. + ``` + noScroll$: + teq bufferStop,taddr + subeq bufferStop,taddr,#128*128*2 + ``` + If the stop address is at the end of the buffer we subtract the buffer length from it to move it back to the start. I set taddr to the address of the end of the buffer at the beginning. + + 9. + ``` + teq bufferStop,bufferStart + addeq bufferStart,#128*2 + ``` + Check if bufferStop equals bufferStart. If so, add one line to bufferStart. + + 10. + ``` + teq bufferStart,taddr + subeq bufferStart,taddr,#128*128*2 + ``` + If the start address is at the end of the buffer we subtract the buffer length from it to move it back to the start. I set taddr to the address of the end of the buffer at the beginning. + +``` +subs length,#1 +add string,#1 +bgt charLoop$ +``` +Loop until the string is done. + +5. +``` +charLoopBreak$: +sub taddr,#128*128*2 +sub taddr,#terminalBuffer-terminalStart +str bufferStop,[taddr,#terminalStop-terminalStart] +str view,[taddr,#terminalView-terminalStart] +str bufferStart,[taddr] + +pop {r4,r5,r6,r7,r8,r9,r10,r11,pc} +.unreq bufferStart +.unreq taddr +.unreq x +.unreq string +.unreq length +.unreq char +.unreq bufferStop +.unreq view +``` +Store back the variables and return. + + +This method allows us to print arbitrary text to the screen. Throughout, I've been using the colour variable, but no where have we actually set it. Normally, terminals use special combinations of characters to change the colour. For example ASCII Escape (1b16) followed by a number 0 to f in hexadecimal could set the foreground colour to that CGA colour number. You can try implementing this yourself; my version is in the further examples section on the download page. + +### 4 Standard Input + +``` +By convention, in many programming languages, every program has access to stdin and stdout, which are an input and and output stream linked to the terminal. This is still true on graphical programs, though many don't use it. +``` + +Now we have an output terminal that in theory can print out text and display it. That is only half the story however, we want input. We want to implement a method, ReadLine, which stores the next line of text a user types to a location given in r0, up to a maximum length given in r1, and returns the length of the string read in r0. The tricky thing is, the user annoyingly wants to see what they're typing as they type it, they want to use backspace to delete mistakes and they want to use return to submit commands. They probably even want a flashing underscore character to indicate the computer would like input! These perfectly reasonable requests make this method a real challenge. One way to achieve all of this is to store the text they type in memory somewhere along with its length, and then after every character, move the terminalStop address back to where it started when ReadLine was called and calling Print. This means we only have to be able to manipulate a string in memory, and then make use of our Print function. + +Lets have a look at what ReadLine will do: + + 1. If the maximum length is 0, return 0 + 2. Retrieve the current values of terminalStop and terminalView + 3. If the maximum length is bigger than half the buffer size, set it to half the buffer size + 4. Subtract one from maximum length to ensure it can store our flashing underscore or a null terminator + 5. Write an underscore to the string + 6. Write the stored terminalView and terminalStop addresses back to the memory + 7. Call Print on the current string + 8. Call TerminalDisplay + 9. Call KeyboardUpdate + 10. Call KeyboardGetChar + 11. If it is a new line character go to 16 + 12. If it is a backspace character, subtract 1 from the length of the string (if it is > 0) + 13. If it is an ordinary character, write it to the string (if the length < maximum length) + 14. If the string ends in an underscore, write a space, otherwise write an underscore + 15. Go to 6 + 16. Write a new line character to the end of the string + 17. Call Print and TerminalDisplay + 18. Replace the new line with a null terminator + 19. Return the length of the string + + + +Convince yourself that this will work, and then try to implement it yourself. My implementation is given below: + +1. +``` +.globl ReadLine +ReadLine: +teq r1,#0 +moveq r0,#0 +moveq pc,lr +``` +Quick special handling for the zero case, which is otherwise difficult. + +2. +``` +string .req r4 +maxLength .req r5 +input .req r6 +taddr .req r7 +length .req r8 +view .req r9 + +push {r4,r5,r6,r7,r8,r9,lr} + +mov string,r0 +mov maxLength,r1 +ldr taddr,=terminalStart +ldr input,[taddr,#terminalStop-terminalStart] +ldr view,[taddr,#terminalView-terminalStart] +mov length,#0 +``` +As per the general theme, I do a lot of initialisations early. input contains the value of terminalStop and view contains terminalView. Length starts at 0. + +3. +``` +cmp maxLength,#128*64 +movhi maxLength,#128*64 +``` +We have to check for unusually large reads, as we can't process them beyond the size of the terminalBuffer (I suppose we CAN, but it would be very buggy, as terminalStart could move past the stored terminalStop). + +4. +``` +sub maxLength,#1 +``` +Since the user wants a flashing cursor, and we ideally want to put a null terminator on this string, we need 1 spare character. + +5. +``` +mov r0,#'_' +strb r0,[string,length] +``` +Write out the underscore to let the user know they can input. + +6. +``` +readLoop$: +str input,[taddr,#terminalStop-terminalStart] +str view,[taddr,#terminalView-terminalStart] +``` +Save the stored terminalStop and terminalView. This is important to reset the terminal after each call to Print, which changes these variables. Strictly speaking it can change terminalStart too, but this is irreversible. + +7. +``` +mov r0,string +mov r1,length +add r1,#1 +bl Print +``` +Write the current input. We add 1 to the length for the underscore. + +8. +``` +bl TerminalDisplay +``` +Copy the new text to the screen. + +9. +``` +bl KeyboardUpdate +``` +Fetch the latest keyboard input. + +10. +``` +bl KeyboardGetChar +``` +Retrieve the key pressed. + +11. +``` +teq r0,#'\n' +beq readLoopBreak$ +teq r0,#0 +beq cursor$ +teq r0,#'\b' +bne standard$ +``` + +Break out of the loop if we have an enter key. Also skip these conditions if we have a null terminator and process a backspace if we have one. + +12. +``` +delete$: +cmp length,#0 +subgt length,#1 +b cursor$ +``` +Remove one from the length to delete a character. + +13. +``` +standard$: +cmp length,maxLength +bge cursor$ +strb r0,[string,length] +add length,#1 +``` +Write out an ordinary character where possible. + +14. +``` +cursor$: +ldrb r0,[string,length] +teq r0,#'_' +moveq r0,#' ' +movne r0,#'_' +strb r0,[string,length] +``` +Load in the last character, and change it to an underscore if it isn't one, and a space if it is. + +15. +``` +b readLoop$ +readLoopBreak$: +``` +Loop until the user presses enter. + +16. +``` +mov r0,#'\n' +strb r0,[string,length] +``` +Store a new line at the end of the string. + +17. +``` +str input,[taddr,#terminalStop-terminalStart] +str view,[taddr,#terminalView-terminalStart] +mov r0,string +mov r1,length +add r1,#1 +bl Print +bl TerminalDisplay +``` +Reset the terminalView and terminalStop and then Print and TerminalDisplay the final input. + +18. +``` +mov r0,#0 +strb r0,[string,length] +``` +Write out the null terminator. + +19. +``` +mov r0,length +pop {r4,r5,r6,r7,r8,r9,pc} +.unreq string +.unreq maxLength +.unreq input +.unreq taddr +.unreq length +.unreq view +``` +Return the length. + + + + +### 5 The Terminal: Rise of the Machine + +So, now we can theoretically interact with the user on the terminal. The most obvious thing to do is to put this to the test! In 'main.s' delete everything after bl UsbInitialise and copy in the following code: + +``` +reset$: + mov sp,#0x8000 + bl TerminalClear + + ldr r0,=welcome + mov r1,#welcomeEnd-welcome + bl Print + +loop$: + ldr r0,=prompt + mov r1,#promptEnd-prompt + bl Print + + ldr r0,=command + mov r1,#commandEnd-command + bl ReadLine + + teq r0,#0 + beq loopContinue$ + + mov r4,r0 + + ldr r5,=command + ldr r6,=commandTable + + ldr r7,[r6,#0] + ldr r9,[r6,#4] + commandLoop$: + ldr r8,[r6,#8] + sub r1,r8,r7 + + cmp r1,r4 + bgt commandLoopContinue$ + + mov r0,#0 + commandName$: + ldrb r2,[r5,r0] + ldrb r3,[r7,r0] + teq r2,r3 + bne commandLoopContinue$ + add r0,#1 + teq r0,r1 + bne commandName$ + + ldrb r2,[r5,r0] + teq r2,#0 + teqne r2,#' ' + bne commandLoopContinue$ + + mov r0,r5 + mov r1,r4 + mov lr,pc + mov pc,r9 + b loopContinue$ + + commandLoopContinue$: + add r6,#8 + mov r7,r8 + ldr r9,[r6,#4] + teq r9,#0 + bne commandLoop$ + + ldr r0,=commandUnknown + mov r1,#commandUnknownEnd-commandUnknown + ldr r2,=formatBuffer + ldr r3,=command + bl FormatString + + mov r1,r0 + ldr r0,=formatBuffer + bl Print + +loopContinue$: + bl TerminalDisplay + b loop$ + +echo: + cmp r1,#5 + movle pc,lr + + add r0,#5 + sub r1,#5 + b Print + +ok: + teq r1,#5 + beq okOn$ + teq r1,#6 + beq okOff$ + mov pc,lr + + okOn$: + ldrb r2,[r0,#3] + teq r2,#'o' + ldreqb r2,[r0,#4] + teqeq r2,#'n' + movne pc,lr + mov r1,#0 + b okAct$ + + okOff$: + ldrb r2,[r0,#3] + teq r2,#'o' + ldreqb r2,[r0,#4] + teqeq r2,#'f' + ldreqb r2,[r0,#5] + teqeq r2,#'f' + movne pc,lr + mov r1,#1 + + okAct$: + + mov r0,#16 + b SetGpio + +.section .data +.align 2 +welcome: .ascii "Welcome to Alex's OS - Everyone's favourite OS" +welcomeEnd: +.align 2 +prompt: .ascii "\n> " +promptEnd: +.align 2 +command: + .rept 128 + .byte 0 + .endr +commandEnd: +.byte 0 +.align 2 +commandUnknown: .ascii "Command `%s' was not recognised.\n" +commandUnknownEnd: +.align 2 +formatBuffer: + .rept 256 + .byte 0 + .endr +formatEnd: + +.align 2 +commandStringEcho: .ascii "echo" +commandStringReset: .ascii "reset" +commandStringOk: .ascii "ok" +commandStringCls: .ascii "cls" +commandStringEnd: + +.align 2 +commandTable: +.int commandStringEcho, echo +.int commandStringReset, reset$ +.int commandStringOk, ok +.int commandStringCls, TerminalClear +.int commandStringEnd, 0 +``` +This code brings everything together into a simple command line operating system. The commands available are echo, reset, ok and cls. echo copies any text after it back to the terminal, reset resets the operating system if things go wrong, ok has two functions: ok on turns the OK LED on, and ok off turns the OK LED off, and cls clears the terminal using TerminalClear. + +Have a go with this code on the Raspberry Pi. If it doesn't work, please see our troubleshooting page. + +When it works, congratulations you've completed a basic terminal Operating System, and have completed the input series. Unfortunately, this is as far as these tutorials go at the moment, but I hope to make more in the future. Please send feedback to awc32@cam.ac.uk. + +You're now in position to start building some simple terminal Operating Systems. My code above builds up a table of available commands in commandTable. Each entry in the table is an int for the address of the string, and an int for the address of the code to run. The last entry has to be commandStringEnd, 0. Try implementing some of your own commands, using our existing functions, or making new ones. The parameters for the functions to run are r0 is the address of the command the user typed, and r1 is the length. You can use this to pass inputs to your commands. Maybe you could make a calculator program, perhaps a drawing program or a chess program. Whatever ideas you've got, give them a go! + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/input02.html + +作者：[Alex Chadwick][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.cl.cam.ac.uk +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/input01.html +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/circular_buffer.png diff --git a/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 6 Screen01.md b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 6 Screen01.md new file mode 100644 index 0000000000..0b3cc3940c --- /dev/null +++ b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 6 Screen01.md @@ -0,0 +1,503 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 6 Screen01) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen01.html) +[#]: author: (Alex Chadwick https://www.cl.cam.ac.uk) + +Computer Laboratory – Raspberry Pi: Lesson 6 Screen01 +====== + +Welcome to the Screen lesson series. In this series, you will learn how to control the screen using the Raspberry Pi in assembly code, starting at just displaying random data, then moving up to displaying a fixed image, displaying text and then formatting numbers into text. It is assumed that you have already completed the OK series, and so things covered in this series will not be repeated here. + +This first screen lesson teaches some basic theory about graphics, and then applies it to display a gradient pattern to the screen or TV. + +### 1 Getting Started + +It is expected that you have completed the OK series, and so functions in the 'gpio.s' file and 'systemTimer.s' file from that series will be called. If you do not have these files, or prefer to use a correct implementation, download the solution to OK05.s. The 'main.s' file from here will also be useful, up to and including mov sp,#0x8000. Please delete anything after that line. + +### 2 Computer Graphics + +There are a few systems for representing colours as numbers. Here we focus on RGB systems, but HSL is another common system used. + +As you're hopefully beginning to appreciate, at a fundamental level, computers are very stupid. They have a limited number of instructions, almost exclusively to do with maths, and yet somehow they are capable of doing many things. The thing we currently wish to understand is how a computer could possibly put an image on the screen. How would we translate this problem into binary? The answer is relatively straightforward; we devise some system of numbering each colour, and then we store one number for every pixel on the screen. A pixel is a small dot on your screen. If you move very close, you will probably be able to make out individual pixels on your screen, and be able to see that everything image is just made out of these pixels in combination. + +As the computer age advanced, people wanted more and more complicated graphics, and so the concept of a graphics card was invented. The graphics card is a secondary processor on your computer which only exists to draw images to the screen. It has the job of turning the pixel value information into light intensity levels to be transmitted to the screen. On modern computers, graphics cards can also do a lot more than that, such as drawing 3D graphics. In this tutorial however, we will just concentrate on the first use of graphics cards; getting pixel colours from memory out to the screen. + +One issue that is raised immediately by all this is the system we use for numbering colours. There are several choices, each producing outputs of different quality. I will outline a few here for completeness. + +Although some images here have few colours they use a technique called spatial dithering. This allows them to still show a good representation of the image, with very few colours. Many early Operating Systems used this technique. + +| Name | Unique Colours | Description | Examples | +| ----------- | --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------- | +| Monochrome | 2 | Use 1 bit to store each pixel, with a 1 being white, and a 0 being black. | ![Monochrome image of a bird][1] | +| Greyscale | 256 | Use 1 byte to store each pixel, with 255 representing white, 0 representing black, and all values in between representing a linear combination of the two. | ![Geryscale image of a bird][2] | +| 8 Colour | 8 | Use 3 bits to store each pixel, the first bit representing the presence of a red channel, the second representing a green channel and the third a blue channel. | ![8 colour image of a bird][3] | +| Low Colour | 256 | Use 8 bits to store each pixel, the first 3 bit representing the intensity of the red channel, the next 3 bits representing the intensity of the green channel and the final 2 bits representing the intensity of the blue channel. | ![Low colour image of a bird][4] | +| High Colour | 65,536 | Use 16 bits to store each pixel, the first 5 bit representing the intensity of the red channel, the next 6 bits representing the intensity of the green channel and the final 5 bits representing the intensity of the blue channel. | ![High colour image of a bird][5] | +| True Colour | 16,777,216 | Use 24 bits to store each pixel, the first 8 bits representing the intensity of the red channel, the second 8 representing the green channel and the final 8 bits the blue channel. | ![True colour image of a bird][6] | +| RGBA32 | 16,777,216 with 256 transparency levels | Use 32 bits to store each pixel, the first 8 bits representing the intensity of the red channel, the second 8 representing the green channel, the third 8 bits the blue channel, and the final 8 bits a transparency channel. The transparency channel is only considered when drawing one image on top of another and is stored such that a value of 0 indicates the image behind's colour, a value of 255 represents this image's colour, and all values between represent a mix. | | + + +In this tutorial we shall use High Colour initially. As you can see form the image, it is produces clear, good quality images, but it doesn't take up as much space as True Colour. That said, for quite a small display of 800x600 pixels, it would still take just under 1 megabyte of space. It also has the advantage that the size is a multiple of a power of 2, which greatly reduces the complexity of getting information compared with True Colour. + +``` +Storing the frame buffer places a heavy memory burden on a computer. For this reason, early computers often cheated, by, for example, storing a screens worth of text, and just drawing each letter to the screen every time it is refreshed separately. +``` + +The Raspberry Pi has a very special and rather odd relationship with it's graphics processor. On the Raspberry Pi, the graphics processor actually runs first, and is responsible for starting up the main processor. This is very unusual. Ultimately it doesn't make too much difference, but in many interactions, it often feels like the processor is secondary, and the graphics processor is the most important. The two communicate on the Raspberry Pi by what is called the 'mailbox'. Each can deposit mail for the other, which will be collected at some future point and then dealt with. We shall use the mailbox to ask the graphics processor for an address. The address will be a location to which we can write the pixel colour information for the screen, called a frame buffer, and the graphics card will regularly check this location, and update the pixels on the screen appropriately. + +### 3 Programming the Postman + +``` +Message passing is quite a common way for components to communicate. Some Operating Systems use virtual message passing to allow programs to communicate. +``` + +The first thing we are going to need to program is a 'postman'. This is just two methods: MailboxRead, reading one message from the mailbox channel in r0. and MailboxWrite, writing the value in the top 28 bits of r0 to the mailbox channel in r1. The Raspberry Pi has 7 mailbox channels for communication with the graphics processor, only the first of which is useful to us, as it is for negotiating the frame buffer. + +The following table and diagrams describe the operation of the mailbox. + +Table 3.1 Mailbox Addresses +| Address | Size / Bytes | Name | Description | Read / Write | +| 2000B880 | 4 | Read | Receiving mail. | R | +| 2000B890 | 4 | Poll | Receive without retrieving. | R | +| 2000B894 | 4 | Sender | Sender information. | R | +| 2000B898 | 4 | Status | Information. | R | +| 2000B89C | 4 | Configuration | Settings. | RW | +| 2000B8A0 | 4 | Write | Sending mail. | W | + +In order to send a message to a particular mailbox: + + 1. The sender waits until the Status field has a 0 in the top bit. + 2. The sender writes to Write such that the lowest 4 bits are the mailbox to write to, and the upper 28 bits are the message to write. + + + +In order to read a message: + + 1. The receiver waits until the Status field has a 0 in the 30th bit. + 2. The receiver reads from Read. + 3. The receiver confirms the message is for the correct mailbox, and tries again if not. + + + +If you're feeling particularly confident, you now have enough information to write the two methods we need. If not, read on. + +As always the first method I recommend you implement is one to get the address of the mailbox region. + +``` +.globl GetMailboxBase +GetMailboxBase: +ldr r0,=0x2000B880 +mov pc,lr +``` + +The sending procedure is least complicated, so we shall implement this first. As your methods become more and more complicated, you will need to start planning them in advance. A good way to do this might be to write out a simple list of the steps that need to be done, in a fair amount of detail, like below. + + 1. Our input will be what to write (r0), and what mailbox to write it to (r1). We must validate this is by checking it is a real mailbox, and that the low 4 bits of the value are 0. Never forget to validate inputs. + 2. Use GetMailboxBase to retrieve the address. + 3. Read from the Status field. + 4. Check the top bit is 0. If not, go back to 3. + 5. Combine the value to write and the channel. + 6. Write to the Write. + + + +Let's handle each of these in order. + +1. +``` +.globl MailboxWrite +MailboxWrite: +tst r0,#0b1111 +movne pc,lr +cmp r1,#15 +movhi pc,lr +``` + +``` +tst reg,#val computes and reg,#val and compares the result with 0. +``` + +This achieves our validation on r0 and r1. tst is a function that compares two numbers by computing the logical and operation of the numbers, and then comparing the result with 0. In this case it checks that the lowest 4 bits of the input in r0 are all 0. + +2. +``` +channel .req r1 +value .req r2 +mov value,r0 +push {lr} +bl GetMailboxBase +mailbox .req r0 +``` + +This code ensures we will not overwrite our value, or link register and calls GetMailboxBase. + +3. +``` +wait1$: +status .req r3 +ldr status,[mailbox,#0x18] +``` + +This code loads in the current status. + +4. +``` +tst status,#0x80000000 +.unreq status +bne wait1$ +``` + +This code checks that the top bit of the status field is 0, and loops back to 3. if it is not. + +5. +``` +add value,channel +.unreq channel +``` + +This code combines the channel and value together. + +6. +``` +str value,[mailbox,#0x20] +.unreq value +.unreq mailbox +pop {pc} +``` + +This code stores the result to the write field. + + + + +The code for MailboxRead is quite similar. + + 1. Our input will be what mailbox to read from (r0). We must validate this is by checking it is a real mailbox. Never forget to validate inputs. + 2. Use GetMailboxBase to retrieve the address. + 3. Read from the Status field. + 4. Check the 30th bit is 0. If not, go back to 3. + 5. Read from the Read field. + 6. Check the mailbox is the one we want, if not go back to 3. + 7. Return the result. + + + +Let's handle each of these in order. + +1. +``` +.globl MailboxRead +MailboxRead: +cmp r0,#15 +movhi pc,lr +``` + +This achieves our validation on r0. + +2. +``` +channel .req r1 +mov channel,r0 +push {lr} +bl GetMailboxBase +mailbox .req r0 +``` + +This code ensures we will not overwrite our value, or link register and calls GetMailboxBase. + +3. +``` +rightmail$: +wait2$: +status .req r2 +ldr status,[mailbox,#0x18] +``` + +This code loads in the current status. + +4. +``` +tst status,#0x40000000 +.unreq status +bne wait2$ +``` + +This code checks that the 30th bit of the status field is 0, and loops back to 3. if it is not. + +5. +``` +mail .req r2 +ldr mail,[mailbox,#0] +``` + +This code reads the next item from the mailbox. + +6. +``` +inchan .req r3 +and inchan,mail,#0b1111 +teq inchan,channel +.unreq inchan +bne rightmail$ +.unreq mailbox +.unreq channel +``` + +This code checks that the channel of the mail we just read is the one we were supplied. If not it loops back to 3. + +7. +``` +and r0,mail,#0xfffffff0 +.unreq mail +pop {pc} +``` + +This code moves the answer (the top 28 bits of mail) to r0. + + + + +### 4 My Dearest Graphics Processor + +Through our new postman, we now have the ability to send a message to the graphics card. What should we send though? This was certainly a difficult question for me to find the answer to, as it isn't in any online manual that I have found. Nevertheless, by looking at the GNU/Linux for the Raspberry Pi, we are able to work out what we needed to send. + +``` +Since the RAM is shared between the graphics processor and the processor on the Pi, we can just send where to find our message. This is called DMA, many complicated devices use this to speed up access times. +``` + +The message is very simple. We describe the framebuffer we would like, and the graphics card either agrees to our request, in which case it sends us back a 0, and fills in a small questionnaire we make, or it sends back a non-zero number, in which case we know it is unhappy. Unfortunately, I have no idea what any of the other numbers it can send back are, nor what they mean, but only when it sends a zero it is happy. Fortunately it always seems to send a zero for sensible inputs, so we don't need to worry too much. + +For simplicity we shall design our request in advance, and store it in the .data section. In a file called 'framebuffer.s' place the following code: + +``` +.section .data +.align 4 +.globl FrameBufferInfo +FrameBufferInfo: +.int 1024 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #0 Physical Width */ +.int 768 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #4 Physical Height */ +.int 1024 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #8 Virtual Width */ +.int 768 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #12 Virtual Height */ +.int 0 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #16 GPU - Pitch */ +.int 16 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #20 Bit Depth */ +.int 0 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #24 X */ +.int 0 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #28 Y */ +.int 0 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #32 GPU - Pointer */ +.int 0 /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var #36 GPU - Size */ +``` + +This is the format of our messages to the graphics processor. The first two words describe the physical width and height. The second pair is the virtual width and height. The framebuffer's width and height are the virtual width and height, and the GPU scales the framebuffer as need to fit the physical screen. The next word is one of the ones the GPU will fill in if it grants our request. It will be the number of bytes on each row of the frame buffer, in this case 2 × 1024 = 2048. The next word is how many bits to allocate to each pixel. Using a value of 16 means that the graphics processor uses High Colour mode described above. A value of 24 would use True Colour, and 32 would use RGBA32. The next two words are x and y offsets, which mean the number of pixels to skip in the top left corner of the screen when copying the framebuffer to the screen. Finally, the last two words are filled in by the graphics processor, the first of which is the actual pointer to the frame buffer, and the second is the size of the frame buffer in bytes. + +``` +When working with devices using DMA, alignment constraints become very important. The GPU expects the message to be 16 byte aligned. +``` + +I was very careful to include a .align 4 here. As discussed before, this ensures the lowest 4 bits of the address of the next line are 0. Thus, we know for sure that FrameBufferInfo will be placed at an address we can send to the graphics processor, as our mailbox only sends values with the low 4 bits all 0. + +So, now that we have our message, we can write code to send it. The communication will go as follows: + + 1. Write the address of FrameBufferInfo + 0x40000000 to mailbox 1. + 2. Read the result from mailbox 1. If it is not zero, we didn't ask for a proper frame buffer. + 3. Copy our images to the pointer, and they will appear on screen! + + + +I've said something that I've not mentioned before in step 1. We have to add 0x40000000 to the address of FrameBufferInfo before sending it. This is actually a special signal to the GPU of how it should write to the structure. If we just send the address, the GPU will write its response, but will not make sure we can see it by flushing its cache. The cache is a piece of memory where a processor stores values its working on before sending them to the RAM. By adding 0x40000000, we tell the GPU not to use its cache for these writes, which ensures we will be able to see the change. + +Since there is quite a lot going on there, it would be best to implement this as a function, rather than just putting the code into main.s. We shall write a function InitialiseFrameBuffer which does all this negotiation and returns the pointer to the frame buffer info data above, once it has a pointer in it. For ease, we should also make it so that the width, height and bit depth of the frame buffer are inputs to this method, so that it is easy to change in main.s without having to get into the details of the negotiation. + +Once again, let's write down in detail the steps we will have to take. If you're feeling confident, try writing the function straight away. + + 1. Validate our inputs. + 2. Write the inputs into the frame buffer. + 3. Send the address of the frame buffer + 0x40000000 to the mailbox. + 4. Receive the reply from the mailbox. + 5. If the reply is not 0, the method has failed. We should return 0 to indicate failure. + 6. Return a pointer to the frame buffer info. + + + +Now we're getting into much bigger methods than before. Below is one implementation of the above. + +1. +``` +.section .text +.globl InitialiseFrameBuffer +InitialiseFrameBuffer: +width .req r0 +height .req r1 +bitDepth .req r2 +cmp width,#4096 +cmpls height,#4096 +cmpls bitDepth,#32 +result .req r0 +movhi result,#0 +movhi pc,lr +``` + +This code checks that the width and height are less than or equal to 4096, and that the bit depth is less than or equal to 32. This is once again using a trick with conditional execution. Convince yourself that this works. + +2. +``` +fbInfoAddr .req r3 +push {lr} +ldr fbInfoAddr,=FrameBufferInfo +str width,[fbInfoAddr,#0] +str height,[fbInfoAddr,#4] +str width,[fbInfoAddr,#8] +str height,[fbInfoAddr,#12] +str bitDepth,[fbInfoAddr,#20] +.unreq width +.unreq height +.unreq bitDepth +``` + +This code simply writes into our frame buffer structure defined above. I also take the opportunity to push the link register onto the stack. + +3. +``` +mov r0,fbInfoAddr +add r0,#0x40000000 +mov r1,#1 +bl MailboxWrite +``` + +The inputs to the MailboxWrite method are the value to write in r0, and the channel to write to in r1. + +4. +``` +mov r0,#1 +bl MailboxRead +``` + +The inputs to the MailboxRead method is the channel to write to in r0, and the output is the value read. + +5. +``` +teq result,#0 +movne result,#0 +popne {pc} +``` + +This code checks if the result of the MailboxRead method is 0, and returns 0 if not. + +6. +``` +mov result,fbInfoAddr +pop {pc} +.unreq result +.unreq fbInfoAddr +``` + +This code finishes off and returns the frame buffer info address. + + + + +### 5 A Pixel Within a Row Within a Frame + +So, we've now created our methods to communicate with the graphics processor. It should now be capable of giving us the pointer to a frame buffer we can draw graphics to. Let's draw something now. + +In this first example, we'll just draw consecutive colours to the screen. It won't look pretty, but at least it will be working. How we will do this is by setting each pixel in the framebuffer to a consecutive number, and continually doing so. + +Copy the following code to 'main.s' after mov sp,#0x8000 + +``` +mov r0,#1024 +mov r1,#768 +mov r2,#16 +bl InitialiseFrameBuffer +``` + +This code simply uses our InitialiseFrameBuffer method to create a frame buffer with width 1024, height 768, and bit depth 16. You can try different values in here if you wish, as long as you are consistent throughout the code. Since it's possible that this method can return 0 if the graphics processor did not give us a frame buffer, we had better check for this, and turn the OK LED on if it happens. + +``` +teq r0,#0 +bne noError$ + +mov r0,#16 +mov r1,#1 +bl SetGpioFunction +mov r0,#16 +mov r1,#0 +bl SetGpio + +error$: +b error$ + +noError$: +fbInfoAddr .req r4 +mov fbInfoAddr,r0 +``` + +Now that we have the frame buffer info address, we need to get the frame buffer pointer from it, and start drawing to the screen. We will do this using two loops, one going down the rows, and one going along the columns. On the Raspberry Pi, indeed in most applications, pictures are stored left to right then top to bottom, so we have to do the loops in the order I have said. + + +``` +render$: + + fbAddr .req r3 + ldr fbAddr,[fbInfoAddr,#32] + + colour .req r0 + y .req r1 + mov y,#768 + drawRow$: + + x .req r2 + mov x,#1024 + drawPixel$: + + strh colour,[fbAddr] + add fbAddr,#2 + sub x,#1 + teq x,#0 + bne drawPixel$ + + sub y,#1 + add colour,#1 + teq y,#0 + bne drawRow$ + + b render$ + +.unreq fbAddr +.unreq fbInfoAddr +``` + +``` +strh reg,[dest] stores the low half word number in reg at the address given by dest. +``` + +This is quite a large chunk of code, and has a loop within a loop within a loop. To help get your head around the looping, I've indented the code which is looped, depending on which loop it is in. This is quite common in most high level programming languages, and the assembler simply ignores the tabs. We see here that I load in the frame buffer address from the frame buffer information structure, and then loop over every row, then every pixel on the row. At each pixel, I use an strh (store half word) command to store the current colour, then increment the address we're writing to. After drawing each row, we increment the colour that we are drawing. After drawing the full screen, we branch back to the beginning. + +### 6 Seeing the Light + +Now you're ready to test this code on the Raspberry Pi. You should see a changing gradient pattern. Be careful: until the first message is sent to the mailbox, the Raspberry Pi displays a still gradient pattern between the four corners. If it doesn't work, please see our troubleshooting page. + +If it does work, congratulations! You can now control the screen! Feel free to alter this code to draw whatever pattern you like. You can do some very nice gradient patterns, and can compute the value of each pixel directly, since y contains a y-coordinate for the pixel, and x contains an x-coordinate. In the next lesson, [Lesson 7: Screen 02][7], we will look at one of the most common drawing tasks, lines. + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen01.html + +作者：[Alex Chadwick][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.cl.cam.ac.uk +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/colour1bImage.png +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/colour8gImage.png +[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/colour3bImage.png +[4]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/colour8bImage.png +[5]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/colour16bImage.png +[6]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/colour24bImage.png +[7]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen02.html diff --git a/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 7 Screen02.md b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 7 Screen02.md new file mode 100644 index 0000000000..3a8fe60f6f --- /dev/null +++ b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 7 Screen02.md @@ -0,0 +1,449 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 7 Screen02) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen02.html) +[#]: author: (Alex Chadwick https://www.cl.cam.ac.uk) + +Computer Laboratory – Raspberry Pi: Lesson 7 Screen02 +====== + +The Screen02 lesson builds on Screen01, by teaching how to draw lines and also a small feature on generating pseudo random numbers. It is assumed you have the code for the [Lesson 6: Screen01][1] operating system as a basis. + +### 1 Dots + +Now that we've got the screen working, it is only natural to start waiting to create sensible images. It would be very nice indeed if we were able to actually draw something. One of the most basic components in all drawings is a line. If we were able to draw a line between any two points on the screen, we could start creating more complicated drawings just using combinations of these lines. + +``` +To allow complex drawing, some systems use a colouring function rather than just one colour to draw things. Each pixel calls the colouring function to determine what colour to draw there. +``` + +We will attempt to implement this in assembly code, but first we could really use some other functions to help. We need a function I will call SetPixel that changes the colour of a particular pixel, supplied as inputs in r0 and r1. It will be helpful for future if we write code that could draw to any memory, not just the screen, so first of all, we need some system to control where we are actually going to draw to. I think that the best way to do this would be to have a piece of memory which stores where we are going to draw to. What we should end up with is a stored address which normally points to the frame buffer structure from last time. We will use this at all times in our drawing method. That way, if we want to draw to a different image in another part of our operating system, we could make this value the address of a different structure, and use the exact same code. For simplicity we will use another piece of data to control the colour of our drawings. + +Copy the following code to a new file called 'drawing.s'. + +``` +.section .data +.align 1 +foreColour: +.hword 0xFFFF + +.align 2 +graphicsAddress: +.int 0 + +.section .text +.globl SetForeColour +SetForeColour: +cmp r0,#0x10000 +movhs pc,lr +ldr r1,=foreColour +strh r0,[r1] +mov pc,lr + +.globl SetGraphicsAddress +SetGraphicsAddress: +ldr r1,=graphicsAddress +str r0,[r1] +mov pc,lr +``` + +This is just the pair of functions that I described above, along with their data. We will use them in 'main.s' before drawing anything to control where and what we are drawing. + +``` +Building generic methods like SetPixel which we can build other methods on top of is a useful idea. We have to make sure the method is fast though, since we will use it a lot. +``` + +Our next task is to implement a SetPixel method. This needs to take two parameters, the x and y co-ordinate of a pixel, and it should use the graphicsAddress and foreColour we have just defined to control exactly what and where it is drawing. If you think you can implement this immediately, do, if not I shall outline the steps to be taken, and then give an example implementation. + + 1. Load in the graphicsAddress. + 2. Check that the x and y co-ordinates of the pixel are less than the width and height. + 3. Compute the address of the pixel to write. (hint: frameBufferAddress + (x + y core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated width) * pixel size) + 4. Load in the foreColour. + 5. Store it at the address. + + + +An implementation of the above follows. + +1. +``` +.globl DrawPixel +DrawPixel: +px .req r0 +py .req r1 +addr .req r2 +ldr addr,=graphicsAddress +ldr addr,[addr] +``` + +2. +``` +height .req r3 +ldr height,[addr,#4] +sub height,#1 +cmp py,height +movhi pc,lr +.unreq height + +width .req r3 +ldr width,[addr,#0] +sub width,#1 +cmp px,width +movhi pc,lr +``` + +Remember that the width and height are stored at offsets of 0 and 4 into the frame buffer description respectively. You can refer back to 'frameBuffer.s' if necessary. + +3. +``` +ldr addr,[addr,#32] +add width,#1 +mla px,py,width,px +.unreq width +.unreq py +add addr, px,lsl #1 +.unreq px +``` + +``` +mla dst,reg1,reg2,reg3 multiplies the values from reg1 and reg2, adds the value from reg3 and places the least significant 32 bits of the result in dst. +``` + +Admittedly, this code is specific to high colour frame buffers, as I use a bit shift directly to compute this address. You may wish to code a version of this function without the specific requirement to use high colour frame buffers, remembering to update the SetForeColour code. It may be significantly more complicated to implement. + +4. +``` +fore .req r3 +ldr fore,=foreColour +ldrh fore,[fore] +``` + +As above, this is high colour specific. + +5. +``` +strh fore,[addr] +.unreq fore +.unreq addr +mov pc,lr +``` + +As above, this is high colour specific. + + + + +### 2 Lines + +The trouble is, line drawing isn't quite as simple as you may expect. By now you must realise that when making operating system, we have to do almost everything ourselves, and line drawing is no exception. I suggest for a few minutes you have a think about how you would draw a line between any two points. + +``` +When programming normally, we tend to be lazy with things like division. Operating Systems must be incredibly efficient, and so we must focus on doing things as best as possible. +``` + +I expect the central idea of most strategies will involve computing the gradient of the line, and stepping along it. This sounds perfectly reasonable, but is actually a terrible idea. The problem with it is it involves division, which is something that we know can't easily be done in assembly, and also keeping track of decimal numbers, which is again difficult. There is, in fact, an algorithm called Bresenham's Algorithm, which is perfect for assembly code because it only involves addition, subtraction and bit shifts. +``` +Let's start off by defining a reasonably straightforward line drawing algorithm as follows: + +if x1 > x0 then + +set deltax to x1 - x0 +set stepx to +1 + +otherwise + +set deltax to x0 - x1 +set stepx to -1 + +end if + +if y1 > y0 then + +set deltay to y1 - y0 +set stepy to +1 + +otherwise + +set deltay to y0 - y1 +set stepy to -1 + +end if + +if deltax > deltay then + +set error to 0 +until x0 = x1 + stepx + +setPixel(x0, y0) +set error to error + deltax ÷ deltay +if error ≥ 0.5 then + +set y0 to y0 + stepy +set error to error - 1 + +end if +set x0 to x0 + stepx + +repeat + +otherwise + +end if + +This algorithm is a representation of the sort of thing you may have imagined. The variable error keeps track of how far away from the actual line we are. Every step we take along the x axis increases this error, and every time we move down the y axis, the error decreases by 1 unit again. The error is measured as a distance along the y axis. + +While this algorithm works, it suffers a major problem in that we clearly have to use decimal numbers to store error, and also we have to do a division. An immediate optimisation would therefore be to change the units of error. There is no need to store it in any particular units, as long as we scale every use of it by the same amount. Therefore, we could rewrite the algorithm simply by multiplying all equations involving error by deltay, and simplifying the result. Just showing the main loop: + +set error to 0 × deltay +until x0 = x1 + stepx + +setPixel(x0, y0) +set error to error + deltax ÷ deltay × deltay +if error ≥ 0.5 × deltay then + +set y0 to y0 + stepy +set error to error - 1 × deltay + +end if +set x0 to x0 + stepx + +repeat + +Which simplifies to: + +set error to 0 +until x0 = x1 + stepx + +setPixel(x0, y0) +set error to error + deltax +if error × 2 ≥ deltay then + +set y0 to y0 + stepy +set error to error - deltay + +end if +set x0 to x0 + stepx + +repeat + +Suddenly we have a much better algorithm. We see now that we've eliminated the need for division altogether. Better still, the only multiplication is by 2, which we know is just a bit shift left by 1! This is now very close to Bresenham's Algorithm, but one further optimisation can be made. At the moment, we have an if statement which leads to two very similar blocks of code, one for lines with larger x differences, and one for lines with larger y differences. It is worth checking if the code could be converted to a single statement for both types of line. + +The difficulty arises somewhat in that in the first case, error is to do with y, and in the second case error is to do with x. The solution is to track the error in both variables simultaneously, using negative error to represent an error in x, and positive error in y. + +set error to deltax - deltay +until x0 = x1 + stepx or y0 = y1 + stepy + +setPixel(x0, y0) +if error × 2 > -deltay then + +set x0 to x0 + stepx +set error to error - deltay + +end if +if error × 2 < deltax then + +set y0 to y0 + stepy +set error to error + deltax + +end if + +repeat + +It may take some time to convince yourself that this actually works. At each step, we consider if it would be correct to move in x or y. We do this by checking if the magnitude of the error would be lower if we moved in the x or y co-ordinates, and then moving if so. +``` + +``` +Bresenham's Line Algorithm was developed in 1962 by Jack Elton Bresenham, 24 at the time, whilst studying for a PhD. +``` + +Bresenham's Algorithm for drawing a line can be described by the following pseudo code. Pseudo code is just text which looks like computer instructions, but is actually intended for programmers to understand algorithms, rather than being machine readable. + +``` +/* We wish to draw a line from (x0,y0) to (x1,y1), using only a function setPixel(x,y) which draws a dot in the pixel given by (x,y). */ +if x1 > x0 then + set deltax to x1 - x0 + set stepx to +1 +otherwise + set deltax to x0 - x1 + set stepx to -1 +end if + +set error to deltax - deltay +until x0 = x1 + stepx or y0 = y1 + stepy + setPixel(x0, y0) + if error × 2 ≥ -deltay then + set x0 to x0 + stepx + set error to error - deltay + end if + if error × 2 ≤ deltax then + set y0 to y0 + stepy + set error to error + deltax + end if +repeat +``` + +Rather than numbered lists as I have used so far, this representation of an algorithm is far more common. See if you can implement this yourself. For reference, I have provided my implementation below. + +``` +.globl DrawLine +DrawLine: +push {r4,r5,r6,r7,r8,r9,r10,r11,r12,lr} +x0 .req r9 +x1 .req r10 +y0 .req r11 +y1 .req r12 + +mov x0,r0 +mov x1,r2 +mov y0,r1 +mov y1,r3 + +dx .req r4 +dyn .req r5 /* Note that we only ever use -deltay, so I store its negative for speed. (hence dyn) */ +sx .req r6 +sy .req r7 +err .req r8 + +cmp x0,x1 +subgt dx,x0,x1 +movgt sx,#-1 +suble dx,x1,x0 +movle sx,#1 + +cmp y0,y1 +subgt dyn,y1,y0 +movgt sy,#-1 +suble dyn,y0,y1 +movle sy,#1 + +add err,dx,dyn +add x1,sx +add y1,sy + +pixelLoop$: + + teq x0,x1 + teqne y0,y1 + popeq {r4,r5,r6,r7,r8,r9,r10,r11,r12,pc} + + mov r0,x0 + mov r1,y0 + bl DrawPixel + + cmp dyn, err,lsl #1 + addle err,dyn + addle x0,sx + + cmp dx, err,lsl #1 + addge err,dx + addge y0,sy + + b pixelLoop$ + +.unreq x0 +.unreq x1 +.unreq y0 +.unreq y1 +.unreq dx +.unreq dyn +.unreq sx +.unreq sy +.unreq err +``` + +### 3 Randomness + +So, now we can draw lines. Although we could use this to draw pictures and whatnot (feel free to do so!), I thought I would take the opportunity to introduce the idea of computer randomness. What we will do is select a pair of random co-ordinates, and then draw a line from the last pair to that point in steadily incrementing colours. I do this purely because it looks quite pretty. + +``` +Hardware random number generators are occasionally used in security, where the predictability sequence of random numbers may affect the security of some encryption. +``` + +So, now it comes down to it, how do we be random? Unfortunately for us there isn't some device which generates random numbers (such devices are very rare). So somehow using only the operations we've learned so far we need to invent 'random numbers'. It shouldn't take you long to realise this is impossible. The operations always have well defined results, executing the same sequence of instructions with the same registers yields the same answer. What we instead do is deduce a sequence that is pseudo random. This means numbers that, to the outside observer, look random, but in fact were completely determined. So, we need a formula to generate random numbers. One might be tempted to just spam mathematical operators out for example: 4x2! / 64, but in actuality this generally produces low quality random numbers. In this case for example, if x were 0, the answer would be 0. Stupid though it sounds, we need a very careful choice of equation to produce high quality random numbers. + +``` +This sort of discussion often begs the question what do we mean by a random number? We generally mean statistical randomness: A sequence of numbers that has no obvious patterns or properties that could be used to generalise it. +``` + +The method I'm going to teach you is called the quadratic congruence generator. This is a good choice because it can be implemented in 5 instructions, and yet generates a seemingly random order of the numbers from 0 to 232-1. + +The reason why the generator can create such long sequence with so few instructions is unfortunately a little beyond the scope of this course, but I encourage the interested to research it. It all centralises on the following quadratic formula, where xn is the nth random number generated. + +x_(n+1) = ax_(n)^2 + bx_(n) + c mod 2^32 + +Subject to the following constraints: + + 1. a is even + + 2. b = a + 1 mod 4 + + 3. c is odd + + + + +If you've not seen mod before, it means the remainder of a division by the number after it. For example b = a + 1 mod 4 means that b is the remainder of dividing a + 1 by 4, so if a were 12 say, b would be 1 as a + 1 is 13, and 13 divided by 4 is 3 remainder 1. + +Copy the following code into a file called 'random.s'. + +``` +.globl Random +Random: +xnm .req r0 +a .req r1 + +mov a,#0xef00 +mul a,xnm +mul a,xnm +add a,xnm +.unreq xnm +add r0,a,#73 + +.unreq a +mov pc,lr +``` + +This is an implementation of the random function, with an input of the last value generated in r0, and an output of the next number. In my case, I've used a = EF0016, b = 1, c = 73. This choice was arbitrary but meets the requirements above. Feel free to use any numbers you wish instead, as long as they obey the rules. + +### 4 Pi-casso + +OK, now we have all the functions we're going to need, let's try it out. Alter main to do the following, after getting the frame buffer info address: + + 1. Call SetGraphicsAddress with r0 containing the frame buffer info address. + 2. Set four registers to 0. One will be the last random number, one will be the colour, one will be the last x co-ordinate and one will be the last y co-ordinate. + 3. Call random to generate the next x-coordinate, using the last random number as the input. + 4. Call random again to generate the next y-coordinate, using the x-coordinate you generated as an input. + 5. Update the last random number to contain the y-coordinate. + 6. Call SetForeColour with the colour, then increment the colour. If it goes above FFFF16, make sure it goes back to 0. + 7. The x and y coordinates we have generated are between 0 and FFFFFFFF16. Convert them to a number between 0 and 102310 by using a logical shift right of 22. + 8. Check the y coordinate is on the screen. Valid y coordinates are between 0 and 76710. If not, go back to 3. + 9. Draw a line from the last x and y coordinates to the current x and y coordinates. + 10. Update the last x and y coordinates to contain the current ones. + 11. Go back to 3. + + + +As always, a solution for this can be found on the downloads page. + +Once you've finished, test it on the Raspberry Pi. You should see a very fast sequence of random lines being drawn on the screen, in steadily incrementing colours. This should never stop. If it doesn't work, please see our troubleshooting page. + +When you have it working, congratulations! We've now learned about meaningful graphics, and also about random numbers. I encourage you to play with line drawing, as it can be used to render almost anything you want. You may also want to explore more complicated shapes. Most can be made out of lines, but is this necessarily the best strategy? If you like the line program, try experimenting with the SetPixel function. What happens if instead of just setting the value of the pixel, you increase it by a small amount? What other patterns can you make? In the next lesson, [Lesson 8: Screen 03][2], we will look at the invaluable skill of drawing text. + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen02.html + +作者：[Alex Chadwick][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.cl.cam.ac.uk +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen01.html +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen03.html diff --git a/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 8 Screen03.md b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 8 Screen03.md new file mode 100644 index 0000000000..08803fd50f --- /dev/null +++ b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 8 Screen03.md @@ -0,0 +1,485 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 8 Screen03) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen03.html) +[#]: author: (Alex Chadwick https://www.cl.cam.ac.uk) + +Computer Laboratory – Raspberry Pi: Lesson 8 Screen03 +====== + +The Screen03 lesson builds on Screen02, by teaching how to draw text, and also a small feature on the command line arguments of the operating system. It is assumed you have the code for the [Lesson 7: Screen02][1] operating system as a basis. + +### 1 String Theory + +So, our task for this operating system is to draw text. We have several problems to address, the most pressing of which is probably about storing text. Unbelievably text has been one of the biggest flaws on computers to date. What should have been a straightforward type of data has brought down operating systems, crippled otherwise wonderful encryption, and caused many problems for users of different alphabets. Nevertheless, it is an incredibly important type of data, as it is an excellent link between the computer and the user. Text can be sufficiently structured that the operating system understands it, as well as sufficiently readable that humans can use it. + +``` +Variable data types such as text require much more complex handling. +``` + +So how exactly is text stored? Simply enough, we have some system by which we give each letter a unique number, and then store a sequence of such numbers. Sounds easy. The problem is that the number of numbers is not fixed. Some pieces of text are longer than others. With storing ordinary numbers, we have some fixed limit, e.g. 32 bits, and then we can't go beyond that, we write methods that use numbers of that length, etc. In terms of text, or strings as we often call it, we want to write functions that work on variable length strings, otherwise we would need a lot of functions! This is not a problem for numbers normally, as there are only a few common number formats (byte, word, half, double). + +``` +Buffer overrun attacks have plagued computers for years. Recently, the Wii, Xbox and Playstation 2 all suffered buffer overrun attacks, as well as large systems like Microsoft's Web and Database servers. +``` + +So, how do we determine how long the string is? I think the obvious answer is just to store how long the string is, and then to store the characters that make it up. This is called length prefixing, as the length comes before the string. Unfortunately, the pioneers of computer science did not agree. They felt it made more sense to have a special character called the null terminator (denoted \0) which represents when a string ends. This does indeed simplify many string algorithms, as you just keep working until the null terminator. Unfortunately this is the source of many security issues. What if a malicious user gives you a very long string? What if you didn't have enough space to store it. You might run a string copying function that copies until the null terminator, but because the string is so long, it overwrites your program. This may sound far fetched, but nevertheless, such buffer overrun attacks are incredibly common. Length prefixing mitigates this problem as it is easy to deduce the size of the buffer required to store the string. As an operating system developer, I leave it to you to decide how best to store text. + +The next thing we need to establish is how best to map characters to numbers. Fortunately, this is reasonably well standardised, so you have two major choices, Unicode and ASCII. Unicode maps almost every single useful symbol that can be written to a number, in exchange for having a lot more numbers, and a more complicated encoding system. ASCII uses one byte per character, and so only stores the Latin alphabet, numbers, a few symbols and a few special characters. Thus, ASCII is very easy to implement, compared to Unicode, in which not every character takes the same space, making string algorithms tricky. Normally operating systems use ASCII for strings which will not be displayed to end users (but perhaps to developers or experts), and Unicode for displaying messages to users, as Unicode can support things like Japanese characters, and so could be localised. + +Fortunately for us, this decision is irrelevant at the moment, as the first 128 characters of both are exactly the same, and are encoded exactly the same. + +Table 1.1 ASCII/Unicode symbols 0-127 + +| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | a | b | c | d | e | f | | +|----| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ----| +| 00 | NUL | SOH | STX | ETX | EOT | ENQ | ACK | BEL | BS | HT | LF | VT | FF | CR | SO | SI | | +| 10 | DLE | DC1 | DC2 | DC3 | DC4 | NAK | SYN | ETB | CAN | EM | SUB | ESC | FS | GS | RS | US | | +| 20 | ! | " | # | $ | % | & | . | ( | ) | * | + | , | - | . | / | | | +| 30 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | : | ; | < | = | > | ? | | +| 40 | @ | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | | +| 50 | P | Q | R | S | T | U | V | W | X | Y | Z | [ | \ | ] | ^ | _ | | +| 60 | ` | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | | +| 70 | p | q | r | s | t | u | v | w | x | y | z | { | | | } | ~ | DEL | + +The table shows the first 128 symbols. The hexadecimal representation of the number for a symbol is the row value added to the column value, for example A is 4116. What you may find surprising is the first two rows, and the very last value. These 33 special characters are not printed at all. In fact, these days, many are ignored. They exist because ASCII was originally intended as a system for transmitting data over computer networks, and so a lot more information than just the symbols had to be sent. The key special symbols that you should learn are NUL, the null terminator character I mentioned before, HT, horizontal tab is what we normally refer to as a tab and LF, the line feed character is used to make a new line. You may wish to research and use the other characters for special meanings in your operating system. + +### 2 Characters + +So, now that we know a bit about strings, we can start to think about how they're displayed. The fundamental thing we need to do in order to be able to display a string is to be able to display a character. Our first task will be making a DrawCharacter function which takes in a character to draw and a location, and then draws the character. + +``` +The true type font format used in many Operating Systems is so powerful, it has its own assembly language built in to ensure letters look correct at any resolution. +``` + +Naturally, this leads to a discussion about fonts. We already know there are many ways to display any given letter in accordance with font choice. So how does a font work? In the very early days of computer science, a font was just a series of little pictures of all the letters, called a bitmap font, and all the draw character method would do is copy one of the pictures to the screen. The trouble with this is when people want to resize the text. Sometimes we need big letters, and sometimes small. Although we could keep drawing new pictures for every font at every size with every character, this would get tedious. Thus, vector fonts were invented. in vector fonts, rather than containing an image of the font, the font file contains a description of how to draw it, e.g. an 'o' could be circle with radius half that of the maximum letter height. Modern operating systems use such fonts almost exclusively, as they are perfect at any resolution. + +Unfortunately, much though I would love to include an implementation of one of the vector font formats, it would take up the remainder of this website. Thus, we will implement a bitmap font, though if you wish to make a decent graphical operating system, a vector font would be useful. +``` +00000000 +00000000 +00000000 +00010000 +00101000 +00101000 +00101000 +01000100 +01000100 +01111100 +11000110 +10000010 +00000000 +00000000 +00000000 +00000000 +``` + +On the downloads page, I have included several '.bin' files in the font section. These are just raw binary data files for a few fonts. For this tutorial, pick your favourite from the monospace, monochrome, 8x16 section. Download it and store it in the 'source' directory as 'font.bin'. These files are just monochrome images of each of the letters in turn, with each letter being exactly 8 by 16 pixels. Thus, each takes 16 bytes, the first byte being the top row, the second the next, etc. + +The diagram shows the 'A' character in the monospace, monochrome, 8x16 font Bitstream Vera Sans Mono. In the file, we would find this starting at the 4116 × 1016 = 41016th byte as the following sequence in hexadecimal: + +00, 00, 00, 10, 28, 28, 28, 44, 44, 7C, C6, 82, 00, 00, 00, 00 + +We're going to use a monospace font here, because in a monospace font every character is the same size. Unfortunately, yet another complication with most fonts is that the character's widths vary, leading to more complex display code. I've included a few other fonts on the downloads page, as well as an explanation of the format I've stored them all in. + +So let's get down to business. Copy the following to 'drawing.s' after the .int 0 of graphicsAddress. + +``` +.align 4 +font: +.incbin "font.bin" +``` + +``` +.incbin "file" inserts the binary data from the file file. +``` + +This code copies the font data from the file to the address labelled font. We've used an .align 4 here to ensure each character starts on a multiple of 16 bytes, which can be used for a speed trick later. + +Now we want to write the draw character method. I'll give the pseudo code for this, so you can try to implement it yourself if you want to. Conventionally >> means logical shift right. + +``` +function drawCharacter(r0 is character, r1 is x, r2 is y) + if character > 127 then exit + set charAddress to font + character × 16 + for row = 0 to 15 + set bits to readByte(charAddress + row) + for bit = 0 to 7 + if test(bits >> bit, 0x1) + then setPixel(x + bit, y + row) + next + next + return r0 = 8, r1 = 16 +end function + +``` +If implemented directly, this is deliberately not very efficient. With things like drawing characters, efficiency is a top priority, as we will do it a lot. Let's explore some improvements that bring this closer to optimal assembly code. Firstly, we have a × 16, which by now you should spot is the same as a logical shift left by 4 places. Next we have a variable row, which is only ever added to charAddress and to y. Thus, we can eliminate it by increasing these variables instead. The only issue now is how to tell when we've finished. This is where the .align 4 comes in handy. We know that charAddress will start with the low nibble containing 0. This means we can see how far into the character data we are by checking that low nibble. + +Though we can eliminate the need for bits, we must introduce a new variable to do so, so it is best left in. The only other improvement that can be made is to remove the nested bits >> bit. + +``` +function drawCharacter(r0 is character, r1 is x, r2 is y) + if character > 127 then exit + set charAddress to font + character << 4 + loop + set bits to readByte(charAddress) + set bit to 8 + loop + set bits to bits << 1 + set bit to bit - 1 + if test(bits, 0x100) + then setPixel(x + bit, y) + until bit = 0 + set y to y + 1 + set chadAddress to chadAddress + 1 + until charAddress AND 0b1111 = 0 + return r0 = 8, r1 = 16 +end function +``` + +Now we've got code that is much closer to assembly code, and is near optimal. Below is the assembly code version of the above. + +``` +.globl DrawCharacter +DrawCharacter: +cmp r0,#127 +movhi r0,#0 +movhi r1,#0 +movhi pc,lr + +push {r4,r5,r6,r7,r8,lr} +x .req r4 +y .req r5 +charAddr .req r6 +mov x,r1 +mov y,r2 +ldr charAddr,=font +add charAddr, r0,lsl #4 + +lineLoop$: + + bits .req r7 + bit .req r8 + ldrb bits,[charAddr] + mov bit,#8 + + charPixelLoop$: + + subs bit,#1 + blt charPixelLoopEnd$ + lsl bits,#1 + tst bits,#0x100 + beq charPixelLoop$ + + add r0,x,bit + mov r1,y + bl DrawPixel + + teq bit,#0 + bne charPixelLoop$ + + charPixelLoopEnd$: + .unreq bit + .unreq bits + add y,#1 + add charAddr,#1 + tst charAddr,#0b1111 + bne lineLoop$ + +.unreq x +.unreq y +.unreq charAddr + +width .req r0 +height .req r1 +mov width,#8 +mov height,#16 + +pop {r4,r5,r6,r7,r8,pc} +.unreq width +.unreq height +``` + +### 3 Strings + +Now that we can draw characters, we can draw text. We need to make a method that, for a given string, draws each character in turn, at incrementing positions. To be nice, we shall also implement new lines and tabs. It's decision time as far as null terminators are concerned, and if you want to make your operating system use them, feel free by changing the code below. To avoid the issue, I will have the length of the string passed as an argument to the DrawString function, along with the address of the string, and the x and y coordinates. + +``` +function drawString(r0 is string, r1 is length, r2 is x, r3 is y) + set x0 to x + for pos = 0 to length - 1 + set char to loadByte(string + pos) + set (cwidth, cheight) to DrawCharacter(char, x, y) + if char = '\n' then + set x to x0 + set y to y + cheight + otherwise if char = '\t' then + set x1 to x + until x1 > x0 + set x1 to x1 + 5 × cwidth + loop + set x to x1 + otherwise + set x to x + cwidth + end if + next +end function +``` + +Once again, this function isn't that close to assembly code. Feel free to try to implement it either directly or by simplifying it. I will give the simplification and then the assembly code below. + +Clearly the person who wrote this function wasn't being very efficient (me in case you were wondering). Once again we have a pos variable that just increments and is added to something else, which is completely unnecessary. We can remove it, and instead simultaneously decrement length until it is 0, saving the need for one register. The rest of the function is probably fine, except for that annoying multiplication by five. A key thing to do here would be to move the multiplication outside the loop; multiplication is slow even with bit shifts, and since we're always adding the same constant multiplied by 5, there is no need to recompute this. It can in fact be implemented in one operation using the argument shifting in assembly code, so I shall rephrase it like that. + +``` +function drawString(r0 is string, r1 is length, r2 is x, r3 is y) + set x0 to x + until length = 0 + set length to length - 1 + set char to loadByte(string) + set (cwidth, cheight) to DrawCharacter(char, x, y) + if char = '\n' then + set x to x0 + set y to y + cheight + otherwise if char = '\t' then + set x1 to x + set cwidth to cwidth + cwidth << 2 + until x1 > x0 + set x1 to x1 + cwidth + loop + set x to x1 + otherwise + set x to x + cwidth + end if + set string to string + 1 + loop +end function +``` + +In assembly code: + +``` +.globl DrawString +DrawString: +x .req r4 +y .req r5 +x0 .req r6 +string .req r7 +length .req r8 +char .req r9 +push {r4,r5,r6,r7,r8,r9,lr} + +mov string,r0 +mov x,r2 +mov x0,x +mov y,r3 +mov length,r1 + +stringLoop$: + subs length,#1 + blt stringLoopEnd$ + + ldrb char,[string] + add string,#1 + + mov r0,char + mov r1,x + mov r2,y + bl DrawCharacter + cwidth .req r0 + cheight .req r1 + + teq char,#'\n' + moveq x,x0 + addeq y,cheight + beq stringLoop$ + + teq char,#'\t' + addne x,cwidth + bne stringLoop$ + + add cwidth, cwidth,lsl #2 + x1 .req r1 + mov x1,x0 + + stringLoopTab$: + add x1,cwidth + cmp x,x1 + bge stringLoopTab$ + mov x,x1 + .unreq x1 + b stringLoop$ +stringLoopEnd$: +.unreq cwidth +.unreq cheight + +pop {r4,r5,r6,r7,r8,r9,pc} +.unreq x +.unreq y +.unreq x0 +.unreq string +.unreq length +``` + +``` +subs reg,#val subtracts val from the register reg and compares the result with 0. +``` + +This code makes clever use of a new operation, subs which subtracts one number from another, stores the result and then compares it with 0. In truth, all comparisons are implemented as a subtraction and then comparison with 0, but the result is normally discarded. This means that this operation is as fast as cmp. + +### 4 Your Wish is My Command Line + +Now that we can print strings, the challenge is to find an interesting one to draw. Normally in tutorials such as this, people just draw "Hello World!", but after all we've done so far, I feel that is a little patronising (feel free to do so if it helps). Instead we're going to draw our command line. + +A convention has been made for computers running ARM. When they boot, it is important they are given certain information about what they have available to them. Most all processors have some way of ascertaining this information, and on ARM this is by data left at the address 10016. The format of the data is as follows: + + 1. The data is broken down into a series of 'tags'. + 2. There are nine types of tag: 'core', 'mem', 'videotext', 'ramdisk', 'initrd2', 'serial' 'revision', 'videolfb', 'cmdline'. + 3. Each can only appear once, but all but the 'core' tag don't have to appear. + 4. The tags are placed from 0x100 in order one after the other. + 5. The end of the list of tags always contains 2 words which are 0. + 6. Every tag's size in bytes is a multiple of 4. + 7. Each tag starts with the size of the tag in words in the tag, including this number. + 8. This is followed by a half word containing the tag's number. These are numbered from 1 in the order above ('core' is 1, 'cmdline' is 9). + 9. This is followed by a half word containing 544116. + 10. After this comes the data of the tag, which varies depending on the tag. The size of the data in words + 2 is always the same as the length mentioned above. + 11. A 'core' tag is either 2 or 5 words in length. If it is 2, there is no data, if it is 5, it has 3 words. + 12. A 'mem' tag is always 4 words in length. The data is the first address in a block of memory, and the length of that block. + 13. A 'cmdline' tag contains a null terminated string which is the parameters of the kernel. + + +``` +Almost all Operating Systems support the notion of programs having a 'command line'. The idea is to provide a common mechanism for choosing the desired behaviour of the program. +``` + +On the current version of the Raspberry Pi, only the 'core', 'mem' and 'cmdline' tags are present. You may find these useful later, and a more complete reference for these is on our Raspberry Pi reference page. The one we're interested in at the moment is the 'cmdline' tag, because it contains a string. We're going to write some code to search for the command line tag, and, if found, to print it out with each item on a new line. The command line is just a list of things that either the graphics processor or the user thought it might be nice for the Operating System to know. On the Raspberry Pi, this includes the MAC Address, serial number and screen resolution. The string itself is just a list of expressions such as 'key.subkey=value' separated by spaces. + +Let's start by finding the 'cmdline' tag. In a new file called 'tags.s' copy the following code. + +``` +.section .data +tag_core: .int 0 +tag_mem: .int 0 +tag_videotext: .int 0 +tag_ramdisk: .int 0 +tag_initrd2: .int 0 +tag_serial: .int 0 +tag_revision: .int 0 +tag_videolfb: .int 0 +tag_cmdline: .int 0 +``` + +Looking through the list of tags will be a slow operation, as it involves a lot of memory access. Therefore, we only want to have to do it once. This code creates some data which will store the memory address of the first tag of each of the types. Then, to find a tag the following pseudo code will suffice. + +``` +function FindTag(r0 is tag) + if tag > 9 or tag = 0 then return 0 + set tagAddr to loadWord(tag_core + (tag - 1) × 4) + if not tagAddr = 0 then return tagAddr + if readWord(tag_core) = 0 then return 0 + set tagAddr to 0x100 + loop forever + set tagIndex to readHalfWord(tagAddr + 4) + if tagIndex = 0 then return FindTag(tag) + if readWord(tag_core+(tagIndex-1)×4) = 0 + then storeWord(tagAddr, tag_core+(tagIndex-1)×4) + set tagAddr to tagAddr + loadWord(tagAddr) × 4 + end loop +end function +``` +This code is already quite well optimised and close to assembly. It is optimistic in that the first thing it tries is loading the tag directly, as all but the first time this should be the case. If that fails, it checks if the core tag has an address. Since there must always be a core tag, the only reason that it would not have an address is if it doesn't exist. If it does have an address, the tag we were looking for didn't. If it doesn't we need to find the addresses of all the tags. It does this by reading the number of the tag. If it is zero, that must mean we are at the end of the list. This means we've now filled in all the tags in our directory. Therefore if we run our function again, it will now be able to produce an answer. If the tag number is not zero, we check to see if this tag type already has an address. If not, we store the address of this tag in our directory. We then add the length of this tag in bytes to the tag address to find the next tag. + +Have a go at implementing this code in assembly. You will need to simplify it. If you get stuck, my answer is below. Don't forget the .section .text! + +``` +.section .text +.globl FindTag +FindTag: +tag .req r0 +tagList .req r1 +tagAddr .req r2 + +sub tag,#1 +cmp tag,#8 +movhi tag,#0 +movhi pc,lr + +ldr tagList,=tag_core +tagReturn$: +add tagAddr,tagList, tag,lsl #2 +ldr tagAddr,[tagAddr] + +teq tagAddr,#0 +movne r0,tagAddr +movne pc,lr + +ldr tagAddr,[tagList] +teq tagAddr,#0 +movne r0,#0 +movne pc,lr + +mov tagAddr,#0x100 +push {r4} +tagIndex .req r3 +oldAddr .req r4 +tagLoop$: +ldrh tagIndex,[tagAddr,#4] +subs tagIndex,#1 +poplt {r4} +blt tagReturn$ + +add tagIndex,tagList, tagIndex,lsl #2 +ldr oldAddr,[tagIndex] +teq oldAddr,#0 +.unreq oldAddr +streq tagAddr,[tagIndex] + +ldr tagIndex,[tagAddr] +add tagAddr, tagIndex,lsl #2 +b tagLoop$ + +.unreq tag +.unreq tagList +.unreq tagAddr +.unreq tagIndex +``` + +### 5 Hello World + +Now that we have everything we need, we can draw our first string. In 'main.s' delete everything after bl SetGraphicsAddress, and replace it with the following: + +``` +mov r0,#9 +bl FindTag +ldr r1,[r0] +lsl r1,#2 +sub r1,#8 +add r0,#8 +mov r2,#0 +mov r3,#0 +bl DrawString +loop$: +b loop$ +``` + +This code simply uses our FindTag method to find the 9th tag (cmdline) and then calculates its length and passes the command and the length to the DrawString method, and tells it to draw the string at 0,0. Now test this on the Raspberry Pi. You should see a line of text on the screen. If not please see our troubleshooting page. + +Once it works, congratulations you've now got the ability to draw text. But there is still room for improvement. What if we wanted to write out a number, or a section of the memory or manipulate our command line? In [Lesson 9: Screen04][2], we will look at manipulating text and displaying useful numbers and information. + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen03.html + +作者：[Alex Chadwick][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.cl.cam.ac.uk +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen02.html +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen04.html diff --git a/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 9 Screen04.md b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 9 Screen04.md new file mode 100644 index 0000000000..1ca2a16609 --- /dev/null +++ b/sources/tech/20150616 Computer Laboratory - Raspberry Pi- Lesson 9 Screen04.md @@ -0,0 +1,540 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 9 Screen04) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen04.html) +[#]: author: (Alex Chadwick https://www.cl.cam.ac.uk) + +Computer Laboratory – Raspberry Pi: Lesson 9 Screen04 +====== + +The Screen04 lesson builds on Screen03, by teaching how to manipulate text. It is assumed you have the code for the [Lesson 8: Screen03][1] operating system as a basis. + +### 1 String Manipulation + +``` +Variadic functions look much less intuitive in assembly code. Nevertheless, they are useful and powerful concepts. +``` + +Being able to draw text is lovely, but unfortunately at the moment you can only draw strings which are already prepared. This is fine for displaying something like the command line, but ideally we would like to be able to display and text we so desire. As per usual, if we put the effort in and make an excellent function that does all the string manipulation we could ever want, we get much easier code later on in return. Once such complicated function in C programming is sprintf. This function generates a string based on a description given as another string and additional arguments. What is interesting about this function is that it is variadic. This means that it takes a variable number of parameters. The number of parameters depends on the exact format string, and so cannot be determined in advance. + +The full function has many options, and I list a few here. I've highlighted the ones which we will implement in this tutorial, though you can try to implement more. + +The function works by reading the format string, and then interpreting it using the table below. Once an argument is used, it is not considered again. The return value of the function is the number of characters written. If the method fails, a negative number is returned. + +Table 1.1 sprintf formatting rules +| Sequence | Meaning | +| ---------------------- | ---------------------- | +| Any character except % | Copies the character to the output. | +| %% | Writes a % character to the output. | +| %c | Writes the next argument as a character. | +| %d or %i | Writes the next argument as a base 10 signed integer. | +| %e | Writes the next argument in scientific notation using eN to mean ×10N. | +| %E | Writes the next argument in scientific notation using EN to mean ×10N. | +| %f | Writes the next argument as a decimal IEEE 754 floating point number. | +| %g | Same as the shorter of %e and %f. | +| %G | Same as the shorter of %E and %f. | +| %o | Writes the next argument as a base 8 unsigned integer. | +| %s | Writes the next argument as if it were a pointer to a null terminated string. | +| %u | Writes the next argument as a base 10 unsigned integer. | +| %x | Writes the next argument as a base 16 unsigned integer, with lowercase a,b,c,d,e and f. | +| %X | Writes the next argument as a base 16 unsigned integer, with uppercase A,B,C,D,E and F. | +| %p | Writes the next argument as a pointer address. | +| %n | Writes nothing. Copies instead the number of characters written so far to the location addressed by the next argument. | + +Further to the above, many additional tweaks exist to the sequences, such as specifying minimum length, signs, etc. More information can be found at [sprintf - C++ Reference][2]. + +Here are a few examples of calls to the method and their results to illustrate its use. + +Table 1.2 sprintf example calls +| Format String | Arguments | Result | +| "%d" | 13 | "13" | +| "+%d degrees" | 12 | "+12 degrees" | +| "+%x degrees" | 24 | "+1c degrees" | +| "'%c' = 0%o" | 65, 65 | "'A' = 0101" | +| "%d * %d%% = %d" | 200, 40, 80 | "200 * 40% = 80" | +| "+%d degrees" | -5 | "+-5 degrees" | +| "+%u degrees" | -5 | "+4294967291 degrees" | + +Hopefully you can already begin to see the usefulness of the function. It does take a fair amount of work to program, but our reward is a very general function we can use for all sorts of purposes. + +### 2 Division + +``` +Division is the slowest and most complicated of the basic mathematical operators. It is not implemented directly in ARM assembly code because it takes so long to deduce the answer, and so isn't a 'simple' operation. +``` + +While this function does look very powerful, it also looks very complicated. The easiest way to deal with its many cases is probably to write functions to deal with some common tasks it has. What would be useful would be a function to generate the string for a signed and an unsigned number in any base. So, how can we go about doing that? Try to devise an algorithm quickly before reading on. + +The easiest way is probably the exact way I mentioned in [Lesson 1: OK01][3], which is the division remainder method. The idea is the following: + + 1. Divide the current value by the base you're working in. + 2. Store the remainder. + 3. If the new value is not 0, go to 1. + 4. Reverse the order of the remainders. This is the answer. + + + +For example: + +Table 2.1 Example base 2 +conversion +| Value | New Value | Remainder | +| ----- | --------- | --------- | +| 137 | 68 | 1 | +| 68 | 34 | 0 | +| 34 | 17 | 0 | +| 17 | 8 | 1 | +| 8 | 4 | 0 | +| 4 | 2 | 0 | +| 2 | 1 | 0 | +| 1 | 0 | 1 | + +So the answer is 100010012 + +The unfortunate part about this procedure is that it unavoidably uses division. Therefore, we must first contemplate division in binary. + +For a refresher on long division expand the box below. + +``` +Let's suppose we wish to divide 4135 by 17. + + 0243 r 4 +17)4135 + 0 0 × 17 = 0000 + 4135 4135 - 0 = 4135 + 34 200 × 17 = 3400 + 735 4135 - 3400 = 735 + 68 40 × 17 = 680 + 55 735 - 680 = 55 + 51 3 × 17 = 51 + 4 55 - 51 = 4 + Answer: 243 remainder 4 + +First of all we would look at the top digit of the dividend. We see that the smallest multiple of the divisor which is less or equal to it is 0. We output a 0 to the result. + +Next we look at the second to top digit of the dividend and all higher digits. We see the smallest multiple of the divisor which is less than or equal is 34. We output a 2 and subtract 3400. + +Next we look at the third digit of the dividend and all higher digits. The smallest multiple of the divisor that is less than or equal to this is 68. We output 4 and subtract 680. + +Finally we look at all remaining digits. We see that the lowest multiple of the divisor that is less than the remaining digits is 51. We output a 3, subtract 51. The result of the subtraction is our remainder. +``` + +To implement division in assembly code, we will implement binary long division. We do this because the numbers are stored in binary, which gives us easy access to the all important bit shift operations, and because division in binary is simpler than in any higher base due to the much lower number of cases. + +``` + 1011 r 1 +1010)1101111 + 1010 + 11111 + 1010 + 1011 + 1010 + 1 +This example shows how binary long division works. You simply shift the divisor as far right as possible without exceeding the dividend, output a 1 according to the poisition and subtract the number. Whatever remains is the remainder. In this case we show 11011112 ÷ 10102 = 10112 remainder 12. In decimal, 111 ÷ 10 = 11 remainder 1. +``` + + +Try to implement long division yourself now. You should write a function, DivideU32 which divides r0 by r1, returning the result in r0, and the remainder in r1. Below, we will go through a very efficient implementation. + +``` +function DivideU32(r0 is dividend, r1 is divisor) + set shift to 31 + set result to 0 + while shift ≥ 0 + if dividend ≥ (divisor << shift) then + set dividend to dividend - (divisor << shift) + set result to result + 1 + end if + set result to result << 1 + set shift to shift - 1 + loop + return (result, dividend) +end function +``` + +This code does achieve what we need, but would not work as assembly code. Our problem comes from the fact that our registers only hold 32 bits, and so the result of divisor << shift may not fit in a register (we call this overflow). This is a real problem. Did your solution have overflow? + +Fortunately, an instruction exists called clz or count leading zeros, which counts the number of zeros in the binary representation of a number starting at the top bit. Conveniently, this is exactly the number of times we can shift the register left before overflow occurs. Another optimisation you may spot is that we compute divisor << shift twice each loop. We could improve upon this by shifting the divisor at the beginning, then shifting it down at the end of each loop to avoid any need to shift it elsewhere. + +Let's have a look at the assembly code to make further improvements. + +``` +.globl DivideU32 +DivideU32: +result .req r0 +remainder .req r1 +shift .req r2 +current .req r3 + +clz shift,r1 +lsl current,r1,shift +mov remainder,r0 +mov result,#0 + +divideU32Loop$: + cmp shift,#0 + blt divideU32Return$ + cmp remainder,current + + addge result,result,#1 + subge remainder,current + sub shift,#1 + lsr current,#1 + lsl result,#1 + b divideU32Loop$ +divideU32Return$: +.unreq current +mov pc,lr + +.unreq result +.unreq remainder +.unreq shift +``` + +``` +clz dest,src stores the number of zeros from the top to the first one of register dest to register src +``` + +You may, quite rightly, think that this looks quite efficient. It is pretty good, but division is a very expensive operation, and one we may wish to do quite often, so it would be good if we could improve the speed in any way. When looking to optimise code with a loop in it, it is always important to consider how many times the loop must run. In this case, the loop will run a maximum of 31 times for an input of 1. Without making special cases, this could often be improved easily. For example when dividing 1 by 1, no shift is required, yet we shift the divisor to each of the positions above it. This could be improved by simply using the new clz command on the dividend and subtracting this from the shift. In the case of 1 ÷ 1, this means shift would be set to 0, rightly indicating no shift is required. If this causes the shift to be negative, the divisor is bigger than the dividend and so we know the result is 0 remainder the dividend. Another quick check we could make is if the current value is ever 0, then we have a perfect division and can stop looping. + +``` +.globl DivideU32 +DivideU32: +result .req r0 +remainder .req r1 +shift .req r2 +current .req r3 + +clz shift,r1 +clz r3,r0 +subs shift,r3 +lsl current,r1,shift +mov remainder,r0 +mov result,#0 +blt divideU32Return$ + +divideU32Loop$: + cmp remainder,current + blt divideU32LoopContinue$ + + add result,result,#1 + subs remainder,current + lsleq result,shift + beq divideU32Return$ +divideU32LoopContinue$: + subs shift,#1 + lsrge current,#1 + lslge result,#1 + bge divideU32Loop$ + +divideU32Return$: +.unreq current +mov pc,lr + +.unreq result +.unreq remainder +.unreq shift +``` + +Copy the code above to a file called 'maths.s'. + +### 3 Number Strings + +Now that we can do division, let's have another look at implementing number to string conversion. The following is pseudo code to convert numbers from registers into strings in up to base 36. By convention, a % b means the remainder of dividing a by b. + +``` +function SignedString(r0 is value, r1 is dest, r2 is base) + if value ≥ 0 + then return UnsignedString(value, dest, base) + otherwise + if dest > 0 then + setByte(dest, '-') + set dest to dest + 1 + end if + return UnsignedString(-value, dest, base) + 1 + end if +end function + +function UnsignedString(r0 is value, r1 is dest, r2 is base) + set length to 0 + do + + set (value, rem) to DivideU32(value, base) + if rem > 10 + then set rem to rem + '0' + otherwise set rem to rem - 10 + 'a' + if dest > 0 + then setByte(dest + length, rem) + set length to length + 1 + + while value > 0 + if dest > 0 + then ReverseString(dest, length) + return length +end function + +function ReverseString(r0 is string, r1 is length) + set end to string + length - 1 + while end > start + set temp1 to readByte(start) + set temp2 to readByte(end) + setByte(start, temp2) + setByte(end, temp1) + set start to start + 1 + set end to end - 1 + end while +end function +``` + +In a file called 'text.s' implement the above. Remember that if you get stuck, a full solution can be found on the downloads page. + +### 4 Format Strings + +Let's get back to our string formatting method. Since we're programming our own operating system, we can add or change formatting rules as we please. We may find it useful to add a %b operation that outputs a number in binary, and if you're not using null terminated strings, you may wish to alter the behaviour of %s to take the length of the string from another argument, or from a length prefix if you wish. I will use a null terminator in the example below. + +One of the main obstacles to implementing this function is that the number of arguments varies. According to the ABI, additional arguments are pushed onto the stack before calling the method in reverse order. So, for example, if we wish to call our method with 8 parameters; 1,2,3,4,5,6,7 and 8, we would do the following: + + 1. Set r0 = 5, r1 = 6, r2 = 7, r3 = 8 + 2. Push {r0,r1,r2,r3} + 3. Set r0 = 1, r1 = 2, r2 = 3, r3 = 4 + 4. Call the function + 5. Add sp,#4*4 + + + +Now we must decide what arguments our function actually needs. In my case, I used the format string address in r0, the length of the format string in r1, the destination string address in r2, followed by the list of arguments required, starting in r3 and continuing on the stack as above. If you wish to use a null terminated format string, the parameter in r1 can be removed. If you wish to have a maximum buffer length, you could store this in r3. As an additional modification, I think it is useful to alter the function so that if the destination string address is 0, no string is outputted, but an accurate length is still returned, so that the length of a formatted string can be accurately determined. + +If you wish to attempt the implementation on your own, try it now. If not, I will first construct the pseudo code for the method, then give the assembly code implementation. + +``` +function StringFormat(r0 is format, r1 is formatLength, r2 is dest, ...) + set index to 0 + set length to 0 + while index < formatLength + if readByte(format + index) = '%' then + set index to index + 1 + if readByte(format + index) = '%' then + if dest > 0 + then setByte(dest + length, '%') + set length to length + 1 + otherwise if readByte(format + index) = 'c' then + if dest > 0 + then setByte(dest + length, nextArg) + set length to length + 1 + otherwise if readByte(format + index) = 'd' or 'i' then + set length to length + SignedString(nextArg, dest, 10) + otherwise if readByte(format + index) = 'o' then + set length to length + UnsignedString(nextArg, dest, 8) + otherwise if readByte(format + index) = 'u' then + set length to length + UnsignedString(nextArg, dest, 10) + otherwise if readByte(format + index) = 'b' then + set length to length + UnsignedString(nextArg, dest, 2) + otherwise if readByte(format + index) = 'x' then + set length to length + UnsignedString(nextArg, dest, 16) + otherwise if readByte(format + index) = 's' then + set str to nextArg + while getByte(str) != '\0' + if dest > 0 + then setByte(dest + length, getByte(str)) + set length to length + 1 + set str to str + 1 + loop + otherwise if readByte(format + index) = 'n' then + setWord(nextArg, length) + end if + otherwise + if dest > 0 + then setByte(dest + length, readByte(format + index)) + set length to length + 1 + end if + set index to index + 1 + loop + return length +end function +``` + +Although this function is massive, it is quite straightforward. Most of the code goes into checking all the various conditions, the code for each one is simple. Further, all the various unsigned integer cases are the same but for the base, and so can be summarised in assembly. This is given below. + +``` +.globl FormatString +FormatString: +format .req r4 +formatLength .req r5 +dest .req r6 +nextArg .req r7 +argList .req r8 +length .req r9 + +push {r4,r5,r6,r7,r8,r9,lr} +mov format,r0 +mov formatLength,r1 +mov dest,r2 +mov nextArg,r3 +add argList,sp,#7*4 +mov length,#0 + +formatLoop$: + subs formatLength,#1 + movlt r0,length + poplt {r4,r5,r6,r7,r8,r9,pc} + + ldrb r0,[format] + add format,#1 + teq r0,#'%' + beq formatArg$ + +formatChar$: + teq dest,#0 + strneb r0,[dest] + addne dest,#1 + add length,#1 + b formatLoop$ + +formatArg$: + subs formatLength,#1 + movlt r0,length + poplt {r4,r5,r6,r7,r8,r9,pc} + + ldrb r0,[format] + add format,#1 + teq r0,#'%' + beq formatChar$ + + teq r0,#'c' + moveq r0,nextArg + ldreq nextArg,[argList] + addeq argList,#4 + beq formatChar$ + + teq r0,#'s' + beq formatString$ + + teq r0,#'d' + beq formatSigned$ + + teq r0,#'u' + teqne r0,#'x' + teqne r0,#'b' + teqne r0,#'o' + beq formatUnsigned$ + + b formatLoop$ + +formatString$: + ldrb r0,[nextArg] + teq r0,#0x0 + ldreq nextArg,[argList] + addeq argList,#4 + beq formatLoop$ + add length,#1 + teq dest,#0 + strneb r0,[dest] + addne dest,#1 + add nextArg,#1 + b formatString$ + +formatSigned$: + mov r0,nextArg + ldr nextArg,[argList] + add argList,#4 + mov r1,dest + mov r2,#10 + bl SignedString + teq dest,#0 + addne dest,r0 + add length,r0 + b formatLoop$ + +formatUnsigned$: + teq r0,#'u' + moveq r2,#10 + teq r0,#'x' + moveq r2,#16 + teq r0,#'b' + moveq r2,#2 + teq r0,#'o' + moveq r2,#8 + + mov r0,nextArg + ldr nextArg,[argList] + add argList,#4 + mov r1,dest + bl UnsignedString + teq dest,#0 + addne dest,r0 + add length,r0 + b formatLoop$ +``` + +### 5 Convert OS + +Feel free to try using this method however you wish. As an example, here is the code to generate a conversion chart from base 10 to binary to hexadecimal to octal and to ASCII. + +Delete all code after bl SetGraphicsAddress in 'main.s' and replace it with the following: + +``` +mov r4,#0 +loop$: +ldr r0,=format +mov r1,#formatEnd-format +ldr r2,=formatEnd +lsr r3,r4,#4 +push {r3} +push {r3} +push {r3} +push {r3} +bl FormatString +add sp,#16 + +mov r1,r0 +ldr r0,=formatEnd +mov r2,#0 +mov r3,r4 + +cmp r3,#768-16 +subhi r3,#768 +addhi r2,#256 +cmp r3,#768-16 +subhi r3,#768 +addhi r2,#256 +cmp r3,#768-16 +subhi r3,#768 +addhi r2,#256 + +bl DrawString + +add r4,#16 +b loop$ + +.section .data +format: +.ascii "%d=0b%b=0x%x=0%o='%c'" +formatEnd: +``` + +Can you work out what will happen before testing? Particularly what happens for r3 ≥ 128? Try it on the Raspberry Pi to see if you're right. If it doesn't work, please see our troubleshooting page. + +When it does work, congratulations, you've completed the Screen04 tutorial, and reached the end of the screen series! We've learned about pixels and frame buffers, and how these apply to the Raspberry Pi. We've learned how to draw simple lines, and also how to draw characters, as well as the invaluable skill of formatting numbers into text. We now have all that you would need to make graphical output on an Operating System. Can you make some more drawing methods? What about 3D graphics? Can you implement a 24bit frame buffer? What about reading the size of the framebuffer in from the command line? + +The next series is the [Input][4] series, which teaches how to use the keyboard and mouse to really get towards a traditional console computer. + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen04.html + +作者：[Alex Chadwick][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.cl.cam.ac.uk +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/screen03.html +[2]: http://www.cplusplus.com/reference/clibrary/cstdio/sprintf/ +[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok01.html +[4]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/input01.html diff --git a/sources/tech/20171215 Top 5 Linux Music Players.md b/sources/tech/20171215 Top 5 Linux Music Players.md index 3725766d2f..a57ad29c52 100644 --- a/sources/tech/20171215 Top 5 Linux Music Players.md +++ b/sources/tech/20171215 Top 5 Linux Music Players.md @@ -1,3 +1,4 @@ +tomjlw is translating Top 5 Linux Music Players ====== @@ -114,7 +115,7 @@ Learn more about Linux through the free ["Introduction to Linux" ][22]course fro via: https://www.linux.com/learn/intro-to-linux/2017/12/top-5-linux-music-players 作者：[][a] -译者：[译者ID](https://github.com/译者ID) +译者：[tomjlw](https://github.com/tomjlw) 校对：[校对者ID](https://github.com/校对者ID) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 diff --git a/sources/tech/20180128 Get started with Org mode without Emacs.md b/sources/tech/20180128 Get started with Org mode without Emacs.md new file mode 100644 index 0000000000..75a5bcb092 --- /dev/null +++ b/sources/tech/20180128 Get started with Org mode without Emacs.md @@ -0,0 +1,78 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Get started with Org mode without Emacs) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-org-mode) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +Get started with Org mode without Emacs +====== +No, you don't need Emacs to use Org, the 16th in our series on open source tools that will make you more productive in 2019. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/web_browser_desktop_devlopment_design_system_computer.jpg?itok=pfqRrJgh) + +There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. + +Here's the 16th of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. + +### Org (without Emacs) + +[Org mode][1] (or just Org) is not in the least bit new, but there are still many people who have never used it. They would love to try it out to get a feel for how Org can help them be productive. But the biggest barrier is that Org is associated with Emacs, and many people think one requires the other. Not so! Org can be used with a variety of other tools and editors once you understand the basics. + +![](https://opensource.com/sites/default/files/uploads/org-1.png) + +Org, at its very heart, is a structured text file. It has headers, subheaders, and keywords that allow other tools to parse files into agendas and to-do lists. Org files can be edited with any flat-text editor (e.g., [Vim][2], [Atom][3], or [Visual Studio Code][4]), and many have plugins that help create and manage Org files. + +A basic Org file looks something like this: + +``` +* Task List +** TODO Write Article for Day 16 - Org w/out emacs +   DEADLINE: <2019-01-25 12:00> +*** DONE Write sample org snippet for article +    - Include at least one TODO and one DONE item +    - Show notes +    - Show SCHEDULED and DEADLINE +*** TODO Take Screenshots +** Dentist Appointment +   SCHEDULED: <2019-01-31 13:30-14:30> +``` + +Org uses an outline format that uses ***** as bullets to indicate an item's level. Any item that begins with the word TODO (yes, in all caps) is just that—a to-do item. The work DONE indicates it is completed. SCHEDULED and DEADLINE indicate dates and times relevant to the item. If there's no time in either field, the item is considered an all-day event. + +With the right plugins, your favorite text editor becomes a powerhouse of productivity and organization. For example, the [vim-orgmode][5] plugin's features include functions to create Org files, syntax highlighting, and key commands to generate agendas and comprehensive to-do lists across files. + +![](https://opensource.com/sites/default/files/uploads/org-2.png) + +The Atom [Organized][6] plugin adds a sidebar on the right side of the screen that shows the agenda and to-do items in Org files. It can read from multiple files by default with a path set up in the configuration options. The Todo sidebar allows you to click on a to-do item to mark it done, then automatically updates the source Org file. + +![](https://opensource.com/sites/default/files/uploads/org-3.png) + +There are also a whole host of tools that "speak Org" to help keep you productive. With libraries in Python, Perl, PHP, NodeJS, and more, you can develop your own scripts and tools. And, of course, there is also [Emacs][7], which has Org support within the core distribution. + +![](https://opensource.com/sites/default/files/uploads/org-4.png) + +Org mode is one of the best tools for keeping on track with what needs to be done and when. And, contrary to myth, it doesn't need Emacs, just a text editor. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-org-mode + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: https://orgmode.org/ +[2]: https://www.vim.org/ +[3]: https://atom.io/ +[4]: https://code.visualstudio.com/ +[5]: https://github.com/jceb/vim-orgmode +[6]: https://atom.io/packages/organized +[7]: https://www.gnu.org/software/emacs/ diff --git a/sources/tech/20180129 Tips and tricks for using CUPS for printing with Linux.md b/sources/tech/20180129 Tips and tricks for using CUPS for printing with Linux.md new file mode 100644 index 0000000000..f676b0efb9 --- /dev/null +++ b/sources/tech/20180129 Tips and tricks for using CUPS for printing with Linux.md @@ -0,0 +1,101 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Tips and tricks for using CUPS for printing with Linux) +[#]: via: (https://opensource.com/article/19/1/cups-printing-linux) +[#]: author: (Antoine Thomas https://opensource.com/users/ttoine) + +Tips and tricks for using CUPS for printing with Linux +====== +One of Apple's most important contributions to GNU/Linux was adopting CUPS in Mac OS X. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/email_paper_envelope_document.png?itok=uPj_kouJ) + +Did you ever try to configure a printer on a GNU/Linux desktop distribution at the end of the '90s? Or even before? + +To make a long story short: That was fine if you worked at a large organization with an IT team to handle it and dedicated hardware or a printing server. There were many different standards and protocols to handle printers. And only a few big vendors (usually Unix vendors) provided specific support and drivers for their entire range of products. + +However, if open source enthusiasts wanted a home printer that would work with their favorite distribution, that was another story. They probably spent a fair amount of time on forums, newsgroups, or IRC (remember those ancestors of social networks and chats?) asking about printers with easy-to-install Linux drivers. + +In 1999, the first version of [CUPS][1] (the Common Unix Printing System) was released by Easy Software Products. Most of the most popular distributions at the time adopted CUPS as their default printing system. That was a huge success: one standard could handle many printers and protocols. + +But if the printer vendor didn't provide a CUPS driver, it was still tricky or impossible to make it work. Some smart people might do reverse engineering. And a few printers, with native support of PostScript and Internet Printing Protocol (IPP), worked "out of the box." + +### Then came Apple + +In the early 2000s, Apple was struggling to build a new printing system for its new Mac OS X. In March 2002, it decided to save time by adopting CUPS for its flagship operating system. + +No printer vendor could ignore Apple computers' market share, so a lot of new printer drivers for Mac OS X's CUPS became available, spanning most vendors and product ranges, including corporate, graphic arts, consumer, and photo printing. + +CUPS became so important for Apple that it bought the software from Easy Software Products in 2007; since then Apple has continued to maintain it and manage its intellectual property. + +### But what does that have to do with GNU/Linux? + +At the time Apple integrated CUPS in Mac OS X, it was already used by default in many distros and available for most others. But few dedicated drivers were available, meaning they were not packaged or listed as "for GNU/Linux." + +However, once CUPS drivers were available for Mac OS X, a simple hack became popular with GNU/Linux enthusiasts: download the Mac driver, extract the PPD files, and test them with your printer. I used this hack many times with my Epson printers. + +That's the CUPS magic: If a driver exists, it usually works with all operating systems that use CUPS for printing, as long as they use a supported protocol (like IPP). + +That's how printer drivers began to be available for GNU/Linux. + +### Nowadays + +Afterward, printer vendors realized it was quite easy to provide drivers for GNU/Linux since they already developed them for Mac. It's now easy to find a GNU/Linux driver for a printer, even a newer one. Some distributions include packages with a lot of drivers, and most vendors provide dedicated drivers—sometimes via a package, other times with PPD files in an archive. + +Advanced control applications are available too, some official, some not, which make it possible (for example) to look at ink levels or clean printing heads. + +In some cases, installing a printer on GNU/Linux is even easier than on other operating systems, particularly with distributions using [zero-configuration networking][2] (e.g., Bonjour, Avahi) to auto-discover and share network printers. + +### Tips and tricks + + * **Install a PDF printer:** Installing a PDF printer on GNU/Linux is very easy. Just look for the **cups-pdf** package in your favorite distribution and install it. If the package doesn't automatically create the PDF printer, you can add one using your system preferences to print in PDF from any application. + + * **Access the CUPS web interface:** If your usual interface for managing printers doesn't work or you don't like it, open a web browser and go to . You can manage all the printers installed on your computer, adjust their settings, and even add new ones—all from this web interface. Note that this might be available on other computers on your network; if so, replace "localhost" with the relevant hostname or IP address. + + * **Check ink level:** If you have an Epson, Canon, HP, or Sony printer, you can see its ink level with a simple application. Look for the "ink" package in your distribution repositories. + + * **Contribute to CUPS:** Like many open source project, CUPS is maintained on GitHub. Check the [CUPS website][1] and [GitHub issues][3] to find out how you can contribute to improving it. + + + + +### CUPS license + +Originally, CUPS was released under GPLv2. I'm not sure why; maybe to make it easier to distribute with GNU/Linux. Or maybe it was just what most open source projects did at the time. + +Apple decided to [change the license][4] in November 2017 to the Apache 2.0 license. Many observers commented that it was consistent with Apple's strategy to move the IP of its open source projects to more business-compliant licenses. + +While this change could create issues with shipping CUPS with GNU/Linux, it is still available in most distributions. + +### Happy 20th birthday, CUPS! + +CUPS was released in 1999, so, let's celebrate and thank all the people involved in this successful open source project, from the original authors to the driver developers to its current maintainers. + +The next time you print with your favorite GNU/Linux operating system, remind yourself to say "thank you" to Apple. + +The company isn't well known for its contributions to open source. But if you look carefully (at, for example, [Apple's Open Source Releases][5] and [Open Source Development][6] pages), you'll see how many open source components are in Apple's operating systems and applications. + +You'll also discover other important open source projects Apple kicked off. For example, it forked KHTML, the KDE browser, to create [WebKit][7] for the Safari Browser. Wait, THE WebKit? Yes, Apple initiated WebKit. But that is another story... + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/cups-printing-linux + +作者：[Antoine Thomas][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ttoine +[b]: https://github.com/lujun9972 +[1]: https://www.cups.org/ +[2]: https://en.wikipedia.org/wiki/Zero-configuration_networking#Major_implementations +[3]: https://github.com/apple/cups/issues +[4]: https://www.cups.org/blog/2017-11-07-cups-license-change.html +[5]: https://opensource.apple.com/ +[6]: https://developer.apple.com/opensource/ +[7]: https://webkit.org/ diff --git a/sources/tech/20180130 tmux - A Powerful Terminal Multiplexer For Heavy Command-Line Linux User.md b/sources/tech/20180130 tmux - A Powerful Terminal Multiplexer For Heavy Command-Line Linux User.md deleted file mode 100644 index 4adaa7a2bc..0000000000 --- a/sources/tech/20180130 tmux - A Powerful Terminal Multiplexer For Heavy Command-Line Linux User.md +++ /dev/null @@ -1,259 +0,0 @@ -tmux – A Powerful Terminal Multiplexer For Heavy Command-Line Linux User -====== -tmux stands for terminal multiplexer, it allows users to create/enable multiple terminals (vertical & horizontal) in single window, this can be accessed and controlled easily from single window when you are working with different issues. - -It uses a client-server model, which allows you to share sessions between users, also you can attach terminals to a tmux session back. We can easily move or rearrange the virtual console as per the need. Terminal sessions can freely rebound from one virtual console to another. - -tmux depends on libevent and ncurses libraries. tmux offers status-line at the bottom of the screen which display information about your current tmux session suc[]h as current window number, window name, username, hostname, current time, and current date. - -When tmux is started it creates a new session with a single window and displays it on screen. It allows users to create Any number of windows in the same session. - -Many of us says it's similar to screen but i'm not since this offers wide range of configuration options. - -**Make a note:** `Ctrl+b` is the default prefix in tmux so, to perform any action in tumx, you have to type the prefix first then required options. - -**Suggested Read :** [List Of Terminal Emulator For Linux][1] - -### tmux Features - - * Create any number of windows - * Create any number of panes in the single window - * It allows vertical and horizontal splits - * Detach and Re-attach window - * Server-client architecture which allows users to share sessions between users - * tmux offers wide range of configuration hacks - - - -**Suggested Read :** -**(#)** [tmate - Instantly Share Your Terminal Session To Anyone In Seconds][2] -**(#)** [Teleconsole - A Tool To Share Your Terminal Session Instantly To Anyone In Seconds][3] - -### How to Install tmux Command - -tmux command is pre-installed by default in most of the Linux systems. If no, follow the below procedure to get installed. - -For **`Debian/Ubuntu`** , use [APT-GET Command][4] or [APT Command][5] to install tmux. -``` -$ sudo apt install tmux - -``` - -For **`RHEL/CentOS`** , use [YUM Command][6] to install tmux. -``` -$ sudo yum install tmux - -``` - -For **`Fedora`** , use [DNF Command][7] to install tmux. -``` -$ sudo dnf install tmux - -``` - -For **`Arch Linux`** , use [Pacman Command][8] to install tmux. -``` -$ sudo pacman -S tmux - -``` - -For **`openSUSE`** , use [Zypper Command][9] to install tmux. -``` -$ sudo zypper in tmux - -``` - -### How to Use tmux - -kick start the tmux session by running following command on terminal. When tmux is started it creates a new session with a single window and will automatically login to your default shell with your user account. -``` -$ tmux - -``` - -[![][10]![][10]][11] - -You will get similar to above screenshot like us. tmux comes with status bar which display an information's about current sessions details, date, time, etc.,. - -The status bar information's are below: - - * **`0 :`** It is indicating the session number which was created by the tmux server. By default it starts with 0. - * **`0:username@host: :`** 0 is indicating the session number. Username and Hostname which is holding the current window. - * **`~ :`** It is indicating the current directory (We are in the Home directory) - * **`* :`** This indicate that the window is active now. - * **`Hostname :`** This shows fully qualified hostname of the server - * **`Date& Time:`** It shows current date and time - - - -### How to Split Window - -tmux allows users to split window vertically and horizontally. Let 's see how to do that. - -Press `**(Ctrl+b), %**` to split the pane vertically. -[![][10]![][10]][13] - -Press `**(Ctrl+b), "**` to split the pane horizontally. -[![][10]![][10]][14] - -### How to Move Between Panes - -Lets say, we have created few panes and want to move between them. How to do that? If you don 't know how to do, then there is no purpose to use tmux. Use the following control keys to perform the actions. There are many ways to move between panes. - -Press `(Ctrl+b), Left arrow` - To Move Left - -Press `(Ctrl+b), Right arrow` - To Move Right - -Press `(Ctrl+b), Up arrow` - To Move Up - -Press `(Ctrl+b), Down arrow` - To Move Down - -Press `(Ctrl+b), {` - To Move Left - -Press `(Ctrl+b), }` - To Move Right - -Press `(Ctrl+b), o` - Switch to next pane (left-to-right, top-down) - -Press `(Ctrl+b), ;` - Move to the previously active pane. - -For testing purpose, we are going to move between panes. Now, we are in the `pane2` which shows `lsb_release -a` command output. -[![][10]![][10]][15] - -And we are going to move to `pane0` which shows `uname -a` command output. -[![][10]![][10]][16] - -### How to Open/Create New Window - -You can open any number of windows within one terminal. Terminal window can be split vertically & horizontally which is called `panes`. Each pane will contain its own, independently running terminal instance. - -Press `(Ctrl+b), c` to create a new window. - -Press `(Ctrl+b), n` move to the next window. - -Press `(Ctrl+b), p` to move to the previous window. - -Press `(Ctrl+b), (0-9)` to immediately move to a specific window. - -Press `(Ctrl+b), l` Move to the previously selected window. - -I have two windows, first window has three panes which contains operating system distribution information, top command output & kernal information. -[![][10]![][10]][17] - -And second window has two panes which contains Linux distributions logo information. Use the following commands perform the action. -[![][10]![][10]][18] - -Press `(Ctrl+b), w` Choose the current window interactively. -[![][10]![][10]][19] - -### How to Zoom Panes - -You are working in some pane which is very small and you want to zoom it out for further work. To do use the following key binds. - -Currently we have three panes and i'm working in `pane1` which shows system activity using **Top** command and am going to zoom that. -[![][10]![][10]][17] - -When you zoom a pane, it will hide all other panes and display only the zoomed pane in the window. -[![][10]![][10]][20] - -Press `(Ctrl+b), z` to zoom the pane and press it again, to bring the zoomed pane back. - -### Display Pane Information - -To know about pane number and it's size, run the following command. - -Press `(Ctrl+b), q` to briefly display pane indexes. -[![][10]![][10]][21] - -### Display Window Information - -To know about window number, layout size, number of panes associated with the window and it's size, etc., run the following command. - -Just run `tmux list-windows` to view window information. -[![][10]![][10]][22] - -### How to Resize Panes - -You may want to resize the panes to fit your requirement. You have to press `(Ctrl+b), :` then type the following details on the `yellow` color bar in the bottom of the page. -[![][10]![][10]][23] - -In the previous section we have print pane index which shows panes size as well. To test this we are going to increase `10 cells UPward`. See the following output that has increased the pane1 & pane2 size from `55x21` to `55x31`. -[![][10]![][10]][24] - -**Syntax:** `(Ctrl+b), :` then type `resize-pane [options] [cells size]` - -`(Ctrl+b), :` then type `resize-pane -D 10` to resize the current pane Down for 10 cells. - -`(Ctrl+b), :` then type `resize-pane -U 10` to resize the current pane UPward for 10 cells. - -`(Ctrl+b), :` then type `resize-pane -L 10` to resize the current pane Left for 10 cells. - -`(Ctrl+b), :` then type `resize-pane -R 10` to resize the current pane Right for 10 cells. - -### Detaching and Re-attaching tmux Session - -One of the most powerful features of tmux is the ability to detach and reattach session whenever you need. - -Run a long running process and press `Ctrl+b` followed by `d` to detach your tmux session safely by leaving the running process. - -**Suggested Read :** [How To Keep A Process/Command Running After Disconnecting SSH Session][25] - -Now, run a long running process. For demonstration purpose, we are going to move this server backup to another remote server for disaster recovery (DR) purpose. - -You will get similar output like below after detached tmux session. -``` -[detached (from session 0)] - -``` - -Run the following command to list the available tmux sessions. -``` -$ tmux ls -0: 3 windows (created Tue Jan 30 06:17:47 2018) [109x45] - -``` - -Now, re-attach the tmux session using an appropriate session ID as follow. -``` -$ tmux attach -t 0 - -``` - -### How to Close Panes & Window - -Just type `exit` or hit `Ctrl-d` in the corresponding pane to close it. It's similar to terminal close. To close window, press `(Ctrl+b), &`. - --------------------------------------------------------------------------------- - -via: https://www.2daygeek.com/tmux-a-powerful-terminal-multiplexer-emulator-for-linux/ - -作者：[Magesh Maruthamuthu][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://www.2daygeek.com/author/magesh/ -[1]:https://www.2daygeek.com/category/terminal-emulator/ -[2]:https://www.2daygeek.com/tmate-instantly-share-your-terminal-session-to-anyone-in-seconds/ -[3]:https://www.2daygeek.com/teleconsole-share-terminal-session-instantly-to-anyone-in-seconds/ -[4]:https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/ -[5]:https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/ -[6]:https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/ -[7]:https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ -[8]:https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/ -[9]:https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/ -[10]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 -[11]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-1.png -[13]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-2.png -[14]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-3.png -[15]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-4.png -[16]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-5.png -[17]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-8.png -[18]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-6.png -[19]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-7.png -[20]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-9.png -[21]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-10.png -[22]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-14.png -[23]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-11.png -[24]:https://www.2daygeek.com/wp-content/uploads/2018/01/tmux-a-powerful-terminal-multiplexer-emulator-for-linux-13.png -[25]:https://www.2daygeek.com/how-to-keep-a-process-command-running-after-disconnecting-ssh-session/ diff --git a/sources/tech/20180402 An introduction to the Flask Python web app framework.md b/sources/tech/20180402 An introduction to the Flask Python web app framework.md index ffb6e9c441..4b07338bc5 100644 --- a/sources/tech/20180402 An introduction to the Flask Python web app framework.md +++ b/sources/tech/20180402 An introduction to the Flask Python web app framework.md @@ -1,5 +1,5 @@ [#]: collector: (lujun9972) -[#]: translator: (fuowang) +[#]: translator: ( ) [#]: reviewer: ( ) [#]: publisher: ( ) [#]: subject: (An introduction to the Flask Python web app framework) diff --git a/sources/tech/20180411 How To Setup Static File Server Instantly.md b/sources/tech/20180411 How To Setup Static File Server Instantly.md deleted file mode 100644 index b388b389fa..0000000000 --- a/sources/tech/20180411 How To Setup Static File Server Instantly.md +++ /dev/null @@ -1,171 +0,0 @@ -How To Setup Static File Server Instantly -====== - -![](https://www.ostechnix.com/wp-content/uploads/2018/04/serve-720x340.png) -Ever wanted to share your files or project over network, but don’t know how to do? No worries! Here is a simple utility named **“serve”** to share your files instantly over network. This simple utility will instantly turn your system into a static file server, allowing you to serve your files over network. You can access the files from any devices regardless of their operating system. All you need is a web browser. This utility also can be used to serve static websites. It is formerly known as “list” and “micro-list”, but now the name has been changed to “serve”, which is much more suitable for the purpose of this utility. - -### Setup Static File Server Using Serve - -To install “serve”, you need to install NodeJS and NPM first. Refer the following link to install NodeJS and NPM in your Linux box. - -Once NodeJS and NPM installed, run the following command to install “serve”. -``` -$ npm install -g serve - -``` - -Done! Now is the time to serve the files or folders. - -The typical syntax to use “serve” is: -``` -$ serve [options] - -``` - -### Serve Specific files or folders - -For example, let us share the contents of the **Documents** directory. To do so, run: -``` -$ serve Documents/ - -``` - -Sample output would be: - -![][2] - -As you can see in the above screenshot, the contents of the given directory have been served over network via two URLs. - -To access the contents from the local system itself, all you have to do is open your web browser and navigate to **** URL. - -![][3] - -The Serve utility displays the contents of the given directory in a simple layout. You can download (right click on the files and choose “Save link as..”) or just view them in the browser. - -If you want to open local address automatically in the browser, use **-o** flag. -``` -$ serve -o Documents/ - -``` - -Once you run the above command, The Serve utility will open your web browser automatically and display the contents of the shared item. - -Similarly, to access the shared directory from a remote system over network, type **** in the browser’s address bar. Replace 192.168.43.192 with your system’s IP. - -**Serve contents via different port** - -As you may noticed, The serve utility uses port **5000** by default. So, make sure the port 5000 is allowed in your firewall or router. If it is blocked for some reason, you can serve the contents using different port using **-p** flag. -``` -$ serve -p 1234 Documents/ - -``` - -The above command will serve the contents of Documents directory via port **1234**. - -![][4] - -To serve a file, instead of a folder, just give it’s full path like below. -``` -$ serve Documents/Papers/notes.txt - -``` - -The contents of the shared directory can be accessed by any user on the network as long as they know the path. - -**Serve the entire $HOME directory** - -Open your Terminal and type: -``` -$ serve - -``` - -This will share the contents of your entire $HOME directory over network. - -To stop the sharing, press **CTRL+C**. - -**Serve selective files or folders** - -You may not want to share all files or directories, but only a few in a directory. You can do this by excluding the files or directories using **-i** flag. -``` -$ serve -i Downloads/ - -``` - -The above command will serve entire file system except **Downloads** directory. - -**Serve contents only on localhost** - -Sometimes, you want to serve the contents only on the local system itself, not on the entire network. To do so, use **-l** flag as shown below: -``` -$ serve -l Documents/ - -``` - -This command will serve the **Documents** directory only on localhost. - -![][5] - -This can be useful when you’re working on a shared server. All users in the in the system can access the share, but not the remote users. - -**Serve content using SSL** - -Since we serve the contents over the local network, we need not to use SSL. However, Serve utility has the ability to shares contents using SSL using **–ssl** flag. -``` -$ serve --ssl Documents/ - -``` - -![][6] - -To access the shares via web browser use “ or “. - -![][7] - -**Serve contents with authentication** - -In all above examples, we served the contents without any authentication. So anyone on the network can access them without any authentication. You might feel some contents should be accessed with username and password. - -To do so, use: -``` -$ SERVE_USER=ostechnix SERVE_PASSWORD=123456 serve --auth - -``` - -Now the users need to enter the username (i.e **ostechnix** in our case) and password (123456) to access the shares. - -![][8] - -The Serve utility has some other features, such as disable [**Gzip compression**][9], setup * CORS headers to allow requests from any origin, prevent copy address automatically to clipboard etc. You can read the complete help section by running the following command: -``` -$ serve help - -``` - -And, that’s all for now. Hope this helps. More good stuffs to come. Stay tuned! - -Cheers! - - - --------------------------------------------------------------------------------- - -via: https://www.ostechnix.com/how-to-setup-static-file-server-instantly/ - -作者：[SK][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) -选题：[lujun9972](https://github.com/lujun9972) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://www.ostechnix.com/author/sk/ -[1]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 -[2]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-1.png -[3]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-2.png -[4]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-4.png -[5]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-3.png -[6]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-6.png -[7]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-5-1.png -[8]:http://www.ostechnix.com/wp-content/uploads/2018/04/serve-7-1.png -[9]:https://www.ostechnix.com/how-to-compress-and-decompress-files-in-linux/ diff --git a/sources/tech/20180514 An introduction to the Pyramid web framework for Python.md b/sources/tech/20180514 An introduction to the Pyramid web framework for Python.md index a16e604774..03a6fa6494 100644 --- a/sources/tech/20180514 An introduction to the Pyramid web framework for Python.md +++ b/sources/tech/20180514 An introduction to the Pyramid web framework for Python.md @@ -1,5 +1,5 @@ [#]: collector: (lujun9972) -[#]: translator: ( ) +[#]: translator: (Flowsnow) [#]: reviewer: ( ) [#]: publisher: ( ) [#]: subject: (An introduction to the Pyramid web framework for Python) diff --git a/sources/tech/20180530 Introduction to the Pony programming language.md b/sources/tech/20180530 Introduction to the Pony programming language.md index 2f32ea6631..2292c65fc2 100644 --- a/sources/tech/20180530 Introduction to the Pony programming language.md +++ b/sources/tech/20180530 Introduction to the Pony programming language.md @@ -1,3 +1,4 @@ +beamrolling is translating. Introduction to the Pony programming language ====== diff --git a/sources/tech/20180611 3 open source alternatives to Adobe Lightroom.md b/sources/tech/20180611 3 open source alternatives to Adobe Lightroom.md index 664c054913..c489b0f0f1 100644 --- a/sources/tech/20180611 3 open source alternatives to Adobe Lightroom.md +++ b/sources/tech/20180611 3 open source alternatives to Adobe Lightroom.md @@ -1,3 +1,5 @@ +scoutydren is translating + 3 open source alternatives to Adobe Lightroom ====== diff --git a/sources/tech/20180625 The life cycle of a software bug.md b/sources/tech/20180625 The life cycle of a software bug.md deleted file mode 100644 index 0f45d7a355..0000000000 --- a/sources/tech/20180625 The life cycle of a software bug.md +++ /dev/null @@ -1,68 +0,0 @@ -translated by lixinyuxx -The life cycle of a software bug -====== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/bug_software_issue_tracking_computer_screen.jpg?itok=6qfIHR5y) - -In 1947, the first computer bug was found—a moth trapped in a computer relay. - -If only all bugs were as simple to uncover. As software has become more complex, so too has the process of testing and debugging. Today, the life cycle of a software bug can be lengthy—though the right technology and business processes can help. For open source software, developers use rigorous ticketing services and collaboration to find and mitigate bugs. - -### Confirming a computer bug - -During the process of testing, bugs are reported to the development team. Quality assurance testers describe the bug in as much detail as possible, reporting on their system state, the processes they were undertaking, and how the bug manifested itself. - -Despite this, some bugs are never confirmed; they may be reported in testing but can never be reproduced in a controlled environment. In such cases they may not be resolved but are instead closed. - -It can be difficult to confirm a computer bug due to the wide array of platforms in use and the many different types of user behavior. Some bugs only occur intermittently or under very specific situations, and others may occur seemingly at random. - -Many people use and interact with open source software, and many bugs and issues may be non-repeatable or may not be adequately described. Still, because every user and developer also plays the role of quality assurance tester, at least in part, there is a good chance that bugs will be revealed. - -When a bug is confirmed, work begins. - -### Assigning a bug to be fixed - -A confirmed bug is assigned to a developer or a development team to be addressed. At this stage, the bug needs to be reproduced, the issue uncovered, and the associated code fixed. Developers may categorize this bug as an issue to be fixed later if the bug is low-priority, or they may assign someone directly if it is high-priority. Either way, a ticket is opened during the process of development, and the bug becomes a known issue. - -In open source solutions, developers may select from the bugs that they want to tackle, either choosing the areas of the program with which they are most familiar or working from the top priorities. Consolidated solutions such as [GitHub][1] make it easy for multiple developers to work on solutions without interfering with each other's work. - -When assigning bugs to be fixed, reporters may also select a priority level for the bug. Major bugs may have a high priority level, whereas bugs related to appearance only, for example, may have a lower level. This priority level determines how and when the development team is assigned to resolve these issues. Either way, all bugs need to be resolved before a product can be considered complete. Using proper traceability back to prioritized requirements can also be helpful in this regard. - -### Resolving the bug - -Once a bug has been fixed, it is usually be sent back to Quality Assurance as a resolved bug. Quality Assurance then puts the product through its paces again to reproduce the bug. If the bug cannot be reproduced, Quality Assurance will assume that it has been properly resolved. - -In open source situations, any changes are distributed—often as a tentative release that is being tested. This test release is distributed to users, who again fulfill the role of Quality Assurance and test the product. - -If the bug occurs again, the issue is sent back to the development team. At this stage, the bug is reopened, and it is up to the development team to repeat the cycle of resolving the bug. This may occur multiple times, especially if the bug is unpredictable or intermittent. Intermittent bugs are notoriously difficult to resolve. - -If the bug does not occur again, the issue will be marked as resolved. In some cases, the initial bug is resolved, but other bugs emerge as a result of the changes made. When this happens, new bug reports may need to be initiated, starting the process over again. - -### Closing the bug - -After a bug has been addressed, identified, and resolved, the bug is closed and developers can move on to other areas of software development and testing. A bug will also be closed if it was never found or if developers were never able to reproduce it—either way, the next stage of development and testing will begin. - -Any changes made to the solution in the testing version will be rolled into the next release of the product. If the bug was a serious one, a patch or a hotfix may be provided for current users until the release of the next version. This is common for security issues. - -Software bugs can be difficult to find, but by following set processes and procedures, developers can make the process faster, easier, and more consistent. Quality Assurance is an important part of this process, as QA testers must find and identify bugs and help developers reproduce them. Bugs cannot be closed and resolved until the error no longer occurs. - -Open source solutions distribute the burden of quality assurance testing, development, and mitigation, which often leads to bugs being discovered and mitigated more quickly and comprehensively. However, because of the nature of open source technology, the speed and accuracy of this process often depends upon the popularity of the solution and the dedication of its maintenance and development team. - -_Rich Butkevic is a PMP certified project manager, certified scum master, and runs[Project Zendo][2] , a website for project management professionals to discover strategies to simplify and improve their project results. Connect with Rich at [Richbutkevic.com][3] or on [LinkedIn][4]._ - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/6/life-cycle-software-bug - -作者：[Rich Butkevic][a] -选题：[lujun9972](https://github.com/lujun9972) -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/rich-butkevic -[1]:https://github.com/ -[2]:https://projectzendo.com -[3]:https://richbutkevic.com -[4]:https://www.linkedin.com/in/richbutkevic diff --git a/sources/tech/20180626 How To Search If A Package Is Available On Your Linux Distribution Or Not.md b/sources/tech/20180626 How To Search If A Package Is Available On Your Linux Distribution Or Not.md deleted file mode 100644 index b731465a55..0000000000 --- a/sources/tech/20180626 How To Search If A Package Is Available On Your Linux Distribution Or Not.md +++ /dev/null @@ -1,347 +0,0 @@ -How To Search If A Package Is Available On Your Linux Distribution Or Not -====== -You can directly install the require package which you want if you know the package name. - -In some cases, if you don’t know the exact package name or you want to search some packages then you can easily search that package with help of distribution package manager. - -Searches automatically include both installed and available packages. - -The format of the results depends upon the option. If the query produces no information, there are no packages matching the criteria. - -This can be done through distribution package managers with variety of options. - -I had added all the possible options in this article and you can select which is the best and suitable for you. - -Alternatively we can achieve this through **whohas** command. This will search the given package to all the major distributions (such as Debian, Ubuntu, Fedora, etc.,) not only your own system distribution. - -**Suggested Read :** -**(#)** [List of Command line Package Managers For Linux & Usage][1] -**(#)** [A Graphical frontend tool for Linux Package Manager][2] - -### How to Search a Package in Debian/Ubuntu - -We can use apt, apt-cache and aptitude package managers to find a given package on Debian based distributions. I had included vast of options with this package managers. - -We can done this on three ways in Debian based systems. - - * apt command - * apt-cache command - * aptitude command - - - -### How to search a package using apt command - -APT stands for Advanced Packaging Tool (APT) which is replacement for apt-get. It’s feature rich command-line tools with included all the futures in one command (APT) such as apt-cache, apt-search, dpkg, apt-cdrom, apt-config, apt-key, etc..,. and several other unique features. - -APT is a powerful command-line tool for installing, downloading, removing, searching and managing as well as querying information about packages as a low-level access to all features of the libapt-pkg library. It’s contains some less used command-line utilities related to package management. -``` -$ apt -q list nano vlc -Listing... -nano/artful,now 2.8.6-3 amd64 [installed] -vlc/artful 2.2.6-6 amd64 - -``` - -Alternatively we can search a given package using below format. -``` -$ apt search ^vlc -Sorting... Done -Full Text Search... Done -vlc/artful 2.2.6-6 amd64 - multimedia player and streamer - -vlc-bin/artful 2.2.6-6 amd64 - binaries from VLC - -vlc-data/artful,artful 2.2.6-6 all - Common data for VLC - -vlc-l10n/artful,artful 2.2.6-6 all - Translations for VLC - -vlc-plugin-access-extra/artful 2.2.6-6 amd64 - multimedia player and streamer (extra access plugins) - -vlc-plugin-base/artful 2.2.6-6 amd64 - multimedia player and streamer (base plugins) - -``` - -### How to search a package using apt-cache command - -apt-cache performs a variety of operations on APT’s package cache. Displays information about the given packages. apt-cache does not manipulate the state of the system but does provide operations to search and generate interesting output from the package metadata. -``` -$ apt-cache search nano | grep ^nano -nano - small, friendly text editor inspired by Pico -nano-tiny - small, friendly text editor inspired by Pico - tiny build -nanoblogger - Small weblog engine for the command line -nanoblogger-extra - Nanoblogger plugins -nanoc - static site generator written in Ruby -nanoc-doc - static site generator written in Ruby - documentation -nanomsg-utils - nanomsg utilities -nanopolish - consensus caller for nanopore sequencing data - -``` - -Alternatively we can search a given package using below format. -``` -$ apt-cache policy vlc -vlc: - Installed: (none) - Candidate: 2.2.6-6 - Version table: - 2.2.6-6 500 - 500 http://in.archive.ubuntu.com/ubuntu artful/universe amd64 Packages - -``` - -Alternatively we can search a given package using below format. -``` -$ apt-cache pkgnames vlc -vlc-bin -vlc-plugin-video-output -vlc-plugin-sdl -vlc-plugin-svg -vlc-plugin-samba -vlc-plugin-fluidsynth -vlc-plugin-qt -vlc-plugin-skins2 -vlc-plugin-visualization -vlc-l10n -vlc-plugin-notify -vlc-plugin-zvbi -vlc-plugin-vlsub -vlc-plugin-jack -vlc-plugin-access-extra -vlc -vlc-data -vlc-plugin-video-splitter -vlc-plugin-base - -``` - -### How to search a package using aptitude command - -aptitude is a text-based interface to the Debian GNU/Linux package system. It allows the user to view the list of packages and to perform package management tasks such as installing, upgrading, and removing packages. Actions may be performed from a visual interface or from the command-line. -``` -$ aptitude search ^vlc -p vlc - multimedia player and streamer -p vlc:i386 - multimedia player and streamer -p vlc-bin - binaries from VLC -p vlc-bin:i386 - binaries from VLC -p vlc-data - Common data for VLC -v vlc-data:i386 - -p vlc-l10n - Translations for VLC -v vlc-l10n:i386 - -p vlc-plugin-access-extra - multimedia player and streamer (extra access plugins) -p vlc-plugin-access-extra:i386 - multimedia player and streamer (extra access plugins) -p vlc-plugin-base - multimedia player and streamer (base plugins) -p vlc-plugin-base:i386 - multimedia player and streamer (base plugins) -p vlc-plugin-fluidsynth - FluidSynth plugin for VLC -p vlc-plugin-fluidsynth:i386 - FluidSynth plugin for VLC -p vlc-plugin-jack - Jack audio plugins for VLC -p vlc-plugin-jack:i386 - Jack audio plugins for VLC -p vlc-plugin-notify - LibNotify plugin for VLC -p vlc-plugin-notify:i386 - LibNotify plugin for VLC -p vlc-plugin-qt - multimedia player and streamer (Qt plugin) -p vlc-plugin-qt:i386 - multimedia player and streamer (Qt plugin) -p vlc-plugin-samba - Samba plugin for VLC -p vlc-plugin-samba:i386 - Samba plugin for VLC -p vlc-plugin-sdl - SDL video and audio output plugin for VLC -p vlc-plugin-sdl:i386 - SDL video and audio output plugin for VLC -p vlc-plugin-skins2 - multimedia player and streamer (Skins2 plugin) -p vlc-plugin-skins2:i386 - multimedia player and streamer (Skins2 plugin) -p vlc-plugin-svg - SVG plugin for VLC -p vlc-plugin-svg:i386 - SVG plugin for VLC -p vlc-plugin-video-output - multimedia player and streamer (video output plugins) -p vlc-plugin-video-output:i386 - multimedia player and streamer (video output plugins) -p vlc-plugin-video-splitter - multimedia player and streamer (video splitter plugins) -p vlc-plugin-video-splitter:i386 - multimedia player and streamer (video splitter plugins) -p vlc-plugin-visualization - multimedia player and streamer (visualization plugins) -p vlc-plugin-visualization:i386 - multimedia player and streamer (visualization plugins) -p vlc-plugin-vlsub - VLC extension to download subtitles from opensubtitles.org -p vlc-plugin-zvbi - VBI teletext plugin for VLC -p vlc-plugin-zvbi:i386 - -``` - -### How to Search a Package in RHEL/CentOS - -Yum (Yellowdog Updater Modified) is one of the package manager utility in Linux operating system. Yum command is used to install, update, search & remove packages on some Linux distributions based on RedHat. -``` -# yum search ftpd -Loaded plugins: fastestmirror, refresh-packagekit, security -Loading mirror speeds from cached hostfile - * base: centos.hyve.com - * epel: mirrors.coreix.net - * extras: centos.hyve.com - * rpmforge: www.mirrorservice.org - * updates: mirror.sov.uk.goscomb.net -============================================================== N/S Matched: ftpd =============================================================== -nordugrid-arc-gridftpd.x86_64 : ARC gridftp server -pure-ftpd.x86_64 : Lightweight, fast and secure FTP server -vsftpd.x86_64 : Very Secure Ftp Daemon - - Name and summary matches only, use "search all" for everything. - -``` - -Alternatively we can search the same using below command. -``` -# yum list ftpd - -``` - -### How to Search a Package in Fedora - -DNF stands for Dandified yum. We can tell DNF, the next generation of yum package manager (Fork of Yum) using hawkey/libsolv library for backend. Aleš Kozumplík started working on DNF since Fedora 18 and its implemented/launched in Fedora 22 finally. -``` -# dnf search ftpd -Last metadata expiration check performed 0:42:28 ago on Tue Jun 9 22:52:44 2018. -============================== N/S Matched: ftpd =============================== -proftpd-utils.x86_64 : ProFTPD - Additional utilities -pure-ftpd-selinux.x86_64 : SELinux support for Pure-FTPD -proftpd-devel.i686 : ProFTPD - Tools and header files for developers -proftpd-devel.x86_64 : ProFTPD - Tools and header files for developers -proftpd-ldap.x86_64 : Module to add LDAP support to the ProFTPD FTP server -proftpd-mysql.x86_64 : Module to add MySQL support to the ProFTPD FTP server -proftpd-postgresql.x86_64 : Module to add PostgreSQL support to the ProFTPD FTP - : server -vsftpd.x86_64 : Very Secure Ftp Daemon -proftpd.x86_64 : Flexible, stable and highly-configurable FTP server -owfs-ftpd.x86_64 : FTP daemon providing access to 1-Wire networks -perl-ftpd.noarch : Secure, extensible and configurable Perl FTP server -pure-ftpd.x86_64 : Lightweight, fast and secure FTP server -pyftpdlib.noarch : Python FTP server library -nordugrid-arc-gridftpd.x86_64 : ARC gridftp server - -``` - -Alternatively we can search the same using below command. -``` -# dnf list proftpd -Failed to synchronize cache for repo 'heikoada-terminix', disabling. -Last metadata expiration check: 0:08:02 ago on Tue 26 Jun 2018 04:30:05 PM IST. -Available Packages -proftpd.x86_64 - -``` - -### How to Search a Package in Arch Linux - -pacman stands for package manager utility (pacman). pacman is a command-line utility to install, build, remove and manage Arch Linux packages. pacman uses libalpm (Arch Linux Package Management (ALPM) library) as a back-end to perform all the actions. - -In my case, i’m going to search chromium package. -``` -# pacman -Ss chromium -extra/chromium 48.0.2564.116-1 - The open-source project behind Google Chrome, an attempt at creating a safer, faster, and more stable browser -extra/qt5-webengine 5.5.1-9 (qt qt5) - Provides support for web applications using the Chromium browser project -community/chromium-bsu 0.9.15.1-2 - A fast paced top scrolling shooter -community/chromium-chromevox latest-1 - Causes the Chromium web browser to automatically install and update the ChromeVox screen reader extention. Note: This - package does not contain the extension code. -community/fcitx-mozc 2.17.2313.102-1 - Fcitx Module of A Japanese Input Method for Chromium OS, Windows, Mac and Linux (the Open Source Edition of Google Japanese - Input) - -``` - -By default `-s`‘s builtin ERE (Extended Regular Expressions) can cause a lot of unwanted results. Use the following format to match the package name only. -``` -# pacman -Ss '^chromium-' - -``` - -pkgfile is a tool for searching files from packages in the Arch Linux official repositories. -``` -# pkgfile chromium - -``` - -### How to Search a Package in openSUSE - -Zypper is a command line package manager for suse & openSUSE distributions. It’s used to install, update, search & remove packages & manage repositories, perform various queries, and more. Zypper command-line interface to ZYpp system management library (libzypp). -``` -# zypper search ftp -or -# zypper se ftp -Loading repository data... -Reading installed packages... -S | Name | Summary | Type ---+----------------+-----------------------------------------+-------- - | proftpd | Highly configurable GPL-licensed FTP -> | package - | proftpd-devel | Development files for ProFTPD | package - | proftpd-doc | Documentation for ProFTPD | package - | proftpd-lang | Languages for package proftpd | package - | proftpd-ldap | LDAP Module for ProFTPD | package - | proftpd-mysql | MySQL Module for ProFTPD | package - | proftpd-pgsql | PostgreSQL Module for ProFTPD | package - | proftpd-radius | Radius Module for ProFTPD | package - | proftpd-sqlite | SQLite Module for ProFTPD | package - | pure-ftpd | A Lightweight, Fast, and Secure FTP S-> | package - | vsftpd | Very Secure FTP Daemon - Written from-> | package - -``` - -### How to Search a Package using whohas command - -whohas command such a intelligent tools which search a given package to all the major distributions such as Debian, Ubuntu, Gentoo, Arch, AUR, Mandriva, Fedora, Fink, FreeBSD, NetBSD. -``` -$ whohas nano -Mandriva nano-debug 2.3.1-1mdv2010.2.x http://sophie.zarb.org/rpms/0b33dc73bca710749ad14bbc3a67e15a -Mandriva nano-debug 2.2.4-1mdv2010.1.i http://sophie.zarb.org/rpms/d9dfb2567681e09287b27e7ac6cdbc05 -Mandriva nano-debug 2.2.4-1mdv2010.1.x http://sophie.zarb.org/rpms/3299516dbc1538cd27a876895f45aee4 -Mandriva nano 2.3.1-1mdv2010.2.x http://sophie.zarb.org/rpms/98421c894ee30a27d9bd578264625220 -Mandriva nano 2.3.1-1mdv2010.2.i http://sophie.zarb.org/rpms/cea07b5ef9aa05bac262fc7844dbd223 -Mandriva nano 2.2.4-1mdv2010.1.s http://sophie.zarb.org/rpms/d61f9341b8981e80424c39c3951067fa -Mandriva spring-mod-nanoblobs 0.65-2mdv2010.0.sr http://sophie.zarb.org/rpms/74bb369d4cbb4c8cfe6f6028e8562460 -Mandriva nanoxml-lite 2.2.3-4.1.4mdv2010 http://sophie.zarb.org/rpms/287a4c37bc2a39c0f277b0020df47502 -Mandriva nanoxml-manual-lite 2.2.3-4.1.4mdv2010 http://sophie.zarb.org/rpms/17dc4f638e5e9964038d4d26c53cc9c6 -Mandriva nanoxml-manual 2.2.3-4.1.4mdv2010 http://sophie.zarb.org/rpms/a1b5092cd01fc8bb78a0f3ca9b90370b -Gentoo nano 9999 http://packages.gentoo.org/package/app-editors/nano -Gentoo nano 9999 http://packages.gentoo.org/package/app-editors/nano -Gentoo nano 2.9.8 http://packages.gentoo.org/package/app-editors/nano -Gentoo nano 2.9.7 http://packages.gentoo.org/package/app-editors/nano - -``` - -If you want to search a given package to only current distribution repository, use the below format. -``` -$ whohas -d Ubuntu vlc -Ubuntu vlc 2.1.6-0ubuntu14.04 1M all http://packages.ubuntu.com/trusty/vlc -Ubuntu vlc 2.1.6-0ubuntu14.04 1M all http://packages.ubuntu.com/trusty-updates/vlc -Ubuntu vlc 2.2.2-5ubuntu0.16. 1M all http://packages.ubuntu.com/xenial/vlc -Ubuntu vlc 2.2.2-5ubuntu0.16. 1M all http://packages.ubuntu.com/xenial-updates/vlc -Ubuntu vlc 2.2.6-6 40K all http://packages.ubuntu.com/artful/vlc -Ubuntu vlc 3.0.1-3build1 32K all http://packages.ubuntu.com/bionic/vlc -Ubuntu vlc 3.0.2-0ubuntu0.1 32K all http://packages.ubuntu.com/bionic-updates/vlc -Ubuntu vlc 3.0.3-1 33K all http://packages.ubuntu.com/cosmic/vlc -Ubuntu browser-plugin-vlc 2.0.6-2 55K all http://packages.ubuntu.com/trusty/browser-plugin-vlc -Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/xenial/browser-plugin-vlc -Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/artful/browser-plugin-vlc -Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/bionic/browser-plugin-vlc -Ubuntu browser-plugin-vlc 2.0.6-4 47K all http://packages.ubuntu.com/cosmic/browser-plugin-vlc -Ubuntu libvlc-bin 2.2.6-6 27K all http://packages.ubuntu.com/artful/libvlc-bin -Ubuntu libvlc-bin 3.0.1-3build1 17K all http://packages.ubuntu.com/bionic/libvlc-bin -Ubuntu libvlc-bin 3.0.2-0ubuntu0.1 17K all http://packages.ubuntu.com/bionic-updates/libvlc-bin - -``` - --------------------------------------------------------------------------------- - -via: https://www.2daygeek.com/how-to-search-if-a-package-is-available-on-your-linux-distribution-or-not/ - -作者：[Prakash Subramanian][a] -选题：[lujun9972](https://github.com/lujun9972) -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://www.2daygeek.com/author/prakash/ -[1]:https://www.2daygeek.com/list-of-command-line-package-manager-for-linux/ -[2]:https://www.2daygeek.com/list-of-graphical-frontend-tool-for-linux-package-manager/ diff --git a/sources/tech/20180803 How to use Fedora Server to create a router - gateway.md b/sources/tech/20180803 How to use Fedora Server to create a router - gateway.md index 934693d1cf..0394826c10 100644 --- a/sources/tech/20180803 How to use Fedora Server to create a router - gateway.md +++ b/sources/tech/20180803 How to use Fedora Server to create a router - gateway.md @@ -1,5 +1,3 @@ -ScarboroughCoral translating! - How to use Fedora Server to create a router / gateway ====== diff --git a/sources/tech/20180809 Perform robust unit tests with PyHamcrest.md b/sources/tech/20180809 Perform robust unit tests with PyHamcrest.md deleted file mode 100644 index 1c7d7e9226..0000000000 --- a/sources/tech/20180809 Perform robust unit tests with PyHamcrest.md +++ /dev/null @@ -1,176 +0,0 @@ -Perform robust unit tests with PyHamcrest -====== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/web_browser_desktop_devlopment_design_system_computer.jpg?itok=pfqRrJgh) - -At the base of the [testing pyramid][1] are unit tests. Unit tests test one unit of code at a time—usually one function or method. - -Often, a single unit test is designed to test one particular flow through a function, or a specific branch choice. This enables easy mapping of a unit test that fails and the bug that made it fail. - -Ideally, unit tests use few or no external resources, isolating them and making them faster. - -_Good_ tests increase developer productivity by catching bugs early and making testing faster. _Bad_ tests decrease developer productivity. - -Unit test suites help maintain high-quality products by signaling problems early in the development process. An effective unit test catches bugs before the code has left the developer machine, or at least in a continuous integration environment on a dedicated branch. This marks the difference between good and bad unit tests:tests increase developer productivity by catching bugs early and making testing faster.tests decrease developer productivity. - -Productivity usually decreases when testing _incidental features_. The test fails when the code changes, even if it is still correct. This happens because the output is different, but in a way that is not part of the function's contract. - -A good unit test, therefore, is one that helps enforce the contract to which the function is committed. - -If a unit test breaks, the contract is violated and should be either explicitly amended (by changing the documentation and tests), or fixed (by fixing the code and leaving the tests as is). - -While limiting tests to enforce only the public contract is a complicated skill to learn, there are tools that can help. - -One of these tools is [Hamcrest][2], a framework for writing assertions. Originally invented for Java-based unit tests, today the Hamcrest framework supports several languages, including [Python][3]. - -Hamcrest is designed to make test assertions easier to write and more precise. -``` -def add(a, b): - -    return a + b - - - -from hamcrest import assert_that, equal_to - - - -def test_add(): - -    assert_that(add(2, 2), equal_to(4))   - -``` - -This is a simple assertion, for simple functionality. What if we wanted to assert something more complicated? -``` -def test_set_removal(): - -    my_set = {1, 2, 3, 4} - -    my_set.remove(3) - -    assert_that(my_set, contains_inanyorder([1, 2, 4])) - -    assert_that(my_set, is_not(has_item(3))) - -``` - -Note that we can succinctly assert that the result has `1`, `2`, and `4` in any order since sets do not guarantee order. - -We also easily negate assertions with `is_not`. This helps us write _precise assertions_ , which allow us to limit ourselves to enforcing public contracts of functions. - -Sometimes, however, none of the built-in functionality is _precisely_ what we need. In those cases, Hamcrest allows us to write our own matchers. - -Imagine the following function: -``` -def scale_one(a, b): - -    scale = random.randint(0, 5) - -    pick = random.choice([a,b]) - -    return scale * pick - -``` - -We can confidently assert that the result divides into at least one of the inputs evenly. - -A matcher inherits from `hamcrest.core.base_matcher.BaseMatcher`, and overrides two methods: -``` -class DivisibleBy(hamcrest.core.base_matcher.BaseMatcher): - - - -    def __init__(self, factor): - -        self.factor = factor - - - -    def _matches(self, item): - -        return (item % self.factor) == 0 - - - -    def describe_to(self, description): - -        description.append_text('number divisible by') - -        description.append_text(repr(self.factor)) - -``` - -Writing high-quality `describe_to` methods is important, since this is part of the message that will show up if the test fails. -``` -def divisible_by(num): - -    return DivisibleBy(num) - -``` - -By convention, we wrap matchers in a function. Sometimes this gives us a chance to further process the inputs, but in this case, no further processing is needed. -``` -def test_scale(): - -    result = scale_one(3, 7) - -    assert_that(result, - -                any_of(divisible_by(3), - -                       divisible_by(7))) - -``` - -Note that we combined our `divisible_by` matcher with the built-in `any_of` matcher to ensure that we test only what the contract commits to. - -While editing this article, I heard a rumor that the name "Hamcrest" was chosen as an anagram for "matches". Hrm... -``` ->>> assert_that("matches", contains_inanyorder(*"hamcrest") - -Traceback (most recent call last): - -  File "", line 1, in - -  File "/home/moshez/src/devops-python/build/devops/lib/python3.6/site-packages/hamcrest/core/assert_that.py", line 43, in assert_that - -    _assert_match(actual=arg1, matcher=arg2, reason=arg3) - -  File "/home/moshez/src/devops-python/build/devops/lib/python3.6/site-packages/hamcrest/core/assert_that.py", line 57, in _assert_match - -    raise AssertionError(description) - -AssertionError: - -Expected: a sequence over ['h', 'a', 'm', 'c', 'r', 'e', 's', 't'] in any order - -      but: no item matches: 'r' in ['m', 'a', 't', 'c', 'h', 'e', 's'] - -``` - -Researching more, I found the source of the rumor: It is an anagram for "matchers". -``` ->>> assert_that("matchers", contains_inanyorder(*"hamcrest")) - ->>> - -``` - -If you are not yet writing unit tests for your Python code, now is a good time to start. If you are writing unit tests for your Python code, using Hamcrest will allow you to make your assertion _precise_ —neither more nor less than what you intend to test. This will lead to fewer false positives when modifying code and less time spent modifying tests for working code. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/8/robust-unit-tests-hamcrest - -作者：[Moshe Zadka][a] -选题：[lujun9972](https://github.com/lujun9972) -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/moshez -[1]:https://martinfowler.com/bliki/TestPyramid.html -[2]:http://hamcrest.org/ -[3]:https://www.python.org/ diff --git a/sources/tech/20180814 5 open source strategy and simulation games for Linux.md b/sources/tech/20180814 5 open source strategy and simulation games for Linux.md deleted file mode 100644 index feb71a5b9a..0000000000 --- a/sources/tech/20180814 5 open source strategy and simulation games for Linux.md +++ /dev/null @@ -1,112 +0,0 @@ -Scoutydren is translating. -5 open source strategy and simulation games for Linux -====== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/arcade_game_gaming.jpg?itok=84Rjk_32) - -Gaming has traditionally been one of Linux's weak points. That has changed somewhat in recent years thanks to Steam, GOG, and other efforts to bring commercial games to multiple operating systems, but those games are often not open source. Sure, the games can be played on an open source operating system, but that is not good enough for an open source purist. - -So, can someone who only uses free and open source software find games that are polished enough to present a solid gaming experience without compromising their open source ideals? Absolutely. While open source games are unlikely ever to rival some of the AAA commercial games developed with massive budgets, there are plenty of open source games, in many genres, that are fun to play and can be installed from the repositories of most major Linux distributions. Even if a particular game is not packaged for a particular distribution, it is usually easy to download the game from the project's website to install and play it. - -This article looks at strategy and simulation games. I have already written about [arcade-style games][1], [board & card games][2], [puzzle games][3], [racing & flying games][4], and [role-playing games][5]. - -### Freeciv - -![](https://opensource.com/sites/default/files/uploads/freeciv.png) - -[Freeciv][6] is an open source version of the [Civilization series][7] of computer games. Gameplay is most similar to the earlier games in the Civilization series, and Freeciv even has options to use Civilization 1 and Civilization 2 rule sets. Freeciv involves building cities, exploring the world map, developing technologies, and competing with other civilizations trying to do the same. Victory conditions include defeating all the other civilizations, developing a space colony, or hitting deadline if neither of the first two conditions are met. The game can be played against AI opponents or other human players. Different tile-sets are available to change the look of the game's map. - -To install Freeciv, run the following command: - - * On Fedora: `dnf install freeciv` - * On Debian/Ubuntu: `apt install freeciv` - - - -### MegaGlest - -![](https://opensource.com/sites/default/files/uploads/megaglest.png) - -[MegaGlest][8] is an open source real-time strategy game in the style of Blizzard Entertainment's [Warcraft][9] and [StarCraft][10] games. Players control one of several different factions, building structures and recruiting units to explore the map and battle their opponents. At the beginning of the match, a player can build only the most basic buildings and recruit the weakest units. To build and recruit better things, players must work their way up their factions technology tree by building structures and recruiting units that unlock more advanced options. Combat units will attack when enemy units come into range, but for optimal strategy, it is best to manage the battle directly by controlling the units. Simultaneously managing the construction of new structures, recruiting new units, and managing battles can be a challenge, but that is the point of a real-time strategy game. MegaGlest provides a nice variety of factions, so there are plenty of reasons to try new and different strategies. - -To install MegaGlest, run the following command: - - * On Fedora: `dnf install megaglest` - * On Debian/Ubuntu: `apt install megaglest` - - - -### OpenTTD - -![](https://opensource.com/sites/default/files/uploads/openttd.png) - -[OpenTTD][11] (see also [our review][12]) is an open source implementation of [Transport Tycoon Deluxe][13]. The object of the game is to create a transportation network and earn money, which allows the player to build an even bigger transportation network. The network can include boats, buses, trains, trucks, and planes. By default, gameplay takes place between 1950 and 2050, with players aiming to get the highest performance rating possible before time runs out. The performance rating is based on things like the amount of cargo delivered, the number of vehicles they have, and how much money they earned. - -To install OpenTTD, run the following command: - - * On Fedora: `dnf install openttd` - * On Debian/Ubuntu: `apt install openttd` - - - -### The Battle for Wesnoth - -![](https://opensource.com/sites/default/files/uploads/the_battle_for_wesnoth.png) - -[The Battle for Wesnoth][14] is one of the most polished open source games available. This turn-based strategy game has a fantasy setting. Play takes place on a hexagonal grid, where individual units battle each other for control. Each type of unit has unique strengths and weaknesses, which requires players to plan their attacks accordingly. There are many different campaigns available for The Battle for Wesnoth, each with different objectives and storylines. The Battle for Wesnoth also comes with a map editor for players interested in creating their own maps or campaigns. - -To install The Battle for Wesnoth, run the following command: - - * On Fedora: `dnf install wesnoth` - * On Debian/Ubuntu: `apt install wesnoth` - - - -### UFO: Alien Invasion - -![](https://opensource.com/sites/default/files/uploads/ufo_alien_invasion.png) - -[UFO: Alien Invasion][15] is an open source tactical strategy game inspired by the [X-COM series][20]. There are two distinct gameplay modes: geoscape and tactical. In geoscape mode, the player takes control of the big picture and deals with managing their bases, researching new technologies, and controlling overall strategy. In tactical mode, the player controls a squad of soldiers and directly confronts the alien invaders in a turn-based battle. Both modes provide different gameplay styles, but both require complex strategy and tactics. - -To install UFO: Alien Invasion, run the following command: - - * On Debian/Ubuntu: `apt install ufoai` - - - -Unfortunately, UFO: Alien Invasion is not packaged for Fedora. - -Did I miss one of your favorite open source strategy or simulation games? Share it in the comments below. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/8/strategy-simulation-games-linux - -作者：[Joshua Allen Holm][a] -选题：[lujun9972](https://github.com/lujun9972) -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/holmja -[1]:https://opensource.com/article/18/1/arcade-games-linux -[2]:https://opensource.com/article/18/3/card-board-games-linux -[3]:https://opensource.com/article/18/6/puzzle-games-linux -[4]:https://opensource.com/article/18/7/racing-flying-games-linux -[5]:https://opensource.com/article/18/8/role-playing-games-linux -[6]:http://www.freeciv.org/ -[7]:https://en.wikipedia.org/wiki/Civilization_(series) -[8]:https://megaglest.org/ -[9]:https://en.wikipedia.org/wiki/Warcraft -[10]:https://en.wikipedia.org/wiki/StarCraft -[11]:https://www.openttd.org/ -[12]:https://opensource.com/life/15/7/linux-game-review-openttd -[13]:https://en.wikipedia.org/wiki/Transport_Tycoon#Transport_Tycoon_Deluxe -[14]:https://www.wesnoth.org/ -[15]:https://ufoai.org/ -[16]:https://opensource.com/downloads/cheat-sheets?intcmp=7016000000127cYAAQ -[17]:https://opensource.com/alternatives?intcmp=7016000000127cYAAQ -[18]:https://opensource.com/tags/linux?intcmp=7016000000127cYAAQ -[19]:https://developers.redhat.com/cheat-sheets/advanced-linux-commands/?intcmp=7016000000127cYAAQ -[20]:https://en.wikipedia.org/wiki/X-COM diff --git a/sources/tech/20180914 A day in the life of a log message.md b/sources/tech/20180914 A day in the life of a log message.md index cc6ebd0f5b..8d60ec9fe6 100644 --- a/sources/tech/20180914 A day in the life of a log message.md +++ b/sources/tech/20180914 A day in the life of a log message.md @@ -1,4 +1,3 @@ -Ryze-Borgia is translating A day in the life of a log message ====== diff --git a/sources/tech/20181128 Arch-Audit - A Tool To Check Vulnerable Packages In Arch Linux.md b/sources/tech/20181128 Arch-Audit - A Tool To Check Vulnerable Packages In Arch Linux.md deleted file mode 100644 index d359a4f57c..0000000000 --- a/sources/tech/20181128 Arch-Audit - A Tool To Check Vulnerable Packages In Arch Linux.md +++ /dev/null @@ -1,128 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( Auk7F7) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: subject: (Arch-Audit : A Tool To Check Vulnerable Packages In Arch Linux) -[#]: via: (https://www.2daygeek.com/arch-audit-a-tool-to-check-vulnerable-packages-in-arch-linux/) -[#]: author: (Prakash Subramanian https://www.2daygeek.com/author/prakash/) -[#]: url: ( ) - - -Arch-Audit : A Tool To Check Vulnerable Packages In Arch Linux -====== - -We have to make the system up-to date to minimize the downtime and issues. - -It’s one of the routine task for Linux administrator to patch the system once in a month or 60 days once or 90 days at maximum. - -It would be sufficient schedule and we can’t do it this less than a month as it’s involve multiple activities and environments. - -Basically infrastructure comes with Test, Development, QA a.k.a Staging & Prod environments. - -Initially we will deploy the patches in the Test environment and corresponding team will be monitoring the system a week then they will give a status report like good or bad. - -If it’s success then we will move forward to other environments. If everything is good then finally we will patch production servers. - -Many of the organization has prepare to patch entire system. i mean full system update. It is a general patching schedule for a typical infrastructure. - -In some of the infrastructure they may have only production environment so, we should not prepare for the full system update instead we can go with security patch to make the system more stable and secure. - -Since Arch Linux and its derivatives distributions are fall under rolling release can be considered to be always up-to-date, as it uses the latest versions of software packages from the upstream. - -In some cases if you want to update security patch alone then you have to use arch-audit tool to identify and fix the security patches. - -### What is a Vulnerability? - -A vulnerability is a security weakness in a software program or hardware components (firmware). It’s a flaw that can leave it open to attack. - -To mitigate this we need to patch accordingly like for application/hardware it could be a code changes or config changes or parameter changes. - -### What is Arch-Audit Tool? - -[Arch-audit][1] is a tool like pkg-audit for Arch Linux system. It Uses data collected by the awesome Arch Security Team. It wont scan and find the vulnerable packages on your system like **yum –security check-update & yum updateinfo list available** and it will simply parse the page and display the results in terminal. So, it would show the accurate data. - -The Arch Security Team is a group of volunteers whose goal is to track security issues with Arch Linux packages. All issues are tracked on the Arch Linux security tracker. - -The team was formerly known as the Arch CVE Monitoring Team. The mission of the Arch Security Team is to contribute to the improvement of the security of Arch Linux. - -### How to Install arch-audit tool in Arch Linux - -The arch-audit tool is available in community repository so you can use the Pacman Package Manager to install it. - -``` -$ sudo pacman -S arch-audit -``` - -Run the `arch-audit` tool to find the open vulnerable packages on Arch based distributions. - -``` -$ arch-audit -Package cairo is affected by CVE-2017-7475. Low risk! -Package exiv2 is affected by CVE-2017-11592, CVE-2017-11591, CVE-2017-11553, CVE-2017-17725, CVE-2017-17724, CVE-2017-17723, CVE-2017-17722. Medium risk! -Package libtiff is affected by CVE-2018-18661, CVE-2018-18557, CVE-2017-9935, CVE-2017-11613. High risk!. Update to 4.0.10-1! -Package openssl is affected by CVE-2018-0735, CVE-2018-0734. Low risk! -Package openssl-1.0 is affected by CVE-2018-5407, CVE-2018-0734. Low risk! -Package patch is affected by CVE-2018-6952, CVE-2018-1000156. High risk!. Update to 2.7.6-7! -Package pcre is affected by CVE-2017-11164. Low risk! -Package systemd is affected by CVE-2018-6954, CVE-2018-15688, CVE-2018-15687, CVE-2018-15686. Critical risk!. Update to 239.300-1! -Package unzip is affected by CVE-2018-1000035. Medium risk! -Package webkit2gtk is affected by CVE-2018-4372. Critical risk!. Update to 2.22.4-1! -``` - -The above result shows the vulnerability risk status as well such as Low, Medium and Critical. - -To Show only vulnerable package names and their versions. - -``` -$ arch-audit -q -cairo -exiv2 -libtiff>=4.0.10-1 -openssl -openssl-1.0 -patch>=2.7.6-7 -pcre -systemd>=239.300-1 -unzip -webkit2gtk>=2.22.4-1 -``` - -To show only packages that have already been fixed. - -``` -$ arch-audit --upgradable --quiet -libtiff>=4.0.10-1 -patch>=2.7.6-7 -systemd>=239.300-1 -webkit2gtk>=2.22.4-1 -``` - -To cross check the above results, i’m going to test one of the package which is listed above in to confirm whether the vulnerability is still open or fixed it. Yes, it’s fixed and published the updated package in repository on yesterday. -![][3] - -To print only package names and associated CVEs alone. - -``` -$ arch-audit -uf "%n|%c" -libtiff|CVE-2018-18661,CVE-2018-18557,CVE-2017-9935,CVE-2017-11613 -patch|CVE-2018-6952,CVE-2018-1000156 -systemd|CVE-2018-6954,CVE-2018-15688,CVE-2018-15687,CVE-2018-15686 -webkit2gtk|CVE-2018-4372 -``` - --------------------------------------------------------------------------------- - -via: https://www.2daygeek.com/arch-audit-a-tool-to-check-vulnerable-packages-in-arch-linux/ - -作者：[Prakash Subramanian][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.2daygeek.com/author/prakash/ -[b]: https://github.com/lujun9972 -[1]: https://github.com/ilpianista/arch-audit -[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 -[3]: https://www.2daygeek.com/wp-content/uploads/2018/11/A-Tool-To-Check-Vulnerable-Packages-In-Arch-Linux.png diff --git a/sources/tech/20181203 How to bring good fortune to your Linux terminal.md b/sources/tech/20181203 How to bring good fortune to your Linux terminal.md deleted file mode 100644 index 7549dc0249..0000000000 --- a/sources/tech/20181203 How to bring good fortune to your Linux terminal.md +++ /dev/null @@ -1,86 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: subject: (How to bring good fortune to your Linux terminal) -[#]: via: (https://opensource.com/article/18/12/linux-toy-fortune) -[#]: author: (Jason Baker https://opensource.com/users/jason-baker) -[#]: url: ( ) - -How to bring good fortune to your Linux terminal -====== -Bring quotes and quips to the command line with the fortune utility. -![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-fortune.png?itok=5PVVZVer) - -It's December, and if you haven't found a [tech advent calendar][1] that sparks your fancy yet, well, maybe this one will do the trick. Every day, from now to the 24th, we're bringing you a different Linux command-line toy. What's a command-line toy, you ask? It could be a game or any simple diversion to bring a little happiness to your terminal. - -You may have seen some of these before. We hope you'll find something new, too. Either way, we hope you have fun following along. - -Today's toy, **fortune** , is an old one. Versions of it date back to the 1980s when it was included with Unix. The version I installed in Fedora was available under a BSD license, and I grabbed it with the following. - -``` -$ sudo dnf install fortune-mod -y -``` - -Your distribution may be different. On some, you may need to install the fortunes separately from **fortune** itself (try searching your package manager for "fortunes*"). You can also check out the source code on [GitHub][2]. Then, just run **fortune** to get, well, a fortune. - -``` -$ fortune -"Time is an illusion.  Lunchtime doubly so." --- Ford Prefect, _Hitchhiker's Guide to the Galaxy_ -``` - -So why do you need fortunes at the terminal? For fun, of course. Perhaps you'd like to add them to the message of the day on your system? - -Personally, I like using the **fortune** command as a built-in piece of dummy data when I'm using the terminal to parse text, particularly with [regular expressions][3], and want something simple to try it out on. - -For example, let's say I was testing our a transformation with the **tr** command to replace letter the letter e with a numeral 3. - -``` -$ fortune | tr 'eE' '3' -Unix 3xpr3ss: -All pass3ng3r bring a pi3c3 of th3 a3roplan3 and a box of tools with th3m to -th3 airport. Th3y gath3r on th3 tarmac, arguing constantly about what kind -of plan3 th3y want to build and how to put it tog3th3r. 3v3ntually, th3 -pass3ng3rs split into groups and build s3v3ral diff3r3nt aircraft, but giv3 -th3m all th3 sam3 nam3. Som3 pass3ng3rs actually r3ach th3ir d3stinations. -All pass3ng3rs b3li3v3 th3y got th3r3. -``` - -So what fortunes come with your distribution? Take a look in your **/usr/share/games/fortune** directory to find them all. Here are a few of my favorites. - -``` -Never laugh at live dragons. -                -- Bilbo Baggins [J.R.R. Tolkien, "The Hobbit"] - -I dunno, I dream in Perl sometimes... -             -- Larry Wall in  <8538@jpl-devvax.JPL.NASA.GOV> - -I have an existential map.  It has "You are here" written all over it. -                -- Steven Wright -``` - -Looking for more on **fortune**? You can, of course, always check out the man page to learn more about the options, or read a little bit more about the history of the command on [Wikipedia][4]. - -Do you have a favorite command-line toy that you think I ought to profile? The calendar for this series is mostly filled out but I've got a few spots left. Let me know in the comments below, and I'll check it out. If there's space, I'll try to include it. If not, but I get some good submissions, I'll do a round-up of honorable mentions at the end. - -Check out yesterday's toy, [Drive a locomotive through your Linux terminal][5], and check back tomorrow for another! - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/12/linux-toy-fortune - -作者：[Jason Baker][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/jason-baker -[b]: https://github.com/lujun9972 -[1]: https://opensource.com/article/16/11/7-tech-advent-calendars-holiday-season -[2]: https://github.com/shlomif/fortune-mod -[3]: https://opensource.com/article/18/5/getting-started-regular-expressions -[4]: https://en.wikipedia.org/wiki/Fortune_%28Unix%29 -[5]: https://opensource.com/article/18/12/linux-toy-sl diff --git a/sources/tech/20181212 Top 5 configuration management tools.md b/sources/tech/20181212 Top 5 configuration management tools.md deleted file mode 100644 index 72aebb209a..0000000000 --- a/sources/tech/20181212 Top 5 configuration management tools.md +++ /dev/null @@ -1,122 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Top 5 configuration management tools) -[#]: via: (https://opensource.com/article/18/12/configuration-management-tools) -[#]: author: (Marco Bravo https://opensource.com/users/marcobravo) - -Top 5 configuration management tools -====== -Learn about configuration management tools and figure out which will work best for your DevOps organization. -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/innovation_lightbulb_gears_devops_ansible.png?itok=TSbmp3_M) - -DevOps is evolving and gaining traction as organizations discover how it enables them to produce better applications and reduce their software products' time to market. - -[DevOps' core values][1] are Culture, Automation, Measurement, and Sharing (CAMS), and an organization's adherence to them influences how successful it is. - - * **Culture** brings people and processes together; - * **Automation** creates a fabric for DevOps; - * **Measurement** permits improvements; and - * **Sharing** enables the feedback loop in the CAMS cycle. - - - -Another DevOps concept is the idea that almost everything can be managed in code: servers, databases, networks, log files, application configurations, documentation, automated tests, deployment processes, and more. - -In this article, I'll focus on one aspect of automation: Configuration management. As part of [Infrastructure as Code][2] (IaC), configuration management tools enable the use of tested and proven software development practices for managing and provisioning data centers through plaintext definition files. - -By manipulating simple configuration files, a DevOps team can use application development best practices, such as version control, testing, small deployments, and design patterns. In short, this means code can be written to provision and manage an infrastructure as well as automate processes. - -### Why use configuration management tools? - -Configuration management tools enable changes and deployments to be faster, repeatable, scalable, predictable, and able to maintain the desired state, which brings controlled assets into an expected state. - -Some advantages of using configuration management tools include: - - * Adherence to coding conventions that make it easier to navigate code - * Idempotency, which means that the end state remains the same, no matter how many times the code is executed - * Distribution design to improve managing large numbers of remote servers - - - -Some configuration management tools use a pull model, in which an agent installed on the servers runs periodically to pull the latest definitions from a central repository and apply them to the server. Other tools use a push model, where a central server triggers updates to managed servers. - -### Top 5 configuration management tools - -There are a variety of configuration management tools available, and each has specific features that make it better for some situations than others. Yet the top five configuration management tools, presented below in alphabetical order, have several things in common that I believe are essential for DevOps success: all have an open source license, use externalized configuration definition files, run unattended, and are scriptable. All of the descriptions are based on information from the tools' software repositories and websites. - -#### Ansible - -"Ansible is a radically simple IT automation platform that makes your applications and systems easier to deploy. Avoid writing scripts or custom code to deploy and update your applications—automate in a language that approaches plain English, using SSH, with no agents to install on remote systems." —[GitHub repository][3] - -Ansible is one of my favorite tools; I started using it several years ago and fell in love with it. You can use Ansible to execute the same command for a list of servers from the command line. You can also use it to automate tasks using "playbooks" written into a YAML file, which facilitate communication between teams and non-technical people. Its main advantages are that it is simple, agentless, and easy to read (especially for non-programmers). - -Because agents are not required, there is less overhead on servers. An SSH connection is necessary when running in push mode (which is the default), but pull mode is available if needed. [Playbooks][4] can be written with a minimal set of commands or they can be scaled for more elaborate automation tasks that could include roles, variables, and modules written by other people. - -You can combine Ansible with other tools to create a central console to control processes. Those tools include Ansible Works (AWX), Jenkins, RunDeck, and [ARA][5], which offers [traceability when running playbooks][6]. - -### CFEngine - -"CFEngine 3 is a popular open source configuration management system. Its primary function is to provide automated configuration and maintenance of large-scale computer systems." —[GitHub repository][7] - -CFEngine was introduced by Mark Burgess in 1993 as a scientific approach to automated configuration management. The goal was to deal with the entropy in computer systems' configuration and resolve it with end-state "convergence." Convergence means a desired end-state and elaborates on idempotence as a capacity to reach the desired end-state. Burgess' research evolved in 2004 when he proposed the [Promise theory][8] as a model of voluntary cooperation between agents. - -The current version of CFEngine incorporates Promise theory and uses agents running on each server that pull the configuration from a central repository. It requires some expert knowledge to deal with configurations, so it's best suited for technical people. - -### Chef - -"A systems integration framework, built to bring the benefits of configuration management to your entire infrastructure." —[GitHub repository][9] - -Chef uses "recipes" written in Ruby to keep your infrastructure running up-to-date and compliant. The recipes describe a series of resources that should be in a particular state. Chef can run in client/server mode or in a standalone configuration named [chef-solo][10]. It has good integration with the major cloud providers to automatically provision and configure new machines. - -Chef has a solid user base and provides a full toolset to allow people with different technical backgrounds and skills to interact around the recipes. But, at its base, it is more technically oriented tool. - -### Puppet - -"Puppet, an automated administrative engine for your Linux, Unix, and Windows systems, performs administrative tasks (such as adding users, installing packages, and updating server configurations) based on a centralized specification." —[GitHub repository][11] - -Conceived as a tool oriented toward operations and sysadmins, Puppet has consolidated as a configuration management tool. It usually works in a client-server architecture, and an agent communicates with the server to fetch configuration instructions. - -Puppet uses a declarative language or Ruby to describe the system configuration. It is organized in modules, and manifest files contain the desired-state goals to keep everything as required. Puppet uses the push model by default, and the pull model can be configured. - -### Salt - -"Software to automate the management and configuration of any infrastructure or application at scale." — [GitHub repository][12] - -Salt was created for high-speed data collection and scale beyond tens of thousands of servers. It uses Python modules to handle configuration details and specific actions. These modules manage all of Salt's remote execution and state management behavior. Some level of technical skills are required to configure the modules. - -Salt uses a client-server topology (with the Salt master as server and Salt minions as clients). Configurations are kept in Salt state files, which describe everything required to keep a system in the desired state. - -### Conclusion - -The landscape of DevOps tools is evolving all the time, and it is important to keep an eye on the changes. I hope this article will encourage you to explore these concepts and tools further. If so, the Cloud Native Computing Foundation (CNCF) maintains a good reference in the [Cloud Native Landscape Project][13]. - - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/12/configuration-management-tools - -作者：[Marco Bravo][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/marcobravo -[b]: https://github.com/lujun9972 -[1]: https://www.oreilly.com/learning/why-use-terraform -[2]: https://www.oreilly.com/library/view/infrastructure-as-code/9781491924334/ch04.html -[3]: https://github.com/ansible/ansible -[4]: https://opensource.com/article/18/8/ansible-playbooks-you-should-try -[5]: https://github.com/openstack/ara -[6]: https://opensource.com/article/18/5/analyzing-ansible-runs-using-ara -[7]: https://github.com/cfengine/core -[8]: https://en.wikipedia.org/wiki/Promise_theory -[9]: https://github.com/chef/chef -[10]: https://docs.chef.io/chef_solo.html -[11]: https://github.com/puppetlabs/puppet -[12]: https://github.com/saltstack/salt -[13]: https://github.com/cncf/landscape diff --git a/sources/tech/20181214 The Linux terminal is no one-trick pony.md b/sources/tech/20181214 The Linux terminal is no one-trick pony.md deleted file mode 100644 index 28964b249c..0000000000 --- a/sources/tech/20181214 The Linux terminal is no one-trick pony.md +++ /dev/null @@ -1,66 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (The Linux terminal is no one-trick pony) -[#]: via: (https://opensource.com/article/18/12/linux-toy-ponysay) -[#]: author: (Jason Baker https://opensource.com/users/jason-baker) - -The Linux terminal is no one-trick pony -====== -Bring the magic of My Little Pony to your Linux command line. -![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-ponysay.png?itok=ehl6pTr_) - -Welcome to another day of the Linux command-line toys advent calendar. If this is your first visit to the series, you might be asking yourself what a command-line toy even is. We’re figuring that out as we go, but generally, it could be a game, or any simple diversion that helps you have fun at the terminal. - -Some of you will have seen various selections from our calendar before, but we hope there’s at least one new thing for everyone. - -Reader [Lori][1] made the suggestion of today's toy in a comment on my previous article on [cowsay][2]: - -"Hmmm, I've been playing with something called ponysay which seems to be a full-color variant on your cowsay." - -Intrigued, I had to check it out, and I was not disappointed with what I found. - -In a nutshell, **[ponysay][3]** is exactly that: a rewrite of **cowsay** that includes many full-color characters from [My Little Pony][4], that you can use to output phrases at the Linux command line. It's actually a really well-done project, that features over 400 characters and character combinations, and is incredibly well documented in a [78-page PDF][5] covering full usage. - -To install **ponysay** , you'll want to check out the project [README][6] to select the installation method that works best for your distribution and situation. Since ponysay didn't appear to be packaged for my distribution, Fedora, I opted to try out the Docker container image, but do what works best for you; installation from source may also work for you. - -I was curious to try out [**podman**][7] as a drop-in replacement for **docker** for a casual container users, and for me at least, it just worked! - -``` -$ podman run -ti --rm mpepping/ponysay 'Ponytastic' -``` - -The outputs are amazing, and I challenge you to try it out and let me know your favorite. Here was one of mine: - -![](https://opensource.com/sites/default/files/uploads/linux-toy-ponysay-output.png) - -It's developers chose to write the code in [Pony][8]! (Update: Sadly, I was wrong about this. It's written in Python, though GitHub believes it to be Pony because of the file extensions.) Ponysay is licensed under the GPL version 3, and you can pick up its source code [on GitHub][3]. - -Do you have a favorite command-line toy that you think I ought to profile? The calendar for this series is mostly filled out but I've got a few spots left. Let me know in the comments below, and I'll check it out. If there's space, I'll try to include it. If not, but I get some good submissions, I'll do a round-up of honorable mentions at the end. - -Check out yesterday's toy, [Relax by the fire at your Linux terminal][9], and check back tomorrow for another! - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/12/linux-toy-ponysay - -作者：[Jason Baker][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/jason-baker -[b]: https://github.com/lujun9972 -[1]: https://opensource.com/users/n8chz -[2]: https://opensource.com/article/18/12/linux-toy-cowsay -[3]: https://github.com/erkin/ponysay -[4]: https://en.wikipedia.org/wiki/My_Little_Pony -[5]: https://github.com/erkin/ponysay/blob/master/ponysay.pdf?raw=true -[6]: https://github.com/erkin/ponysay/blob/master/README.md -[7]: https://opensource.com/article/18/10/podman-more-secure-way-run-containers -[8]: https://opensource.com/article/18/5/pony -[9]: https://opensource.com/article/18/12/linux-toy-aafire diff --git a/sources/tech/20181215 Head to the arcade in your Linux terminal with this Pac-man clone.md b/sources/tech/20181215 Head to the arcade in your Linux terminal with this Pac-man clone.md deleted file mode 100644 index 3bd36352a4..0000000000 --- a/sources/tech/20181215 Head to the arcade in your Linux terminal with this Pac-man clone.md +++ /dev/null @@ -1,52 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Head to the arcade in your Linux terminal with this Pac-man clone) -[#]: via: (https://opensource.com/article/18/12/linux-toy-myman) -[#]: author: (Jason Baker https://opensource.com/users/jason-baker) - -Head to the arcade in your Linux terminal with this Pac-man clone -====== -Want to recreate the magic of your favorite arcade game? Today's command-line toy will transport you back in time. -![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-myman.png?itok=9j1DFgH0) - -Welcome back to another day of the Linux command-line toys advent calendar. If this is your first visit to the series, you might be asking yourself what command-line toys are all about. Basically, they're games and simple diversions that help you have fun at the terminal. - -Some are new, and some are old classics. We hope you enjoy. - -Today's toy, MyMan, is a fun clone of the classic arcade game [Pac-Man][1]. (You didn't think this was going to be about the [similarly-named][2] Linux package manager, did you?) If you're anything like me, you spent more than your fair share of quarters trying to hit a high score Pac-Man back in the day, and still give it a go whenever you get a chance. - -MyMan isn't the only Pac-Man clone for the Linux terminal, but it's the one I chose to include because 1) I like its visual style, which rings true to the original and 2) it's conveniently packaged for my Linux distribution so it was an easy install. But you should check out your other options as well. Here's [another one][3] that looks like it may be promising, but I haven't tried it. - -Since MyMan was packaged for Fedora, installation was as simple as: - -``` -$ dnf install myman -``` - -MyMan is made available under an MIT license and you can check out the source code on [SourceForge][4]. -![](https://opensource.com/sites/default/files/uploads/linux-toy-myman-animated.gif) -Do you have a favorite command-line toy that you think I ought to profile? The calendar for this series is mostly filled out but I've got a few spots left. Let me know in the comments below, and I'll check it out. If there's space, I'll try to include it. If not, but I get some good submissions, I'll do a round-up of honorable mentions at the end. - -Check out yesterday's toy, [The Linux terminal is no one-trick pony][5], and check back tomorrow for another! - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/12/linux-toy-myman - -作者：[Jason Baker][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/jason-baker -[b]: https://github.com/lujun9972 -[1]: https://en.wikipedia.org/wiki/Pac-Man -[2]: https://wiki.archlinux.org/index.php/pacman -[3]: https://github.com/YoctoForBeaglebone/pacman4console -[4]: https://myman.sourceforge.io/ -[5]: https://opensource.com/article/18/12/linux-toy-ponysay diff --git a/sources/tech/20181219 How to open source your Python library.md b/sources/tech/20181219 How to open source your Python library.md deleted file mode 100644 index e4d6adf3c6..0000000000 --- a/sources/tech/20181219 How to open source your Python library.md +++ /dev/null @@ -1,114 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (HankChow) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (How to open source your Python library) -[#]: via: (https://opensource.com/article/18/12/tips-open-sourcing-python-libraries) -[#]: author: (Moshe Zadka https://opensource.com/users/moshez) - -How to open source your Python library -====== -This 12-step checklist will ensure a successful launch. -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/button_push_open_keyboard_file_organize.png?itok=KlAsk1gx) - -You wrote a Python library. I'm sure it's amazing! Wouldn't it be neat if it was easy for people to use it? Here is a checklist of things to think about and concrete steps to take when open sourcing your Python library. - -### 1\. Source - -Put the code up on [GitHub][1], where most open source projects happen and where it is easiest for people to submit pull requests. - -### 2\. License - -Choose an open source license. A good, permissive default is the [MIT License][2]. If you have specific requirements, Creative Common's [Choose a License][3] can guide you through the alternatives. Most importantly, there are three rules to keep in mind when choosing a license: - - * Don't create your own license. - * Don't create your own license. - * Don't create your own license. - - - -### 3\. README - -Put a file called README.rst, formatted with ReStructured Text, at the top of your tree. - -GitHub will render ReStructured Text just as well as Markdown, and ReST plays better with Python's documentation ecosystem. - -### 4\. Tests - -Write tests. This is not useful just for you: it is useful for people who want to make patches that avoid breaking related functionality. - -Tests help collaborators collaborate. - -Usually, it is best if they are runnable with [**pytest**][4]. There are other test runners—but very little reason to use them. - -### 5\. Style - -Enforce style with a linter: PyLint, Flake8, or Black with **\--check**. Unless you use Black, make sure to specify configuration options in a file checked into source control. - -### 6\. API documentation - -Use docstrings to document modules, functions, classes, and methods. - -There are a few styles you can use. I prefer the [Google-style docstrings][5], but [ReST docstrings][6] are an option. - -Both Google-style and ReST docstrings can be processed by Sphinx to integrate API documentation with prose documentation. - -### 7\. Prose documentation - -Use [Sphinx][7]. (Read [our article on it][8].) A tutorial is useful, but it is also important to specify what this thing is, what it is good for, what it is bad for, and any special considerations. - -### 8\. Building - -Use **tox** or **nox** to automatically run your tests and linter and build the documentation. These tools support a "dependency matrix." These matrices tend to explode fast, but try to test against a reasonable sample, such as Python versions, versions of dependencies, and possibly optional dependencies you install. - -### 9\. Packaging - -Use [setuptools][9]. Write a **setup.py** and a **setup.cfg**. If you support both Python 2 and 3, specify universal wheels in the **setup.cfg**. - -One thing **tox** or **nox** should do is build a wheel and run tests against the installed wheel. - -Avoid C extensions. If you absolutely need them for performance or binding reasons, put them in a separate package. Properly packaging C extensions deserves its own post. There are a lot of gotchas! - -### 10\. Continuous integration - -### 11\. Versions - -Use a public continuous integration runner. [TravisCI][10] and [CircleCI][11] offer free tiers for open source projects. Configure GitHub or other repo to require passing checks before merging pull requests, and you'll never have to worry about telling people to fix their tests or their style in code reviews. - -Use either [SemVer][12] or [CalVer][13]. There are many tools to help manage versions: [incremental][14], [bumpversion][15], and [setuptools_scm][16] are all packages on PyPI that help manage versions for you. - -### 12\. Release - -Release by running **tox** or **nox** and using **twine** to upload the artifacts to PyPI. You can do a "test upload" by running [DevPI][17]. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/12/tips-open-sourcing-python-libraries - -作者：[Moshe Zadka][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/moshez -[b]: https://github.com/lujun9972 -[1]: https://github.com/ -[2]: https://en.wikipedia.org/wiki/MIT_License -[3]: https://choosealicense.com/ -[4]: https://docs.pytest.org/en/latest/ -[5]: https://github.com/google/styleguide/blob/gh-pages/pyguide.md -[6]: https://www.python.org/dev/peps/pep-0287/ -[7]: http://www.sphinx-doc.org/en/master/ -[8]: https://opensource.com/article/18/11/building-custom-workflows-sphinx -[9]: https://pypi.org/project/setuptools/ -[10]: https://travis-ci.org/ -[11]: https://circleci.com/ -[12]: https://semver.org/ -[13]: https://calver.org/ -[14]: https://pypi.org/project/incremental/ -[15]: https://pypi.org/project/bumpversion/ -[16]: https://pypi.org/project/setuptools_scm/ -[17]: https://opensource.com/article/18/7/setting-devpi diff --git a/sources/tech/20181224 An Introduction to Go.md b/sources/tech/20181224 An Introduction to Go.md deleted file mode 100644 index 5989b6c913..0000000000 --- a/sources/tech/20181224 An Introduction to Go.md +++ /dev/null @@ -1,278 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (LazyWolfLin) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (An Introduction to Go) -[#]: via: (https://blog.jak-linux.org/2018/12/24/introduction-to-go/) -[#]: author: (Julian Andres Klode https://blog.jak-linux.org/) - -An Introduction to Go -====== - -(What follows is an excerpt from my master’s thesis, almost all of section 2.1, quickly introducing Go to people familiar with CS) - -Go is an imperative programming language for concurrent programming created at and mainly developed by Google, initially mostly by Robert Griesemer, Rob Pike, and Ken Thompson. Design of the language started in 2007, and an initial version was released in 2009; with the first stable version, 1.0 released in 2012 . - -Go has a C-like syntax (without a preprocessor), garbage collection, and, like its predecessors devloped at Bell Labs – Newsqueak (Rob Pike), Alef (Phil Winterbottom), and Inferno (Pike, Ritchie, et al.) – provides built-in support for concurrency using so-called goroutines and channels, a form of co-routines, based on the idea of Hoare’s ‘Communicating Sequential Processes’ . - -Go programs are organised in packages. A package is essentially a directory containing Go files. All files in a package share the same namespace, and there are two visibilities for symbols in a package: Symbols starting with an upper case character are visible to other packages, others are private to the package: - -``` -func PublicFunction() { - fmt.Println("Hello world") -} - -func privateFunction() { - fmt.Println("Hello package") -} -``` - -### Types - -Go has a fairly simple type system: There is no subtyping (but there are conversions), no generics, no polymorphic functions, and there are only a few basic categories of types: - - 1. base types: `int`, `int64`, `int8`, `uint`, `float32`, `float64`, etc. - - 2. `struct` - - 3. `interface` \- a set of methods - - 4. `map[K, V]` \- a map from a key type to a value type - - 5. `[number]Type` \- an array of some element type - - 6. `[]Type` \- a slice (pointer to array with length and capability) of some type - - 7. `chan Type` \- a thread-safe queue - - 8. pointer `*T` to some other type - - 9. functions - - 10. named type - aliases for other types that may have associated methods: - -``` -type T struct { foo int } -type T *T -type T OtherNamedType -``` - -Named types are mostly distinct from their underlying types, so you cannot assign them to each other, but some operators like `+` do work on objects of named types with an underlying numerical type (so you could add two `T` in the example above). - - -Maps, slices, and channels are reference-like types - they essentially are structs containing pointers. Other types are passed by value (copied), including arrays (which have a fixed length and are copied). - -#### Conversions - -Conversions are the similar to casts in C and other languages. They are written like this: - -``` -TypeName(value) -``` - -#### Constants - -Go has “untyped” literals and constants. - -``` -1 // untyped integer literal -const foo = 1 // untyped integer constant -const foo int = 1 // int constant -``` - -Untyped values are classified into the following categories: `UntypedBool`, `UntypedInt`, `UntypedRune`, `UntypedFloat`, `UntypedComplex`, `UntypedString`, and `UntypedNil` (Go calls them basic kinds, other basic kinds are available for the concrete types like `uint8`). An untyped value can be assigned to a named type derived from a base type; for example: - -``` -type someType int - -const untyped = 2 // UntypedInt -const bar someType = untyped // OK: untyped can be assigned to someType -const typed int = 2 // int -const bar2 someType = typed // error: int cannot be assigned to someType -``` - -### Interfaces and ‘objects’ - -As mentioned before, interfaces are a set of methods. Go is not an object-oriented language per se, but it has some support for associating methods with named types: When declaring a function, a receiver can be provided - a receiver is an additional function argument that is passed before the function and involved in the function lookup, like this: - -``` -type SomeType struct { ... } - -func (s *SomeType) MyMethod() { -} - -func main() { - var s SomeType - s.MyMethod() -} -``` - -An object implements an interface if it implements all methods; for example, the following interface `MyMethoder` is implemented by `*SomeType` (note the pointer), and values of `*SomeType` can thus be used as values of `MyMethoder`. The most basic interface is `interface{}`, that is an interface with an empty method set - any object satisfies that interface. - -``` -type MyMethoder interface { - MyMethod() -} -``` - -There are some restrictions on valid receiver types; for example, while a named type could be a pointer (for example, `type MyIntPointer *int`), such a type is not a valid receiver type. - -### Control flow - -Go provides three primary statements for control flow: `if`, `switch`, and `for`. The statements are fairly similar to their equivalent in other C-like languages, with some exceptions: - - * There are no parentheses around conditions, so it is `if a == b {}`, not `if (a == b) {}`. The braces are mandatory. - - * All of them can have initialisers, like this - -`if result, err := someFunction(); err == nil { // use result }` - - * The `switch` statement can use arbitrary expressions in cases - - * The `switch` statement can switch over nothing (equals switching over true) - - * Cases do not fall through by default (no `break` needed), use `fallthrough` at the end of a block to fall through. - - * The `for` loop can loop over ranges: `for key, val := range map { do something }` - - - - -### Goroutines - -The keyword `go` spawns a new goroutine, a concurrently executed function. It can be used with any function call, even a function literal: - -``` -func main() { - ... - go func() { - ... - }() - - go some_function(some_argument) -} -``` - -### Channels - -Goroutines are often combined with channels to provide an extended form of Communicating Sequential Processes . A channel is a concurrent-safe queue, and can be buffered or unbuffered: - -``` -var unbuffered = make(chan int) // sending blocks until value has been read -var buffered = make(chan int, 5) // may have up to 5 unread values queued -``` - -The `<-` operator is used to communicate with a single channel. - -``` -valueReadFromChannel := <- channel -otherChannel <- valueToSend -``` - -The `select` statement allows communication with multiple channels: - -``` -select { - case incoming := <- inboundChannel: - // A new message for me - case outgoingChannel <- outgoing: - // Could send a message, yay! -} -``` - -### The `defer` statement - -Go provides a `defer` statement that allows a function call to be scheduled for execution when the function exits. It can be used for resource clean-up, for example: - -``` -func myFunc(someFile io.ReadCloser) { - defer someFile.close() - /bin /boot /dev /etc /home /lib /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /srv /sys /tmp /usr /var Do stuff with file */ -} -``` - -It is of course possible to use function literals as the function to call, and any variables can be used as usual when writing the call. - -### Error handling - -Go does not provide exceptions or structured error handling. Instead, it handles errors by returning them in a second or later return value: - -``` -func Read(p []byte) (n int, err error) - -// Built-in type: -type error interface { - Error() string -} -``` - -Errors have to be checked in the code, or can be assigned to `_`: - -``` -n0, _ := Read(Buffer) // ignore error -n, err := Read(buffer) -if err != nil { - return err -} -``` - -There are two functions to quickly unwind and recover the call stack, though: `panic()` and `recover()`. When `panic()` is called, the call stack is unwound, and any deferred functions are run as usual. When a deferred function invokes `recover()`, the unwinding stops, and the value given to `panic()` is returned. If we are unwinding normally and not due to a panic, `recover()` simply returns `nil`. In the example below, a function is deferred and any `error` value that is given to `panic()` will be recovered and stored in an error return value. Libraries sometimes use that approach to make highly recursive code like parsers more readable, while still maintaining the usual error return value for public functions. - -``` -func Function() (err error) { - defer func() { - s := recover() - switch s := s.(type) { // type switch - case error: - err = s // s has type error now - default: - panic(s) - } - } -} -``` - -### Arrays and slices - -As mentioned before, an array is a value type and a slice is a pointer into an array, created either by slicing an existing array or by using `make()` to create a slice, which will create an anonymous array to hold the elements. - -``` -slice1 := make([]int, 2, 5) // 5 elements allocated, 2 initialized to 0 -slice2 := array[:] // sliced entire array -slice3 := array[1:] // slice of array without first element -``` - -There are some more possible combinations for the slicing operator than mentioned above, but this should give a good first impression. - -A slice can be used as a dynamically growing array, using the `append()` function. - -``` -slice = append(slice, value1, value2) -slice = append(slice, arrayOrSlice...) -``` - -Slices are also used internally to represent variable parameters in variable length functions. - -### Maps - -Maps are simple key-value stores and support indexing and assigning. They are not thread-safe. - -``` -someValue := someMap[someKey] -someValue, ok := someMap[someKey] // ok is false if key not in someMap -someMap[someKey] = someValue -``` --------------------------------------------------------------------------------- - -via: https://blog.jak-linux.org/2018/12/24/introduction-to-go/ - -作者：[Julian Andres Klode][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://blog.jak-linux.org/ -[b]: https://github.com/lujun9972 diff --git a/sources/tech/20181224 Go on an adventure in your Linux terminal.md b/sources/tech/20181224 Go on an adventure in your Linux terminal.md new file mode 100644 index 0000000000..f1b46340bb --- /dev/null +++ b/sources/tech/20181224 Go on an adventure in your Linux terminal.md @@ -0,0 +1,54 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Go on an adventure in your Linux terminal) +[#]: via: (https://opensource.com/article/18/12/linux-toy-adventure) +[#]: author: (Jason Baker https://opensource.com/users/jason-baker) + +Go on an adventure in your Linux terminal +====== + +Our final day of the Linux command-line toys advent calendar ends with the beginning of a grand adventure. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/uploads/linux-toy-advent.png?itok=OImUJJI5) + +Today is the final day of our 24-day-long Linux command-line toys advent calendar. Hopefully, you've been following along, but if not, start back at [the beginning][1] and work your way through. You'll find plenty of games, diversions, and oddities for your Linux terminal. + +And while you may have seen some toys from our calendar before, we hope there’s at least one new thing for everyone. + +Today's toy was suggested by Opensource.com moderator [Joshua Allen Holm][2]: + +"If the last day of your advent calendar is not ESR's [Eric S. Raymond's] [open source release of Adventure][3], which retains use of the classic 'advent' command (Adventure in the BSD Games package uses 'adventure), I will be very, very, very disappointed. ;-)" + +What a perfect way to end our series. + +Colossal Cave Adventure (often just called Adventure), is a text-based game from the 1970s that gave rise to the entire adventure game genre. Despite its age, Adventure is still an easy way to lose hours as you explore a fantasy world, much like a Dungeons and Dragons dungeon master might lead you through an imaginary place. + +Rather than take you through the history of Adventure here, I encourage you to go read Joshua's [history of the game][4] itself and why it was resurrected and re-ported a few years ago. Then, go [clone the source][5] and follow the [installation instructions][6] to launch the game with **advent** **** on your system. Or, as Joshua mentions, another version of the game can be obtained from the **bsd-games** package, which is probably available from your default repositories in your distribution of choice. + +Do you have a favorite command-line toy that you we should have included? Our series concludes today, but we'd still love to feature some cool command-line toys in the new year. Let me know in the comments below, and I'll check it out. And let me know what you thought of today's amusement. + +Be sure to check out yesterday's toy, [The Linux command line can fetch fun from afar][7], and I'll see you next year! + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/18/12/linux-toy-adventure + +作者：[Jason Baker][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/jason-baker +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/article/18/12/linux-toy-boxes +[2]: https://opensource.com/users/holmja +[3]: https://gitlab.com/esr/open-adventure (https://gitlab.com/esr/open-adventure) +[4]: https://opensource.com/article/17/6/revisit-colossal-cave-adventure-open-adventure +[5]: https://gitlab.com/esr/open-adventure +[6]: https://gitlab.com/esr/open-adventure/blob/master/INSTALL.adoc +[7]: https://opensource.com/article/18/12/linux-toy-remote diff --git a/sources/tech/20190103 How to use Magit to manage Git projects.md b/sources/tech/20190103 How to use Magit to manage Git projects.md new file mode 100644 index 0000000000..dbcb63d736 --- /dev/null +++ b/sources/tech/20190103 How to use Magit to manage Git projects.md @@ -0,0 +1,93 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (How to use Magit to manage Git projects) +[#]: via: (https://opensource.com/article/19/1/how-use-magit) +[#]: author: (Sachin Patil https://opensource.com/users/psachin) + +How to use Magit to manage Git projects +====== +Emacs' Magit extension makes it easy to get started with Git version control. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/rh_003588_01_rd3os.combacktoschoolseriesk12_rh_021x_0.png?itok=fvorN0e-) + +[Git][1] is an excellent [version control][2] tool for managing projects, but it can be hard for novices to learn. It's difficult to work from the Git command line unless you're familiar with the flags and options and the appropriate situations to use them. This can be discouraging and cause people to be stuck with very limited usage. + +Fortunately, most of today's integrated development environments (IDEs) include Git extensions that make using it a lot easier. One such Git extension available in Emacs is called [Magit][3]. + +The Magit project has been around for 10 years and defines itself as "a Git porcelain inside Emacs." In other words, it's an interface where every action can be managed by pressing a key. This article walks you through the Magit interface and explains how to use it to manage a Git project. + +If you haven't already, [install Emacs][4], then [install Magit][5] before you continue with this tutorial. + +### Magit's interface + +Start by visiting a project directory in Emacs' [Dired mode][6]. For example, all my Emacs configurations are stored in the **~/.emacs.d/** directory, which is managed by Git. + +![](https://opensource.com/sites/default/files/uploads/visiting_a_git_project.png) + +If you were working from the command line, you would enter **git status** to find a project's current status. Magit has a similar function: **magit-status**. You can call this function using **M-x magit-status** (short for the keystroke **Alt+x magit-status** ). Your result will look something like this: + +![](https://opensource.com/sites/default/files/uploads/magit_status.png) + +Magit shows much more information than you would get from the **git status** command. It shows a list of untracked files, files that aren't staged, and staged files. It also shows the stash list and the most recent commits—all in a single window. + +If you want to know what has changed, use the Tab key. For example, if I move my cursor over the unstaged file **custom_functions.org** and press the Tab key, Magit will display the changes: + +![](https://opensource.com/sites/default/files/uploads/show_unstaged_content.png) + +This is similar to using the command **git diff custom_functions.org**. Staging a file is even easier. Simply move the cursor over a file and press the **s** key. The file will be quickly moved to the staged file list: + +![](https://opensource.com/sites/default/files/uploads/staging_a_file.png) + +To unstage a file, use the **u** key. It is quicker and more fun to use **s** and **u** instead of entering **git add -u ** and **git reset HEAD ** on the command line. + +### Commit changes + +In the same Magit window, pressing the **c** key will display a commit window that provides flags like **\--all** to stage all files or **\--signoff** to add a signoff line to a commit message. + +![](https://opensource.com/sites/default/files/uploads/magit_commit_popup.png) + +Move your cursor to the line where you want to enable a signoff flag and press Enter. This will highlight the **\--signoff** text, which indicates that the flag is enabled. + +![](https://opensource.com/sites/default/files/uploads/magit_signoff_commit.png) + +Pressing **c** again will display the window to write the commit message. + +![](https://opensource.com/sites/default/files/uploads/magit_commit_message.png) + +Finally, use **C-c C-c **(short form of the keys Ctrl+cc) to commit the changes. + +![](https://opensource.com/sites/default/files/uploads/magit_commit_message_2.png) + +### Push changes + +Once the changes are committed, the commit line will appear in the **Recent commits** section. + +![](https://opensource.com/sites/default/files/uploads/magit_commit_log.png) + +Place the cursor on that commit and press **p** to push the changes. + +I've uploaded a [demonstration][7] on YouTube if you want to get a feel for using Magit. I have just scratched the surface in this article. It has many cool features to help you with Git branches, rebasing, and more. You can find [documentation, support, and more][8] linked from Magit's homepage. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/how-use-magit + +作者：[Sachin Patil][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/psachin +[b]: https://github.com/lujun9972 +[1]: https://git-scm.com +[2]: https://git-scm.com/book/en/v2/Getting-Started-About-Version-Control +[3]: https://magit.vc +[4]: https://www.gnu.org/software/emacs/download.html +[5]: https://magit.vc/manual/magit/Installing-from-Melpa.html#Installing-from-Melpa +[6]: https://www.gnu.org/software/emacs/manual/html_node/emacs/Dired-Enter.html#Dired-Enter +[7]: https://youtu.be/Vvw75Pqp7Mc +[8]: https://magit.vc/ diff --git a/sources/tech/20190103 s-tui- A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux.md b/sources/tech/20190103 s-tui- A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux.md deleted file mode 100644 index 8861e90cac..0000000000 --- a/sources/tech/20190103 s-tui- A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux.md +++ /dev/null @@ -1,131 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (geekpi) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (s-tui: A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux) -[#]: via: (https://www.2daygeek.com/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency/) -[#]: author: (Prakash Subramanian https://www.2daygeek.com/author/prakash/) - -s-tui: A Terminal Tool To Monitor CPU Temperature, Frequency, Power And Utilization In Linux -====== - -By default every Linux administrator would go with **[lm_sensors to monitor CPU temperature][1]**. - -lm_sensors (Linux monitoring sensors) is a free and open-source application that provides tools and drivers for monitoring temperatures, voltage, and fans. - -It’s a CLI utility and if you are looking for alternative tools. - -I would suggest you to go for s-tui. - -It’s a Stress Terminal UI which helps administrator to view CPU temperature with colors. - -### What is s-tui - -s-tui is a terminal UI for monitoring your computer. s-tui allows to monitor CPU temperature, frequency, power and utilization in a graphical way from the terminal. - -Also, shows performance dips caused by thermal throttling, it requires minimal resources and doesn’t requires X-server. It was written in Python and requires root privilege to use this. - -s-tui is a self-contained application which can run out-of-the-box and doesn’t need config files to drive its core features. - -s-tui uses psutil to probe some of your hardware information. If your hardware is not supported, you might not see all the information. - -Running s-tui as root gives access to the maximum Turbo Boost frequency available to your CPU when stressing all cores. - -It uses Stress utility in the background to check the temperature of its components do not exceed their acceptable range by imposes certain types of compute stress on your system. - -Running an overclocked PC is fine as long as it is stable and that the temperature of its components do not exceed their acceptable range. - -There are several programs available to assess system stability through stress testing the system and thereby the overclock level. - -### How to Install s-tui In Linux - -It was written in Python and pip installation is a recommended method to install s-tui on Linux. Make sure you should have installed python-pip package on your system. If no, use the following command to install it. - -For Debian/Ubuntu users, use **[Apt Command][2]** or **[Apt-Get Command][3]** to install pip package. - -``` -$ sudo apt install python-pip stress -``` - -For Archlinux users, use **[Pacman Command][4]** to install pip package. - -``` -$ sudo pacman -S python-pip stress -``` - -For Fedora users, use **[DNF Command][5]** to install pip package. - -``` -$ sudo dnf install python-pip stress -``` - -For CentOS/RHEL users, use **[YUM Command][6]** to install pip package. - -``` -$ sudo yum install python-pip stress -``` - -For openSUSE users, use **[Zypper Command][7]** to install pip package. - -``` -$ sudo zypper install python-pip stress -``` - -Finally run the following **[pip command][8]** to install s-tui tool in Linux. - -For Python 2.x: - -``` -$ sudo pip install s-tui -``` - -For Python 3.x: - -``` -$ sudo pip3 install s-tui -``` - -### How to Access s-tui - -As i told in the beginning of the article. It requires root privilege to get all the information from your system. Just run the following command to launch s-tui. - -``` -$ sudo s-tui -``` - -![][10] - -By default it enable hardware monitoring and select the “Stress” option to do the stress test on your system. -![][11] - -To check other options, navigate to help page. - -``` -$ s-tui --help -``` - --------------------------------------------------------------------------------- - -via: https://www.2daygeek.com/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency/ - -作者：[Prakash Subramanian][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.2daygeek.com/author/prakash/ -[b]: https://github.com/lujun9972 -[1]: https://www.2daygeek.com/view-check-cpu-hard-disk-temperature-linux/ -[2]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/ -[3]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/ -[4]: https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/ -[5]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ -[6]: https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/ -[7]: https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/ -[8]: https://www.2daygeek.com/install-pip-manage-python-packages-linux/ -[9]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 -[10]: https://www.2daygeek.com/wp-content/uploads/2018/12/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency-1.jpg -[11]: https://www.2daygeek.com/wp-content/uploads/2018/12/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency-2.jpg diff --git a/sources/tech/20190104 Managing dotfiles with rcm.md b/sources/tech/20190104 Managing dotfiles with rcm.md deleted file mode 100644 index f046c70538..0000000000 --- a/sources/tech/20190104 Managing dotfiles with rcm.md +++ /dev/null @@ -1,116 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (geekpi) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Managing dotfiles with rcm) -[#]: via: (https://fedoramagazine.org/managing-dotfiles-rcm/) -[#]: author: (Link Dupont https://fedoramagazine.org/author/linkdupont/) - -Managing dotfiles with rcm -====== - -![](https://fedoramagazine.org/wp-content/uploads/2018/12/dotfiles-816x345.jpg) - -A hallmark feature of many GNU/Linux programs is the easy-to-edit configuration file. Nearly all common free software programs store configuration settings inside a plain text file, often in a structured format like JSON, YAML or [“INI-like”][1]. These configuration files are frequently found hidden inside a user’s home directory. However, a basic ls won’t reveal them. UNIX standards require that any file or directory name that begins with a period (or “dot”) is considered “hidden” and will not be listed in directory listings unless requested by the user. For example, to list all files using the ls program, pass the -a command-line option. - -Over time, these configuration files become highly customized, and managing them becomes increasingly more challenging as time goes on. Not only that, but keeping them synchronized between multiple computers is a common challenge in large organizations. Finally, many users find a sense of pride in their unique configuration settings and want an easy way to share them with friends. That’s where **rcm** steps in. - -**rcm** is a “rc” file management suite (“rc” is another convention for naming configuration files that has been adopted by some GNU/Linux programs like screen or bash). **rcm** provides a suite of commands to manage and list files it tracks. Install **rcm** using **dnf**. - -### Getting started - -By default, **rcm** uses ~/.dotfiles for storing all the dotfiles it manages. A managed dotfile is actually stored inside ~/.dotfiles, and a symlink is placed in the expected file’s location. For example, if ~/.bashrc is tracked by **rcm** , a long listing would look like this. - -``` -[link@localhost ~]$ ls -l ~/.bashrc -lrwxrwxrwx. 1 link link 27 Dec 16 05:19 .bashrc -> /home/link/.dotfiles/bashrc -[link@localhost ~]$ -``` - -**rcm** consists of 4 commands: - - * mkrc – convert a file into a dotfile managed by rcm - * lsrc – list files managed by rcm - * rcup – synchronize dotfiles managed by rcm - * rcdn – remove all the symlinks managed by rcm - - - -### Share bashrc across two computers - -It is not uncommon today for a user to have shell accounts on more than one computer. Keeping dotfiles synchronized between those computers can be a challenge. This scenario will present one possible solution, using only **rcm** and **git**. - -First, convert (or “bless”) a file into a dotfile managed by **rcm** with mkrc. - -``` -[link@localhost ~]$ mkrc -v ~/.bashrc -Moving... -'/home/link/.bashrc' -> '/home/link/.dotfiles/bashrc' -Linking... -'/home/link/.dotfiles/bashrc' -> '/home/link/.bashrc' -[link@localhost ~]$ -``` - -Next, verify the listings are correct with lsrc. - -``` -[link@localhost ~]$ lsrc -/home/link/.bashrc:/home/link/.dotfiles/bashrc -[link@localhost ~]$ -``` - -Now create a git repository inside ~/.dotfiles and set up an accessible remote repository using your choice of hosted git repositories. Commit the bashrc file and push a new branch. - -``` -[link@localhost ~]$ cd ~/.dotfiles -[link@localhost .dotfiles]$ git init -Initialized empty Git repository in /home/link/.dotfiles/.git/ -[link@localhost .dotfiles]$ git remote add origin git@github.com:linkdupont/dotfiles.git -[link@localhost .dotfiles]$ git add bashrc -[link@localhost .dotfiles]$ git commit -m "initial commit" -[master (root-commit) b54406b] initial commit -1 file changed, 15 insertions(+) -create mode 100644 bashrc -[link@localhost .dotfiles]$ git push -u origin master -... -[link@localhost .dotfiles]$ -``` - -On the second machine, clone this repository into ~/.dotfiles. - -``` -[link@remotehost ~]$ git clone git@github.com:linkdupont/dotfiles.git ~/.dotfiles -... -[link@remotehost ~]$ -``` - -Now update the symlinks managed by **rcm** with rcup. - -``` -[link@remotehost ~]$ rcup -v -replacing identical but unlinked /home/link/.bashrc -removed '/home/link/.bashrc' -'/home/link/.dotfiles/bashrc' -> '/home/link/.bashrc' -[link@remotehost ~]$ -``` - -Overwrite the existing ~/.bashrc (if it exists) and restart the shell. - -That’s it! The host-specific option (-o) is a useful addition to the scenario above. And as always, be sure to read the manpages; they contain a wealth of example commands. - - --------------------------------------------------------------------------------- - -via: https://fedoramagazine.org/managing-dotfiles-rcm/ - -作者：[Link Dupont][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://fedoramagazine.org/author/linkdupont/ -[b]: https://github.com/lujun9972 -[1]: https://en.wikipedia.org/wiki/INI_file diff --git a/sources/tech/20190104 Midori- A Lightweight Open Source Web Browser.md b/sources/tech/20190104 Midori- A Lightweight Open Source Web Browser.md new file mode 100644 index 0000000000..a2e31daf6c --- /dev/null +++ b/sources/tech/20190104 Midori- A Lightweight Open Source Web Browser.md @@ -0,0 +1,110 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Midori: A Lightweight Open Source Web Browser) +[#]: via: (https://itsfoss.com/midori-browser) +[#]: author: (Abhishek Prakash https://itsfoss.com/author/abhishek/) + +Midori: A Lightweight Open Source Web Browser +====== + +**Here’s a quick review of the lightweight, fast, open source web browser Midori, which has returned from the dead.** + +If you are looking for a lightweight [alternative web browser][1], try Midori. + +[Midori][2] is an open source web browser that focuses more on being lightweight than on providing a ton of features. + +If you have never heard of Midori, you might think that it is a new application but Midori was first released in 2007. + +Because it focused on speed, Midori soon gathered a niche following and became the default browser in lightweight Linux distributions like Bodhi Linux, SilTaz etc. + +Other distributions like [elementary OS][3] also used Midori as its default browser. But the development of Midori stalled around 2016 and its fans started wondering if Midori was dead already. elementary OS dropped it from its latest release, I believe, for this reason. + +The good news is that Midori is not dead. After almost two years of inactivity, the development resumed in the last quarter of 2018. A few extensions including an ad-blocker were added in the later releases. + +### Features of Midori web browser + +![Midori web browser][4] + +Here are some of the main features of the Midori browser + + * Written in Vala with GTK+3 and WebKit rendering engine. + * Tabs, windows and session management + * Speed dial + * Saves tab for the next session by default + * Uses DuckDuckGo as a default search engine. It can be changed to Google or Yahoo. + * Bookmark management + * Customizable and extensible interface + * Extension modules can be written in C and Vala + * Supports HTML5 + * An extremely limited set of extensions include an ad-blocker, colorful tabs etc. No third-party extensions. + * Form history + * Private browsing + * Available for Linux and Windows + + + +Trivia: Midori is a Japanese word that means green. The Midori developer is not Japanese if you were guessing something along that line. + +### Experiencing Midori + +![Midori web browser in Ubuntu 18.04][5] + +I have been using Midori for the past few days. The experience is mostly fine. It supports HTML5 and renders the websites quickly. The ad-blocker is okay. The browsing experience is more or less smooth as you would expect in any standard web browser. + +The lack of extensions has always been a weak point of Midori so I am not going to talk about that. + +What I did notice is that it doesn’t support international languages. I couldn’t find a way to add new language support. It could not render the Hindi fonts at all and I am guessing it’s the same with many other non-[Romance languages][6]. + +I also had my fair share of troubles with YouTube videos. Some videos would throw playback error while others would run just fine. + +Midori didn’t eat my RAM like Chrome so that’s a big plus here. + +If you want to try out Midori, let’s see how can you get your hands on it. + +### Install Midori on Linux + +Midori is no longer available in the Ubuntu 18.04 repository. However, the newer versions of Midori can be easily installed using the [Snap packages][7]. + +If you are using Ubuntu, you can find Midori (Snap version) in the Software Center and install it from there. + +![Midori browser is available in Ubuntu Software Center][8]Midori browser is available in Ubuntu Software Center + +For other Linux distributions, make sure that you have [Snap support enabled][9] and then you can install Midori using the command below: + +``` +sudo snap install midori +``` + +You always have the option to compile from the source code. You can download the source code of Midori from its website. + +If you like Midori and want to help this open source project, please donate to them or [buy Midori merchandise from their shop][10]. + +Do you use Midori or have you ever tried it? How’s your experience with it? What other web browser do you prefer to use? Please share your views in the comment section below. + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/midori-browser + +作者：[Abhishek Prakash][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/abhishek/ +[b]: https://github.com/lujun9972 +[1]: https://itsfoss.com/open-source-browsers-linux/ +[2]: https://www.midori-browser.org/ +[3]: https://itsfoss.com/elementary-os-juno-features/ +[4]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/Midori-web-browser.jpeg?resize=800%2C450&ssl=1 +[5]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/midori-browser-linux.jpeg?resize=800%2C491&ssl=1 +[6]: https://en.wikipedia.org/wiki/Romance_languages +[7]: https://itsfoss.com/use-snap-packages-ubuntu-16-04/ +[8]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/midori-ubuntu-software-center.jpeg?ssl=1 +[9]: https://itsfoss.com/install-snap-linux/ +[10]: https://www.midori-browser.org/shop +[11]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/Midori-web-browser.jpeg?fit=800%2C450&ssl=1 diff --git a/sources/tech/20190104 Take to the virtual skies with FlightGear.md b/sources/tech/20190104 Take to the virtual skies with FlightGear.md new file mode 100644 index 0000000000..c3793e4128 --- /dev/null +++ b/sources/tech/20190104 Take to the virtual skies with FlightGear.md @@ -0,0 +1,93 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Take to the virtual skies with FlightGear) +[#]: via: (https://opensource.com/article/19/1/flightgear) +[#]: author: (Don Watkins https://opensource.com/users/don-watkins) + +Take to the virtual skies with FlightGear +====== +Dreaming of piloting a plane? Try open source flight simulator FlightGear. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/flightgear_cockpit_plane_sky.jpg?itok=LRy0lpOS) + +If you've ever dreamed of piloting a plane, you'll love [FlightGear][1]. It's a full-featured, [open source][2] flight simulator that runs on Linux, MacOS, and Windows. + +The FlightGear project began in 1996 due to dissatisfaction with commercial flight simulation programs, which were not scalable. Its goal was to create a sophisticated, robust, extensible, and open flight simulator framework for use in academia and pilot training or by anyone who wants to play with a flight simulation scenario. + +### Getting started + +FlightGear's hardware requirements are fairly modest, including an accelerated 3D video card that supports OpenGL for smooth framerates. It runs well on my Linux laptop with an i5 processor and only 4GB of RAM. Its documentation includes an [online manual][3]; a [wiki][4] with portals for [users][5] and [developers][6]; and extensive tutorials (such as one for its default aircraft, the [Cessna 172p][7]) to teach you how to operate it. + +It's easy to install on both [Fedora][8] and [Ubuntu][9] Linux. Fedora users can consult the [Fedora installation page][10] to get FlightGear running. + +On Ubuntu 18.04, I had to install a repository: + +``` +$ sudo add-apt-repository ppa:saiarcot895/flightgear +$ sudo apt-get update +$ sudo apt-get install flightgear +``` + +Once the installation finished, I launched it from the GUI, but you can also launch the application from a terminal by entering: + +``` +$ fgfs +``` + +### Configuring FlightGear + +The menu on the left side of the application window provides configuration options. + +![](https://opensource.com/sites/default/files/uploads/flightgear_menu.png) + +**Summary** returns you to the application's home screen. + +**Aircraft** shows the aircraft you have installed and offers the option to install up to 539 other aircraft available in FlightGear's default "hangar." I installed a Cessna 150L, a Piper J-3 Cub, and a Bombardier CRJ-700. Some of the aircraft (including the CRJ-700) have tutorials to teach you how to fly a commercial jet; I found the tutorials informative and accurate. + +![](https://opensource.com/sites/default/files/uploads/flightgear_aircraft.png) + +To select an aircraft to pilot, highlight it and click on **Fly!** at the bottom of the menu. I chose the default Cessna 172p and found the cockpit depiction extremely accurate. + +![](https://opensource.com/sites/default/files/uploads/flightgear_cockpit-view.png) + +The default airport is Honolulu, but you can change it in the **Location** menu by providing your favorite airport's [ICAO airport code][11] identifier. I found some small, local, non-towered airports like Olean and Dunkirk, New York, as well as larger airports including Buffalo, O'Hare, and Raleigh—and could even choose a specific runway. + +Under **Environment** , you can adjust the time of day, the season, and the weather. The simulation includes advance weather modeling and the ability to download current weather from [NOAA][12]. + +**Settings** provides an option to start the simulation in Paused mode by default. Also in Settings, you can select multi-player mode, which allows you to "fly" with other players on FlightGear supporters' global network of servers that allow for multiple users. You must have a moderately fast internet connection to support this functionality. + +The **Add-ons** menu allows you to download aircraft and additional scenery. + +### Take flight + +To "fly" my Cessna, I used a Logitech joystick that worked well. You can calibrate your joystick using an option in the **File** menu at the top. + +Overall, I found the simulation very accurate and think the graphics are great. Try FlightGear yourself — I think you will find it a very fun and complete simulation package. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/flightgear + +作者：[Don Watkins][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/don-watkins +[b]: https://github.com/lujun9972 +[1]: http://home.flightgear.org/ +[2]: http://wiki.flightgear.org/GNU_General_Public_License +[3]: http://flightgear.sourceforge.net/getstart-en/getstart-en.html +[4]: http://wiki.flightgear.org/FlightGear_Wiki +[5]: http://wiki.flightgear.org/Portal:User +[6]: http://wiki.flightgear.org/Portal:Developer +[7]: http://wiki.flightgear.org/Cessna_172P +[8]: http://rpmfind.net/linux/rpm2html/search.php?query=flightgear +[9]: https://launchpad.net/~saiarcot895/+archive/ubuntu/flightgear +[10]: https://apps.fedoraproject.org/packages/FlightGear/ +[11]: https://en.wikipedia.org/wiki/ICAO_airport_code +[12]: https://www.noaa.gov/ diff --git a/sources/tech/20190107 Getting started with Pelican- A Python-based static site generator.md b/sources/tech/20190107 Getting started with Pelican- A Python-based static site generator.md deleted file mode 100644 index 29772d473c..0000000000 --- a/sources/tech/20190107 Getting started with Pelican- A Python-based static site generator.md +++ /dev/null @@ -1,223 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Getting started with Pelican: A Python-based static site generator) -[#]: via: (https://opensource.com/article/19/1/getting-started-pelican) -[#]: author: (Craig Sebenik https://opensource.com/users/craig5) - -Getting started with Pelican: A Python-based static site generator -====== -Pelican is a great choice for Python users who want to self-host a simple website or blog. - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/web-design-monitor-website.png?itok=yUK7_qR0) - -If you want to create a custom website or blog, you have a lot of options. Many providers will host your website and do much of the work for you. (WordPress is an extremely popular option.) But you lose some flexibility by using a hosted solution. As a software developer, I prefer to manage my own server and keep more freedom in how my website operates. - -However, it is a fair amount of work to manage a web server. Installing it and getting a simple application up to serve content is easy enough. But keeping on top of security patches and updates is very time-consuming. If you just want to serve static web pages, having a web server and a host of applications may be more effort than it's worth. Creating HTML pages by hand is also not a good option. - -This is where a static site generator can come in. These applications use templates to create all the static pages you want and cross-link them with associated metadata. (e.g., showing all the pages with a common tag or keyword.) Static site generators help you create a site with a common look and feel using elements like navigation areas and a header and footer. - -I have been using [Python][1] for years now. So, when I first started looking for something to generate static HTML pages, I wanted something written in Python. The main reason is that I often want to peek into the internals of how an application works, and using a language that I already know makes that easier. (If that isn't important to you or you don't use Python, there are some other great [static site generators][2] that use Ruby, JavaScript, and other languages.) - -I decided to give [Pelican][3] a try. It is a commonly used static site generator written in Python. It directly supports [reStructuredText][4] and can support [Markdown][5] when the required package is installed. All the tasks are performed via command-line interface (CLI) tools, which makes it simple for anyone familiar with the command line. And its simple quickstart CLI tool makes creating a website extremely easy. - -In this article, I'll explain how to install Pelican 4, add an article, and change the default theme. (Note: This was all developed on MacOS; it should work the same using any flavor of Unix/Linux, but I don't have a Windows host to test on.) - -### Installation and configuration - -The first step is to create a [virtualenv][6] and install Pelican. - -``` -$ mkdir test-site -$ cd test-site -$ python3 -m venv venv -$ ./venv/bin/pip install --upgrade pip -... -Successfully installed pip-18.1 -$ ./venv/bin/pip install pelican -Collecting pelican -... -Successfully installed MarkupSafe-1.1.0 blinker-1.4 docutils-0.14 feedgenerator-1.9 jinja2-2.10 pelican-4.0.1 pygments-2.3.1 python-dateutil-2.7.5 pytz-2018.7 six-1.12.0 unidecode-1.0.23 -``` - -To keep things simple, I entered values for the title and author and replied N to URL prefix and article pagination. (For the rest of the questions, I used the default given.) - -Pelican's quickstart CLI tool will create the basic layout and a few files to get you started. Run the **pelican-quickstart** command. To keep things simple, I entered values for the **title** and **author** and replied **N** to URL prefix and article pagination. It is very easy to change these settings in the configuration file later. - -``` -$ ./venv/bin/pelicanquickstart -Welcome to pelicanquickstart v4.0.1. - -This script will help you create a new Pelican-based website. - -Please answer the following questions so this script can generate the files needed by Pelican. - -> Where do you want to create your new web site? [.] -> What will be the title of this web site? My Test Blog -> Who will be the author of this web site? Craig -> What will be the default language of this web site? [en] -> Do you want to specify a URL prefix? e.g., https://example.com (Y/n) n -> Do you want to enable article pagination? (Y/n) n -> What is your time zone? [Europe/Paris] -> Do you want to generate a tasks.py/Makefile to automate generation and publishing? (Y/n) -> Do you want to upload your website using FTP? (y/N) -> Do you want to upload your website using SSH? (y/N) -> Do you want to upload your website using Dropbox? (y/N) -> Do you want to upload your website using S3? (y/N) -> Do you want to upload your website using Rackspace Cloud Files? (y/N) -> Do you want to upload your website using GitHub Pages? (y/N) -Done. Your new project is available at /Users/craig/tmp/pelican/test-site -``` - -All the files you need to get started are ready to go. - -The quickstart defaults to the Europe/Paris time zone, so change that before proceeding. Open the **pelicanconf.py** file in your favorite text editor. Look for the **TIMEZONE** variable. - -``` -TIMEZONE = 'Europe/Paris' -``` - -Change it to **UTC**. - -``` -TIMEZONE = 'UTC' -``` - -To update the social settings, look for the **SOCIAL** variable in **pelicanconf.py**. - -``` -SOCIAL = (('You can add links in your config file', '#'), -          ('Another social link', '#'),) -``` - -I'll add a link to my Twitter account. - -``` -SOCIAL = (('Twitter (#craigs55)', 'https://twitter.com/craigs55'),) -``` - -Notice that trailing comma—it's important. That comma helps Python recognize the variable is actually a set. Make sure you don't delete that comma. - -Now you have the basics of a site. The quickstart created a Makefile with a number of targets. Giving the **devserver** target to **make** will start a development server on your machine so you can preview everything. The CLI commands used in the Makefile are assumed to be part of your **PATH** , so you need to **activate** the **virtualenv** first. - -``` -$ source ./venv/bin/activate -$ make devserver -pelican -lr /Users/craig/tmp/pelican/test-site/content o -/Users/craig/tmp/pelican/test-site/output -s /Users/craig/tmp/pelican/test-site/pelicanconf.py - --> Modified: theme, settings. regenerating... -WARNING: No valid files found in content for the active readers: -   | BaseReader (static) -   | HTMLReader (htm, html) -   | RstReader (rst) -Done: Processed 0 articles, 0 drafts, 0 pages, 0 hidden pages and 0 draft pages in 0.18 seconds. -``` - -Point your favorite browser to to see your simple test blog. - -![](https://opensource.com/sites/default/files/uploads/pelican_test-site1.png) - -You can see the Twitter link on the right side and some links to Pelican, Python, and Jinja to the left of it. (Jinja is a great templating language that Pelican can use. You can learn more about it in [Jinja's documentation][7].) - -### Adding content - -Now that you have a basic site, add some content. First, add a file called **welcome.rst** to the site's **content** directory. In your favorite text editor, create a file with the following text: - -``` -$ pwd -/Users/craig/tmp/pelican/test-site -$ cat content/welcome.rst - -Welcome to my blog! -################### - -:date: 20181216 08:30 -:tags: welcome -:category: Intro -:slug: welcome -:author: Craig -:summary: Welcome document - -Welcome to my blog. -This is a short page just to show how to put up a static page. -``` - -The metadata lines—date, tags, etc.—are automatically parsed by Pelican. - -After you write the file, the **devserver** should output something like this: - -``` --> Modified: content. regenerating... -Done: Processed 1 article, 0 drafts, 0 pages, 0 hidden pages and 0 draft pages in 0.10 seconds. -``` - -Reload your test site in your browser to view the changes. - -![](https://opensource.com/sites/default/files/uploads/pelican_test-site2.png) - -The metadata (e.g., date and tags) were automatically added to the page. Also, Pelican automatically detected the **intro** category and added the section to the top navigation. - -### Change the theme - -One of the nicest parts of working with popular, open source software like Pelican is that many users will make changes and contribute them back to the project. Many of the contributions are in the form of themes. - -A site's theme sets colors, layout options, etc. It's really easy to try out new themes. You can preview many of them at [Pelican Themes][8]. - -First, clone the GitHub repo: - -``` -$ cd .. -$ git clone --recursive https://github.com/getpelican/pelicanthemes -Cloning into 'pelicanthemes'... -``` - -Since I like the color blue, I'll try [blueidea][9]. - -Edit **pelicanconf.py** and add the following line: - -``` -THEME = '/Users/craig/tmp/pelican/pelican-themes/blueidea/' -``` - -The **devserver** will regenerate your output. Reload the webpage in your browser to see the new theme. - -![](https://opensource.com/sites/default/files/uploads/pelican_test-site3.png) - -The theme controls many aspects of the layout. For example, in the default theme, you can see the category (Intro) with the meta tags next to the article. But that category is not displayed in the blueidea theme. - -### Other considerations - -This was a pretty quick introduction to Pelican. There are a couple of important topics that I did not cover. - -First, one reason I was hesitant to move to a static site was that it wouldn't allow discussions on the articles. Fortunately, there are some third-party providers that will host discussions for you. The one I am currently looking at is [Disqus][10]. - -Next, everything above was done on my local machine. If I want others to view my site, I'll have to upload the pre-generated HTML files somewhere. If you look at the **pelican-quickstart** output, you will see options for using FTP, SSH, S3, and even GitHub Pages. Each option has its pros and cons. But, if I had to choose one, I would likely publish to GitHub Pages. - -Pelican has many other features—I am still learning more about it every day. If you want to self-host a website or a blog with simple, static content and you want to use Python, Pelican is a great choice. It has an active user community that is fixing bugs, adding features, and creating new and interesting themes. Give it a try! - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/19/1/getting-started-pelican - -作者：[Craig Sebenik][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/craig5 -[b]: https://github.com/lujun9972 -[1]: https://opensource.com/resources/python -[2]: https://opensource.com/sitewide-search?search_api_views_fulltext=static%20site%20generator -[3]: http://docs.getpelican.com/en/stable/ -[4]: http://docutils.sourceforge.net/rst.html -[5]: https://daringfireball.net/projects/markdown/ -[6]: https://virtualenv.pypa.io/en/latest/ -[7]: http://jinja.pocoo.org/docs/2.10/ -[8]: http://www.pelicanthemes.com/ -[9]: https://github.com/nasskach/pelican-blueidea/tree/58fb13112a2707baa7d65075517c40439ab95c0a -[10]: https://disqus.com/ diff --git a/sources/tech/20190109 Bash 5.0 Released with New Features.md b/sources/tech/20190109 Bash 5.0 Released with New Features.md deleted file mode 100644 index 46d9aeae59..0000000000 --- a/sources/tech/20190109 Bash 5.0 Released with New Features.md +++ /dev/null @@ -1,80 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Bash 5.0 Released with New Features) -[#]: via: (https://itsfoss.com/bash-5-release) -[#]: author: (Ankush Das https://itsfoss.com/author/ankush/) - -Bash 5.0 Released with New Features -====== - -The [mailing list][1] confirmed the release of Bash-5.0 recently. And, it is exciting to know that it comes baked with new features and variable. - -Well, if you’ve been using Bash 4.4.XX, you will definitely love the fifth major release of [Bash][2]. - -The fifth release focuses on new shell variables and a lot of major bug fixes with an overhaul. It also introduces a couple of new features along with some incompatible changes between bash-4.4 and bash-5.0. - -![Bash logo][3] - -### What about the new features? - -The mailing list explains the bug fixed in this new release: - -> This release fixes several outstanding bugs in bash-4.4 and introduces several new features. The most significant bug fixes are an overhaul of how nameref variables resolve and a number of potential out-of-bounds memory errors discovered via fuzzing. There are a number of changes to the expansion of $@ and $* in various contexts where word splitting is not performed to conform to a Posix standard interpretation, and additional changes to resolve corner cases for Posix conformance. - -It also introduces some new features. As per the release note, these are the most notable new features are several new shell variables: - -> The BASH_ARGV0, EPOCHSECONDS, and EPOCHREALTIME. The ‘history’ builtin can remove ranges of history entries and understands negative arguments as offsets from the end of the history list. There is an option to allow local variables to inherit the value of a variable with the same name at a preceding scope. There is a new shell option that, when enabled, causes the shell to attempt to expand associative array subscripts only once (this is an issue when they are used in arithmetic expressions). The ‘globasciiranges‘ shell option is now enabled by default; it can be set to off by default at configuration time. - -### What about the changes between Bash-4.4 and Bash-5.0? - -The update log mentioned about the incompatible changes and the supported readline version history. Here’s what it said: - -> There are a few incompatible changes between bash-4.4 and bash-5.0. The changes to how nameref variables are resolved means that some uses of namerefs will behave differently, though I have tried to minimize the compatibility issues. By default, the shell only sets BASH_ARGC and BASH_ARGV at startup if extended debugging mode is enabled; it was an oversight that it was set unconditionally and caused performance issues when scripts were passed large numbers of arguments. -> -> Bash can be linked against an already-installed Readline library rather than the private version in lib/readline if desired. Only readline-8.0 and later versions are able to provide all of the symbols that bash-5.0 requires; earlier versions of the Readline library will not work correctly. - -I believe some of the features/variables added are very useful. Some of my favorites are: - - * There is a new (disabled by default, undocumented) shell option to enable and disable sending history to syslog at runtime. - * The shell doesn’t automatically set BASH_ARGC and BASH_ARGV at startup unless it’s in debugging mode, as the documentation has always said, but will dynamically create them if a script references them at the top level without having enabled debugging mode. - * The ‘history’ can now delete ranges of history entries using ‘-d start-end’. - * If a non-interactive shell with job control enabled detects that a foreground job died due to SIGINT, it acts as if it received the SIGINT. - * BASH_ARGV0: a new variable that expands to $0 and sets $0 on assignment. - - - -To check the complete list of changes and features you should refer to the [Mailing list post][1]. - -### Wrapping Up - -You can check your current Bash version, using this command: - -``` -bash --version -``` - -It’s more likely that you’ll have Bash 4.4 installed. If you want to get the new version, I would advise waiting for your distribution to provide it. - -With Bash-5.0 available, what do you think about it? Are you using any alternative to bash? If so, would this update change your mind? - -Let us know your thoughts in the comments below. - --------------------------------------------------------------------------------- - -via: https://itsfoss.com/bash-5-release - -作者：[Ankush Das][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://itsfoss.com/author/ankush/ -[b]: https://github.com/lujun9972 -[1]: https://lists.gnu.org/archive/html/bug-bash/2019-01/msg00063.html -[2]: https://www.gnu.org/software/bash/ -[3]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/bash-logo.jpg?resize=800%2C450&ssl=1 diff --git a/sources/tech/20190109 GoAccess - A Real-Time Web Server Log Analyzer And Interactive Viewer.md b/sources/tech/20190109 GoAccess - A Real-Time Web Server Log Analyzer And Interactive Viewer.md new file mode 100644 index 0000000000..3bad5ba969 --- /dev/null +++ b/sources/tech/20190109 GoAccess - A Real-Time Web Server Log Analyzer And Interactive Viewer.md @@ -0,0 +1,187 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (GoAccess – A Real-Time Web Server Log Analyzer And Interactive Viewer) +[#]: via: (https://www.2daygeek.com/goaccess-a-real-time-web-server-log-analyzer-and-interactive-viewer/) +[#]: author: (Vinoth Kumar https://www.2daygeek.com/author/vinoth/) + +GoAccess – A Real-Time Web Server Log Analyzer And Interactive Viewer +====== + +Analyzing a log file is a big headache for Linux administrators as it’s capturing a lot of things. + +Most of the newbies and L1 administrators doesn’t know how to analyze this. + +If you have good knowledge to analyze a logs then you will be a legend for NIX system. + +There are many tools available in Linux to analyze the logs easily. + +GoAccess is one of the tool which allow users to analyze web server logs easily. + +We will be going to discuss in details about GoAccess tool in this article. + +### What is GoAccess? + +GoAccess is a real-time web log analyzer and interactive viewer that runs in a terminal in *nix systems or through your browser. + +GoAccess has minimal requirements, it’s written in C and requires only ncurses. + +It will support Apache, Nginx and Lighttpd logs. It provides fast and valuable HTTP statistics for system administrators that require a visual server report on the fly. + +GoAccess parses the specified web log file and outputs the data to the X terminal and browser. + +GoAccess was designed to be a fast, terminal-based log analyzer. Its core idea is to quickly analyze and view web server statistics in real time without needing to use your browser. + +Terminal output is the default output, it has the capability to generate a complete, self-contained, real-time HTML report, as well as a JSON, and CSV report. + +GoAccess allows any custom log format and the following (Combined Log Format (XLF/ELF) Apache | Nginx & Common Log Format (CLF) Apache) predefined log format options are included, but not limited to. + +### GoAccess Features + + * **`Completely Real Time:`** All the metrics are updated every 200 ms on the terminal and every second on the HTML output. + * **`Track Application Response Time:`** Track the time taken to serve the request. Extremely useful if you want to track pages that are slowing down your site. + * **`Visitors:`** Determine the amount of hits, visitors, bandwidth, and metrics for slowest running requests by the hour, or date. + * **`Metrics per Virtual Host:`** Have multiple Virtual Hosts (Server Blocks)? It features a panel that displays which virtual host is consuming most of the web server resources. + + + +### How to Install GoAccess? + +I would advise users to install GoAccess from distribution official repository with help of Package Manager. It is available in most of the distributions official repository. + +As we know, we will be getting bit outdated package for standard release distribution and rolling release distributions always include latest package. + +If you are running the OS with standard release distributions, i would suggest you to check the alternative options such as PPA or Official GoAccess maintainer repository, etc, to get a latest package. + +For **`Debian/Ubuntu`** systems, use **[APT-GET Command][1]** or **[APT Command][2]** to install GoAccess on your systems. + +``` +# apt install goaccess +``` + +To get a latest GoAccess package, use the below GoAccess official repository. + +``` +$ echo "deb https://deb.goaccess.io/ $(lsb_release -cs) main" | sudo tee -a /etc/apt/sources.list.d/goaccess.list +$ wget -O - https://deb.goaccess.io/gnugpg.key | sudo apt-key add - +$ sudo apt-get update +$ sudo apt-get install goaccess +``` + +For **`RHEL/CentOS`** systems, use **[YUM Package Manager][3]** to install GoAccess on your systems. + +``` +# yum install goaccess +``` + +For **`Fedora`** system, use **[DNF Package Manager][4]** to install GoAccess on your system. + +``` +# dnf install goaccess +``` + +For **`ArchLinux/Manjaro`** based systems, use **[Pacman Package Manager][5]** to install GoAccess on your systems. + +``` +# pacman -S goaccess +``` + +For **`openSUSE Leap`** system, use **[Zypper Package Manager][6]** to install GoAccess on your system. + +``` +# zypper install goaccess + +# zypper ar -f obs://server:http + +# zypper ref && zypper in goaccess +``` + +### How to Use GoAccess? + +After successful installation of GoAccess. Just enter the goaccess command and followed by the web server log location to view it. + +``` +# goaccess [options] /path/to/Web Server/access.log + +# goaccess /var/log/apache/2daygeek_access.log +``` + +When you execute the above command, it will ask you to select the **Log Format Configuration**. +![][8] + +I had tested this with Apache access log. The Apache log is splitted in fifteen section. The details are below. The main section shows the summary about the fifteen section. + +The below screenshots included four sessions such as Unique Visitors, Requested files, Static Requests, Not found URLs. +![][9] + +The below screenshots included four sessions such as Visitor Hostnames and IPs, Operating Systems, Browsers, Time Distribution. +![][10] + +The below screenshots included four sessions such as Referrers URLs, Referring Sites, Google’s search engine results, HTTP status codes. +![][11] + +If you would like to generate a html report, use the following format. + +Initially i got an error when i was trying to generate the html report. + +``` +# goaccess 2daygeek_access.log -a > report.html + +GoAccess - version 1.3 - Nov 23 2018 11:28:19 +Config file: No config file used + +Fatal error has occurred +Error occurred at: src/parser.c - parse_log - 2764 +No time format was found on your conf file.Parsing... [0] [0/s] +``` + +It says “No time format was found on your conf file”. To overcome this issue, add the “COMBINED” log format option on it. + +``` +# goaccess -f 2daygeek_access.log --log-format=COMBINED -o 2daygeek.html +Parsing...[0,165] [50,165/s] +``` + +![][12] + +GoAccess allows you to access and analyze the real-time log filtering and parsing. + +``` +# tail -f /var/log/apache/2daygeek_access.log | goaccess - +``` + +For more details navigate to man or help page. + +``` +# man goaccess +or +# goaccess --help +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/goaccess-a-real-time-web-server-log-analyzer-and-interactive-viewer/ + +作者：[Vinoth Kumar][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/vinoth/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/ +[2]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/ +[3]: https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/ +[4]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ +[5]: https://www.2daygeek.com/pacman-command-examples-manage-packages-arch-linux-system/ +[6]: https://www.2daygeek.com/zypper-command-examples-manage-packages-opensuse-system/ +[7]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[8]: https://www.2daygeek.com/wp-content/uploads/2019/01/goaccess-a-real-time-web-server-log-analyzer-and-interactive-viewer-1.png +[9]: https://www.2daygeek.com/wp-content/uploads/2019/01/goaccess-a-real-time-web-server-log-analyzer-and-interactive-viewer-2.png +[10]: https://www.2daygeek.com/wp-content/uploads/2019/01/goaccess-a-real-time-web-server-log-analyzer-and-interactive-viewer-3.png +[11]: https://www.2daygeek.com/wp-content/uploads/2019/01/goaccess-a-real-time-web-server-log-analyzer-and-interactive-viewer-4.png +[12]: https://www.2daygeek.com/wp-content/uploads/2019/01/goaccess-a-real-time-web-server-log-analyzer-and-interactive-viewer-5.png diff --git a/sources/tech/20190113 Get started with Joplin, a note-taking app.md b/sources/tech/20190113 Get started with Joplin, a note-taking app.md deleted file mode 100644 index 55b639ae7b..0000000000 --- a/sources/tech/20190113 Get started with Joplin, a note-taking app.md +++ /dev/null @@ -1,61 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (geekpi) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Get started with Joplin, a note-taking app) -[#]: via: (https://opensource.com/article/19/1/productivity-tool-joplin) -[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) - -Get started with Joplin, a note-taking app -====== -Learn how open source tools can help you be more productive in 2019. First up, Joplin. -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/programming-code-keyboard-laptop.png?itok=pGfEfu2S) - -There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. - -Here's the first of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. - -### Joplin - -In the realm of productivity tools, note-taking apps are VERY handy. Yes, you can use the open source [NixNote][1] to access [Evernote][2] notes, but it's still linked to the Evernote servers and still relies on a third party for security. And while you CAN export your Evernote notes from NixNote, the only format options are NixNote XML or PDF files. - -![](https://opensource.com/sites/default/files/uploads/joplin-1.png) - -Enter [Joplin][3]. Joplin is a NodeJS application that runs and stores notes locally, allows you to encrypt your notes and supports multiple sync methods. Joplin can run as a console or graphical application on Windows, Mac, and Linux. Joplin also has mobile apps for Android and iOS, meaning you can take your notes with you without a major hassle. Joplin even allows you to format notes with Markdown, HTML, or plain text. - -![](https://opensource.com/sites/default/files/uploads/joplin-3.png) - -One really nice thing about Joplin is it supports two kinds of notes: plain notes and to-do notes. Plain notes are what you expect—documents containing text. To-do notes, on the other hand, have a checkbox in the notes list that allows you to mark them "done." And since the to-do note is still a note, you can include lists, documentation, and additional to-do items in a to-do note. - -When using the GUI, you can toggle editor views between plain text, WYSIWYG, and a split screen showing both the source text and the rendered view. You can also specify an external editor in the GUI, making it easy to update notes with Vim, Emacs, or any other editor capable of handling text documents. - -![Joplin console version][5] - -Joplin in the console. - -The console interface is absolutely fantastic. While it lacks a WYSIWYG editor, it defaults to the text editor for your login. It also has a powerful command mode that allows you to do almost everything you can do in the GUI version. And it renders Markdown correctly in the viewer. - -You can group notes in notebooks and tag notes for easy grouping across your notebooks. And it even has built-in search, so you can find things if you forget where you put them. - -Overall, Joplin is a first-class note-taking app ([and a great alternative to Evernote][6]) that will help you be organized and more productive over the next year. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/19/1/productivity-tool-joplin - -作者：[Kevin Sonney][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/ksonney (Kevin Sonney) -[b]: https://github.com/lujun9972 -[1]: http://nixnote.org/NixNote-Home/ -[2]: https://evernote.com/ -[3]: https://joplin.cozic.net/ -[4]: https://opensource.com/article/19/1/file/419776 -[5]: https://opensource.com/sites/default/files/uploads/joplin-2_0.png (Joplin console version) -[6]: https://opensource.com/article/17/12/joplin-open-source-evernote-alternative diff --git a/sources/tech/20190114 Hegemon - A Modular System And Hardware Monitoring Tool For Linux.md b/sources/tech/20190114 Hegemon - A Modular System And Hardware Monitoring Tool For Linux.md deleted file mode 100644 index 28b5d5cd27..0000000000 --- a/sources/tech/20190114 Hegemon - A Modular System And Hardware Monitoring Tool For Linux.md +++ /dev/null @@ -1,139 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Hegemon – A Modular System And Hardware Monitoring Tool For Linux) -[#]: via: (https://www.2daygeek.com/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux/) -[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) - -Hegemon – A Modular System And Hardware Monitoring Tool For Linux -====== - -I know that everybody is preferring for **[TOP Command][1]** to monitor system utilization. - -It’s one of the best and native command which used by vast of Linux administrators. - -In Linux there is an alternative for everything respective of packages. - -There are many utilities are available for this purpose in Linux and i prefer **[HTOP Command][2]**. - -If you want to know about other alternatives, i would suggest you to navigate to the each link to know more about it. - -Those are htop, CorFreq, glances, atop, Dstat, Gtop, Linux Dash, Netdata, Monit, etc. - -All these tools only allow us to monitor system utilization and not for the system hardware’s. - -But Hegemon is allow us to monitor both in the single dashboard. - -If you are looking for system hardware monitoring then i would suggest you to check **[lm_sensors][3]** and **[s-tui Stress Terminal UI][4]** utilities. - -### What’s Hegemon? - -Hegemon is a work-in-progress modular system monitor written in safe Rust. - -It allow users to monitor both utilization in a single dashboard. It’s system utilization and hardware temperatures. - -### Currently Available Features in Hegemon - - * Monitor CPU and memory usage, temperatures, and fan speeds - * Expand any data stream to reveal a more detailed graph and additional information - * Adjustable update interval - * Clean MVC architecture with good code quality - * Unit tests - - - -### Planned Features include - - * macOS and BSD support (only Linux is supported at the moment) - * Monitor disk and network I/O, GPU usage (maybe), and more - * Select and reorder data streams - * Mouse control - - - -### How to Install Hegemon in Linux? - -Hegemon is requires Rust 1.26 or later and the development files for libsensors. So, make sure these packages were installed before your perform Hegemon installation. - -libsensors library package is available in most of the distribution official repository so, use the following command to install it. - -For **`Debian/Ubuntu`** systems, use **[APT-GET Command][5]** or **[APT Command][6]** to install libsensors on your systems. - -``` -# apt install lm_sensors-devel -``` - -For **`Fedora`** system, use **[DNF Package Manager][7]** to install libsensors on your system. - -``` -# dnf install libsensors4-dev -``` - -Run the following command to install Rust programming language and follow the instruction. Navigate to the following URL if you want handy tutorials for **[Rust installation][8]**. - -``` -$ curl https://sh.rustup.rs -sSf | sh -``` - -If you have successfully installed Rust. Run the following command to install Hegemon. - -``` -$ cargo install hegemon -``` - -### How to Lunch Hegemon in Linux? - -Once you successfully install Hegemon package. Run run the below command to launch it. - -``` -$ hegemon -``` - -![][10] - -I was facing an issue when i was launching the “Hegemon” application due to libsensors.so.4 libraries issue. - -``` -$ hegemon -error while loading shared libraries: libsensors.so.4: cannot open shared object file: No such file or directory manjaro -``` - -I’m using Manjaro 18.04. It has the libsensors.so & libsensors.so.5 shared libraries and not for libsensors.so.4. So, i just created the following symlink to fix the issue. - -``` -$ sudo ln -s /usr/lib/libsensors.so /usr/lib/libsensors.so.4 -``` - -Here is the sample gif file which was taken from my Lenovo-Y700 laptop. -![][11] - -By default it shows only overall summary and if you would like to see the detailed output then you need to expand the each section. See the expanded output with Hegemon. -![][12] - --------------------------------------------------------------------------------- - -via: https://www.2daygeek.com/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux/ - -作者：[Magesh Maruthamuthu][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.2daygeek.com/author/magesh/ -[b]: https://github.com/lujun9972 -[1]: https://www.2daygeek.com/top-command-examples-to-monitor-server-performance/ -[2]: https://www.2daygeek.com/linux-htop-command-linux-system-performance-resource-monitoring-tool/ -[3]: https://www.2daygeek.com/view-check-cpu-hard-disk-temperature-linux/ -[4]: https://www.2daygeek.com/s-tui-stress-terminal-ui-monitor-linux-cpu-temperature-frequency/ -[5]: https://www.2daygeek.com/apt-get-apt-cache-command-examples-manage-packages-debian-ubuntu-systems/ -[6]: https://www.2daygeek.com/apt-command-examples-manage-packages-debian-ubuntu-systems/ -[7]: https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ -[8]: https://www.2daygeek.com/how-to-install-rust-programming-language-in-linux/ -[9]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 -[10]: https://www.2daygeek.com/wp-content/uploads/2019/01/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux-1.png -[11]: https://www.2daygeek.com/wp-content/uploads/2019/01/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux-2a.gif -[12]: https://www.2daygeek.com/wp-content/uploads/2019/01/hegemon-a-modular-system-and-hardware-monitoring-tool-for-linux-3.png diff --git a/sources/tech/20190114 How To Move Multiple File Types Simultaneously From Commandline.md b/sources/tech/20190114 How To Move Multiple File Types Simultaneously From Commandline.md deleted file mode 100644 index dd135f20e0..0000000000 --- a/sources/tech/20190114 How To Move Multiple File Types Simultaneously From Commandline.md +++ /dev/null @@ -1,96 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (MjSeven) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (How To Move Multiple File Types Simultaneously From Commandline) -[#]: via: (https://www.ostechnix.com/how-to-move-multiple-file-types-simultaneously-from-commandline/) -[#]: author: (SK https://www.ostechnix.com/author/sk/) - -How To Move Multiple File Types Simultaneously From Commandline -====== - -![](https://www.ostechnix.com/wp-content/uploads/2019/01/Move-Multiple-File-Types-720x340.png) - -The other day I was wondering how can I move (not copy) multiple file types from directory to another. I already knew how to [**find and copy certain type of files from one directory to another**][1]. But, I don’t know how to move multiple file types simultaneously. If you’re ever in a situation like this, I know a easy way to do it from commandline in Unix-like systems. - -### Move Multiple File Types Simultaneously - -Picture this scenario.You have multiple type of files, for example .pdf, .doc, .mp3, .mp4, .txt etc., on a directory named **‘dir1’**. Let us take a look at the dir1 contents: - -``` -$ ls dir1 -file.txt image.jpg mydoc.doc personal.pdf song.mp3 video.mp4 -``` - -You want to move some of the file types (not all of them) to different location. For example, let us say you want to move doc, pdf and txt files only to another directory named **‘dir2’** in one go. - -To copy .doc, .pdf and .txt files from dir1 to dir2 simultaneously, the command would be: - -``` -$ mv dir1/*.{doc,pdf,txt} dir2/ -``` - -It’s easy, isn’t it? - -Now, let us check the contents of dir2: - -``` -$ ls dir2/ -file.txt mydoc.doc personal.pdf -``` - -See? Only the file types .doc, .pdf and .txt from dir1 have been moved to dir2. - -![][3] - -You can add as many file types as you want to inside curly braces in the above command to move them across different directories. The above command just works fine for me on Bash. - -Another way to move multiple file types is go to the source directory i.e dir1 in our case: - -``` -$ cd ~/dir1 -``` - -And, move file types of your choice to the destination (E.g dir2) as shown below. - -``` -$ mv *.doc *.txt *.pdf /home/sk/dir2/ -``` - -To move all files having a particular extension, for example **.doc** only, run: - -``` -$ mv dir1/*.doc dir2/ -``` - -For more details, refer man pages. - -``` -$ man mv -``` - -Moving a few number of same or different file types is easy! You could do this with couple mouse clicks in GUI mode or use a one-liner command in CLI mode. However, If you have thousands of different file types in a directory and wanted to move multiple file types to different directory in one go, it would be a cumbersome task. To me, the above method did the job easily! If you know any other one-liner commands to move multiple file types at a time, please share it in the comment section below. I will check and update the guide accordingly. - -And, that’s all for now. Hope this was useful. More good stuffs to come. Stay tuned! - -Cheers! - - - --------------------------------------------------------------------------------- - -via: https://www.ostechnix.com/how-to-move-multiple-file-types-simultaneously-from-commandline/ - -作者：[SK][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.ostechnix.com/author/sk/ -[b]: https://github.com/lujun9972 -[1]: https://www.ostechnix.com/find-copy-certain-type-files-one-directory-another-linux/ -[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 -[3]: http://www.ostechnix.com/wp-content/uploads/2019/01/mv-command.gif diff --git a/sources/tech/20190114 How to Build a Netboot Server, Part 4.md b/sources/tech/20190114 How to Build a Netboot Server, Part 4.md deleted file mode 100644 index 3b5286df03..0000000000 --- a/sources/tech/20190114 How to Build a Netboot Server, Part 4.md +++ /dev/null @@ -1,632 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (qhwdw) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (How to Build a Netboot Server, Part 4) -[#]: via: (https://fedoramagazine.org/how-to-build-a-netboot-server-part-4/) -[#]: author: (Gregory Bartholomew https://fedoramagazine.org/author/glb/) - -How to Build a Netboot Server, Part 4 -====== -![](https://fedoramagazine.org/wp-content/uploads/2018/11/netboot4-816x345.jpg) - -One significant limitation of the netboot server built in this series is the operating system image being served is read-only. Some use cases may require the end user to modify the image. For example, an instructor may want to have the students install and configure software packages like MariaDB and Node.js as part of their course walk-through. - -An added benefit of writable netboot images is the end user’s “personalized” operating system can follow them to different workstations they may use at later times. - -### Change the Bootmenu Application to use HTTPS - -Create a self-signed certificate for the bootmenu application: - -``` -$ sudo -i -# MY_NAME=$( .*#listen => ['https://$MY_NAME:443?cert=$MY_TLSD/$MY_NAME.pem\&key=$MY_TLSD/$MY_NAME.key\&ciphers=AES256-SHA256:AES128-SHA256:AES256-SHA:AES128-SHA'],#" /opt/bootmenu/bootmenu.conf -``` - -Note the ciphers have been restricted to [those currently supported by iPXE][1]. - -GnuTLS requires the “CAP_DAC_READ_SEARCH” capability, so add it to the bootmenu application’s systemd service: - -``` -# sed -i '/^AmbientCapabilities=/ s/$/ CAP_DAC_READ_SEARCH/' /etc/systemd/system/bootmenu.service -# sed -i 's/Serves iPXE Menus over HTTP/Serves iPXE Menus over HTTPS/' /etc/systemd/system/bootmenu.service -# systemctl daemon-reload -``` - -Now, add an exception for the bootmenu service to the firewall and restart the service: - -``` -# MY_SUBNET=192.0.2.0 -# MY_PREFIX=24 -# firewall-cmd --add-rich-rule="rule family='ipv4' source address='$MY_SUBNET/$MY_PREFIX' service name='https' accept" -# firewall-cmd --runtime-to-permanent -# systemctl restart bootmenu.service -``` - -Use wget to verify it’s working: - -``` -$ MY_NAME=server-01.example.edu -$ MY_TLSD=/opt/bootmenu/tls -$ wget -q --ca-certificate=$MY_TLSD/$MY_NAME.pem -O - https://$MY_NAME/menu -``` - -### Add HTTPS to iPXE - -Update init.ipxe to use HTTPS. Then recompile the ipxe bootloader with options to embed and trust the self-signed certificate you created for the bootmenu application: - -``` -$ echo '#define DOWNLOAD_PROTO_HTTPS' >> $HOME/ipxe/src/config/local/general.h -$ sed -i 's/^chain http:/chain https:/' $HOME/ipxe/init.ipxe -$ cp $MY_TLSD/$MY_NAME.pem $HOME/ipxe -$ cd $HOME/ipxe/src -$ make clean -$ make bin-x86_64-efi/ipxe.efi EMBED=../init.ipxe CERT="../$MY_NAME.pem" TRUST="../$MY_NAME.pem" -``` - -You can now copy the HTTPS-enabled iPXE bootloader out to your clients and test that everything is working correctly: - -``` -$ cp $HOME/ipxe/src/bin-x86_64-efi/ipxe.efi $HOME/esp/efi/boot/bootx64.efi -``` - -### Add User Authentication to Mojolicious - -Create a PAM service definition for the bootmenu application: - -``` -# dnf install -y pam_krb5 -# echo 'auth required pam_krb5.so' > /etc/pam.d/bootmenu -``` - -Add a library to the bootmenu application that uses the Authen-PAM perl module to perform user authentication: - -``` -# dnf install -y perl-Authen-PAM; -# MY_MOJO=/opt/bootmenu -# mkdir $MY_MOJO/lib -# cat << 'END' > $MY_MOJO/lib/PAM.pm -package PAM; - -use Authen::PAM; - -sub auth { - my $success = 0; - - my $username = shift; - my $password = shift; - - my $callback = sub { - my @res; - while (@_) { - my $code = shift; - my $msg = shift; - my $ans = ""; - - $ans = $username if ($code == PAM_PROMPT_ECHO_ON()); - $ans = $password if ($code == PAM_PROMPT_ECHO_OFF()); - - push @res, (PAM_SUCCESS(), $ans); - } - push @res, PAM_SUCCESS(); - - return @res; - }; - - my $pamh = new Authen::PAM('bootmenu', $username, $callback); - - { - last unless ref $pamh; - last unless $pamh->pam_authenticate() == PAM_SUCCESS; - $success = 1; - } - - return $success; -} - -return 1; -END -``` - -The above code is taken almost verbatim from the Authen::PAM::FAQ man page. - -Redefine the bootmenu application so it returns a netboot template only if a valid username and password are supplied: - -``` -# cat << 'END' > $MY_MOJO/bootmenu.pl -#!/usr/bin/env perl - -use lib 'lib'; - -use PAM; -use Mojolicious::Lite; -use Mojolicious::Plugins; -use Mojo::Util ('url_unescape'); - -plugin 'Config'; - -get '/menu'; -get '/boot' => sub { - my $c = shift; - - my $instance = $c->param('instance'); - my $username = $c->param('username'); - my $password = $c->param('password'); - - my $template = 'menu'; - - { - last unless $instance =~ /^fc[[:digit:]]{2}$/; - last unless $username =~ /^[[:alnum:]]+$/; - last unless PAM::auth($username, url_unescape($password)); - $template = $instance; - } - - return $c->render(template => $template); -}; - -app->start; -END -``` - -The bootmenu application now looks for the lib directory relative to its WorkingDirectory. However, by default the working directory is set to the root directory of the server for systemd units. Therefore, you must update the systemd unit to set WorkingDirectory to the root of the bootmenu application instead: - -``` -# sed -i "/^RuntimeDirectory=/ a WorkingDirectory=$MY_MOJO" /etc/systemd/system/bootmenu.service -# systemctl daemon-reload -``` - -Update the templates to work with the redefined bootmenu application: - -``` -# cd $MY_MOJO/templates -# MY_BOOTMENU_SERVER=$( fc$i.html.ep; grep "^kernel\|initrd" menu.html.ep | grep "fc$i" >> fc$i.html.ep; echo "boot || chain https://$MY_BOOTMENU_SERVER/menu" >> fc$i.html.ep; sed -i "/^:f$i$/,/^boot /c :f$i\nlogin\nchain https://$MY_BOOTMENU_SERVER/boot?instance=fc$i\&username=\${username}\&password=\${password:uristring} || goto failed" menu.html.ep; done -``` - -The result of the last command above should be three files similar to the following: - -**menu.html.ep** : - -``` -#!ipxe - -set timeout 5000 - -:menu -menu iPXE Boot Menu -item --key 1 lcl 1. Microsoft Windows 10 -item --key 2 f29 2. RedHat Fedora 29 -item --key 3 f28 3. RedHat Fedora 28 -choose --timeout ${timeout} --default lcl selected || goto shell -set timeout 0 -goto ${selected} - -:failed -echo boot failed, dropping to shell... -goto shell - -:shell -echo type 'exit' to get the back to the menu -set timeout 0 -shell -goto menu - -:lcl -exit - -:f29 -login -chain https://server-01.example.edu/boot?instance=fc29&username=${username}&password=${password:uristring} || goto failed - -:f28 -login -chain https://server-01.example.edu/boot?instance=fc28&username=${username}&password=${password:uristring} || goto failed -``` - -**fc29.html.ep** : - -``` -#!ipxe -kernel --name kernel.efi ${prefix}/vmlinuz-4.19.5-300.fc29.x86_64 initrd=initrd.img ro ip=dhcp rd.peerdns=0 nameserver=192.0.2.91 nameserver=192.0.2.92 root=/dev/disk/by-path/ip-192.0.2.158:3260-iscsi-iqn.edu.example.server-01:fc29-lun-1 netroot=iscsi:192.0.2.158::::iqn.edu.example.server-01:fc29 console=tty0 console=ttyS0,115200n8 audit=0 selinux=0 quiet -initrd --name initrd.img ${prefix}/initramfs-4.19.5-300.fc29.x86_64.img -boot || chain https://server-01.example.edu/menu -``` - -**fc28.html.ep** : - -``` -#!ipxe -kernel --name kernel.efi ${prefix}/vmlinuz-4.19.3-200.fc28.x86_64 initrd=initrd.img ro ip=dhcp rd.peerdns=0 nameserver=192.0.2.91 nameserver=192.0.2.92 root=/dev/disk/by-path/ip-192.0.2.158:3260-iscsi-iqn.edu.example.server-01:fc28-lun-1 netroot=iscsi:192.0.2.158::::iqn.edu.example.server-01:fc28 console=tty0 console=ttyS0,115200n8 audit=0 selinux=0 quiet -initrd --name initrd.img ${prefix}/initramfs-4.19.3-200.fc28.x86_64.img -boot || chain https://server-01.example.edu/menu -``` - -Now, restart the bootmenu application and verify authentication is working: - -``` -# systemctl restart bootmenu.service -``` - -### Make the iSCSI Target Writeable - -Now that user authentication works through iPXE, you can create per-user, writeable overlays on top of the read-only image on demand when users connect. Using a [copy-on-write][2] overlay has three advantages over simply copying the original image file for each user: - - 1. The copy can be created very quickly. This allows creation on-demand. - 2. The copy does not increase the disk usage on the server. Only what the user writes to their personal copy of the image is stored in addition to the original image. - 3. Since most sectors for each copy are the same sectors on the server’s storage, they’ll likely already be loaded in RAM when subsequent users access their copies of the operating system. This improves the server’s performance because RAM is faster than disk I/O. - - - -One potential pitfall of using copy-on-write is that once overlays are created, the images on which they are overlayed must not be changed. If they are changed, all the overlays will be corrupted. Then the overlays must be deleted and replaced with new, blank overlays. Even simply mounting the image file in read-write mode can cause sufficient filesystem updates to corrupt the overlays. - -Due to the potential for the overlays to be corrupted if the original image is modified, mark the original image as immutable by running: - -``` -# chattr +i -``` - -You can use lsattr to view the status of the immutable flag and use to chattr -i unset the immutable flag. While the immutable flag is set, even the root user or a system process running as root cannot modify or delete the file. - -Begin by stopping the tgtd.service so you can change the image files: - -``` -# systemctl stop tgtd.service -``` - -It’s normal for this command to take a minute or so to stop when there are connections still open. - -Now, remove the read-only iSCSI export. Then update the readonly-root configuration file in the template so the image is no longer read-only: - -``` -# MY_FC=fc29 -# rm -f /etc/tgt/conf.d/$MY_FC.conf -# TEMP_MNT=$(mktemp -d) -# mount /$MY_FC.img $TEMP_MNT -# sed -i 's/^READONLY=yes$/READONLY=no/' $TEMP_MNT/etc/sysconfig/readonly-root -# sed -i 's/^Storage=volatile$/#Storage=auto/' $TEMP_MNT/etc/systemd/journald.conf -# umount $TEMP_MNT -``` - -Journald was changed from logging to volatile memory back to its default (log to disk if /var/log/journal exists) because a user reported his clients would freeze with an out-of-memory error due to an application generating excessive system logs. The downside to setting logging to disk is that extra write traffic is generated by the clients, and might burden your netboot server with unnecessary I/O. You should decide which option — log to memory or log to disk — is preferable depending on your environment. - -Since you won’t make any further changes to the template image, set the immutable flag on it and restart the tgtd.service: - -``` -# chattr +i /$MY_FC.img -# systemctl start tgtd.service -``` - -Now, update the bootmenu application: - -``` -# cat << 'END' > $MY_MOJO/bootmenu.pl -#!/usr/bin/env perl - -use lib 'lib'; - -use PAM; -use Mojolicious::Lite; -use Mojolicious::Plugins; -use Mojo::Util ('url_unescape'); - -plugin 'Config'; - -get '/menu'; -get '/boot' => sub { - my $c = shift; - - my $instance = $c->param('instance'); - my $username = $c->param('username'); - my $password = $c->param('password'); - - my $chapscrt; - my $template = 'menu'; - - { - last unless $instance =~ /^fc[[:digit:]]{2}$/; - last unless $username =~ /^[[:alnum:]]+$/; - last unless PAM::auth($username, url_unescape($password)); - last unless $chapscrt = `sudo scripts/mktgt $instance $username`; - $template = $instance; - } - - return $c->render(template => $template, username => $username, chapscrt => $chapscrt); -}; - -app->start; -END -``` - -This new version of the bootmenu application calls a custom mktgt script which, on success, returns a random [CHAP][3] password for each new iSCSI target that it creates. The CHAP password prevents one user from mounting another user’s iSCSI target by indirect means. The app only returns the correct iSCSI target password to a user who has successfully authenticated. - -The mktgt script is prefixed with sudo because it needs root privileges to create the target. - -The $username and $chapscrt variables also pass to the render command so they can be incorporated into the templates returned to the user when necessary. - -Next, update our boot templates so they can read the username and chapscrt variables and pass them along to the end user. Also update the templates to mount the root filesystem in rw (read-write) mode: - -``` -# cd $MY_MOJO/templates -# sed -i "s/:$MY_FC/:$MY_FC-<%= \$username %>/g" $MY_FC.html.ep -# sed -i "s/ netroot=iscsi:/ netroot=iscsi:<%= \$username %>:<%= \$chapscrt %>@/" $MY_FC.html.ep -# sed -i "s/ ro / rw /" $MY_FC.html.ep -``` - -After running the above commands, you should have boot templates like the following: - -``` -#!ipxe -kernel --name kernel.efi ${prefix}/vmlinuz-4.19.5-300.fc29.x86_64 initrd=initrd.img rw ip=dhcp rd.peerdns=0 nameserver=192.0.2.91 nameserver=192.0.2.92 root=/dev/disk/by-path/ip-192.0.2.158:3260-iscsi-iqn.edu.example.server-01:fc29-<%= $username %>-lun-1 netroot=iscsi:<%= $username %>:<%= $chapscrt %>@192.0.2.158::::iqn.edu.example.server-01:fc29-<%= $username %> console=tty0 console=ttyS0,115200n8 audit=0 selinux=0 quiet -initrd --name initrd.img ${prefix}/initramfs-4.19.5-300.fc29.x86_64.img -boot || chain https://server-01.example.edu/menu -``` - -NOTE: If you need to view the boot template after the variables have been [interpolated][4], you can insert the “shell” command on its own line just before the “boot” command. Then, when you netboot your client, iPXE gives you an interactive shell where you can enter “imgstat” to view the parameters being passed to the kernel. If everything looks correct, you can type “exit” to leave the shell and continue the boot process. - -Now allow the bootmenu user to run the mktgt script (and only that script) as root via sudo: - -``` -# echo "bootmenu ALL = NOPASSWD: $MY_MOJO/scripts/mktgt *" > /etc/sudoers.d/bootmenu -``` - -The bootmenu user should not have write access to the mktgt script or any other files under its home directory. All the files under /opt/bootmenu should be owned by root, and should not be writable by any user other than root. - -Sudo does not work well with systemd’s DynamicUser option, so create a normal user account and set the systemd service to run as that user: - -``` -# useradd -r -c 'iPXE Boot Menu Service' -d /opt/bootmenu -s /sbin/nologin bootmenu -# sed -i 's/^DynamicUser=true$/User=bootmenu/' /etc/systemd/system/bootmenu.service -# systemctl daemon-reload -``` - -Finally, create a directory for the copy-on-write overlays and create the mktgt script that manages the iSCSI targets and their overlayed backing stores: - -``` -# mkdir /$MY_FC.cow -# mkdir $MY_MOJO/scripts -# cat << 'END' > $MY_MOJO/scripts/mktgt -#!/usr/bin/env perl - -# if another instance of this script is running, wait for it to finish -"$ENV{FLOCKER}" eq 'MKTGT' or exec "env FLOCKER=MKTGT flock /tmp $0 @ARGV"; - -# use "RETURN" to print to STDOUT; everything else goes to STDERR by default -open(RETURN, '>&', STDOUT); -open(STDOUT, '>&', STDERR); - -my $instance = shift or die "instance not provided"; -my $username = shift or die "username not provided"; - -my $img = "/$instance.img"; -my $dir = "/$instance.cow"; -my $top = "$dir/$username"; - --f "$img" or die "'$img' is not a file"; --d "$dir" or die "'$dir' is not a directory"; - -my $base; -die unless $base = `losetup --show --read-only --nooverlap --find $img`; -chomp $base; - -my $size; -die unless $size = `blockdev --getsz $base`; -chomp $size; - -# create the per-user sparse file if it does not exist -if (! -e "$top") { - die unless system("dd if=/dev/zero of=$top status=none bs=512 count=0 seek=$size") == 0; -} - -# create the copy-on-write overlay if it does not exist -my $cow="$instance-$username"; -my $dev="/dev/mapper/$cow"; -if (! -e "$dev") { - my $over; - die unless $over = `losetup --show --nooverlap --find $top`; - chomp $over; - die unless system("echo 0 $size snapshot $base $over p 8 | dmsetup create $cow") == 0; -} - -my $tgtadm = '/usr/sbin/tgtadm --lld iscsi'; - -# get textual representations of the iscsi targets -my $text = `$tgtadm --op show --mode target`; -my @targets = $text =~ /(?:^T.*\n)(?:^ .*\n)*/mg; - -# convert the textual representations into a hash table -my $targets = {}; -foreach (@targets) { - my $tgt; - my $sid; - - foreach (split /\n/) { - /^Target (\d+)(?{ $tgt = $targets->{$^N} = [] })/; - /I_T nexus: (\d+)(?{ $sid = $^N })/; - /Connection: (\d+)(?{ push @{$tgt}, [ $sid, $^N ] })/; - } -} - -my $hostname; -die unless $hostname = `hostname`; -chomp $hostname; - -my $target = 'iqn.' . join('.', reverse split('\.', $hostname)) . ":$cow"; - -# find the target id corresponding to the provided target name and -# close any existing connections to it -my $tid = 0; -foreach (@targets) { - next unless /^Target (\d+)(?{ $tid = $^N }): $target$/m; - foreach (@{$targets->{$tid}}) { - die unless system("$tgtadm --op delete --mode conn --tid $tid --sid $_->[0] --cid $_->[1]") == 0; - } -} - -# create a new target if an existing one was not found -if ($tid == 0) { - # find an available target id - my @ids = (0, sort keys %{$targets}); - $tid = 1; while ($ids[$tid]==$tid) { $tid++ } - - # create the target - die unless -e "$dev"; - die unless system("$tgtadm --op new --mode target --tid $tid --targetname $target") == 0; - die unless system("$tgtadm --op new --mode logicalunit --tid $tid --lun 1 --backing-store $dev") == 0; - die unless system("$tgtadm --op bind --mode target --tid $tid --initiator-address ALL") == 0; -} - -# (re)set the provided target's chap password -my $password = join('', map(chr(int(rand(26))+65), 1..8)); -my $accounts = `$tgtadm --op show --mode account`; -if ($accounts =~ / $username$/m) { - die unless system("$tgtadm --op delete --mode account --user $username") == 0; -} -die unless system("$tgtadm --op new --mode account --user $username --password $password") == 0; -die unless system("$tgtadm --op bind --mode account --tid $tid --user $username") == 0; - -# return the new password to the iscsi target on stdout -print RETURN $password; -END -# chmod +x $MY_MOJO/scripts/mktgt -``` - -The above script does five things: - - 1. It creates the /.cow/ sparse file if it does not already exist. - 2. It creates the /dev/mapper/- device node that serves as the copy-on-write backing store for the iSCSI target if it does not already exist. - 3. It creates the iqn.:- iSCSI target if it does not exist. Or, if the target does exist, it closes any existing connections to it because the image can only be opened in read-write mode from one place at a time. - 4. It (re)sets the chap password on the iqn.:- iSCSI target to a new random value. - 5. It prints the new chap password on [standard output][5] if all of the previous tasks compeleted successfully. - - - -You should be able to test the mktgt script from the command line by running it with valid test parameters. For example: - -``` -# echo `$MY_MOJO/scripts/mktgt fc29 jsmith` -``` - -When run from the command line, the mktgt script should print out either the eight-character random password for the iSCSI target if it succeeded or the line number on which something went wrong if it failed. - -On occasion, you may want to delete an iSCSI target without having to stop the entire service. For example, a user might inadvertently corrupt their personal image, in which case you would need to systematically undo everything that the above mktgt script does so that the next time they log in they will get a copy of the original image. - -Below is an rmtgt script that undoes, in reverse order, what the above mktgt script did: - -``` -# mkdir $HOME/bin -# cat << 'END' > $HOME/bin/rmtgt -#!/usr/bin/env perl - -@ARGV >= 2 or die "usage: $0 [+d|+f]\n"; - -my $instance = shift; -my $username = shift; - -my $rmd = ($ARGV[0] eq '+d'); #remove device node if +d flag is set -my $rmf = ($ARGV[0] eq '+f'); #remove sparse file if +f flag is set -my $cow = "$instance-$username"; - -my $hostname; -die unless $hostname = `hostname`; -chomp $hostname; - -my $tgtadm = '/usr/sbin/tgtadm'; -my $target = 'iqn.' . join('.', reverse split('\.', $hostname)) . ":$cow"; - -my $text = `$tgtadm --op show --mode target`; -my @targets = $text =~ /(?:^T.*\n)(?:^ .*\n)*/mg; - -my $targets = {}; -foreach (@targets) { - my $tgt; - my $sid; - - foreach (split /\n/) { - /^Target (\d+)(?{ $tgt = $targets->{$^N} = [] })/; - /I_T nexus: (\d+)(?{ $sid = $^N })/; - /Connection: (\d+)(?{ push @{$tgt}, [ $sid, $^N ] })/; - } -} - -my $tid = 0; -foreach (@targets) { - next unless /^Target (\d+)(?{ $tid = $^N }): $target$/m; - foreach (@{$targets->{$tid}}) { - die unless system("$tgtadm --op delete --mode conn --tid $tid --sid $_->[0] --cid $_->[1]") == 0; - } - die unless system("$tgtadm --op delete --mode target --tid $tid") == 0; - print "target $tid deleted\n"; - sleep 1; -} - -my $dev = "/dev/mapper/$cow"; -if ($rmd or ($rmf and -e $dev)) { - die unless system("dmsetup remove $cow") == 0; - print "device node $dev deleted\n"; -} - -if ($rmf) { - my $sf = "/$instance.cow/$username"; - die "sparse file $sf not found" unless -e "$sf"; - die unless system("rm -f $sf") == 0; - die unless not -e "$sf"; - print "sparse file $sf deleted\n"; -} -END -# chmod +x $HOME/bin/rmtgt -``` - -For example, to use the above script to completely remove the fc29-jsmith target including its backing store device node and its sparse file, run the following: - -``` -# rmtgt fc29 jsmith +f -``` - -Once you’ve verified that the mktgt script is working properly, you can restart the bootmenu service. The next time someone netboots, they should receive a personal copy of the the netboot image they can write to: - -``` -# systemctl restart bootmenu.service -``` - -Users should now be able to modify the root filesystem as demonstrated in the below screenshot: - -![][6] - - --------------------------------------------------------------------------------- - -via: https://fedoramagazine.org/how-to-build-a-netboot-server-part-4/ - -作者：[Gregory Bartholomew][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://fedoramagazine.org/author/glb/ -[b]: https://github.com/lujun9972 -[1]: http://ipxe.org/crypto -[2]: https://en.wikipedia.org/wiki/Copy-on-write -[3]: https://en.wikipedia.org/wiki/Challenge-Handshake_Authentication_Protocol -[4]: https://en.wikipedia.org/wiki/String_interpolation -[5]: https://en.wikipedia.org/wiki/Standard_streams -[6]: https://fedoramagazine.org/wp-content/uploads/2018/11/netboot-fix-pam_mount-1024x819.png diff --git a/sources/tech/20190114 Turn a Raspberry Pi 3B- into a PriTunl VPN.md b/sources/tech/20190114 Turn a Raspberry Pi 3B- into a PriTunl VPN.md deleted file mode 100644 index b7e55e0efb..0000000000 --- a/sources/tech/20190114 Turn a Raspberry Pi 3B- into a PriTunl VPN.md +++ /dev/null @@ -1,113 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Turn a Raspberry Pi 3B+ into a PriTunl VPN) -[#]: via: (https://opensource.com/article/19/1/pritunl-vpn-raspberry-pi) -[#]: author: (Stephen Bancroft https://opensource.com/users/stevereaver) - -Turn a Raspberry Pi 3B+ into a PriTunl VPN -====== -PriTunl is a VPN solution for small businesses and individuals who want private access to their network. - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/life-raspberrypi_0.png?itok=Kczz87J2) - -[PriTunl][1] is a fantastic VPN terminator solution that's perfect for small businesses and individuals who want a quick and simple way to access their network privately. It's open source, and the basic free version is more than enough to get you started and cover most simple use cases. There is also a paid enterprise version with advanced features like Active Directory integration. - -### Special considerations on Raspberry Pi 3B+ - -PriTunl is generally simple to install, but this project—turning a Raspberry Pi 3B+ into a PriTunl VPN appliance—adds some complexity. For one thing, PriTunl is supplied only as AMD64 and i386 binaries, but the 3B+ uses ARM architecture. This means you must compile your own binaries from source. That's nothing to be afraid of; it can be as simple as copying and pasting a few commands and watching the terminal for a short while. - -Another problem: PriTunl seems to require 64-bit architecture. I found this out when I got errors when I tried to compile PriTunl on my Raspberry Pi's 32-bit operating system. Fortunately, Ubuntu's beta version of 18.04 for ARM64 boots on the Raspberry Pi 3B+. - -Also, the Raspberry Pi 3B+ uses a different bootloader from other Raspberry Pi models. This required a complicated set of steps to install and update the necessary files to get a Raspberry Pi 3B+ to boot. - -### Installing PriTunl - -You can overcome these problems by installing a 64-bit operating system on the Raspberry Pi 3B+ before installing PriTunl. I'll assume you have basic knowledge of how to get around the Linux command line and a Raspberry Pi. - -Start by opening a terminal and downloading the Ubuntu 18.04 ARM64 beta release by entering: - -``` -$ wget http://cdimage.ubuntu.com/releases/18.04/beta/ubuntu-18.04-beta-preinstalled-server-arm64+raspi3.img.xz -``` - -Unpack the download: - -``` -$ xz -d ubuntu-18.04-beta-preinstalled-server-arm64+raspi3.xz -``` - -Insert the SD card you'll use with your Raspberry Pi into your desktop or laptop computer. Your computer will assign the SD card a drive letter—something like **/dev/sda** or **/dev/sdb**. Enter the **dmesg** command and examine the last lines of the output to find out the card's drive assignment. - -**Be VERY CAREFUL with the next step! I can't stress that enough; if you get the drive assignment wrong, you could destroy your system.** - -Write the image to your SD card with the following command, changing **< DRIVE>** to your SD card's drive assignment (obtained in the previous step): - -``` -$ dd if=ubuntu-18.04-beta-preinstalled-server-arm64+raspi3.img of= bs=8M -``` - -After it finishes, insert the SD card into your Pi and power it up. Make sure the Pi is connected to your network, then log in with username/password combination ubuntu/ubuntu. - -Enter the following commands on your Pi to install a few things to prepare to compile PriTunl: - -``` -$ sudo apt-get -y install build-essential git bzr python python-dev python-pip net-tools openvpn bridge-utils psmisc golang-go libffi-dev mongodb -``` - -There are a few changes from the standard PriTunl source [installation instructions on GitHub][2]. Make sure you are logged into your Pi and **sudo** to root: - -``` -$ sudo su - -``` - -This should leave you in root's home directory. To install PriTunl version 1.29.1914.98, enter (per GitHub): - -``` -export VERSION=1.29.1914.98 -tee -a ~/.bashrc << EOF -export GOPATH=\$HOME/go -export PATH=/usr/local/go/bin:\$PATH -EOF -source ~/.bashrc -mkdir pritunl && cd pritunl -go get -u github.com/pritunl/pritunl-dns -go get -u github.com/pritunl/pritunl-web -sudo ln -s ~/go/bin/pritunl-dns /usr/bin/pritunl-dns -sudo ln -s ~/go/bin/pritunl-web /usr/bin/pritunl-web -wget https://github.com/pritunl/pritunl/archive/$VERSION.tar.gz -tar -xf $VERSION.tar.gz -cd pritunl-$VERSION -python2 setup.py build -pip install -r requirements.txt -python2 setup.py install --prefix=/usr/local -``` - -Now the MongoDB and PriTunl systemd units should be ready to start up. Assuming you're still logged in as root, enter: - -``` -systemctl daemon-reload -systemctl start mongodb pritunl -systemctl enable mongodb pritunl -``` - -That's it! You're ready to hit PriTunl's browser user interface and configure it by following PriTunl's [installation and configuration instructions][3] on its website. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/19/1/pritunl-vpn-raspberry-pi - -作者：[Stephen Bancroft][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/stevereaver -[b]: https://github.com/lujun9972 -[1]: https://pritunl.com/ -[2]: https://github.com/pritunl/pritunl -[3]: https://docs.pritunl.com/docs/configuration-5 diff --git a/sources/tech/20190115 Getting started with Sandstorm, an open source web app platform.md b/sources/tech/20190115 Getting started with Sandstorm, an open source web app platform.md new file mode 100644 index 0000000000..2389a5d243 --- /dev/null +++ b/sources/tech/20190115 Getting started with Sandstorm, an open source web app platform.md @@ -0,0 +1,58 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Getting started with Sandstorm, an open source web app platform) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-sandstorm) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +Getting started with Sandstorm, an open source web app platform +====== +Learn about Sandstorm, the third in our series on open source tools that will make you more productive in 2019. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/sand_dunes_desert_hills_landscape_nature.jpg?itok=wUByylBb) + +There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. + +Here's the third of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. + +### Sandstorm + +Being productive isn't just about to-do lists and keeping things organized. Often it requires a suite of tools linked to make a workflow go smoothly. + +![](https://opensource.com/sites/default/files/uploads/sandstorm_1.png) + +[Sandstorm][1] is an open source collection of packaged apps, all accessible from a single web interface and managed from a central console. You can host it yourself or use the [Sandstorm Oasis][2] service—for a per-user fee. + +![](https://opensource.com/sites/default/files/uploads/sandstorm_2.png) + +Sandstorm has a marketplace that makes it simple to install the apps that are available. It includes apps for productivity, finance, note taking, task tracking, chat, games, and a whole lot more. You can also package your own apps and upload them by following the application-packaging guidelines in the [developer documentation][3]. + +![](https://opensource.com/sites/default/files/uploads/sandstorm_3.png) + +Once installed, a user can create [grains][4]—basically containerized instances of app data. Grains are private by default and can be shared with other Sandstorm users. This means they are secure by default, and users can chose what to share with others. + +![](https://opensource.com/sites/default/files/uploads/sandstorm_4.png) + +Sandstorm can authenticate from several different external sources as well as use a "passwordless" email-based authentication. Using an external service means you don't have to manage yet another set of credentials if you already use one of the supported services. + +In the end, Sandstorm makes installing and using supported collaborative apps quick, easy, and secure. + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-sandstorm + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: https://sandstorm.io/ +[2]: https://oasis.sandstorm.io +[3]: https://docs.sandstorm.io/en/latest/developing/ +[4]: https://sandstorm.io/how-it-works diff --git a/sources/tech/20190115 Linux Tools- The Meaning of Dot.md b/sources/tech/20190115 Linux Tools- The Meaning of Dot.md deleted file mode 100644 index 5e18c7603d..0000000000 --- a/sources/tech/20190115 Linux Tools- The Meaning of Dot.md +++ /dev/null @@ -1,183 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: ( ) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Linux Tools: The Meaning of Dot) -[#]: via: (https://www.linux.com/blog/learn/2019/1/linux-tools-meaning-dot) -[#]: author: (Paul Brown https://www.linux.com/users/bro66) - -Linux Tools: The Meaning of Dot -====== - -![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/psychedelic-dot.jpg?itok=giKEHvwQ) - -Let's face it: writing one-liners and scripts using shell commands can be confusing. Many of the names of the tools at your disposal are far from obvious in terms of what they do ( _grep_ , _tee_ and _awk_ , anyone?) and, when you combine two or more, the resulting "sentence" looks like some kind of alien gobbledygook. - -None of the above is helped by the fact that many of the symbols you use to build a chain of instructions can mean different things depending on their context. - -### Location, location, location - -Take the humble dot (`.`) for example. Used with instructions that are expecting the name of a directory, it means "this directory" so this: - -``` -find . -name "*.jpg" -``` - -translates to " _find in this directory (and all its subdirectories) files that have names that end in`.jpg`_ ". - -Both `ls .` and `cd .` act as expected, so they list and "change" to the current directory, respectively, although including the dot in these two cases is not necessary. - -Two dots, one after the other, in the same context (i.e., when your instruction is expecting a directory path) means " _the directory immediately above the current one_ ". If you are in _/home/your_directory_ and run - -``` -cd .. -``` - -you will be taken to _/home_. So, you may think this still kind of fits into the “dots represent nearby directories” narrative and is not complicated at all, right? - -How about this, then? If you use a dot at the beginning of a directory or file, it means the directory or file will be hidden: - -``` -$ touch somedir/file01.txt somedir/file02.txt somedir/.secretfile.txt -$ ls -l somedir/ -total 0 --rw-r--r-- 1 paul paul 0 Jan 13 19:57 file01.txt --rw-r--r-- 1 paul paul 0 Jan 13 19:57 file02.txt -$ # Note how there is no .secretfile.txt in the listing above -$ ls -la somedir/ -total 8 -drwxr-xr-x 2 paul paul 4096 Jan 13 19:57 . -drwx------ 48 paul paul 4096 Jan 13 19:57 .. --rw-r--r-- 1 paul paul 0 Jan 13 19:57 file01.txt --rw-r--r-- 1 paul paul 0 Jan 13 19:57 file02.txt --rw-r--r-- 1 paul paul 0 Jan 13 19:57 .secretfile.txt -$ # The -a option tells ls to show "all" files, including the hidden ones -``` - -And then there's when you use `.` as a command. Yep! You heard me: `.` is a full-fledged command. It is a synonym of `source` and you use that to execute a file in the current shell, as opposed to running a script some other way (which usually mean Bash will spawn a new shell in which to run it). - -Confused? Don't worry -- try this: Create a script called _myscript_ that contains the line - -``` -myvar="Hello" -``` - -and execute it the regular way, that is, with `sh myscript` (or by making the script executable with `chmod a+x myscript` and then running `./myscript`). Now try and see the contents of `myvar` with `echo $myvar` (spoiler: You will get nothing). This is because, when your script plunks " _Hello_ " into `myvar`, it does so in a separate bash shell instance. When the script ends, the spawned instance disappears and control returns to the original shell, where `myvar` never even existed. - -However, if you run _myscript_ like this: - -``` -. myscript -``` - -`echo $myvar` will print _Hello_ to the command line. - -You will often use the `.` (or `source`) command after making changes to your _.bashrc_ file, [like when you need to expand your `PATH` variable][1]. You use `.` to make the changes available immediately in your current shell instance. - -### Double Trouble - -Just like the seemingly insignificant single dot has more than one meaning, so has the double dot. Apart from pointing to the parent of the current directory, the double dot (`..`) is also used to build sequences. - -Try this: - -``` -echo {1..10} -``` - -It will print out the list of numbers from 1 to 10. In this context, `..` means " _starting with the value on my left, count up to the value on my right_ ". - -Now try this: - -``` -echo {1..10..2} -``` - -You'll get _1 3 5 7 9_. The `..2` part of the command tells Bash to print the sequence, but not one by one, but two by two. In other words, you'll get all the odd numbers from 1 to 10. - -It works backwards, too: - -``` -echo {10..1..2} -``` - -You can also pad your numbers with 0s. Doing: - -``` -echo {000..121..2} -``` - -will print out every even number from 0 to 121 like this: - -``` -000 002 004 006 ... 050 052 054 ... 116 118 120 -``` - -But how is this sequence-generating construct useful? Well, suppose one of your New Year's resolutions is to be more careful with your accounts. As part of that, you want to create directories in which to classify your digital invoices of the last 10 years: - -``` -mkdir {2009..2019}_Invoices -``` - -Job done. - -Or maybe you have a hundreds of numbered files, say, frames extracted from a video clip, and, for whatever reason, you want to remove only every third frame between the frames 43 and 61: - -``` -rm frame_{043..61..3} -``` - -It is likely that, if you have more than 100 frames, they will be named with padded 0s and look like this: - -``` -frame_000 frame_001 frame_002 ... -``` - -That’s why you will use `043` in your command instead of just `43`. - -### Curly~Wurly - -Truth be told, the magic of sequences lies not so much in the double dot as in the sorcery of the curly braces (`{}`). Look how it works for letters, too. Doing: - -``` -touch file_{a..z}.txt -``` - -creates the files _file_a.txt_ through _file_z.txt_. - -You must be careful, however. Using a sequence like `{Z..a}` will run through a bunch of non-alphanumeric characters (glyphs that are neither numbers or letters) that live between the uppercase alphabet and the lowercase one. Some of these glyphs are unprintable or have a special meaning of their own. Using them to generate names of files could lead to a whole bevy of unexpected and potentially unpleasant effects. - -One final thing worth pointing out about sequences encased between `{...}` is that they can also contain lists of strings: - -``` -touch {blahg, splurg, mmmf}_file.txt -``` - -Creates _blahg_file.txt_ , _splurg_file.txt_ and _mmmf_file.txt_. - -Of course, in other contexts, the curly braces have different meanings (surprise!). But that is the stuff of another article. - -### Conclusion - -Bash and the utilities you can run within it have been shaped over decades by system administrators looking for ways to solve very particular problems. To say that sysadmins and their ways are their own breed of special would be an understatement. Consequently, as opposed to other languages, Bash was not designed to be user-friendly, easy or even logical. - -That doesn't mean it is not powerful -- quite the contrary. Bash's grammar and shell tools may be inconsistent and sprawling, but they also provide a dizzying range of ways to do everything you can possibly imagine. It is like having a toolbox where you can find everything from a power drill to a spoon, as well as a rubber duck, a roll of duct tape, and some nail clippers. - -Apart from fascinating, it is also fun to discover all you can achieve directly from within the shell, so next time we will delve ever deeper into how you can build bigger and better Bash command lines. - -Until then, have fun! - --------------------------------------------------------------------------------- - -via: https://www.linux.com/blog/learn/2019/1/linux-tools-meaning-dot - -作者：[Paul Brown][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.linux.com/users/bro66 -[b]: https://github.com/lujun9972 -[1]: https://www.linux.com/blog/learn/2018/12/bash-variables-environmental-and-otherwise diff --git a/sources/tech/20190116 Best Audio Editors For Linux.md b/sources/tech/20190116 Best Audio Editors For Linux.md new file mode 100644 index 0000000000..d588c886e2 --- /dev/null +++ b/sources/tech/20190116 Best Audio Editors For Linux.md @@ -0,0 +1,156 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Best Audio Editors For Linux) +[#]: via: (https://itsfoss.com/best-audio-editors-linux) +[#]: author: (Ankush Das https://itsfoss.com/author/ankush/) + +Best Audio Editors For Linux +====== + +You’ve got a lot of choices when it comes to audio editors for Linux. No matter whether you are a professional music producer or just learning to create awesome music, the audio editors will always come in handy. + +Well, for professional-grade usage, a [DAW][1] (Digital Audio Workstation) is always recommended. However, not everyone needs all the functionalities, so you should know about some of the most simple audio editors as well. + +In this article, we will talk about a couple of DAWs and basic audio editors which are available as **free and open source** solutions for Linux and (probably) for other operating systems. + +### Top Audio Editors for Linux + +![Best audio editors and DAW for Linux][2] + +We will not be focusing on all the functionalities that DAWs offer – but the basic audio editing capabilities. You may still consider this as the list of best DAW for Linux. + +**Installation instruction:** You will find all the mentioned audio editors or DAWs in your AppCenter or Software center. In case, you do not find them listed, please head to their official website for more information. + +#### 1\. Audacity + +![audacity audio editor][3] + +Audacity is one of the most basic yet a capable audio editor available for Linux. It is a free and open-source cross-platform tool. A lot of you must be already knowing about it. + +It has improved a lot when compared to the time when it started trending. I do recall that I utilized it to “try” making karaokes by removing the voice from an audio file. Well, you can still do it – but it depends. + +**Features:** + +It also supports plug-ins that include VST effects. Of course, you should not expect it to support VST Instruments. + + * Live audio recording through a microphone or a mixer + * Export/Import capability supporting multiple formats and multiple files at the same time + * Plugin support: LADSPA, LV2, Nyquist, VST and Audio Unit effect plug-ins + * Easy editing with cut, paste, delete and copy functions. + * Spectogram view mode for analyzing frequencies + + + +#### 2\. LMMS + +![][4] + +LMMS is a free and open source (cross-platform) digital audio workstation. It includes all the basic audio editing functionalities along with a lot of advanced features. + +You can mix sounds, arrange them, or create them using VST instruments. It does support them. Also, it comes baked in with some samples, presets, VST Instruments, and effects to get started. In addition, you also get a spectrum analyzer for some advanced audio editing. + +**Features:** + + * Note playback via MIDI + * VST Instrument support + * Native multi-sample support + * Built-in compressor, limiter, delay, reverb, distortion and bass enhancer + + + +#### 3\. Ardour + +![Ardour audio editor][5] + +Ardour is yet another free and open source digital audio workstation. If you have an audio interface, Ardour will support it. Of course, you can add unlimited multichannel tracks. The multichannel tracks can also be routed to different mixer tapes for the ease of editing and recording. + +You can also import a video to it and edit the audio to export the whole thing. It comes with a lot of built-in plugins and supports VST plugins as well. + +**Features:** + + * Non-linear editing + * Vertical window stacking for easy navigation + * Strip silence, push-pull trimming, Rhythm Ferret for transient and note onset-based editing + + + +#### 4\. Cecilia + +![cecilia audio editor][6] + +Cecilia is not an ordinary audio editor application. It is meant to be used by sound designers or if you are just in the process of becoming one. It is technically an audio signal processing environment. It lets you create ear-bending sound out of them. + +You get in-build modules and plugins for sound effects and synthesis. It is tailored for a specific use – if that is what you were looking for – look no further! + +**Features:** + + * Modules to achieve more (UltimateGrainer – A state-of-the-art granulation processing, RandomAccumulator – Variable speed recording accumulator, +UpDistoRes – Distortion with upsampling and resonant lowpass filter) + * Automatic Saving of modulations + + + +#### 5\. Mixxx + +![Mixxx audio DJ ][7] + +If you want to mix and record something while being able to have a virtual DJ tool, [Mixxx][8] would be a perfect tool. You get to know the BPM, key, and utilize the master sync feature to match the tempo and beats of a song. Also, do not forget that it is yet another free and open source application for Linux! + +It supports custom DJ equipment as well. So, if you have one or a MIDI – you can record your live mixes using this tool. + +**Features** + + * Broadcast and record DJ Mixes of your song + * Ability to connect your equipment and perform live + * Key detection and BPM detection + + + +#### 6\. Rosegarden + +![rosegarden audio editor][9] + +Rosegarden is yet another impressive audio editor for Linux which is free and open source. It is neither a fully featured DAW nor a basic audio editing tool. It is a mixture of both with some scaled down functionalities. + +I wouldn’t recommend this for professionals but if you have a home studio or just want to experiment, this would be one of the best audio editors for Linux to have installed. + +**Features:** + + * Music notation editing + * Recording, Mixing, and samples + + + +### Wrapping Up + +These are some of the best audio editors you could find out there for Linux. No matter whether you need a DAW, a cut-paste editing tool, or a basic mixing/recording audio editor, the above-mentioned tools should help you out. + +Did we miss any of your favorite? Let us know about it in the comments below. + + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/best-audio-editors-linux + +作者：[Ankush Das][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/ankush/ +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Digital_audio_workstation +[2]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/linux-audio-editors-800x450.jpeg?resize=800%2C450&ssl=1 +[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/audacity-audio-editor.jpg?fit=800%2C591&ssl=1 +[4]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/lmms-daw.jpg?fit=800%2C472&ssl=1 +[5]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/ardour-audio-editor.jpg?fit=800%2C639&ssl=1 +[6]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/cecilia.jpg?fit=800%2C510&ssl=1 +[7]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/01/mixxx.jpg?fit=800%2C486&ssl=1 +[8]: https://itsfoss.com/dj-mixxx-2/ +[9]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/rosegarden.jpg?fit=800%2C391&ssl=1 +[10]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/linux-audio-editors.jpeg?fit=800%2C450&ssl=1 diff --git a/sources/tech/20190116 GameHub - An Unified Library To Put All Games Under One Roof.md b/sources/tech/20190116 GameHub - An Unified Library To Put All Games Under One Roof.md new file mode 100644 index 0000000000..bdaae74b43 --- /dev/null +++ b/sources/tech/20190116 GameHub - An Unified Library To Put All Games Under One Roof.md @@ -0,0 +1,139 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (GameHub – An Unified Library To Put All Games Under One Roof) +[#]: via: (https://www.ostechnix.com/gamehub-an-unified-library-to-put-all-games-under-one-roof/) +[#]: author: (SK https://www.ostechnix.com/author/sk/) + +GameHub – An Unified Library To Put All Games Under One Roof +====== + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/gamehub-720x340.png) + +**GameHub** is an unified gaming library that allows you to view, install, run and remove games on GNU/Linux operating system. It supports both native and non-native games from various sources including Steam, GOG, Humble Bundle, and Humble Trove etc. The non-native games are supported by [Wine][1], Proton, [DOSBox][2], ScummVM and RetroArch. It also allows you to add custom emulators and download bonus content and DLCs for GOG games. Simply put, Gamehub is a frontend for Steam/GoG/Humblebundle/Retroarch. It can use steam technologies like Proton to run windows gog games. GameHub is free, open source gaming platform written in **Vala** using **GTK+3**. If you’re looking for a way to manage all games under one roof, GameHub might be a good choice. + +### Installing GameHub + +The author of GameHub has designed it specifically for elementary OS. So, you can install it on Debian, Ubuntu, elementary OS and other Ubuntu-derivatives using GameHub PPA. + +``` +$ sudo apt install --no-install-recommends software-properties-common +$ sudo add-apt-repository ppa:tkashkin/gamehub +$ sudo apt update +$ sudo apt install com.github.tkashkin.gamehub +``` + +GameHub is available in [**AUR**][3], so just install it on Arch Linux and its variants using any AUR helpers, for example [**YaY**][4]. + +``` +$ yay -S gamehub-git +``` + +It is also available as **AppImage** and **Flatpak** packages in [**releases page**][5]. + +If you prefer AppImage package, do the following: + +``` +$ wget https://github.com/tkashkin/GameHub/releases/download/0.12.1-91-dev/GameHub-bionic-0.12.1-91-dev-cd55bb5-x86_64.AppImage -O gamehub +``` + +Make it executable: + +``` +$ chmod +x gamehub +``` + +And, run GameHub using command: + +``` +$ ./gamehub +``` + +If you want to use Flatpak installer, run the following commands one by one. + +``` +$ git clone https://github.com/tkashkin/GameHub.git +$ cd GameHub +$ scripts/build.sh build_flatpak +``` + +### Put All Games Under One Roof + +Launch GameHub from menu or application launcher. At first launch, you will see the following welcome screen. + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/gamehub1.png) + +As you can see in the above screenshot, you need to login to the given sources namely Steam, GoG or Humble Bundle. If you don’t have Steam client on your Linux system, you need to install it first to access your steam account. For GoG and Humble bundle sources, click on the icon to log in to the respective source. + +Once you logged in to your account(s), all games from the all sources can be visible on GameHub dashboard. + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/gamehub2.png) + +You will see list of logged-in sources on the top left corner. To view the games from each source, just click on the respective icon. + +You can also switch between list view or grid view, sort the games by applying the filters and search games from the list in GameHub dashboard. + +#### Installing a game + +Click on the game of your choice from the list and click Install button. If the game is non-native, GameHub will automatically choose the compatibility layer (E.g Wine) that suits to run the game and install the selected game. As you see in the below screenshot, Indiana Jones game is not available for Linux platform. + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/gamehub3-1.png) + +If it is a native game (i.e supports Linux), simply press the Install button. + +![][7] + +If you don’t want to install the game, just hit the **Download** button to save it in your games directory. It is also possible to add locally installed games to GameHub using the **Import** option. + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/gamehub5.png) + +#### GameHub Settings + +GameHub Settings window can be launched by clicking on the four straight lines on top right corner. + +From Settings section, we can enable, disable and set various settings such as, + + * Switch between light/dark themes. + * Use Symbolic icons instead of colored icons for games. + * Switch to compact list. + * Enable/disable merging games from different sources. + * Enable/disable compatibility layers. + * Set games collection directory. The default directory for storing the collection is **$HOME/Games/_Collection**. + * Set games directories for each source. + * Add/remove emulators, + * And many. + + + +For more details, refer the project links given at the end of this guide. + +**Related read:** + +And, that’s all for now. Hope this helps. I will be soon here with another guide. Until then, stay tuned with OSTechNix. + +Cheers! + + + +-------------------------------------------------------------------------------- + +via: https://www.ostechnix.com/gamehub-an-unified-library-to-put-all-games-under-one-roof/ + +作者：[SK][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.ostechnix.com/author/sk/ +[b]: https://github.com/lujun9972 +[1]: https://www.ostechnix.com/run-windows-games-softwares-ubuntu-16-04/ +[2]: https://www.ostechnix.com/how-to-run-ms-dos-games-and-programs-in-linux/ +[3]: https://aur.archlinux.org/packages/gamehub-git/ +[4]: https://www.ostechnix.com/yay-found-yet-another-reliable-aur-helper/ +[5]: https://github.com/tkashkin/GameHub/releases +[6]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[7]: http://www.ostechnix.com/wp-content/uploads/2019/01/gamehub4.png diff --git a/sources/tech/20190116 The Evil-Twin Framework- A tool for improving WiFi security.md b/sources/tech/20190116 The Evil-Twin Framework- A tool for improving WiFi security.md new file mode 100644 index 0000000000..81b5d2ddf1 --- /dev/null +++ b/sources/tech/20190116 The Evil-Twin Framework- A tool for improving WiFi security.md @@ -0,0 +1,236 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (The Evil-Twin Framework: A tool for improving WiFi security) +[#]: via: (https://opensource.com/article/19/1/evil-twin-framework) +[#]: author: (André Esser https://opensource.com/users/andreesser) + +The Evil-Twin Framework: A tool for improving WiFi security +====== +Learn about a pen-testing tool intended to test the security of WiFi access points for all types of threats. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/security-lock-cloud-safe.png?itok=yj2TFPzq) + +The increasing number of devices that connect over-the-air to the internet over-the-air and the wide availability of WiFi access points provide many opportunities for attackers to exploit users. By tricking users to connect to [rogue access points][1], hackers gain full control over the users' network connection, which allows them to sniff and alter traffic, redirect users to malicious sites, and launch other attacks over the network.. + +To protect users and teach them to avoid risky online behaviors, security auditors and researchers must evaluate users' security practices and understand the reasons they connect to WiFi access points without being confident they are safe. There are a significant number of tools that can conduct WiFi audits, but no single tool can test the many different attack scenarios and none of the tools integrate well with one another. + +The **Evil-Twin Framework** (ETF) aims to fix these problems in the WiFi auditing process by enabling auditors to examine multiple scenarios and integrate multiple tools. This article describes the framework and its functionalities, then provides some examples to show how it can be used. + +### The ETF architecture + +The ETF framework was written in [Python][2] because the development language is very easy to read and make contributions to. In addition, many of the ETF's libraries, such as **[Scapy][3]** , were already developed for Python, making it easy to use them for ETF. + +The ETF architecture (Figure 1) is divided into different modules that interact with each other. The framework's settings are all written in a single configuration file. The user can verify and edit the settings through the user interface via the **ConfigurationManager** class. Other modules can only read these settings and run according to them. + +![Evil-Twin Framework Architecture][5] + +Figure 1: Evil-Twin framework architecture + +The ETF supports multiple user interfaces that interact with the framework. The current default interface is an interactive console, similar to the one on [Metasploit][6]. A graphical user interface (GUI) and a command line interface (CLI) are under development for desktop/browser use, and mobile interfaces may be an option in the future. The user can edit the settings in the configuration file using the interactive console (and eventually with the GUI). The user interface can interact with every other module that exists in the framework. + +The WiFi module ( **AirCommunicator** ) was built to support a wide range of WiFi capabilities and attacks. The framework identifies three basic pillars of Wi-Fi communication: **packet sniffing** , **custom packet injection** , and **access point creation**. The three main WiFi communication modules are **AirScanner** , **AirInjector** , and **AirHost** , which are responsible for packet sniffing, packet injection, and access point creation, respectively. The three classes are wrapped inside the main WiFi module, AirCommunicator, which reads the configuration file before starting the services. Any type of WiFi attack can be built using one or more of these core features. + +To enable man-in-the-middle (MITM) attacks, which are a common way to attack WiFi clients, the framework has an integrated module called ETFITM (Evil-Twin Framework-in-the-Middle). This module is responsible for the creation of a web proxy used to intercept and manipulate HTTP/HTTPS traffic. + +There are many other tools that can leverage the MITM position created by the ETF. Through its extensibility, ETF can support them—and, instead of having to call them separately, you can add the tools to the framework just by extending the Spawner class. This enables a developer or security auditor to call the program with a preconfigured argument string from within the framework. + +The other way to extend the framework is through plugins. There are two categories of plugins: **WiFi plugins** and **MITM plugins**. MITM plugins are scripts that can run while the MITM proxy is active. The proxy passes the HTTP(S) requests and responses through to the plugins where they can be logged or manipulated. WiFi plugins follow a more complex flow of execution but still expose a fairly simple API to contributors who wish to develop and use their own plugins. WiFi plugins can be further divided into three categories, one for each of the core WiFi communication modules. + +Each of the core modules has certain events that trigger the execution of a plugin. For instance, AirScanner has three defined events to which a response can be programmed. The events usually correspond to a setup phase before the service starts running, a mid-execution phase while the service is running, and a teardown or cleanup phase after a service finishes. Since Python allows multiple inheritance, one plugin can subclass more than one plugin class. + +Figure 1 above is a summary of the framework's architecture. Lines pointing away from the ConfigurationManager mean that the module reads information from it and lines pointing towards it mean that the module can write/edit configurations. + +### Examples of using the Evil-Twin Framework + +There are a variety of ways ETF can conduct penetration testing on WiFi network security or work on end users' awareness of WiFi security. The following examples describe some of the framework's pen-testing functionalities, such as access point and client detection, WPA and WEP access point attacks, and evil twin access point creation. + +These examples were devised using ETF with WiFi cards that allow WiFi traffic capture. They also utilize the following abbreviations for ETF setup commands: + + * **APS** access point SSID + * **APB** access point BSSID + * **APC** access point channel + * **CM** client MAC address + + + +In a real testing scenario, make sure to replace these abbreviations with the correct information. + +#### Capturing a WPA 4-way handshake after a de-authentication attack + +This scenario (Figure 2) takes two aspects into consideration: the de-authentication attack and the possibility of catching a 4-way WPA handshake. The scenario starts with a running WPA/WPA2-enabled access point with one connected client device (in this case, a smartphone). The goal is to de-authenticate the client with a general de-authentication attack then capture the WPA handshake once it tries to reconnect. The reconnection will be done manually immediately after being de-authenticated. + +![Scenario for capturing a WPA handshake after a de-authentication attack][8] + +Figure 2: Scenario for capturing a WPA handshake after a de-authentication attack + +The consideration in this example is the ETF's reliability. The goal is to find out if the tools can consistently capture the WPA handshake. The scenario will be performed multiple times with each tool to check its reliability when capturing the WPA handshake. + +There is more than one way to capture a WPA handshake using the ETF. One way is to use a combination of the AirScanner and AirInjector modules; another way is to just use the AirInjector. The following scenario uses a combination of both modules. + +The ETF launches the AirScanner module and analyzes the IEEE 802.11 frames to find a WPA handshake. Then the AirInjector can launch a de-authentication attack to force a reconnection. The following steps must be done to accomplish this on the ETF: + + 1. Enter the AirScanner configuration mode: **config airscanner** + 2. Configure the AirScanner to not hop channels: **config airscanner** + 3. Set the channel to sniff the traffic on the access point channel (APC): **set fixed_sniffing_channel = ** + 4. Start the AirScanner module with the CredentialSniffer plugin: **start airscanner with credentialsniffer** + 5. Add a target access point BSSID (APS) from the sniffed access points list: **add aps where ssid = ** + 6. Start the AirInjector, which by default lauches the de-authentication attack: **start airinjector** + + + +This simple set of commands enables the ETF to perform an efficient and successful de-authentication attack on every test run. The ETF can also capture the WPA handshake on every test run. The following code makes it possible to observe the ETF's successful execution. + +``` +███████╗████████╗███████╗ +██╔════╝╚══██╔══╝██╔════╝ +█████╗     ██║   █████╗   +██╔══╝     ██║   ██╔══╝   +███████╗   ██║   ██║     +╚══════╝   ╚═╝   ╚═╝     +                                        + +[+] Do you want to load an older session? [Y/n]: n +[+] Creating new temporary session on 02/08/2018 +[+] Enter the desired session name: +ETF[etf/aircommunicator/]::> config airscanner +ETF[etf/aircommunicator/airscanner]::> listargs +  sniffing_interface =               wlan1; (var) +              probes =                True; (var) +             beacons =                True; (var) +        hop_channels =               false; (var) +fixed_sniffing_channel =                  11; (var) +ETF[etf/aircommunicator/airscanner]::> start airscanner with +arpreplayer        caffelatte         credentialsniffer  packetlogger       selfishwifi         +ETF[etf/aircommunicator/airscanner]::> start airscanner with credentialsniffer +[+] Successfully added credentialsniffer plugin. +[+] Starting packet sniffer on interface 'wlan1' +[+] Set fixed channel to 11 +ETF[etf/aircommunicator/airscanner]::> add aps where ssid = CrackWPA +ETF[etf/aircommunicator/airscanner]::> start airinjector +ETF[etf/aircommunicator/airscanner]::> [+] Starting deauthentication attack +                    - 1000 bursts of 1 packets +                    - 1 different packets +[+] Injection attacks finished executing. +[+] Starting post injection methods +[+] Post injection methods finished +[+] WPA Handshake found for client '70:3e:ac:bb:78:64' and network 'CrackWPA' +``` + +#### Launching an ARP replay attack and cracking a WEP network + +The next scenario (Figure 3) will also focus on the [Address Resolution Protocol][9] (ARP) replay attack's efficiency and the speed of capturing the WEP data packets containing the initialization vectors (IVs). The same network may require a different number of caught IVs to be cracked, so the limit for this scenario is 50,000 IVs. If the network is cracked during the first test with less than 50,000 IVs, that number will be the new limit for the following tests on the network. The cracking tool to be used will be **aircrack-ng**. + +The test scenario starts with an access point using WEP encryption and an offline client that knows the key—the key for testing purposes is 12345, but it can be a larger and more complex key. Once the client connects to the WEP access point, it will send out a gratuitous ARP packet; this is the packet that's meant to be captured and replayed. The test ends once the limit of packets containing IVs is captured. + +![Scenario for capturing a WPA handshake after a de-authentication attack][11] + +Figure 3: Scenario for capturing a WPA handshake after a de-authentication attack + +ETF uses Python's Scapy library for packet sniffing and injection. To minimize known performance problems in Scapy, ETF tweaks some of its low-level libraries to significantly speed packet injection. For this specific scenario, the ETF uses **tcpdump** as a background process instead of Scapy for more efficient packet sniffing, while Scapy is used to identify the encrypted ARP packet. + +This scenario requires the following commands and operations to be performed on the ETF: + + 1. Enter the AirScanner configuration mode: **config airscanner** + 2. Configure the AirScanner to not hop channels: **set hop_channels = false** + 3. Set the channel to sniff the traffic on the access point channel (APC): **set fixed_sniffing_channel = ** + 4. Enter the ARPReplayer plugin configuration mode: **config arpreplayer** + 5. Set the target access point BSSID (APB) of the WEP network: **set target_ap_bssid ** + 6. Start the AirScanner module with the ARPReplayer plugin: **start airscanner with arpreplayer** + + + +After executing these commands, ETF correctly identifies the encrypted ARP packet, then successfully performs an ARP replay attack, which cracks the network. + +#### Launching a catch-all honeypot + +The scenario in Figure 4 creates multiple access points with the same SSID. This technique discovers the encryption type of a network that was probed for but out of reach. By launching multiple access points with all security settings, the client will automatically connect to the one that matches the security settings of the locally cached access point information. + +![Scenario for capturing a WPA handshake after a de-authentication attack][13] + +Figure 4: Scenario for capturing a WPA handshake after a de-authentication attack + +Using the ETF, it is possible to configure the **hostapd** configuration file then launch the program in the background. Hostapd supports launching multiple access points on the same wireless card by configuring virtual interfaces, and since it supports all types of security configurations, a complete catch-all honeypot can be set up. For the WEP and WPA(2)-PSK networks, a default password is used, and for the WPA(2)-EAP, an "accept all" policy is configured. + +For this scenario, the following commands and operations must be performed on the ETF: + + 1. Enter the APLauncher configuration mode: **config aplauncher** + 2. Set the desired access point SSID (APS): **set ssid = ** + 3. Configure the APLauncher as a catch-all honeypot: **set catch_all_honeypot = true** + 4. Start the AirHost module: **start airhost** + + + +With these commands, the ETF can launch a complete catch-all honeypot with all types of security configurations. ETF also automatically launches the DHCP and DNS servers that allow clients to stay connected to the internet. ETF offers a better, faster, and more complete solution to create catch-all honeypots. The following code enables the successful execution of the ETF to be observed. + +``` +███████╗████████╗███████╗ +██╔════╝╚══██╔══╝██╔════╝ +█████╗     ██║   █████╗   +██╔══╝     ██║   ██╔══╝   +███████╗   ██║   ██║     +╚══════╝   ╚═╝   ╚═╝     +                                        + +[+] Do you want to load an older session? [Y/n]: n +[+] Creating ne´,cxzw temporary session on 03/08/2018 +[+] Enter the desired session name: +ETF[etf/aircommunicator/]::> config aplauncher +ETF[etf/aircommunicator/airhost/aplauncher]::> setconf ssid CatchMe +ssid = CatchMe +ETF[etf/aircommunicator/airhost/aplauncher]::> setconf catch_all_honeypot true +catch_all_honeypot = true +ETF[etf/aircommunicator/airhost/aplauncher]::> start airhost +[+] Killing already started processes and restarting network services +[+] Stopping dnsmasq and hostapd services +[+] Access Point stopped... +[+] Running airhost plugins pre_start +[+] Starting hostapd background process +[+] Starting dnsmasq service +[+] Running airhost plugins post_start +[+] Access Point launched successfully +[+] Starting dnsmasq service +``` + +### Conclusions and future work + +These scenarios use common and well-known attacks to help validate the ETF's capabilities for testing WiFi networks and clients. The results also validate that the framework's architecture enables new attack vectors and features to be developed on top of it while taking advantage of the platform's existing capabilities. This should accelerate development of new WiFi penetration-testing tools, since a lot of the code is already written. Furthermore, the fact that complementary WiFi technologies are all integrated in a single tool will make WiFi pen-testing simpler and more efficient. + +The ETF's goal is not to replace existing tools but to complement them and offer a broader choice to security auditors when conducting WiFi pen-testing and improving user awareness. + +The ETF is an open source project [available on GitHub][14] and community contributions to its development are welcomed. Following are some of the ways you can help. + +One of the limitations of current WiFi pen-testing is the inability to log important events during tests. This makes reporting identified vulnerabilities both more difficult and less accurate. The framework could implement a logger that can be accessed by every class to create a pen-testing session report. + +The ETF tool's capabilities cover many aspects of WiFi pen-testing. On one hand, it facilitates the phases of WiFi reconnaissance, vulnerability discovery, and attack. On the other hand, it doesn't offer a feature that facilitates the reporting phase. Adding the concept of a session and a session reporting feature, such as the logging of important events during a session, would greatly increase the value of the tool for real pen-testing scenarios. + +Another valuable contribution would be extending the framework to facilitate WiFi fuzzing. The IEEE 802.11 protocol is very complex, and considering there are multiple implementations of it, both on the client and access point side, it's safe to assume these implementations contain bugs and even security flaws. These bugs could be discovered by fuzzing IEEE 802.11 protocol frames. Since Scapy allows custom packet creation and injection, a fuzzer can be implemented through it. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/evil-twin-framework + +作者：[André Esser][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/andreesser +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Rogue_access_point +[2]: https://www.python.org/ +[3]: https://scapy.net +[4]: /file/417776 +[5]: https://opensource.com/sites/default/files/uploads/pic1.png (Evil-Twin Framework Architecture) +[6]: https://www.metasploit.com +[7]: /file/417781 +[8]: https://opensource.com/sites/default/files/uploads/pic2.png (Scenario for capturing a WPA handshake after a de-authentication attack) +[9]: https://en.wikipedia.org/wiki/Address_Resolution_Protocol +[10]: /file/417786 +[11]: https://opensource.com/sites/default/files/uploads/pic3.png (Scenario for capturing a WPA handshake after a de-authentication attack) +[12]: /file/417791 +[13]: https://opensource.com/sites/default/files/uploads/pic4.png (Scenario for capturing a WPA handshake after a de-authentication attack) +[14]: https://github.com/Esser420/EvilTwinFramework diff --git a/sources/tech/20190116 Zipping files on Linux- the many variations and how to use them.md b/sources/tech/20190116 Zipping files on Linux- the many variations and how to use them.md new file mode 100644 index 0000000000..fb98f78b06 --- /dev/null +++ b/sources/tech/20190116 Zipping files on Linux- the many variations and how to use them.md @@ -0,0 +1,324 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Zipping files on Linux: the many variations and how to use them) +[#]: via: (https://www.networkworld.com/article/3333640/linux/zipping-files-on-linux-the-many-variations-and-how-to-use-them.html) +[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/) + +Zipping files on Linux: the many variations and how to use them +====== +![](https://images.idgesg.net/images/article/2019/01/zipper-100785364-large.jpg) + +Some of us have been zipping files on Unix and Linux systems for many decades — to save some disk space and package files together for archiving. Even so, there are some interesting variations on zipping that not all of us have tried. So, in this post, we’re going to look at standard zipping and unzipping as well as some other interesting zipping options. + +### The basic zip command + +First, let’s look at the basic **zip** command. It uses what is essentially the same compression algorithm as **gzip** , but there are a couple important differences. For one thing, the gzip command is used only for compressing a single file where zip can both compress files and join them together into an archive. For another, the gzip command zips “in place”. In other words, it leaves a compressed file — not the original file alongside the compressed copy. Here's an example of gzip at work: + +``` +$ gzip onefile +$ ls -l +-rw-rw-r-- 1 shs shs 10514 Jan 15 13:13 onefile.gz +``` + +And here's zip. Notice how this command requires that a name be provided for the zipped archive where gzip simply uses the original file name and adds the .gz extension. + +``` +$ zip twofiles.zip file* + adding: file1 (deflated 82%) + adding: file2 (deflated 82%) +$ ls -l +-rw-rw-r-- 1 shs shs 58021 Jan 15 13:25 file1 +-rw-rw-r-- 1 shs shs 58933 Jan 15 13:34 file2 +-rw-rw-r-- 1 shs shs 21289 Jan 15 13:35 twofiles.zip +``` + +Notice also that the original files are still sitting there. + +The amount of disk space that is saved (i.e., the degree of compression obtained) will depend on the content of each file. The variation in the example below is considerable. + +``` +$ zip mybin.zip ~/bin/* + adding: bin/1 (deflated 26%) + adding: bin/append (deflated 64%) + adding: bin/BoD_meeting (deflated 18%) + adding: bin/cpuhog1 (deflated 14%) + adding: bin/cpuhog2 (stored 0%) + adding: bin/ff (deflated 32%) + adding: bin/file.0 (deflated 1%) + adding: bin/loop (deflated 14%) + adding: bin/notes (deflated 23%) + adding: bin/patterns (stored 0%) + adding: bin/runme (stored 0%) + adding: bin/tryme (deflated 13%) + adding: bin/tt (deflated 6%) +``` + +### The unzip command + +The **unzip** command will recover the contents from a zip file and, as you'd likely suspect, leave the zip file intact, whereas a similar gunzip command would leave only the uncompressed file. + +``` +$ unzip twofiles.zip +Archive: twofiles.zip + inflating: file1 + inflating: file2 +$ ls -l +-rw-rw-r-- 1 shs shs 58021 Jan 15 13:25 file1 +-rw-rw-r-- 1 shs shs 58933 Jan 15 13:34 file2 +-rw-rw-r-- 1 shs shs 21289 Jan 15 13:35 twofiles.zip +``` + +### The zipcloak command + +The **zipcloak** command encrypts a zip file, prompting you to enter a password twice (to help ensure you don't "fat finger" it) and leaves the file in place. You can expect the file size to vary a little from the original. + +``` +$ zipcloak twofiles.zip +Enter password: +Verify password: +encrypting: file1 +encrypting: file2 +$ ls -l +total 204 +-rw-rw-r-- 1 shs shs 58021 Jan 15 13:25 file1 +-rw-rw-r-- 1 shs shs 58933 Jan 15 13:34 file2 +-rw-rw-r-- 1 shs shs 21313 Jan 15 13:46 twofiles.zip <== slightly larger than + unencrypted version +``` + +Keep in mind that the original files are still sitting there unencrypted. + +### The zipdetails command + +The **zipdetails** command is going to show you details — a _lot_ of details about a zipped file, likely a lot more than you care to absorb. Even though we're looking at an encrypted file, zipdetails does display the file names along with file modification dates, user and group information, file length data, etc. Keep in mind that this is all "metadata." We don't see the contents of the files. + +``` +$ zipdetails twofiles.zip + +0000 LOCAL HEADER #1 04034B50 +0004 Extract Zip Spec 14 '2.0' +0005 Extract OS 00 'MS-DOS' +0006 General Purpose Flag 0001 + [Bit 0] 1 'Encryption' + [Bits 1-2] 1 'Maximum Compression' +0008 Compression Method 0008 'Deflated' +000A Last Mod Time 4E2F6B24 'Tue Jan 15 13:25:08 2019' +000E CRC F1B115BD +0012 Compressed Length 00002904 +0016 Uncompressed Length 0000E2A5 +001A Filename Length 0005 +001C Extra Length 001C +001E Filename 'file1' +0023 Extra ID #0001 5455 'UT: Extended Timestamp' +0025 Length 0009 +0027 Flags '03 mod access' +0028 Mod Time 5C3E2584 'Tue Jan 15 13:25:08 2019' +002C Access Time 5C3E27BB 'Tue Jan 15 13:34:35 2019' +0030 Extra ID #0002 7875 'ux: Unix Extra Type 3' +0032 Length 000B +0034 Version 01 +0035 UID Size 04 +0036 UID 000003E8 +003A GID Size 04 +003B GID 000003E8 +003F PAYLOAD + +2943 LOCAL HEADER #2 04034B50 +2947 Extract Zip Spec 14 '2.0' +2948 Extract OS 00 'MS-DOS' +2949 General Purpose Flag 0001 + [Bit 0] 1 'Encryption' + [Bits 1-2] 1 'Maximum Compression' +294B Compression Method 0008 'Deflated' +294D Last Mod Time 4E2F6C56 'Tue Jan 15 13:34:44 2019' +2951 CRC EC214569 +2955 Compressed Length 00002913 +2959 Uncompressed Length 0000E635 +295D Filename Length 0005 +295F Extra Length 001C +2961 Filename 'file2' +2966 Extra ID #0001 5455 'UT: Extended Timestamp' +2968 Length 0009 +296A Flags '03 mod access' +296B Mod Time 5C3E27C4 'Tue Jan 15 13:34:44 2019' +296F Access Time 5C3E27BD 'Tue Jan 15 13:34:37 2019' +2973 Extra ID #0002 7875 'ux: Unix Extra Type 3' +2975 Length 000B +2977 Version 01 +2978 UID Size 04 +2979 UID 000003E8 +297D GID Size 04 +297E GID 000003E8 +2982 PAYLOAD + +5295 CENTRAL HEADER #1 02014B50 +5299 Created Zip Spec 1E '3.0' +529A Created OS 03 'Unix' +529B Extract Zip Spec 14 '2.0' +529C Extract OS 00 'MS-DOS' +529D General Purpose Flag 0001 + [Bit 0] 1 'Encryption' + [Bits 1-2] 1 'Maximum Compression' +529F Compression Method 0008 'Deflated' +52A1 Last Mod Time 4E2F6B24 'Tue Jan 15 13:25:08 2019' +52A5 CRC F1B115BD +52A9 Compressed Length 00002904 +52AD Uncompressed Length 0000E2A5 +52B1 Filename Length 0005 +52B3 Extra Length 0018 +52B5 Comment Length 0000 +52B7 Disk Start 0000 +52B9 Int File Attributes 0001 + [Bit 0] 1 Text Data +52BB Ext File Attributes 81B40000 +52BF Local Header Offset 00000000 +52C3 Filename 'file1' +52C8 Extra ID #0001 5455 'UT: Extended Timestamp' +52CA Length 0005 +52CC Flags '03 mod access' +52CD Mod Time 5C3E2584 'Tue Jan 15 13:25:08 2019' +52D1 Extra ID #0002 7875 'ux: Unix Extra Type 3' +52D3 Length 000B +52D5 Version 01 +52D6 UID Size 04 +52D7 UID 000003E8 +52DB GID Size 04 +52DC GID 000003E8 + +52E0 CENTRAL HEADER #2 02014B50 +52E4 Created Zip Spec 1E '3.0' +52E5 Created OS 03 'Unix' +52E6 Extract Zip Spec 14 '2.0' +52E7 Extract OS 00 'MS-DOS' +52E8 General Purpose Flag 0001 + [Bit 0] 1 'Encryption' + [Bits 1-2] 1 'Maximum Compression' +52EA Compression Method 0008 'Deflated' +52EC Last Mod Time 4E2F6C56 'Tue Jan 15 13:34:44 2019' +52F0 CRC EC214569 +52F4 Compressed Length 00002913 +52F8 Uncompressed Length 0000E635 +52FC Filename Length 0005 +52FE Extra Length 0018 +5300 Comment Length 0000 +5302 Disk Start 0000 +5304 Int File Attributes 0001 + [Bit 0] 1 Text Data +5306 Ext File Attributes 81B40000 +530A Local Header Offset 00002943 +530E Filename 'file2' +5313 Extra ID #0001 5455 'UT: Extended Timestamp' +5315 Length 0005 +5317 Flags '03 mod access' +5318 Mod Time 5C3E27C4 'Tue Jan 15 13:34:44 2019' +531C Extra ID #0002 7875 'ux: Unix Extra Type 3' +531E Length 000B +5320 Version 01 +5321 UID Size 04 +5322 UID 000003E8 +5326 GID Size 04 +5327 GID 000003E8 + +532B END CENTRAL HEADER 06054B50 +532F Number of this disk 0000 +5331 Central Dir Disk no 0000 +5333 Entries in this disk 0002 +5335 Total Entries 0002 +5337 Size of Central Dir 00000096 +533B Offset to Central Dir 00005295 +533F Comment Length 0000 +Done +``` + +### The zipgrep command + +The **zipgrep** command is going to use a grep-type feature to locate particular content in your zipped files. If the file is encrypted, you will need to enter the password provided for the encryption for each file you want to examine. If you only want to check the contents of a single file from the archive, add its name to the end of the zipgrep command as shown below. + +``` +$ zipgrep hazard twofiles.zip file1 +[twofiles.zip] file1 password: +Certain pesticides should be banned since they are hazardous to the environment. +``` + +### The zipinfo command + +The **zipinfo** command provides information on the contents of a zipped file whether encrypted or not. This includes the file names, sizes, dates and permissions. + +``` +$ zipinfo twofiles.zip +Archive: twofiles.zip +Zip file size: 21313 bytes, number of entries: 2 +-rw-rw-r-- 3.0 unx 58021 Tx defN 19-Jan-15 13:25 file1 +-rw-rw-r-- 3.0 unx 58933 Tx defN 19-Jan-15 13:34 file2 +2 files, 116954 bytes uncompressed, 20991 bytes compressed: 82.1% +``` + +### The zipnote command + +The **zipnote** command can be used to extract comments from zip archives or add them. To display comments, just preface the name of the archive with the command. If no comments have been added previously, you will see something like this: + +``` +$ zipnote twofiles.zip +@ file1 +@ (comment above this line) +@ file2 +@ (comment above this line) +@ (zip file comment below this line) +``` + +If you want to add comments, write the output from the zipnote command to a file: + +``` +$ zipnote twofiles.zip > comments +``` + +Next, edit the file you've just created, inserting your comments above the **(comment above this line)** lines. Then add the comments using a zipnote command like this one: + +``` +$ zipnote -w twofiles.zip < comments +``` + +### The zipsplit command + +The **zipsplit** command can be used to break a zip archive into multiple zip archives when the original file is too large — maybe because you're trying to add one of the files to a small thumb drive. The easiest way to do this seems to be to specify the max size for each of the zipped file portions. This size must be large enough to accomodate the largest included file. + +``` +$ zipsplit -n 12000 twofiles.zip +2 zip files will be made (100% efficiency) +creating: twofile1.zip +creating: twofile2.zip +$ ls twofile*.zip +-rw-rw-r-- 1 shs shs 10697 Jan 15 14:52 twofile1.zip +-rw-rw-r-- 1 shs shs 10702 Jan 15 14:52 twofile2.zip +-rw-rw-r-- 1 shs shs 21377 Jan 15 14:27 twofiles.zip +``` + +Notice how the extracted files are sequentially named "twofile1" and "twofile2". + +### Wrap-up + +The **zip** command, along with some of its zipping compatriots, provide a lot of control over how you generate and work with compressed file archives. + +**[ Also see:[Invaluable tips and tricks for troubleshooting Linux][1] ]** + +Join the Network World communities on [Facebook][2] and [LinkedIn][3] to comment on topics that are top of mind. + +-------------------------------------------------------------------------------- + +via: https://www.networkworld.com/article/3333640/linux/zipping-files-on-linux-the-many-variations-and-how-to-use-them.html + +作者：[Sandra Henry-Stocker][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/ +[b]: https://github.com/lujun9972 +[1]: https://www.networkworld.com/article/3242170/linux/invaluable-tips-and-tricks-for-troubleshooting-linux.html +[2]: https://www.facebook.com/NetworkWorld/ +[3]: https://www.linkedin.com/company/network-world diff --git a/sources/tech/20190117 Pyvoc - A Command line Dictionary And Vocabulary Building Tool.md b/sources/tech/20190117 Pyvoc - A Command line Dictionary And Vocabulary Building Tool.md new file mode 100644 index 0000000000..b0aa45d618 --- /dev/null +++ b/sources/tech/20190117 Pyvoc - A Command line Dictionary And Vocabulary Building Tool.md @@ -0,0 +1,239 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Pyvoc – A Command line Dictionary And Vocabulary Building Tool) +[#]: via: (https://www.ostechnix.com/pyvoc-a-command-line-dictionary-and-vocabulary-building-tool/) +[#]: author: (SK https://www.ostechnix.com/author/sk/) + +Pyvoc – A Command line Dictionary And Vocabulary Building Tool +====== + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/pyvoc-720x340.jpg) + +Howdy! I have a good news for non-native English speakers. Now, you can improve your English vocabulary and find the meaning of English words, right from your Terminal. Say hello to **Pyvoc** , a cross-platform, open source, command line dictionary and vocabulary building tool written in **Python** programming language. Using this tool, you can brush up some English words meanings, test or improve your vocabulary skill or simply use it as a CLI dictionary on Unix-like operating systems. + +### Installing Pyvoc + +Since Pyvoc is written using Python language, you can install it using [**Pip3**][1] package manager. + +``` +$ pip3 install pyvoc +``` + +Once installed, run the following command to automatically create necessary configuration files in your $HOME directory. + +``` +$ pyvoc word +``` + +Sample output: + +``` +|Creating necessary config files +/getting api keys. please handle with care! +| + +word +Noun: single meaningful element of speech or writing +example: I don't like the word ‘unofficial’ + +Verb: express something spoken or written +example: he words his request in a particularly ironic way + +Interjection: used to express agreement or affirmation +example: Word, that's a good record, man +``` + +Done! Let us go ahead and brush the English skills. + +### Use Pyvoc as a command line Dictionary tool + +Pyvoc fetches the word meaning from **Oxford Dictionary API**. + +Let us say, you want to find the meaning of a word **‘digression’**. To do so, run: + +``` +$ pyvoc digression +``` + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/pyvoc1.png) + +See? Pyvoc not only displays the meaning of word **‘digression’** , but also an example sentence which shows how to use that word in practical. + +Let us see an another example. + +``` +$ pyvoc subterfuge +| + +subterfuge +Noun: deceit used in order to achieve one's goal +example: he had to use subterfuge and bluff on many occasions +``` + +It also shows the word classes as well. As you already know, English has four major **word classes** : + + 1. Nouns, + + 2. Verbs, + + 3. Adjectives, + + 4. Adverbs. + + + + +Take a look at the following example. + +``` +$ pyvoc welcome + / + +welcome +Noun: instance or manner of greeting someone +example: you will receive a warm welcome + +Interjection: used to greet someone in polite or friendly way +example: welcome to the Wildlife Park + +Verb: greet someone arriving in polite or friendly way +example: hotels should welcome guests in their own language + +Adjective: gladly received +example: I'm pleased to see you, lad—you're welcome +``` + +As you see in the above output, the word ‘welcome’ can be used as a verb, noun, adjective and interjection. Pyvoc has given example for each class. + +If you misspell a word, it will inform you to check the spelling of the given word. + +``` +$ pyvoc wlecome +\ +No definition found. Please check the spelling!! +``` + +Useful, isn’t it? + +### Create vocabulary groups + +A vocabulary group is nothing but a collection words added by the user. You can later revise or take quiz from these groups. 100 groups of 60 words are **reserved** for the user. + +To add a word (E.g **sporadic** ) to a group, just run: + +``` +$ pyvoc sporadic -a +- + +sporadic +Adjective: occurring at irregular intervals or only in few places +example: sporadic fighting broke out + + +writing to vocabulary group... +word added to group number 51 +``` + +As you can see, I didn’t provide any group number and pyvoc displayed the meaning of given word and automatically added that word to group number **51**. If you don’t provide the group number, Pyvoc will **incrementally add words** to groups **51-100**. + +Pyvoc also allows you to specify a group number if you want to. You can specify a group from 1-50 using **-g** option. For example, I am going to add a word to Vocabulary group 20 using the following command. + +``` +$ pyvoc discrete -a -g 20 + / + +discrete +Adjective: individually separate and distinct +example: speech sounds are produced as a continuous sound signal rather + than discrete units + +creating group Number 20... +writing to vocabulary group... +word added to group number 20 +``` + +See? The above command displays the meaning of ‘discrete’ word and adds it to the vocabulary group 20. If the group doesn’t exists, Pyvoc will create it and add the word. + +By default, Pyvoc includes three predefined vocabulary groups (101, 102, and 103). These custom groups has 800 words of each. All words in these groups are taken from **GRE** and **SAT** preparation websites. + +To view the user-generated groups, simply run: + +``` +$ pyvoc word -l + - + +word +Noun: single meaningful element of speech or writing +example: I don't like the word ‘unofficial’ + +Verb: express something spoken or written +example: he words his request in a particularly ironic way + +Interjection: used to express agreement or affirmation +example: Word, that's a good record, man + + +USER GROUPS +Group no. No. of words +20 1 + +DEFAULT GROUP +Group no. No. of words +51 1 +``` +``` + +``` + +As you see, I have created one group (20) including the default group (51). + +### Test and improve English vocabulary + +As I already said, you can use the Vocabulary groups to revise or take quiz from them. + +For instance, to revise the group no. **101** , use **-r** option like below. + +``` +$ pyvoc 101 -r +``` + +You can now revise the meaning of all words in the Vocabulary group 101 in random order. Just hit ENTER to go through next questions. Once done, hit **CTRL+C** to exit. + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/pyvoc2-1.png) + +Also, you take quiz from the existing groups to brush up your vocabulary. To do so, use **-q** option like below. + +``` +$ pyvoc 103 -q 50 +``` + +This command allows you to take quiz of 50 questions from vocabulary group 103. Choose the correct answer from the list by entering the appropriate number. You will get 1 point for every correct answer. The more you score the more your vocabulary skill will be. + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/pyvoc3.png) + +Pyvoc is in the early-development stage. I hope the developer will improve it and add more features in the days to come. + +As a non-native English speaker, I personally find it useful to test and learn new word meanings in my free time. If you’re a heavy command line user and wanted to quickly check the meaning of a word, Pyvoc is the right tool. You can also test your English Vocabulary at your free time to memorize and improve your English language skill. Give it a try. You won’t be disappointed. + +And, that’s all for now. Hope this was useful. More good stuffs to come. Stay tuned! + +Cheers! + + +-------------------------------------------------------------------------------- + +via: https://www.ostechnix.com/pyvoc-a-command-line-dictionary-and-vocabulary-building-tool/ + +作者：[SK][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.ostechnix.com/author/sk/ +[b]: https://github.com/lujun9972 +[1]: https://www.ostechnix.com/manage-python-packages-using-pip/ diff --git a/sources/tech/20190118 Secure Email Service Tutanota Has a Desktop App Now.md b/sources/tech/20190118 Secure Email Service Tutanota Has a Desktop App Now.md new file mode 100644 index 0000000000..f56f1272f2 --- /dev/null +++ b/sources/tech/20190118 Secure Email Service Tutanota Has a Desktop App Now.md @@ -0,0 +1,119 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Secure Email Service Tutanota Has a Desktop App Now) +[#]: via: (https://itsfoss.com/tutanota-desktop) +[#]: author: (John Paul https://itsfoss.com/author/john/) + +Secure Email Service Tutanota Has a Desktop App Now +====== + +[Tutanota][1] recently [announced][2] the release of a desktop app for their email service. The beta is available for Linux, Windows, and macOS. + +### What is Tutanota? + +There are plenty of free, ad-supported email services available online. However, the majority of those email services are not exactly secure or privacy-minded. In this post-[Snowden][3] world, [Tutanota][4] offers a free, secure email service with a focus on privacy. + +Tutanota has a number of eye-catching features, such as: + + * End-to-end encrypted mailbox + * End-to-end encrypted address book + * Automatic end-to-end encrypted emails between users + * End-to-end encrypted emails to any email address with a shared password + * Secure password reset that gives Tutanota absolutely no access + * Strips IP addresses from emails sent and received + * The code that runs Tutanota is [open source][5] + * Two-factor authentication + * Focus on privacy + * Passwords are salted and hashed locally with Bcrypt + * Secure servers located in Germany + * TLS with support for PFS, DMARC, DKIM, DNSSEC, and DANE + * Full-text search of encrypted data executed locally + + + +![][6] +Tutanota on the web + +You can [sign up for an account for free][7]. You can also upgrade your account to get extra features, such as custom domains, custom domain login, domain rules, extra storage, and aliases. They also have accounts available for businesses. + +Tutanota is also available on mobile devices. In fact, it’s [Android app is open source as well][8]. + +This German company is planning to expand beyond email. They hope to offer an encrypted calendar and cloud storage. You can help them reach their goals by [donating][9] via PayPal and cryptocurrency. + +### The New Desktop App from Tutanota + +Tutanota announced the [beta release][2] of the desktop app right before Christmas. They based this app on [Electron][10]. + +![][11] +Tutanota desktop app + +They went the Electron route: + + * to support all three major operating systems with minimum effort. + * to quickly adapt the new desktop clients so that they match new features added to the webmail client. + * to allocate development time to particular desktop features, e.g. offline availability, email import, that will simultaneously be available in all three desktop clients. + + + +Because this is a beta, there are several features missing from the app. The development team at Tutanota is working to add the following features: + + * Email import and synchronization with external mailboxes. This will “enable Tutanota to import emails from external mailboxes and encrypt the data locally on your device before storing it on the Tutanota servers.” + * Offline availability of emails + * Two-factor authentication + + + +### How to Install the Tutanota desktop client? + +![][12]Composing email in Tutanota + +You can [download][2] the beta app directly from Tutanota’s website. They have an [AppImage file for Linux][13], a .exe file for Windows, and a .app file for macOS. You can post any bugs that you encounter to the Tutanota [GitHub account][14]. + +To prove the security of the app, Tutanota signed each version. “The signatures make sure that the desktop clients as well as any updates come directly from us and have not been tampered with.” You can verify the signature using from Tutanota’s [GitHub page][15]. + +Remember, you will need to create a Tutanota account before you can use it. This is email client is designed to work solely with Tutanota. + +### Wrapping up + +I tested out the Tutanota email app on Linux Mint MATE. As to be expected, it was a mirror image of the web app. At this point in time, I don’t see any difference between the desktop app and the web app. The only use case that I can see to use the app now is to have Tutanota in its own window. + +Have you ever used [Tutanota][16]? If not, what is your favorite privacy conscience email service? Let us know in the comments below. + +If you found this article interesting, please take a minute to share it on social media, Hacker News or [Reddit][17]. + +![][18] + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/tutanota-desktop + +作者：[John Paul][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/john/ +[b]: https://github.com/lujun9972 +[1]: https://itsfoss.com/tutanota-review/ +[2]: https://tutanota.com/blog/posts/desktop-clients/ +[3]: https://en.wikipedia.org/wiki/Edward_Snowden +[4]: https://tutanota.com/ +[5]: https://tutanota.com/blog/posts/open-source-email +[6]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2018/12/tutanota2.jpg?resize=800%2C490&ssl=1 +[7]: https://tutanota.com/pricing +[8]: https://itsfoss.com/tutanota-fdroid-release/ +[9]: https://tutanota.com/community +[10]: https://electronjs.org/ +[11]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/01/tutanota-app1.png?fit=800%2C486&ssl=1 +[12]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2018/12/tutanota1.jpg?resize=800%2C405&ssl=1 +[13]: https://itsfoss.com/use-appimage-linux/ +[14]: https://github.com/tutao/tutanota +[15]: https://github.com/tutao/tutanota/blob/master/buildSrc/installerSigner.js +[16]: https://tutanota.com/polo/ +[17]: http://reddit.com/r/linuxusersgroup +[18]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2018/02/tutanota-featured.png?fit=800%2C450&ssl=1 diff --git a/sources/tech/20190121 Akira- The Linux Design Tool We-ve Always Wanted.md b/sources/tech/20190121 Akira- The Linux Design Tool We-ve Always Wanted.md new file mode 100644 index 0000000000..bd58eca5bf --- /dev/null +++ b/sources/tech/20190121 Akira- The Linux Design Tool We-ve Always Wanted.md @@ -0,0 +1,92 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Akira: The Linux Design Tool We’ve Always Wanted?) +[#]: via: (https://itsfoss.com/akira-design-tool) +[#]: author: (Ankush Das https://itsfoss.com/author/ankush/) + +Akira: The Linux Design Tool We’ve Always Wanted? +====== + +Let’s make it clear, I am not a professional designer – but I’ve used certain tools on Windows (like Photoshop, Illustrator, etc.) and [Figma][1] (which is a browser-based interface design tool). I’m sure there are a lot more design tools available for Mac and Windows. + +Even on Linux, there is a limited number of dedicated [graphic design tools][2]. A few of these tools like [GIMP][3] and [Inkscape][4] are used by professionals as well. But most of them are not considered professional grade, unfortunately. + +Even if there are a couple more solutions – I’ve never come across a native Linux application that could replace [Sketch][5], Figma, or Adobe **** XD. Any professional designer would agree to that, isn’t it? + +### Is Akira going to replace Sketch, Figma, and Adobe XD on Linux? + +Well, in order to develop something that would replace those awesome proprietary tools – [Alessandro Castellani][6] – came up with a [Kickstarter campaign][7] by teaming up with a couple of experienced developers – +[Alberto Fanjul][8], [Bilal Elmoussaoui][9], and [Felipe Escoto][10]. + +So, yes, Akira is still pretty much just an idea- with a working prototype of its interface (as I observed in their [live stream session][11] via Kickstarter recently). + +### If it does not exist, why the Kickstarter campaign? + +![][12] + +The aim of the Kickstarter campaign is to gather funds in order to hire the developers and take a few months off to dedicate their time in order to make Akira possible. + +Nonetheless, if you want to support the project, you should know some details, right? + +Fret not, we asked a couple of questions in their livestream session – let’s get into it… + +### Akira: A few more details + +![Akira prototype interface][13] +Image Credits: Kickstarter + +As the Kickstarter campaign describes: + +> The main purpose of Akira is to offer a fast and intuitive tool to **create Web and Mobile interfaces** , more like **Sketch** , **Figma** , or **Adobe XD** , with a completely native experience for Linux. + +They’ve also written a detailed description as to how the tool will be different from Inkscape, Glade, or QML Editor. Of course, if you want all the technical details, [Kickstarter][7] is the way to go. But, before that, let’s take a look at what they had to say when I asked some questions about Akira. + +Q: If you consider your project – similar to what Figma offers – why should one consider installing Akira instead of using the web-based tool? Is it just going to be a clone of those tools – offering a native Linux experience or is there something really interesting to encourage users to switch (except being an open source solution)? + +**Akira:** A native experience on Linux is always better and fast in comparison to a web-based electron app. Also, the hardware configuration matters if you choose to utilize Figma – but Akira will be light on system resource and you will still be able to do similar stuff without needing to go online. + +Q: Let’s assume that it becomes the open source solution that Linux users have been waiting for (with similar features offered by proprietary tools). What are your plans to sustain it? Do you plan to introduce any pricing plans – or rely on donations? + +**Akira** : The project will mostly rely on Donations (something like [Krita Foundation][14] could be an idea). But, there will be no “pro” pricing plans – it will be available for free and it will be an open source project. + +So, with the response I got, it definitely seems to be something promising that we should probably support. + +### Wrapping Up + +What do you think about Akira? Is it just going to remain a concept? Or do you hope to see it in action? + +Let us know your thoughts in the comments below. + +![][15] + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/akira-design-tool + +作者：[Ankush Das][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/ankush/ +[b]: https://github.com/lujun9972 +[1]: https://www.figma.com/ +[2]: https://itsfoss.com/best-linux-graphic-design-software/ +[3]: https://itsfoss.com/gimp-2-10-release/ +[4]: https://inkscape.org/ +[5]: https://www.sketchapp.com/ +[6]: https://github.com/Alecaddd +[7]: https://www.kickstarter.com/projects/alecaddd/akira-the-linux-design-tool/description +[8]: https://github.com/albfan +[9]: https://github.com/bilelmoussaoui +[10]: https://github.com/Philip-Scott +[11]: https://live.kickstarter.com/alessandro-castellani/live-stream/the-current-state-of-akira +[12]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/01/akira-design-tool-kickstarter.jpg?resize=800%2C451&ssl=1 +[13]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/akira-mockup.png?ssl=1 +[14]: https://krita.org/en/about/krita-foundation/ +[15]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/01/akira-design-tool-kickstarter.jpg?fit=812%2C458&ssl=1 diff --git a/sources/tech/20190121 Get started with TaskBoard, a lightweight kanban board.md b/sources/tech/20190121 Get started with TaskBoard, a lightweight kanban board.md new file mode 100644 index 0000000000..e083d650e5 --- /dev/null +++ b/sources/tech/20190121 Get started with TaskBoard, a lightweight kanban board.md @@ -0,0 +1,59 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Get started with TaskBoard, a lightweight kanban board) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-taskboard) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +Get started with TaskBoard, a lightweight kanban board +====== +Check out the ninth tool in our series on open source tools that will make you more productive in 2019. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/checklist_hands_team_collaboration.png?itok=u82QepPk) + +There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. + +Here's the ninth of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. + +### TaskBoard + +As I wrote in the [second article][1] in this series, [kanban boards][2] are pretty popular these days. And not all kanban boards are created equal. [TaskBoard][3] is a PHP application that is easy to set up on an existing web server and has a set of functions that make it easy to use and manage. + +![](https://opensource.com/sites/default/files/uploads/taskboard-1.png) + +[Installation][4] is as simple as unzipping the files on your web server, running a script or two, and making sure the correct directories are accessible. The first time you start it up, you're presented with a login form, and then it's time to start adding users and making boards. Board creation options include adding the columns you want to use and setting the default color of the cards. You can also assign users to boards so everyone sees only the boards they need to see. + +User management is lightweight, and all accounts are local to the server. You can set a default board for everyone on the server, and users can set their own default boards, too. These options can be useful when someone works on one board more than others. + +![](https://opensource.com/sites/default/files/uploads/taskboard-2.png) + +TaskBoard also allows you to create automatic actions, which are actions taken upon changes to user assignment, columns, or card categories. Although TaskBoard is not as powerful as some other kanban apps, you can set up automatic actions to make cards more visible for board users, clear due dates, and auto-assign new cards to people as needed. For example, in the screenshot below, if a card is assigned to the "admin" user, its color is changed to red, and when a card is assigned to my user, its color is changed to teal. I've also added an action to clear an item's due date if it's added to the "To-Do" column and to auto-assign cards to my user when that happens. + +![](https://opensource.com/sites/default/files/uploads/taskboard-3.png) + +The cards are very straightforward. While they don't have a start date, they do have end dates and a points field. Points can be used for estimating the time needed, effort required, or just general priority. Using points is optional, but if you are using TaskBoard for scrum planning or other agile techniques, it is a really handy feature. You can also filter the view by users and categories. This can be helpful on a team with multiple work streams going on, as it allows a team lead or manager to get status information about progress or a person's workload. + +![](https://opensource.com/sites/default/files/uploads/taskboard-4.png) + +If you need a reasonably lightweight kanban board, check out TaskBoard. It installs quickly, has some nice features, and is very, very easy to use. It's also flexible enough to be used for development teams, personal task tracking, and a whole lot more. + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-taskboard + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/article/19/1/productivity-tool-wekan +[2]: https://en.wikipedia.org/wiki/Kanban +[3]: https://taskboard.matthewross.me/ +[4]: https://taskboard.matthewross.me/docs/ diff --git a/sources/tech/20190121 How to Resize OpenStack Instance (Virtual Machine) from Command line.md b/sources/tech/20190121 How to Resize OpenStack Instance (Virtual Machine) from Command line.md new file mode 100644 index 0000000000..e235cabdbf --- /dev/null +++ b/sources/tech/20190121 How to Resize OpenStack Instance (Virtual Machine) from Command line.md @@ -0,0 +1,149 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (How to Resize OpenStack Instance (Virtual Machine) from Command line) +[#]: via: (https://www.linuxtechi.com/resize-openstack-instance-command-line/) +[#]: author: (Pradeep Kumar http://www.linuxtechi.com/author/pradeep/) + +How to Resize OpenStack Instance (Virtual Machine) from Command line +====== + +Being a Cloud administrator, resizing or changing resources of an instance or virtual machine is one of the most common tasks. + +![](https://www.linuxtechi.com/wp-content/uploads/2019/01/Resize-openstack-instance.jpg) + +In Openstack environment, there are some scenarios where cloud user has spin a vm using some flavor( like m1.smalll) where root partition disk size is 20 GB, but at some point of time user wants to extends the root partition size to 40 GB. So resizing of vm’s root partition can be accomplished by using the resize option in nova command. During the resize, we need to specify the new flavor that will include disk size as 40 GB. + +**Note:** Once you extend the instance resources like RAM, CPU and disk using resize option in openstack then you can’t reduce it. + +**Read More on** : [**How to Create and Delete Virtual Machine(VM) from Command line in OpenStack**][1] + +In this tutorial I will demonstrate how to resize an openstack instance from command line. Let’s assume I have an existing instance named “ **test_resize_vm** ” and it’s associated flavor is “m1.small” and root partition disk size is 20 GB. + +Execute the below command from controller node to check on which compute host our vm “test_resize_vm” is provisioned and its flavor details + +``` +:~# openstack server show test_resize_vm | grep -E "flavor|hypervisor" +| OS-EXT-SRV-ATTR:hypervisor_hostname  | compute-57    | +| flavor                               | m1.small (2)  | +:~# +``` + +Login to VM as well and check the root partition size, + +``` +[[email protected] ~]# df -Th +Filesystem     Type      Size  Used Avail Use% Mounted on +/dev/vda1      xfs        20G  885M   20G   5% / +devtmpfs       devtmpfs  900M     0  900M   0% /dev +tmpfs          tmpfs     920M     0  920M   0% /dev/shm +tmpfs          tmpfs     920M  8.4M  912M   1% /run +tmpfs          tmpfs     920M     0  920M   0% /sys/fs/cgroup +tmpfs          tmpfs     184M     0  184M   0% /run/user/1000 +[[email protected] ~]# echo "test file for resize operation" > demofile +[[email protected] ~]# cat demofile +test file for resize operation +[[email protected] ~]# +``` + +Get the available flavor list using below command, + +``` +:~# openstack flavor list ++--------------------------------------|-----------------|-------|------|-----------|-------|-----------+ +| ID                                   | Name            |   RAM | Disk | Ephemeral | VCPUs | Is Public | ++--------------------------------------|-----------------|-------|------|-----------|-------|-----------+ +| 2                                    | m1.small        |  2048 |   20 |         0 |     1 | True      | +| 3                                    | m1.medium       |  4096 |   40 |         0 |     2 | True      | +| 4                                    | m1.large        |  8192 |   80 |         0 |     4 | True      | +| 5                                    | m1.xlarge       | 16384 |  160 |         0 |     8 | True      | ++--------------------------------------|-----------------|-------|------|-----------|-------|-----------+ +``` + +So we will be using the flavor “m1.medium” for resize operation, Run the beneath nova command to resize “test_resize_vm”, + +Syntax: # nova resize {VM_Name} {flavor_id} —poll + +``` +:~# nova resize test_resize_vm 3 --poll +Server resizing... 100% complete +Finished +:~# +``` + +Now confirm the resize operation using “ **openstack server –confirm”** command, + +``` +~# openstack server list | grep -i test_resize_vm +| 1d56f37f-94bd-4eef-9ff7-3dccb4682ce0 | test_resize_vm | VERIFY_RESIZE |private-net=10.20.10.51                                  | +:~# +``` + +As we can see in the above command output the current status of the vm is “ **verify_resize** “, execute below command to confirm resize, + +``` +~# openstack server resize --confirm 1d56f37f-94bd-4eef-9ff7-3dccb4682ce0 +~# +``` + +After the resize confirmation, status of VM will become active, now re-verify hypervisor and flavor details for the vm + +``` +:~# openstack server show test_resize_vm | grep -E "flavor|hypervisor" +| OS-EXT-SRV-ATTR:hypervisor_hostname  | compute-58   | +| flavor                               | m1.medium (3)| +``` + +Login to your VM now and verify the root partition size + +``` +[[email protected] ~]# df -Th +Filesystem     Type      Size  Used Avail Use% Mounted on +/dev/vda1      xfs        40G  887M   40G   3% / +devtmpfs       devtmpfs  1.9G     0  1.9G   0% /dev +tmpfs          tmpfs     1.9G     0  1.9G   0% /dev/shm +tmpfs          tmpfs     1.9G  8.4M  1.9G   1% /run +tmpfs          tmpfs     1.9G     0  1.9G   0% /sys/fs/cgroup +tmpfs          tmpfs     380M     0  380M   0% /run/user/1000 +[[email protected] ~]# cat demofile +test file for resize operation +[[email protected] ~]# +``` + +This confirm that VM root partition has been resized successfully. + +**Note:** Due to some reason if resize operation was not successful and you want to revert the vm back to previous state, then run the following command, + +``` +# openstack server resize --revert {instance_uuid} +``` + +If have noticed “ **openstack server show** ” commands output, VM is migrated from compute-57 to compute-58 after resize. This is the default behavior of “nova resize” command ( i.e nova resize command will migrate the instance to another compute & then resize it based on the flavor details) + +In case if you have only one compute node then nova resize will not work, but we can make it work by changing the below parameter in nova.conf file on compute node, + +Login to compute node, verify the parameter value + +If “ **allow_resize_to_same_host** ” is set as False then change it to True and restart the nova compute service. + +**Read More on** [**OpenStack Deployment using Devstack on CentOS 7 / RHEL 7 System**][2] + +That’s all from this tutorial, in case it helps you technically then please do share your feedback and comments. + +-------------------------------------------------------------------------------- + +via: https://www.linuxtechi.com/resize-openstack-instance-command-line/ + +作者：[Pradeep Kumar][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.linuxtechi.com/author/pradeep/ +[b]: https://github.com/lujun9972 +[1]: https://www.linuxtechi.com/create-delete-virtual-machine-command-line-openstack/ +[2]: https://www.linuxtechi.com/openstack-deployment-devstack-centos-7-rhel-7/ diff --git a/sources/tech/20190122 Get started with Go For It, a flexible to-do list application.md b/sources/tech/20190122 Get started with Go For It, a flexible to-do list application.md new file mode 100644 index 0000000000..56dde41884 --- /dev/null +++ b/sources/tech/20190122 Get started with Go For It, a flexible to-do list application.md @@ -0,0 +1,60 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Get started with Go For It, a flexible to-do list application) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-go-for-it) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +Get started with Go For It, a flexible to-do list application +====== +Go For It, the tenth in our series on open source tools that will make you more productive in 2019, builds on the Todo.txt system to help you get more things done. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/coffee_cafe_brew_laptop_desktop.jpg?itok=G-n1o1-o) + +There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. + +Here's the tenth of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. + +### Go For It + +Sometimes what a person needs to be productive isn't a fancy kanban board or a set of notes, but a simple, straightforward to-do list. Something that is as basic as "add item to list, check it off when done." And for that, the [plain-text Todo.txt system][1] is possibly one of the easiest to use, and it's supported on almost every system out there. + +![](https://opensource.com/sites/default/files/uploads/go-for-it_1_1.png) + +[Go For It][2] is a simple, easy-to-use graphical interface for Todo.txt. It can be used with an existing file, if you are already using Todo.txt, and will create both a to-do and a done file if you aren't. It allows drag-and-drop ordering of tasks, allowing users to organize to-do items in the order they want to execute them. It also supports priorities, projects, and contexts, as outlined in the [Todo.txt format guidelines][3]. And, it can filter tasks by context or project simply by clicking on the project or context in the task list. + +![](https://opensource.com/sites/default/files/uploads/go-for-it_2.png) + +At first, Go For It may look the same as just about any other Todo.txt program, but looks can be deceiving. The real feature that sets Go For It apart is that it includes a built-in [Pomodoro Technique][4] timer. Select the task you want to complete, switch to the Timer tab, and click Start. When the task is done, simply click Done, and it will automatically reset the timer and pick the next task on the list. You can pause and restart the timer as well as click Skip to jump to the next task (or break). It provides a warning when 60 seconds are left for the current task. The default time for tasks is set at 25 minutes, and the default time for breaks is set at five minutes. You can adjust this in the Settings screen, as well as the location of the directory containing your Todo.txt and done.txt files. + +![](https://opensource.com/sites/default/files/uploads/go-for-it_3.png) + +Go For It's third tab, Done, allows you to look at the tasks you've completed and clean them out when you want. Being able to look at what you've accomplished can be very motivating and a good way to get a feel for where you are in a longer process. + +![](https://opensource.com/sites/default/files/uploads/go-for-it_4.png) + +It also has all of Todo.txt's other advantages. Go For It's list is accessible by other programs that use the same format, including [Todo.txt's original command-line tool][5] and any [add-ons][6] you've installed. + +Go For It seeks to be a simple tool to help manage your to-do list and get those items done. If you already use Todo.txt, Go For It is a fantastic addition to your toolkit, and if you don't, it's a really good way to start using one of the simplest and most flexible systems available. + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-go-for-it + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: http://todotxt.org/ +[2]: http://manuel-kehl.de/projects/go-for-it/ +[3]: https://github.com/todotxt/todo.txt +[4]: https://en.wikipedia.org/wiki/Pomodoro_Technique +[5]: https://github.com/todotxt/todo.txt-cli +[6]: https://github.com/todotxt/todo.txt-cli/wiki/Todo.sh-Add-on-Directory diff --git a/sources/tech/20190122 How To Copy A File-Folder From A Local System To Remote System In Linux.md b/sources/tech/20190122 How To Copy A File-Folder From A Local System To Remote System In Linux.md new file mode 100644 index 0000000000..6de6cd173f --- /dev/null +++ b/sources/tech/20190122 How To Copy A File-Folder From A Local System To Remote System In Linux.md @@ -0,0 +1,398 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (How To Copy A File/Folder From A Local System To Remote System In Linux?) +[#]: via: (https://www.2daygeek.com/linux-scp-rsync-pscp-command-copy-files-folders-in-multiple-servers-using-shell-script/) +[#]: author: (Prakash Subramanian https://www.2daygeek.com/author/prakash/) + +How To Copy A File/Folder From A Local System To Remote System In Linux? +====== + +Copying a file from one server to another server or local to remote is one of the routine task for Linux administrator. + +If anyone says no, i won’t accept because this is one of the regular activity wherever you go. + +It can be done in many ways and we are trying to cover all the possible options. + +You can choose the one which you would prefer. Also, check other commands as well that may help you for some other purpose. + +I have tested all these commands and script in my test environment so, you can use this for your routine work. + +By default every one go with SCP because it’s one of the native command that everyone use for file copy. But commands which is listed in this article are be smart so, give a try if you would like to try new things. + +This can be done in below four ways easily. + + * **`SCP:`** scp copies files between hosts on a network. It uses ssh for data transfer, and uses the same authentication and provides the same security as ssh. + * **`RSYNC:`** rsync is a fast and extraordinarily versatile file copying tool. It can copy locally, to/from another host over any remote shell, or to/from a remote rsync daemon. + * **`PSCP:`** pscp is a program for copying files in parallel to a number of hosts. It provides features such as passing a password to scp, saving output to files, and timing out. + * **`PRSYNC:`** prsync is a program for copying files in parallel to a number of hosts. It provides features such as passing a password to ssh, saving output to files, and timing out. + + + +### Method-1: Copy Files/Folders From A Local System To Remote System In Linux Using SCP Command? + +scp command allow us to copy files/folders from a local system to remote system. + +We are going to copy the `output.txt` file from my local system to `2g.CentOS.com` remote system under `/opt/backup` directory. + +``` +# scp output.txt root@2g.CentOS.com:/opt/backup + +output.txt 100% 2468 2.4KB/s 00:00 +``` + +We are going to copy two files `output.txt` and `passwd-up.sh` files from my local system to `2g.CentOS.com` remote system under `/opt/backup` directory. + +``` +# scp output.txt passwd-up.sh root@2g.CentOS.com:/opt/backup + +output.txt 100% 2468 2.4KB/s 00:00 +passwd-up.sh 100% 877 0.9KB/s 00:00 +``` + +We are going to copy the `shell-script` directory from my local system to `2g.CentOS.com` remote system under `/opt/backup` directory. + +This will copy the `shell-script` directory and associated files under `/opt/backup` directory. + +``` +# scp -r /home/daygeek/2g/shell-script/ [email protected]:/opt/backup/ + +output.txt 100% 2468 2.4KB/s 00:00 +ovh.sh 100% 76 0.1KB/s 00:00 +passwd-up.sh 100% 877 0.9KB/s 00:00 +passwd-up1.sh 100% 7 0.0KB/s 00:00 +server-list.txt 100% 23 0.0KB/s 00:00 +``` + +### Method-2: Copy Files/Folders From A Local System To Multiple Remote System In Linux Using Shell Script with scp Command? + +If you would like to copy the same file into multiple remote servers then create the following small shell script to achieve this. + +To do so, get the servers list and add those into `server-list.txt` file. Make sure you have to update the servers list into `server-list.txt` file. Each server should be in separate line. + +Finally mention the file location which you want to copy like below. + +``` +# file-copy.sh + +#!/bin/sh +for server in `more server-list.txt` +do + scp /home/daygeek/2g/shell-script/output.txt [email protected]$server:/opt/backup +done +``` + +Once you done, set an executable permission to password-update.sh file. + +``` +# chmod +x file-copy.sh +``` + +Finally run the script to achieve this. + +``` +# ./file-copy.sh + +output.txt 100% 2468 2.4KB/s 00:00 +output.txt 100% 2468 2.4KB/s 00:00 +``` + +Use the following script to copy the multiple files into multiple remote servers. + +``` +# file-copy.sh + +#!/bin/sh +for server in `more server-list.txt` +do + scp /home/daygeek/2g/shell-script/output.txt passwd-up.sh [email protected]$server:/opt/backup +done +``` + +The below output shows all the files twice as this copied into two servers. + +``` +# ./file-cp.sh + +output.txt 100% 2468 2.4KB/s 00:00 +passwd-up.sh 100% 877 0.9KB/s 00:00 +output.txt 100% 2468 2.4KB/s 00:00 +passwd-up.sh 100% 877 0.9KB/s 00:00 +``` + +Use the following script to copy the directory recursively into multiple remote servers. + +``` +# file-copy.sh + +#!/bin/sh +for server in `more server-list.txt` +do + scp -r /home/daygeek/2g/shell-script/ [email protected]$server:/opt/backup +done +``` + +Output for the above script. + +``` +# ./file-cp.sh + +output.txt 100% 2468 2.4KB/s 00:00 +ovh.sh 100% 76 0.1KB/s 00:00 +passwd-up.sh 100% 877 0.9KB/s 00:00 +passwd-up1.sh 100% 7 0.0KB/s 00:00 +server-list.txt 100% 23 0.0KB/s 00:00 + +output.txt 100% 2468 2.4KB/s 00:00 +ovh.sh 100% 76 0.1KB/s 00:00 +passwd-up.sh 100% 877 0.9KB/s 00:00 +passwd-up1.sh 100% 7 0.0KB/s 00:00 +server-list.txt 100% 23 0.0KB/s 00:00 +``` + +### Method-3: Copy Files/Folders From A Local System To Multiple Remote System In Linux Using PSCP Command? + +pscp command directly allow us to perform the copy to multiple remote servers. + +Use the following pscp command to copy a single file to remote server. + +``` +# pscp.pssh -H 2g.CentOS.com /home/daygeek/2g/shell-script/output.txt /opt/backup + +[1] 18:46:11 [SUCCESS] 2g.CentOS.com +``` + +Use the following pscp command to copy a multiple files to remote server. + +``` +# pscp.pssh -H 2g.CentOS.com /home/daygeek/2g/shell-script/output.txt ovh.sh /opt/backup + +[1] 18:47:48 [SUCCESS] 2g.CentOS.com +``` + +Use the following pscp command to copy a directory recursively to remote server. + +``` +# pscp.pssh -H 2g.CentOS.com -r /home/daygeek/2g/shell-script/ /opt/backup + +[1] 18:48:46 [SUCCESS] 2g.CentOS.com +``` + +Use the following pscp command to copy a single file to multiple remote servers. + +``` +# pscp.pssh -h server-list.txt /home/daygeek/2g/shell-script/output.txt /opt/backup + +[1] 18:49:48 [SUCCESS] 2g.CentOS.com +[2] 18:49:48 [SUCCESS] 2g.Debian.com +``` + +Use the following pscp command to copy a multiple files to multiple remote servers. + +``` +# pscp.pssh -h server-list.txt /home/daygeek/2g/shell-script/output.txt passwd-up.sh /opt/backup + +[1] 18:50:30 [SUCCESS] 2g.Debian.com +[2] 18:50:30 [SUCCESS] 2g.CentOS.com +``` + +Use the following pscp command to copy a directory recursively to multiple remote servers. + +``` +# pscp.pssh -h server-list.txt -r /home/daygeek/2g/shell-script/ /opt/backup + +[1] 18:51:31 [SUCCESS] 2g.Debian.com +[2] 18:51:31 [SUCCESS] 2g.CentOS.com +``` + +### Method-4: Copy Files/Folders From A Local System To Multiple Remote System In Linux Using rsync Command? + +Rsync is a fast and extraordinarily versatile file copying tool. It can copy locally, to/from another host over any remote shell, or to/from a remote rsync daemon. + +Use the following rsync command to copy a single file to remote server. + +``` +# rsync -avz /home/daygeek/2g/shell-script/output.txt [email protected]:/opt/backup + +sending incremental file list +output.txt + +sent 598 bytes received 31 bytes 1258.00 bytes/sec +total size is 2468 speedup is 3.92 +``` + +Use the following pscp command to copy a multiple files to remote server. + +``` +# rsync -avz /home/daygeek/2g/shell-script/output.txt passwd-up.sh root@2g.CentOS.com:/opt/backup + +sending incremental file list +output.txt +passwd-up.sh + +sent 737 bytes received 50 bytes 1574.00 bytes/sec +total size is 2537 speedup is 3.22 +``` + +Use the following rsync command to copy a single file to remote server overh ssh. + +``` +# rsync -avzhe ssh /home/daygeek/2g/shell-script/output.txt root@2g.CentOS.com:/opt/backup + +sending incremental file list +output.txt + +sent 598 bytes received 31 bytes 419.33 bytes/sec +total size is 2.47K speedup is 3.92 +``` + +Use the following pscp command to copy a directory recursively to remote server over ssh. This will copy only files not the base directory. + +``` +# rsync -avzhe ssh /home/daygeek/2g/shell-script/ root@2g.CentOS.com:/opt/backup + +sending incremental file list +./ +output.txt +ovh.sh +passwd-up.sh +passwd-up1.sh +server-list.txt + +sent 3.85K bytes received 281 bytes 8.26K bytes/sec +total size is 9.12K speedup is 2.21 +``` + +### Method-5: Copy Files/Folders From A Local System To Multiple Remote System In Linux Using Shell Script with rsync Command? + +If you would like to copy the same file into multiple remote servers then create the following small shell script to achieve this. + +``` +# file-copy.sh + +#!/bin/sh +for server in `more server-list.txt` +do + rsync -avzhe ssh /home/daygeek/2g/shell-script/ root@2g.CentOS.com$server:/opt/backup +done +``` + +Output for the above shell script. + +``` +# ./file-copy.sh + +sending incremental file list +./ +output.txt +ovh.sh +passwd-up.sh +passwd-up1.sh +server-list.txt + +sent 3.86K bytes received 281 bytes 8.28K bytes/sec +total size is 9.13K speedup is 2.21 + +sending incremental file list +./ +output.txt +ovh.sh +passwd-up.sh +passwd-up1.sh +server-list.txt + +sent 3.86K bytes received 281 bytes 2.76K bytes/sec +total size is 9.13K speedup is 2.21 +``` + +### Method-6: Copy Files/Folders From A Local System To Multiple Remote System In Linux Using Shell Script with scp Command? + +In the above two shell script, we need to mention the file and folder location as a prerequiesties but here i did a small modification that allow the script to get a file or folder as a input. It could be very useful when you want to perform the copy multiple times in a day. + +``` +# file-copy.sh + +#!/bin/sh +for server in `more server-list.txt` +do +scp -r $1 root@2g.CentOS.com$server:/opt/backup +done +``` + +Run the shell script and give the file name as a input. + +``` +# ./file-copy.sh output1.txt + +output1.txt 100% 3558 3.5KB/s 00:00 +output1.txt 100% 3558 3.5KB/s 00:00 +``` + +### Method-7: Copy Files/Folders From A Local System To Multiple Remote System In Linux With Non-Standard Port Number? + +Use the below shell script to copy a file or folder if you are using Non-Standard port. + +If you are using `Non-Standard` port, make sure you have to mention the port number as follow for SCP command. + +``` +# file-copy-scp.sh + +#!/bin/sh +for server in `more server-list.txt` +do +scp -P 2222 -r $1 root@2g.CentOS.com$server:/opt/backup +done +``` + +Run the shell script and give the file name as a input. + +``` +# ./file-copy.sh ovh.sh + +ovh.sh 100% 3558 3.5KB/s 00:00 +ovh.sh 100% 3558 3.5KB/s 00:00 +``` + +If you are using `Non-Standard` port, make sure you have to mention the port number as follow for rsync command. + +``` +# file-copy-rsync.sh + +#!/bin/sh +for server in `more server-list.txt` +do +rsync -avzhe 'ssh -p 2222' $1 root@2g.CentOS.com$server:/opt/backup +done +``` + +Run the shell script and give the file name as a input. + +``` +# ./file-copy-rsync.sh passwd-up.sh +sending incremental file list +passwd-up.sh + +sent 238 bytes received 35 bytes 26.00 bytes/sec +total size is 159 speedup is 0.58 + +sending incremental file list +passwd-up.sh + +sent 238 bytes received 35 bytes 26.00 bytes/sec +total size is 159 speedup is 0.58 +``` +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/linux-scp-rsync-pscp-command-copy-files-folders-in-multiple-servers-using-shell-script/ + +作者：[Prakash Subramanian][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/prakash/ +[b]: https://github.com/lujun9972 diff --git a/sources/tech/20190123 Dockter- A container image builder for researchers.md b/sources/tech/20190123 Dockter- A container image builder for researchers.md new file mode 100644 index 0000000000..359d0c1d1e --- /dev/null +++ b/sources/tech/20190123 Dockter- A container image builder for researchers.md @@ -0,0 +1,121 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Dockter: A container image builder for researchers) +[#]: via: (https://opensource.com/article/19/1/dockter-image-builder-researchers) +[#]: author: (Nokome Bentley https://opensource.com/users/nokome) + +Dockter: A container image builder for researchers +====== +Dockter supports the specific requirements of researchers doing data analysis, including those using R. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/building_skyscaper_organization.jpg?itok=Ir5epxm8) + +Dependency hell is ubiquitous in the world of software for research, and this affects research transparency and reproducibility. Containerization is one solution to this problem, but it creates new challenges for researchers. Docker is gaining popularity in the research community—but using it efficiently requires solid Dockerfile writing skills. + +As a part of the [Stencila][1] project, which is a platform for creating, collaborating on, and sharing data-driven content, we are developing [Dockter][2], an open source tool that makes it easier for researchers to create Docker images for their projects. Dockter scans a research project's source code, generates a Dockerfile, and builds a Docker image. It has a range of features that allow flexibility and can help researchers learn more about working with Docker. + +Dockter also generates a JSON file with information about the software environment (based on [CodeMeta][3] and [Schema.org][4]) to enable further processing and interoperability with other tools. + +Several other projects create Docker images from source code and/or requirements files, including: [alibaba/derrick][5], [jupyter/repo2docker][6], [Gueils/whales][7], [o2r-project/containerit][8]; [openshift/source-to-image][9], and [ViDA-NYU/reprozip][10]. Dockter is similar to repo2docker, containerit, and ReproZip in that it is aimed at researchers doing data analysis (and supports R), whereas most other tools are aimed at software developers (and don't support R). + +Dockter differs from these projects principally in that it: + + * Performs static code analysis for multiple languages to determine package requirements + * Uses package databases to determine package system dependencies and generate linked metadata (containerit does this for R) + * Installs language package dependencies quicker (which can be useful during research projects where dependencies often change) + * By default but optionally, installs Stencila packages so that Stencila client interfaces can execute code in the container + + + +### Dockter's features + +Following are some of the ways researchers can use Dockter. + +#### Generating Docker images from code + +Dockter scans a research project folder and builds a Docker image for it. If the folder already has a Dockerfile, Dockter will build the image from that. If not, Dockter will scan the source code files in the folder and generate one. Dockter currently handles R, Python, and Node.js source code. The .dockerfile (with the dot at the beginning) it generates is fully editable so users can take over from Dockter and carry on with editing the file as they see fit. + +If the folder contains an R package [DESCRIPTION][11] file, Dockter will install the R packages listed under Imports into the image. If the folder does not contain a DESCRIPTION file, Dockter will scan all the R files in the folder for package import or usage statements and create a .DESCRIPTION file. + +If the folder contains a [requirements.txt][12] file for Python, Dockter will copy it into the Docker image and use [pip][13] to install the specified packages. If the folder does not contain either of those files, Dockter will scan all the folder's .py files for import statements and create a .requirements.txt file. + +If the folder contains a [package.json][14] file, Dockter will copy it into the Docker image and use npm to install the specified packages. If the folder does not contain a package.json file, Dockter will scan all the folder's .js files for require calls and create a .package.json file. + +#### Capturing system requirements automatically + +One of the headaches researchers face when hand-writing Dockerfiles is figuring out which system dependencies their project needs. Often this involves a lot of trial and error. Dockter automatically checks if any dependencies (or dependencies of dependencies, or dependencies of…) require system packages and installs those into the image. No more trial and error cycles of build, fail, add dependency, repeat… + +#### Reinstalling language packages faster + +If you have ever built a Docker image, you know it can be frustrating waiting for all your project's dependencies to reinstall when you add or remove just one. + +This happens because of Docker's layered filesystem: When you update a requirements file, Docker throws away all the subsequent layers—including the one where you previously installed your dependencies. That means all the packages have to be reinstalled. + +Dockter takes a different approach. It leaves the installation of language packages to the language package managers: Python's pip, Node.js's npm, and R's install.packages. These package managers are good at the job they were designed for: checking which packages need to be updated and updating only them. The result is much faster rebuilds, especially for R packages, which often involve compilation. + +Dockter does this by looking for a special **# dockter** comment in a Dockerfile. Instead of throwing away layers, it executes all instructions after this comment in the same layer—thereby reusing packages that were previously installed. + +#### Generating structured metadata for a project + +Dockter uses [JSON-LD][15] as its internal data structure. When it parses a project's source code, it generates a JSON-LD tree using vocabularies from schema.org and CodeMeta. + +Dockter also fetches metadata on a project's dependencies, which could be used to generate a complete software citation for the project. + +### Easy to pick up, easy to throw away + +Dockter is designed to make it easier to get started creating Docker images for your project. But it's also designed to not get in your way or restrict you from using bare Docker. You can easily and individually override any of the steps Dockter takes to build an image. + + * **Code analysis:** To stop Dockter from doing code analysis and specify your project's package dependencies, just remove the leading **.** (dot) from the .DESCRIPTION, .requirements.txt, or .package.json files. + + * **Dockerfile generation:** Dockter aims to generate readable Dockerfiles that conform to best practices. They include comments on what each section does and are a good way to start learning how to write your own Dockerfiles. To stop Dockter from generating a .Dockerfile and start editing it yourself, just rename it Dockerfile (without the leading dot). + + + + +### Install Dockter + +[Dockter is available][16] as pre-compiled, standalone command line tool or as a Node.js package. Click [here][17] for a demo. + +We welcome and encourage all [contributions][18]! + +A longer version of this article is available on the project's [GitHub page][19]. + +Aleksandra Pawlik will present [Building reproducible computing environments: a workshop for non-experts][20] at [linux.conf.au][21], January 21-25 in Christchurch, New Zealand. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/dockter-image-builder-researchers + +作者：[Nokome Bentley][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/nokome +[b]: https://github.com/lujun9972 +[1]: https://stenci.la/ +[2]: https://stencila.github.io/dockter/ +[3]: https://codemeta.github.io/index.html +[4]: http://Schema.org +[5]: https://github.com/alibaba/derrick +[6]: https://github.com/jupyter/repo2docker +[7]: https://github.com/Gueils/whales +[8]: https://github.com/o2r-project/containerit +[9]: https://github.com/openshift/source-to-image +[10]: https://github.com/ViDA-NYU/reprozip +[11]: http://r-pkgs.had.co.nz/description.html +[12]: https://pip.readthedocs.io/en/1.1/requirements.html +[13]: https://pypi.org/project/pip/ +[14]: https://docs.npmjs.com/files/package.json +[15]: https://json-ld.org/ +[16]: https://github.com/stencila/dockter/releases/ +[17]: https://asciinema.org/a/pOHpxUqIVkGdA1dqu7bENyxZk?size=medium&cols=120&autoplay=1 +[18]: https://github.com/stencila/dockter/blob/master/CONTRIBUTING.md +[19]: https://github.com/stencila/dockter +[20]: https://2019.linux.conf.au/schedule/presentation/185/ +[21]: https://linux.conf.au/ diff --git a/sources/tech/20190123 GStreamer WebRTC- A flexible solution to web-based media.md b/sources/tech/20190123 GStreamer WebRTC- A flexible solution to web-based media.md new file mode 100644 index 0000000000..bb7e129ff3 --- /dev/null +++ b/sources/tech/20190123 GStreamer WebRTC- A flexible solution to web-based media.md @@ -0,0 +1,108 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (GStreamer WebRTC: A flexible solution to web-based media) +[#]: via: (https://opensource.com/article/19/1/gstreamer) +[#]: author: (Nirbheek Chauhan https://opensource.com/users/nirbheek) + +GStreamer WebRTC: A flexible solution to web-based media +====== +GStreamer's WebRTC implementation eliminates some of the shortcomings of using WebRTC in native apps, server applications, and IoT devices. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/LAW-Internet_construction_9401467_520x292_0512_dc.png?itok=RPkPPtDe) + +Currently, [WebRTC.org][1] is the most popular and feature-rich WebRTC implementation. It is used in Chrome and Firefox and works well for browsers, but the Native API and implementation have several shortcomings that make it a less-than-ideal choice for uses outside of browsers, including native apps, server applications, and internet of things (IoT) devices. + +Last year, our company ([Centricular][2]) made an independent implementation of a Native WebRTC API available in GStreamer 1.14. This implementation is much easier to use and more flexible than the WebRTC.org Native API, is transparently compatible with WebRTC.org, has been tested with all browsers, and is already in production use. + +### What are GStreamer and WebRTC? + +[GStreamer][3] is an open source, cross-platform multimedia framework and one of the easiest and most flexible ways to implement any application that needs to play, record, or transform media-like data across a diverse scale of devices and products, including embedded (IoT, in-vehicle infotainment, phones, TVs, etc.), desktop (video/music players, video recording, non-linear editing, video conferencing, [VoIP][4] clients, browsers, etc.), servers (encode/transcode farms, video/voice conferencing servers, etc.), and [more][5]. + +The main feature that makes GStreamer the go-to multimedia framework for many people is its pipeline-based model, which solves one of the hardest problems in API design: catering to applications of varying complexity; from the simplest one-liners and quick solutions to those that need several hundreds of thousands of lines of code to implement their full feature set. If you want to learn how to use GStreamer, [Jan Schmidt's tutorial][6] from [LCA 2018][7] is a good place to start. + +[WebRTC][8] is a set of draft specifications that build upon existing [RTP][9], [RTCP][10], [SDP][11], [DTLS][12], [ICE][13], and other real-time communication (RTC) specifications and define an API for making them accessible using browser JavaScript (JS) APIs. + +People have been doing real-time communication over [IP][14] for [decades][15] with the protocols WebRTC builds upon. WebRTC's real innovation was creating a bridge between native applications and web apps by defining a standard yet flexible API that browsers can expose to untrusted JavaScript code. + +These specifications are [constantly being improved][16], which, combined with the ubiquitous nature of browsers, means WebRTC is fast becoming the standard choice for video conferencing on all platforms and for most applications. + +### **Everything is great, let's build amazing apps!** + +Not so fast, there's more to the story! For web apps, the [PeerConnection API][17] is [everywhere][18]. There are some browser-specific quirks, and the API keeps changing, but the [WebRTC JS adapter][19] handles most of that. Overall, the web app experience is mostly 👍. + +Unfortunately, for native code or applications that need more flexibility than a sandboxed JavaScript app can achieve, there haven't been a lot of great options. + +[Libwebrtc][20] (Google's implementation), [Janus][21], [Kurento][22], and [OpenWebRTC][23] have traditionally been the main contenders, but each implementation has its own inflexibilities, shortcomings, and constraints. + +Libwebrtc is still the most mature implementation, but it is also the most difficult to work with. Since it's embedded inside Chrome, it's a moving target and the project [is quite difficult to build and integrate][24]. These are all obstacles for native or server app developers trying to quickly prototype and experiment with things. + +Also, WebRTC was not built for multimedia, so the lower layers get in the way of non-browser use cases and applications. It is quite painful to do anything other than the default "set raw media, transmit" and "receive from remote, get raw media." This means if you want to use your own filters or hardware-specific codecs or sinks/sources, you end up having to fork libwebrtc. + +[**OpenWebRTC**][23] by Ericsson was the first attempt to rectify this situation. It was built on top of GStreamer. Its target audience was app developers, and it fit the bill quite well as a proof of concept—even though it used a custom API and some of the architectural decisions made it quite inflexible for most other uses. However, after an initial flurry of activity around the project, momentum petered out, the project failed to gather a community, and it is now effectively dead. Full disclosure: Centricular worked with Ericsson to polish some of the rough edges around the project immediately prior to its public release. + +### WebRTC in GStreamer + +GStreamer's WebRTC implementation gives you full control, as it does with any other [GStreamer pipeline][25]. + +As we said, the WebRTC standards build upon existing standards and protocols that serve similar purposes. GStreamer has supported almost all of them for a while now because they were being used for real-time communication, live streaming, and many other IP-based applications. This led Ericsson to choose GStreamer as the base for its OpenWebRTC project. + +Combined with the [SRTP][26] and DTLS plugins that were written during OpenWebRTC's development, it means that the implementation is built upon a solid and well-tested base, and implementing WebRTC features does not involve as much code-from-scratch work as one might presume. However, WebRTC is a large collection of standards, and reaching feature-parity with libwebrtc is an ongoing task. + +Due to decisions made while architecting WebRTCbin's internals, the API follows the PeerConnection specification quite closely. Therefore, almost all its missing features involve writing code that would plug into clearly defined sockets. For instance, since the GStreamer 1.14 release, the following features have been added to the WebRTC implementation and will be available in the next release of the GStreamer WebRTC: + + * Forward error correction + * RTP retransmission (RTX) + * RTP BUNDLE + * Data channels over SCTP + + + +We believe GStreamer's API is the most flexible, versatile, and easy to use WebRTC implementation out there, and it will only get better as time goes by. Bringing the power of pipeline-based multimedia manipulation to WebRTC opens new doors for interesting, unique, and highly efficient applications. If you'd like to demo the technology and play with the code, build and run [these demos][27], which include C, Rust, Python, and C# examples. + +Matthew Waters will present [GStreamer WebRTC—The flexible solution to web-based media][28] at [linux.conf.au][29], January 21-25 in Christchurch, New Zealand. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/gstreamer + +作者：[Nirbheek Chauhan][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/nirbheek +[b]: https://github.com/lujun9972 +[1]: http://webrtc.org/ +[2]: https://www.centricular.com/ +[3]: https://gstreamer.freedesktop.org/documentation/application-development/introduction/gstreamer.html +[4]: https://en.wikipedia.org/wiki/Voice_over_IP +[5]: https://wiki.ligo.org/DASWG/GstLAL +[6]: https://www.youtube.com/watch?v=ZphadMGufY8 +[7]: http://lca2018.linux.org.au/ +[8]: https://en.wikipedia.org/wiki/WebRTC +[9]: https://en.wikipedia.org/wiki/Real-time_Transport_Protocol +[10]: https://en.wikipedia.org/wiki/RTP_Control_Protocol +[11]: https://en.wikipedia.org/wiki/Session_Description_Protocol +[12]: https://en.wikipedia.org/wiki/Datagram_Transport_Layer_Security +[13]: https://en.wikipedia.org/wiki/Interactive_Connectivity_Establishment +[14]: https://en.wikipedia.org/wiki/Internet_Protocol +[15]: https://en.wikipedia.org/wiki/Session_Initiation_Protocol +[16]: https://datatracker.ietf.org/wg/rtcweb/documents/ +[17]: https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection +[18]: https://caniuse.com/#feat=rtcpeerconnection +[19]: https://github.com/webrtc/adapter +[20]: https://github.com/aisouard/libwebrtc +[21]: https://janus.conf.meetecho.com/ +[22]: https://www.kurento.org/kurento-architecture +[23]: https://en.wikipedia.org/wiki/OpenWebRTC +[24]: https://webrtchacks.com/building-webrtc-from-source/ +[25]: https://gstreamer.freedesktop.org/documentation/application-development/introduction/basics.html +[26]: https://en.wikipedia.org/wiki/Secure_Real-time_Transport_Protocol +[27]: https://github.com/centricular/gstwebrtc-demos/ +[28]: https://linux.conf.au/schedule/presentation/143/ +[29]: https://linux.conf.au/ diff --git a/sources/tech/20190123 Mind map yourself using FreeMind and Fedora.md b/sources/tech/20190123 Mind map yourself using FreeMind and Fedora.md new file mode 100644 index 0000000000..146f95752a --- /dev/null +++ b/sources/tech/20190123 Mind map yourself using FreeMind and Fedora.md @@ -0,0 +1,81 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Mind map yourself using FreeMind and Fedora) +[#]: via: (https://fedoramagazine.org/mind-map-yourself-using-freemind-and-fedora/) +[#]: author: (Paul W. Frields https://fedoramagazine.org/author/pfrields/) + +Mind map yourself using FreeMind and Fedora +====== +![](https://fedoramagazine.org/wp-content/uploads/2019/01/freemind-816x345.jpg) + +A mind map of yourself sounds a little far-fetched at first. Is this process about neural pathways? Or telepathic communication? Not at all. Instead, a mind map of yourself is a way to describe yourself to others visually. It also shows connections among the characteristics you use to describe yourself. It’s a useful way to share information with others in a clever but also controllable way. You can use any mind map application for this purpose. This article shows you how to get started using [FreeMind][1], available in Fedora. + +### Get the application + +The FreeMind application has been around a while. While the UI is a bit dated and could use a refresh, it’s a powerful app that offers many options for building mind maps. And of course it’s 100% open source. There are other mind mapping apps available for Fedora and Linux users, as well. Check out [this previous article that covers several mind map options][2]. + +Install FreeMind from the Fedora repositories using the Software app if you’re running Fedora Workstation. Or use this [sudo][3] command in a terminal: + +``` +$ sudo dnf install freemind +``` + +You can launch the app from the GNOME Shell Overview in Fedora Workstation. Or use the application start service your desktop environment provides. FreeMind shows you a new, blank map by default: + +![][4] +FreeMind initial (blank) mind map + +A map consists of linked items or descriptions — nodes. When you think of something related to a node you want to capture, simply create a new node connected to it. + +### Mapping yourself + +Click in the initial node. Replace it with your name by editing the text and hitting **Enter**. You’ve just started your mind map. + +What would you think of if you had to fully describe yourself to someone? There are probably many things to cover. How do you spend your time? What do you enjoy? What do you dislike? What do you value? Do you have a family? All of this can be captured in nodes. + +To add a node connection, select the existing node, and hit **Insert** , or use the “light bulb” icon for a new child node. To add another node at the same level as the new child, use **Enter**. + +Don’t worry if you make a mistake. You can use the **Delete** key to remove an unwanted node. There’s no rules about content. Short nodes are best, though. They allow your mind to move quickly when creating the map. Concise nodes also let viewers scan and understand the map easily later. + +This example uses nodes to explore each of these major categories: + +![][5] +Personal mind map, first level + +You could do another round of iteration for each of these areas. Let your mind freely connect ideas to generate the map. Don’t worry about “getting it right.” It’s better to get everything out of your head and onto the display. Here’s what a next-level map might look like. + +![][6] +Personal mind map, second level + +You could expand on any of these nodes in the same way. Notice how much information you can quickly understand about John Q. Public in the example. + +### How to use your personal mind map + +This is a great way to have team or project members introduce themselves to each other. You can apply all sorts of formatting and color to the map to give it personality. These are fun to do on paper, of course. But having one on your Fedora system means you can always fix mistakes, or even make changes as you change. + +Have fun exploring your personal mind map! + + + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/mind-map-yourself-using-freemind-and-fedora/ + +作者：[Paul W. Frields][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/author/pfrields/ +[b]: https://github.com/lujun9972 +[1]: http://freemind.sourceforge.net/wiki/index.php/Main_Page +[2]: https://fedoramagazine.org/three-mind-mapping-tools-fedora/ +[3]: https://fedoramagazine.org/howto-use-sudo/ +[4]: https://fedoramagazine.org/wp-content/uploads/2019/01/Screenshot-from-2019-01-19-15-17-04-1024x736.png +[5]: https://fedoramagazine.org/wp-content/uploads/2019/01/Screenshot-from-2019-01-19-15-32-38-1024x736.png +[6]: https://fedoramagazine.org/wp-content/uploads/2019/01/Screenshot-from-2019-01-19-15-38-00-1024x736.png diff --git a/sources/tech/20190124 Get started with LogicalDOC, an open source document management system.md b/sources/tech/20190124 Get started with LogicalDOC, an open source document management system.md new file mode 100644 index 0000000000..21687c0ce3 --- /dev/null +++ b/sources/tech/20190124 Get started with LogicalDOC, an open source document management system.md @@ -0,0 +1,62 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Get started with LogicalDOC, an open source document management system) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-logicaldoc) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney) + +Get started with LogicalDOC, an open source document management system +====== +Keep better track of document versions with LogicalDOC, the 12th in our series on open source tools that will make you more productive in 2019. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/document_free_access_cut_security.png?itok=ocvCv8G2) + +There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. + +Here's the 12th of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. + +### LogicalDOC + +Part of being productive is being able to find what you need when you need it. We've all seen directories full of similar files with similar names, a result of renaming them every time a document changes to keep track of all the versions. For example, my wife is a writer, and she often saves document revisions with new names before she sends them to reviewers. + +![](https://opensource.com/sites/default/files/uploads/logicaldoc-1.png) + +A coder's natural solution to this problem—Git or another version control tool—won't work for document creators because the systems used for code often don't play nice with the formats used by commercial text editors. And before someone says, "just change formats," [that isn't an option for everyone][1]. Also, many version control tools are not very friendly for the less technically inclined. In large organizations, there are tools to solve this problem, but they also require the resources of a large organization to run, manage, and support them. + +![](https://opensource.com/sites/default/files/uploads/logicaldoc-2.png) + +[LogicalDOC CE][2] is an open source document management system built to solve this problem. It allows users to check in, check out, version, search, and lock document files and keeps a history of versions, similar to the version control tools used by coders. + +LogicalDOC can be [installed][3] on Linux, MacOS, and Windows using a Java-based installer. During installation, you'll be prompted for details on the database where its data will be stored and have an option for a local-only file store. You'll get the URL and a default username and password to access the server as well as an option to save a script to automate future installations. + +After you log in, LogicalDOC's default screen lists the documents you have tagged, checked out, and any recent notes on them. Switching to the Documents tab will show the files you have access to. You can upload documents by selecting a file through the interface or using drag and drop. If you upload a ZIP file, LogicalDOC will expand it and add its individual files to the repository. + +![](https://opensource.com/sites/default/files/uploads/logicaldoc-3.png) + +Right-clicking on a file will bring up a menu of options to check out files, lock files against changes, and do a whole host of other things. Checking out a file downloads it to your local machine where it can be edited. A checked-out file cannot be modified by anyone else until it's checked back in. When the file is checked back in (using the same menu), the user can add tags to the version and is required to comment on what was done to it. + +![](https://opensource.com/sites/default/files/uploads/logicaldoc-4.png) + +Going back and looking at earlier versions is as easy as downloading them from the Versions page. There are also import and export options for some third-party services, with [Dropbox][4] support built-in. + +Document management is not just for big companies that can afford expensive solutions. LogicalDOC helps you keep track of the documents you're using with a revision history and a safe repository for documents that are otherwise difficult to manage. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-logicaldoc + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: http://www.antipope.org/charlie/blog-static/2013/10/why-microsoft-word-must-die.html +[2]: https://www.logicaldoc.com/download-logicaldoc-community +[3]: https://docs.logicaldoc.com/en/installation +[4]: https://dropbox.com diff --git a/sources/tech/20190124 ODrive (Open Drive) - Google Drive GUI Client For Linux.md b/sources/tech/20190124 ODrive (Open Drive) - Google Drive GUI Client For Linux.md new file mode 100644 index 0000000000..71a91ec3d8 --- /dev/null +++ b/sources/tech/20190124 ODrive (Open Drive) - Google Drive GUI Client For Linux.md @@ -0,0 +1,127 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (ODrive (Open Drive) – Google Drive GUI Client For Linux) +[#]: via: (https://www.2daygeek.com/odrive-open-drive-google-drive-gui-client-for-linux/) +[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) + +ODrive (Open Drive) – Google Drive GUI Client For Linux +====== + +This we had discussed in so many times. However, i will give a small introduction about it. + +As of now there is no official Google Drive Client for Linux and we need to use unofficial clients. + +There are many applications available in Linux for Google Drive integration. + +Each application has came out with set of features. + +We had written few articles about this in our website in the past. + +Those are **[DriveSync][1]** , **[Google Drive Ocamlfuse Client][2]** and **[Mount Google Drive in Linux Using Nautilus File Manager][3]**. + +Today also we are going to discuss about the same topic and the utility name is ODrive. + +### What’s ODrive? + +ODrive stands for Open Drive. It’s a GUI client for Google Drive which was written in electron framework. + +It’s simple GUI which allow users to integrate the Google Drive with few steps. + +### How To Install & Setup ODrive on Linux? + +Since the developer is offering the AppImage package and there is no difficulty for installing the ODrive on Linux. + +Simple download the latest ODrive AppImage package from developer github page using **wget Command**. + +``` +$ wget https://github.com/liberodark/ODrive/releases/download/0.1.3/odrive-0.1.3-x86_64.AppImage +``` + +You have to set executable file permission to the ODrive AppImage file. + +``` +$ chmod +x odrive-0.1.3-x86_64.AppImage +``` + +Simple run the following ODrive AppImage file to launch the ODrive GUI for further setup. + +``` +$ ./odrive-0.1.3-x86_64.AppImage +``` + +You might get the same window like below when you ran the above command. Just hit the **`Next`** button for further setup. +![][5] + +Click **`Connect`** link to add a Google drive account. +![][6] + +Enter your email id which you want to setup a Google Drive account. +![][7] + +Enter your password for the given email id. +![][8] + +Allow ODrive (Open Drive) to access your Google account. +![][9] + +By default, it will choose the folder location. You can change if you want to use the specific one. +![][10] + +Finally hit **`Synchronize`** button to start download the files from Google Drive to your local system. +![][11] + +Synchronizing is in progress. +![][12] + +Once synchronizing is completed. It will show you all files downloaded. +Once synchronizing is completed. It’s shows you that all the files has been downloaded. +![][13] + +I have seen all the files were downloaded in the mentioned directory. +![][14] + +If you want to sync any new files from local system to Google Drive. Just start the `ODrive` from the application menu but it won’t actual launch the application. But it will be running in the background that we can able to see by using the ps command. + +``` +$ ps -df | grep odrive +``` + +![][15] + +It will automatically sync once you add a new file into the google drive folder. The same has been checked through notification menu. Yes, i can see one file was synced to Google Drive. +![][16] + +GUI is not loading after sync, and i’m not sure this functionality. I will check with developer and will add update based on his input. + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/odrive-open-drive-google-drive-gui-client-for-linux/ + +作者：[Magesh Maruthamuthu][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/magesh/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/drivesync-google-drive-sync-client-for-linux/ +[2]: https://www.2daygeek.com/mount-access-google-drive-on-linux-with-google-drive-ocamlfuse-client/ +[3]: https://www.2daygeek.com/mount-access-setup-google-drive-in-linux/ +[4]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[5]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-1.png +[6]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-2.png +[7]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-3.png +[8]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-4.png +[9]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-5.png +[10]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-6.png +[11]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-7.png +[12]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-8a.png +[13]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-9.png +[14]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-11.png +[15]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-9b.png +[16]: https://www.2daygeek.com/wp-content/uploads/2019/01/odrive-open-drive-google-drive-gui-client-for-linux-10.png diff --git a/sources/tech/20190124 Orpie- A command-line reverse Polish notation calculator.md b/sources/tech/20190124 Orpie- A command-line reverse Polish notation calculator.md new file mode 100644 index 0000000000..10e666f625 --- /dev/null +++ b/sources/tech/20190124 Orpie- A command-line reverse Polish notation calculator.md @@ -0,0 +1,128 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Orpie: A command-line reverse Polish notation calculator) +[#]: via: (https://opensource.com/article/19/1/orpie) +[#]: author: (Peter Faller https://opensource.com/users/peterfaller) + +Orpie: A command-line reverse Polish notation calculator +====== +Orpie is a scientific calculator that functions much like early, well-loved HP calculators. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/calculator_money_currency_financial_tool.jpg?itok=2QMa1y8c) +Orpie is a text-mode [reverse Polish notation][1] (RPN) calculator for the Linux console. It works very much like the early, well-loved Hewlett-Packard calculators. + +### Installing Orpie + +RPM and DEB packages are available for most distributions, so installation is just a matter of using either: + +``` +$ sudo apt install orpie +``` + +or + +``` +$ sudo yum install orpie +``` + +Orpie has a comprehensive man page; new users may want to have it open in another terminal window as they get started. Orpie can be customized for each user by editing the **~/.orpierc** configuration file. The [orpierc(5)][2] man page describes the contents of this file, and **/etc/orpierc** describes the default configuration. + +### Starting up + +Start Orpie by typing **orpie** at the command line. The main screen shows context-sensitive help on the left and the stack on the right. The cursor, where you enter numbers you want to calculate, is at the bottom-right corner. + +![](https://opensource.com/sites/default/files/uploads/orpie_start.png) + +### Example calculation + +For a simple example, let's calculate the factorial of **5 (2 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 3 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 4 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 5)**. First the long way: + +| Keys | Result | +| --------- | --------- | +| 2 | Push 2 onto the stack | +| 3 | Push 3 onto the stack | +| * | Multiply to get 6 | +| 4 | Push 4 onto the stack | +| * | Multiply to get 24 | +| 5 | Push 5 onto the stack | +| * | Multiply to get 120 | + +Note that the multiplication happens as soon as you type *****. If you hit **< enter>** after ***** , Orpie will duplicate the value at position 1 on the stack. (If this happens, you can drop the duplicate with **\**.) + +Equivalent sequences are: + +| Keys | Result | +| ------------- | ------------- | +| 2 3 * 4 * 5 * | Faster! | +| 2 3 4 5 * * * | Same result | +| 5 ' fact | Fastest: Use the built-in function | + +Observe that when you enter **'** , the left pane changes to show matching functions as you type. In the example above, typing **fa** is enough to get the **fact** function. Orpie offers many functions—experiment by typing **'** and a few letters to see what's available. + +![](https://opensource.com/sites/default/files/uploads/orpie_functions.png) + +Note that each operation replaces one or more values on the stack. If you want to store the value at position 1 in the stack, key in (for example) **@factot ** and **S'**. To retrieve the value, key in (for example) **@factot ** then **;** (if you want to see it; otherwise just leave **@factot** as the value for the next calculation). + +### Constants and units + +Orpie understands units and predefines many useful scientific constants. For example, to calculate the energy in a blue light photon at 400nm, calculate **E=hc/(400nm)**. The key sequences are: + +| Keys | Result | +| -------------- | -------------- | +| C c | Get the speed of light in m/s | +| C h | Get Planck's constant in Js | +| * | Calculate h*c | +| 400 9 n _ m | Input 4 _ 10^-9 m | +| / | Do the division and get the result: 4.966 _ 10^-19 J | + +Like choosing functions after typing **'** , typing **C** shows matching constants based on what you type. + +![](https://opensource.com/sites/default/files/uploads/orpie_constants.png) + +### Matrices + +Orpie can also do operations with matrices. For example, to multiply two 2x2 matrices: + +| Keys | Result | +| -------- | -------- | +| [ 1 , 2 [ 3 , 4 | Stack contains the matrix [[ 1, 2 ][ 3, 4 ]] | +| [ 1 , 0 [ 1 , 1 | Push the multiplier matrix onto the stack | +| * | The result is: [[ 3, 2 ][ 7, 4 ]] | + +Note that the **]** characters are automatically inserted—entering **[** starts a new row. + +### Complex numbers + +Orpie can also calculate with complex numbers. They can be entered or displayed in either polar or rectangular form. You can toggle between the polar and rectangular display using the **p** key, and between degrees and radians using the **r** key. For example, to multiply **3 + 4i** by **4 + 4i** : + +| Keys | Result | +| -------- | -------- | +| ( 3 , 4 | The stack contains (3, 4) | +| ( 4 , 4 | Push (4, 4) | +| * | Get the result: (-4, 28) | + +Note that as you go, the results are kept on the stack so you can observe intermediate results in a lengthy calculation. + +![](https://opensource.com/sites/default/files/uploads/orpie_final.png) + +### Quitting Orpie + +You can exit from Orpie by typing **Q**. Your state is saved, so the next time you start Orpie, you'll find the stack as you left it. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/orpie + +作者：[Peter Faller][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/peterfaller +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Reverse_Polish_notation +[2]: https://github.com/pelzlpj/orpie/blob/master/doc/orpierc.5 diff --git a/sources/tech/20190124 What does DevOps mean to you.md b/sources/tech/20190124 What does DevOps mean to you.md new file mode 100644 index 0000000000..c62f0f83ba --- /dev/null +++ b/sources/tech/20190124 What does DevOps mean to you.md @@ -0,0 +1,143 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (What does DevOps mean to you?) +[#]: via: (https://opensource.com/article/19/1/what-does-devops-mean-you) +[#]: author: (Girish Managoli https://opensource.com/users/gammay) + +What does DevOps mean to you? +====== +6 experts break down DevOps and the practices and philosophies key to making it work. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/innovation_lightbulb_gears_devops_ansible.png?itok=TSbmp3_M) + +It's said if you ask 10 people about DevOps, you will get 12 answers. This is a result of the diversity in opinions and expectations around DevOps—not to mention the disparity in its practices. + +To decipher the paradoxes around DevOps, we went to the people who know it the best—its top practitioners around the industry. These are people who have been around the horn, who know the ins and outs of technology, and who have practiced DevOps for years. Their viewpoints should encourage, stimulate, and provoke your thoughts around DevOps. + +### What does DevOps mean to you? + +Let's start with the fundamentals. We're not looking for textbook answers, rather we want to know what the experts say. + +In short, the experts say DevOps is about principles, practices, and tools. + +[Ann Marie Fred][1], DevOps lead for IBM Digital Business Group's Commerce Platform, says, "to me, DevOps is a set of principles and practices designed to make teams more effective in designing, developing, delivering, and operating software." + +According to [Daniel Oh][2], senior DevOps evangelist at Red Hat, "in general, DevOps is compelling for enterprises to evolve current IT-based processes and tools related to app development, IT operations, and security protocol." + +[Brent Reed][3], founder of Tactec Strategic Solutions, talks about continuous improvement for the stakeholders. "DevOps means to me a way of working that includes a mindset that allows for continuous improvement for operational performance, maturing to organizational performance, resulting in delighted stakeholders." + +Many of the experts also emphasize culture. Ann Marie says, "it's also about continuous improvement and learning. It's about people and culture as much as it is about tools and technology." + +To [Dan Barker][4], chief architect and DevOps leader at the National Association of Insurance Commissioners (NAIC), "DevOps is primarily about culture. … It has brought several independent areas together like lean, [just culture][5], and continuous learning. And I see culture as being the most critical and the hardest to execute on." + +[Chris Baynham-Hughes][6], head of DevOps at Atos, says, "[DevOps] practice is adopted through the evolution of culture, process, and tooling within an organization. The key focus is culture change, and the key tenants of DevOps culture are collaboration, experimentation, fast-feedback, and continuous improvement." + +[Geoff Purdy][7], cloud architect, talks about agility and feedback "shortening and amplifying feedback loops. We want teams to get feedback in minutes rather than weeks." + +But in the end, Daniel nails it by explaining how open source and open culture allow him to achieve his goals "in easy and quick ways. In DevOps initiatives, the most important thing for me should be open culture rather than useful tools, multiple solutions." + +### What DevOps practices have you found effective? + +"Picking one, automated provisioning has been hugely effective for my team. " + +The most effective practices cited by the experts are pervasive yet disparate. + +According to Ann Marie, "some of the most powerful [practices] are agile project management; breaking down silos between cross-functional, autonomous squads; fully automated continuous delivery; green/blue deploys for zero downtime; developers setting up their own monitoring and alerting; blameless post-mortems; automating security and compliance." + +Chris says, "particular breakthroughs have been empathetic collaboration; continuous improvement; open leadership; reducing distance to the business; shifting from vertical silos to horizontal, cross-functional product teams; work visualization; impact mapping; Mobius loop; shortening of feedback loops; automation (from environments to CI/CD)." + +Brent supports "evolving a learning culture that includes TDD [test-driven development] and BDD [behavior-driven development] capturing of a story and automating the sequences of events that move from design, build, and test through implementation and production with continuous integration and delivery pipelines. A fail-first approach to testing, the ability to automate integration and delivery processes and include fast feedback throughout the lifecycle." + +Geoff highlights automated provisioning. "Picking one, automated provisioning has been hugely effective for my team. More specifically, automated provisioning from a versioned Infrastructure-as-Code codebase." + +Dan uses fun. "We do a lot of different things to create a DevOps culture. We hold 'lunch and learns' with free food to encourage everyone to come and learn together; we buy books and study in groups." + +### How do you motivate your team to achieve DevOps goals? + +``` +"Celebrate wins and visualize the progress made." +``` + +Daniel emphasizes "automation that matters. In order to minimize objection from multiple teams in a DevOps initiative, you should encourage your team to increase the automation capability of development, testing, and IT operations along with new processes and procedures. For example, a Linux container is the key tool to achieve the automation capability of DevOps." + +Geoff agrees, saying, "automate the toil. Are there tasks you hate doing? Great. Engineer them out of existence if possible. Otherwise, automate them. It keeps the job from becoming boring and routine because the job constantly evolves." + +Dan, Ann Marie, and Brent stress team motivation. + +Dan says, "at the NAIC, we have a great awards system for encouraging specific behaviors. We have multiple tiers of awards, and two of them can be given to anyone by anyone. We also give awards to teams after they complete something significant, but we often award individual contributors." + +According to Ann Marie, "the biggest motivator for teams in my area is seeing the success of others. We have a weekly playback for each other, and part of that is sharing what we've learned from trying out new tools or practices. When teams are enthusiastic about something they're doing and willing to help others get started, more teams will quickly get on board." + +Brent agrees. "Getting everyone educated and on the same baseline of knowledge is essential ... assessing what helps the team achieve [and] what it needs to deliver with the product owner and users is the first place I like to start." + +Chris recommends a two-pronged approach. "Run small, weekly goals that are achievable and agreed by the team as being important and [where] they can see progress outside of the feature work they are doing. Celebrate wins and visualize the progress made." + +### How do DevOps and agile work together? + +``` +"DevOps != Agile, second Agile != Scrum." +``` + +This is an important question because both DevOps and agile are cornerstones of modern software development. + +DevOps is a process of software development focusing on communication and collaboration to facilitate rapid application and product deployment, whereas agile is a development methodology involving continuous development, continuous iteration, and continuous testing to achieve predictable and quality deliverables. + +So, how do they relate? Let's ask the experts. + +In Brent's view, "DevOps != Agile, second Agile != Scrum. … Agile tools and ways of working—that support DevOps strategies and goals—are how they mesh together." + +Chris says, "agile is a fundamental component of DevOps for me. Sure, we could talk about how we adopt DevOps culture in a non-agile environment, but ultimately, improving agility in the way software is engineered is a key indicator as to the maturity of DevOps adoption within the organization." + +Dan relates DevOps to the larger [Agile Manifesto][8]. "I never talk about agile without referencing the Agile Manifesto in order to set the baseline. There are many implementations that don't focus on the Manifesto. When you read the Manifesto, they've really described DevOps from a development perspective. Therefore, it is very easy to fit agile into a DevOps culture, as agile is focused on communication, collaboration, flexibility to change, and getting to production quickly." + +Geoff sees "DevOps as one of many implementations of agile. Agile is essentially a set of principles, while DevOps is a culture, process, and toolchain that embodies those principles." + +Ann Marie keeps it succinct, saying "agile is a prerequisite for DevOps. DevOps makes agile more effective." + +### Has DevOps benefited from open source? + +``` +"Open source done well requires a DevOps culture." +``` + +This question receives a fervent "yes" from all participants followed by an explanation of the benefits they've seen. + +Ann Marie says, "we get to stand on the shoulders of giants and build upon what's already available. The open source model of maintaining software, with pull requests and code reviews, also works very well for DevOps teams." + +Chris agrees that DevOps has "undoubtedly" benefited from open source. "From the engineering and tooling side (e.g., Ansible), to the process and people side, through the sharing of stories within the industry and the open leadership community." + +A benefit Geoff cites is "grassroots adoption. Nobody had to sign purchase requisitions for free (as in beer) software. Teams found tooling that met their needs, were free (as in freedom) to modify, [then] built on top of it, and contributed enhancements back to the larger community. Rinse, repeat." + +Open source has shown DevOps "better ways you can adopt new changes and overcome challenges, just like open source software developers are doing it," says Daniel. + +Brent concurs. "DevOps has benefited in many ways from open source. One way is the ability to use the tools to understand how they can help accelerate DevOps goals and strategies. Educating the development and operations folks on crucial things like automation, virtualization and containerization, auto-scaling, and many of the qualities that are difficult to achieve without introducing technology enablers that make DevOps easier." + +Dan notes the two-way, symbiotic relationship between DevOps and open source. "Open source done well requires a DevOps culture. Most open source projects have very open communication structures with very little obscurity. This has actually been a great learning opportunity for DevOps practitioners around what they might bring into their own organizations. Also, being able to use tools from a community that is similar to that of your own organization only encourages your own culture growth. I like to use GitLab as an example of this symbiotic relationship. When I bring [GitLab] into a company, we get a great tool, but what I'm really buying is their unique culture. That brings substantial value through our interactions with them and our ability to contribute back. Their tool also has a lot to offer for a DevOps organization, but their culture has inspired awe in the companies where I've introduced it." + +Now that our DevOps experts have weighed in, please share your thoughts on what DevOps means—as well as the other questions we posed—in the comments. + + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/what-does-devops-mean-you + +作者：[Girish Managoli][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/gammay +[b]: https://github.com/lujun9972 +[1]: https://twitter.com/DukeAMO +[2]: https://twitter.com/danieloh30?lang=en +[3]: https://twitter.com/brentareed +[4]: https://twitter.com/barkerd427 +[5]: https://psnet.ahrq.gov/resources/resource/1582 +[6]: https://twitter.com/onlychrisbh?lang=en +[7]: https://twitter.com/geoff_purdy +[8]: https://agilemanifesto.org/ diff --git a/sources/tech/20190124 ffsend - Easily And Securely Share Files From Linux Command Line Using Firefox Send Client.md b/sources/tech/20190124 ffsend - Easily And Securely Share Files From Linux Command Line Using Firefox Send Client.md new file mode 100644 index 0000000000..fcbdd3c5c7 --- /dev/null +++ b/sources/tech/20190124 ffsend - Easily And Securely Share Files From Linux Command Line Using Firefox Send Client.md @@ -0,0 +1,330 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (ffsend – Easily And Securely Share Files From Linux Command Line Using Firefox Send Client) +[#]: via: (https://www.2daygeek.com/ffsend-securely-share-files-folders-from-linux-command-line-using-firefox-send-client/) +[#]: author: (Vinoth Kumar https://www.2daygeek.com/author/vinoth/) + +ffsend – Easily And Securely Share Files From Linux Command Line Using Firefox Send Client +====== + +Linux users were preferred to go with scp or rsync for files or folders copy. + +However, so many new options are coming to Linux because it’s a opensource. + +Anyone can develop a secure software for Linux. + +We had written multiple articles in our site in the past about this topic. + +Even, today we are going to discuss the same kind of topic called ffsend. + +Those are **[OnionShare][1]** , **[Magic Wormhole][2]** , **[Transfer.sh][3]** and **[Dcp – Dat Copy][4]**. + +### What’s ffsend? + +[ffsend][5] is a command line Firefox Send client that allow users to transfer and receive files and folders through command line. + +It allow us to easily and securely share files and directories from the command line through a safe, private and encrypted link using a single simple command. + +Files are shared using the Send service and the allowed file size is up to 2GB. + +Others are able to download these files with this tool, or through their web browser. + +All files are always encrypted on the client, and secrets are never shared with the remote host. + +Additionally you can add a password for the file upload. + +The uploaded files will be removed after the download (default count is 1 up to 10) or after 24 hours. This will make sure that your files does not remain online forever. + +This tool is currently in the alpha phase. Use at your own risk. Also, only limited installation options are available right now. + +### ffsend Features: + + * Fully featured and friendly command line tool + * Upload and download files and directories securely + * Always encrypted on the client + * Additional password protection, generation and configurable download limits + * Built-in file and directory archiving and extraction + * History tracking your files for easy management + * Ability to use your own Send host + * Inspect or delete shared files + * Accurate error reporting + * Low memory footprint, due to encryption and download/upload streaming + * Intended to be used in scripts without interaction + + + +### How To Install ffsend in Linux? + +There is no package for each distributions except Debian and Arch Linux systems. However, we can easily get this utility by downloading the prebuilt appropriate binaries file based on the operating system and architecture. + +Run the below command to download the latest available version for your operating system. + +``` +$ wget https://github.com/timvisee/ffsend/releases/download/v0.1.2/ffsend-v0.1.2-linux-x64.tar.gz +``` + +Extract the tar archive using the following command. + +``` +$ tar -xvf ffsend-v0.1.2-linux-x64.tar.gz +``` + +Run the following command to identify your path variable. + +``` +$ echo $PATH +/home/daygeek/.cargo/bin:/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl +``` + +As i told previously, just move the executable file to your path directory. + +``` +$ sudo mv ffsend /usr/local/sbin +``` + +Run the `ffsend` command alone to get the basic usage information. + +``` +$ ffsend +ffsend 0.1.2 +Usage: ffsend [FLAGS] ... + +Easily and securely share files from the command line. +A fully featured Firefox Send client. + +Missing subcommand. Here are the most used: + ffsend upload ... + ffsend download ... + +To show all subcommands, features and other help: + ffsend help [SUBCOMMAND] +``` + +For Arch Linux based users can easily install it with help of **[AUR Helper][6]** , as this package is available in AUR repository. + +``` +$ yay -S ffsend +``` + +For **`Debian/Ubuntu`** systems, use **[DPKG Command][7]** to install ffsend. + +``` +$ wget https://github.com/timvisee/ffsend/releases/download/v0.1.2/ffsend_0.1.2_amd64.deb +$ sudo dpkg -i ffsend_0.1.2_amd64.deb +``` + +### How To Send A File Using ffsend? + +It’s not complicated. We can easily send a file using simple syntax. + +**Syntax:** + +``` +$ ffsend upload [/Path/to/the/file/name] +``` + +In the following example, we are going to upload a file called `passwd-up1.sh`. Once you upload the file then you will be getting the unique URL. + +``` +$ ffsend upload passwd-up1.sh --copy +Upload complete +Share link: https://send.firefox.com/download/a4062553f4/#yy2_VyPaUMG5HwXZzYRmpQ +``` + +![][9] + +Just download the above unique URL to get the file in any remote system. + +**Syntax:** + +``` +$ ffsend download [Generated URL] +``` + +Output for the above command. + +``` +$ ffsend download https://send.firefox.com/download/a4062553f4/#yy2_VyPaUMG5HwXZzYRmpQ +Download complete +``` + +![][10] + +Use the following syntax format for directory upload. + +``` +$ ffsend upload [/Path/to/the/Directory] --copy +``` + +In this example, we are going to upload `2g` directory. + +``` +$ ffsend upload /home/daygeek/2g --copy +You've selected a directory, only a single file may be uploaded. +Archive the directory into a single file? [Y/n]: y +Archiving... +Upload complete +Share link: https://send.firefox.com/download/90aa5cfe67/#hrwu6oXZRG2DNh8vOc3BGg +``` + +Just download the above generated the unique URL to get a folder in any remote system. + +``` +$ ffsend download https://send.firefox.com/download/90aa5cfe67/#hrwu6oXZRG2DNh8vOc3BGg +You're downloading an archive, extract it into the selected directory? [Y/n]: y +Extracting... +Download complete +``` + +As this already send files through a safe, private, and encrypted link. However, if you would like to add a additional security at your level. Yes, you can add a password for a file. + +``` +$ ffsend upload file-copy-rsync.sh --copy --password +Password: +Upload complete +Share link: https://send.firefox.com/download/0742d24515/#P7gcNiwZJ87vF8cumU71zA +``` + +It will prompt you to update a password when you are trying to download a file in the remote system. + +``` +$ ffsend download https://send.firefox.com/download/0742d24515/#P7gcNiwZJ87vF8cumU71zA +This file is protected with a password. +Password: +Download complete +``` + +Alternatively you can limit a download speed by providing the download speed while uploading a file. + +``` +$ ffsend upload file-copy-scp.sh --copy --downloads 10 +Upload complete +Share link: https://send.firefox.com/download/23cb923c4e/#LVg6K0CIb7Y9KfJRNZDQGw +``` + +Just download the above unique URL to get a file in any remote system. + +``` +ffsend download https://send.firefox.com/download/23cb923c4e/#LVg6K0CIb7Y9KfJRNZDQGw +Download complete +``` + +If you want to see more details about the file, use the following format. It will shows you the file name, file size, Download counts and when it will going to expire. + +**Syntax:** + +``` +$ ffsend info [Generated URL] + +$ ffsend info https://send.firefox.com/download/23cb923c4e/#LVg6K0CIb7Y9KfJRNZDQGw +ID: 23cb923c4e +Name: file-copy-scp.sh +Size: 115 B +MIME: application/x-sh +Downloads: 3 of 10 +Expiry: 23h58m (86280s) +``` + +You can view your transaction history using the following format. + +``` +$ ffsend history +# LINK EXPIRY +1 https://send.firefox.com/download/23cb923c4e/#LVg6K0CIb7Y9KfJRNZDQGw 23h57m +2 https://send.firefox.com/download/0742d24515/#P7gcNiwZJ87vF8cumU71zA 23h55m +3 https://send.firefox.com/download/90aa5cfe67/#hrwu6oXZRG2DNh8vOc3BGg 23h52m +4 https://send.firefox.com/download/a4062553f4/#yy2_VyPaUMG5HwXZzYRmpQ 23h46m +5 https://send.firefox.com/download/74ff30e43e/#NYfDOUp_Ai-RKg5g0fCZXw 23h44m +6 https://send.firefox.com/download/69afaab1f9/#5z51_94jtxcUCJNNvf6RcA 23h43m +``` + +If you don’t want the link anymore then we can delete it. + +**Syntax:** + +``` +$ ffsend delete [Generated URL] + +$ ffsend delete https://send.firefox.com/download/69afaab1f9/#5z51_94jtxcUCJNNvf6RcA +File deleted +``` + +Alternatively this can be done using firefox browser by opening the page . + +Just drag and drop a file to upload it. +![][11] + +Once the file is downloaded, it will show you that 100% download completed. +![][12] + +To check other possible options, navigate to man page or help page. + +``` +$ ffsend --help +ffsend 0.1.2 +Tim Visee +Easily and securely share files from the command line. +A fully featured Firefox Send client. + +USAGE: + ffsend [FLAGS] [OPTIONS] [SUBCOMMAND] + +FLAGS: + -f, --force Force the action, ignore warnings + -h, --help Prints help information + -i, --incognito Don't update local history for actions + -I, --no-interact Not interactive, do not prompt + -q, --quiet Produce output suitable for logging and automation + -V, --version Prints version information + -v, --verbose Enable verbose information and logging + -y, --yes Assume yes for prompts + +OPTIONS: + -H, --history Use the specified history file [env: FFSEND_HISTORY] + -t, --timeout Request timeout (0 to disable) [env: FFSEND_TIMEOUT] + -T, --transfer-timeout Transfer timeout (0 to disable) [env: FFSEND_TRANSFER_TIMEOUT] + +SUBCOMMANDS: + upload Upload files [aliases: u, up] + download Download files [aliases: d, down] + debug View debug information [aliases: dbg] + delete Delete a shared file [aliases: del] + exists Check whether a remote file exists [aliases: e] + help Prints this message or the help of the given subcommand(s) + history View file history [aliases: h] + info Fetch info about a shared file [aliases: i] + parameters Change parameters of a shared file [aliases: params] + password Change the password of a shared file [aliases: pass, p] + +The public Send service that is used as default host is provided by Mozilla. +This application is not affiliated with Mozilla, Firefox or Firefox Send. +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/ffsend-securely-share-files-folders-from-linux-command-line-using-firefox-send-client/ + +作者：[Vinoth Kumar][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/vinoth/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/onionshare-secure-way-to-share-files-sharing-tool-linux/ +[2]: https://www.2daygeek.com/wormhole-securely-share-files-from-linux-command-line/ +[3]: https://www.2daygeek.com/transfer-sh-easy-fast-way-share-files-over-internet-from-command-line/ +[4]: https://www.2daygeek.com/dcp-dat-copy-secure-way-to-transfer-files-between-linux-systems/ +[5]: https://github.com/timvisee/ffsend +[6]: https://www.2daygeek.com/category/aur-helper/ +[7]: https://www.2daygeek.com/dpkg-command-to-manage-packages-on-debian-ubuntu-linux-mint-systems/ +[8]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[9]: https://www.2daygeek.com/wp-content/uploads/2019/01/ffsend-easily-and-securely-share-files-from-linux-command-line-using-firefox-send-client-1.png +[10]: https://www.2daygeek.com/wp-content/uploads/2019/01/ffsend-easily-and-securely-share-files-from-linux-command-line-using-firefox-send-client-2.png +[11]: https://www.2daygeek.com/wp-content/uploads/2019/01/ffsend-easily-and-securely-share-files-from-linux-command-line-using-firefox-send-client-3.png +[12]: https://www.2daygeek.com/wp-content/uploads/2019/01/ffsend-easily-and-securely-share-files-from-linux-command-line-using-firefox-send-client-4.png diff --git a/sources/tech/20190125 PyGame Zero- Games without boilerplate.md b/sources/tech/20190125 PyGame Zero- Games without boilerplate.md new file mode 100644 index 0000000000..f60c2b3407 --- /dev/null +++ b/sources/tech/20190125 PyGame Zero- Games without boilerplate.md @@ -0,0 +1,99 @@ +[#]: collector: (lujun9972) +[#]: translator: (xiqingongzi) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (PyGame Zero: Games without boilerplate) +[#]: via: (https://opensource.com/article/19/1/pygame-zero) +[#]: author: (Moshe Zadka https://opensource.com/users/moshez) + +PyGame Zero: Games without boilerplate +====== +Say goodbye to boring boilerplate in your game development with PyGame Zero. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/python3-game.png?itok=jG9UdwC3) + +Python is a good beginner programming language. And games are a good beginner project: they are visual, self-motivating, and fun to show off to friends and family. However, the most common library to write games in Python, [PyGame][1], can be frustrating for beginners because forgetting seemingly small details can easily lead to nothing rendering. + +Until people understand why all the parts are there, they treat many of them as "mindless boilerplate"—magic paragraphs that need to be copied and pasted into their program to make it work. + +[PyGame Zero][2] is intended to bridge that gap by putting a layer of abstraction over PyGame so it requires literally no boilerplate. + +When we say literally, we mean it. + +This is a valid PyGame Zero file: + +``` +# This comment is here for clarity reasons +``` + +We can run put it in a **game.py** file and run: + +``` +$ pgzrun game.py +``` + +This will show a window and run a game loop that can be shut down by closing the window or interrupting the program with **CTRL-C**. + +This will, sadly, be a boring game. Nothing happens. + +To make it slightly more interesting, we can draw a different background: + +``` +def draw(): +    screen.fill((255, 0, 0)) +``` + +This will make the background red instead of black. But it is still a boring game. Nothing is happening. We can make it slightly more interesting: + +``` +colors = [0, 0, 0] + +def draw(): +    screen.fill(tuple(colors)) + +def update(): +    colors[0] = (colors[0] + 1) % 256 +``` + +This will make a window that starts black, becomes brighter and brighter red, then goes back to black, over and over again. + +The **update** function updates parameters, while the **draw** function renders the game based on these parameters. + +However, there is no way for the player to interact with the game! Let's try something else: + +``` +colors = [0, 0, 0] + +def draw(): +    screen.fill(tuple(colors)) + +def update(): +    colors[0] = (colors[0] + 1) % 256 + +def on_key_down(key, mod, unicode): +    colors[1] = (colors[1] + 1) % 256 +``` + +Now pressing keys on the keyboard will increase the "greenness." + +These comprise the three important parts of a game loop: respond to user input, update parameters, and re-render the screen. + +PyGame Zero offers much more, including functions for drawing sprites and playing sound clips. + +Try it out and see what type of game you can come up with! + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/pygame-zero + +作者：[Moshe Zadka][a] +选题：[lujun9972][b] +译者：[xiqingongzi](https://github.com/xiqingongzi) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/moshez +[b]: https://github.com/lujun9972 +[1]: https://www.pygame.org/news +[2]: https://pygame-zero.readthedocs.io/en/stable/ diff --git a/sources/tech/20190125 Top 5 Linux Distributions for Development in 2019.md b/sources/tech/20190125 Top 5 Linux Distributions for Development in 2019.md new file mode 100644 index 0000000000..b3e2de22ba --- /dev/null +++ b/sources/tech/20190125 Top 5 Linux Distributions for Development in 2019.md @@ -0,0 +1,161 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Top 5 Linux Distributions for Development in 2019) +[#]: via: (https://www.linux.com/blog/2019/1/top-5-linux-distributions-development-2019) +[#]: author: (Jack Wallen https://www.linux.com/users/jlwallen) + +Top 5 Linux Distributions for Development in 2019 +====== + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/dev-main.jpg?itok=DEe9pYtb) + +One of the most popular tasks undertaken on Linux is development. With good reason: Businesses rely on Linux. Without Linux, technology simply wouldn’t meet the demands of today’s ever-evolving world. Because of that, developers are constantly working to improve the environments with which they work. One way to manage such improvements is to have the right platform to start with. Thankfully, this is Linux, so you always have a plethora of choices. + +But sometimes, too many choices can be a problem in and of itself. Which distribution is right for your development needs? That, of course, depends on what you’re developing, but certain distributions that just make sense to use as a foundation for your task. I’ll highlight five distributions I consider the best for developers in 2019. + +### Ubuntu + +Let’s not mince words here. Although the Linux Mint faithful are an incredibly loyal group (with good reason, their distro of choice is fantastic), Ubuntu Linux gets the nod here. Why? Because, thanks to the likes of [AWS][1], Ubuntu is one of the most deployed server operating systems. That means developing on a Ubuntu desktop distribution makes for a much easier translation to Ubuntu Server. And because Ubuntu makes it incredibly easy to develop for, work with, and deploy containers, it makes perfect sense that you’d want to work with this platform. Couple that with Ubuntu’s inclusion of Snap Packages, and Canonical's operating system gets yet another boost in popularity. + +But it’s not just about what you can do with Ubuntu, it’s how easily you can do it. For nearly every task, Ubuntu is an incredibly easy distribution to use. And because Ubuntu is so popular, chances are every tool and IDE you want to work with can be easily installed from the Ubuntu Software GUI (Figure 1). + +![Ubuntu][3] + +Figure 1: Developer tools found in the Ubuntu Software tool. + +[Used with permission][4] + +If you’re looking for ease of use, simplicity of migration, and plenty of available tools, you cannot go wrong with Ubuntu as a development platform. + +### openSUSE + +There’s a very specific reason why I add openSUSE to this list. Not only is it an outstanding desktop distribution, it’s also one of the best rolling releases you’ll find on the market. So if you’re wanting to develop with and release for the most recent software available, [openSUSE Tumbleweed][5] should be one of your top choices. If you want to leverage the latest releases of your favorite IDEs, if you always want to make sure you’re developing with the most recent libraries and toolkits, Tumbleweed is your platform. + +But openSUSE doesn’t just offer a rolling release distribution. If you’d rather make use of a standard release platform, [openSUSE Leap][6] is what you want. + +Of course, it’s not just about standard or rolling releases. The openSUSE platform also has a Kubernetes-specific release, called [Kubic][7], which is based on Kubernetes atop openSUSE MicroOS. But even if you aren’t developing for Kubernetes, you’ll find plenty of software and tools to work with. + +And openSUSE also offers the ability to select your desktop environment, or (should you chose) a generic desktop or server (Figure 2). + +![openSUSE][9] + +Figure 2: The openSUSE Tumbleweed installation in action. + +[Used with permission][4] + +### Fedora + +Using Fedora as a development platform just makes sense. Why? The distribution itself seems geared toward developers. With a regular, six month release cycle, developers can be sure they won’t be working with out of date software for long. This can be important, when you need the most recent tools and libraries. And if you’re developing for enterprise-level businesses, Fedora makes for an ideal platform, as it is the upstream for Red Hat Enterprise Linux. What that means is the transition to RHEL should be painless. That’s important, especially if you hope to bring your project to a much larger market (one with deeper pockets than a desktop-centric target). + +Fedora also offers one of the best GNOME experiences you’ll come across (Figure 3). This translates to a very stable and fast desktops. + +![GNOME][11] + +Figure 3: The GNOME desktop on Fedora. + +[Used with permission][4] + +But if GNOME isn’t your jam, you can opt to install one of the [Fedora spins][12] (which includes KDE, XFCE, LXQT, Mate-Compiz, Cinnamon, LXDE, and SOAS). + +### Pop!_OS + +I’d be remiss if I didn’t include [System76][13]’s platform, customized specifically for their hardware (although it does work fine on other hardware). Why would I include such a distribution, especially one that doesn’t really venture far away from the Ubuntu platform for which is is based? Primarily because this is the distribution you want if you plan on purchasing a desktop or laptop from System76. But why would you do that (especially given that Linux works on nearly all off-the-shelf hardware)? Because System76 sells outstanding hardware. With the release of their Thelio desktop, you have available one of the most powerful desktop computers on the market. If you’re developing seriously large applications (especially ones that lean heavily on very large databases or require a lot of processing power for compilation), why not go for the best? And since Pop!_OS is perfectly tuned for System76 hardware, this is a no-brainer. +Since Pop!_OS is based on Ubuntu, you’ll have all the tools available to the base platform at your fingertips (Figure 4). + +![Pop!_OS][15] + +Figure 4: The Anjunta IDE running on Pop!_OS. + +[Used with permission][4] + +Pop!_OS also defaults to encrypted drives, so you can trust your work will be safe from prying eyes (should your hardware fall into the wrong hands). + +### Manjaro + +For anyone that likes the idea of developing on Arch Linux, but doesn’t want to have to jump through all the hoops of installing and working with Arch Linux, there’s Manjaro. Manjaro makes it easy to have an Arch Linux-based distribution up and running (as easily as installing and using, say, Ubuntu). + +But what makes Manjaro developer-friendly (besides enjoying that Arch-y goodness at the base) is how many different flavors you’ll find available for download. From the [Manjaro download page][16], you can grab the following flavors: + + * GNOME + + * XFCE + + * KDE + + * OpenBox + + * Cinnamon + + * I3 + + * Awesome + + * Budgie + + * Mate + + * Xfce Developer Preview + + * KDE Developer Preview + + * GNOME Developer Preview + + * Architect + + * Deepin + + + + +Of note are the developer editions (which are geared toward testers and developers), the Architect edition (which is for users who want to build Manjaro from the ground up), and the Awesome edition (Figure 5 - which is for developers dealing with everyday tasks). The one caveat to using Manjaro is that, like any rolling release, the code you develop today may not work tomorrow. Because of this, you need to think with a certain level of agility. Of course, if you’re not developing for Manjaro (or Arch), and you’re doing more generic (or web) development, that will only affect you if the tools you use are updated and no longer work for you. Chances of that happening, however, are slim. And like with most Linux distributions, you’ll find a ton of developer tools available for Manjaro. + +![Manjaro][18] + +Figure 5: The Manjaro Awesome Edition is great for developers. + +[Used with permission][4] + +Manjaro also supports the Arch User Repository (a community-driven repository for Arch users), which includes cutting edge software and libraries, as well as proprietary applications like [Unity Editor][19] or yEd. A word of warning, however, about the Arch User Repository: It was discovered that the AUR contained software considered to be malicious. So, if you opt to work with that repository, do so carefully and at your own risk. + +### Any Linux Will Do + +Truth be told, if you’re a developer, just about any Linux distribution will work. This is especially true if you do most of your development from the command line. But if you prefer a good GUI running on top of a reliable desktop, give one of these distributions a try, they will not disappoint. + +Learn more about Linux through the free ["Introduction to Linux" ][20]course from The Linux Foundation and edX. + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/blog/2019/1/top-5-linux-distributions-development-2019 + +作者：[Jack Wallen][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/users/jlwallen +[b]: https://github.com/lujun9972 +[1]: https://aws.amazon.com/ +[2]: https://www.linux.com/files/images/dev1jpg +[3]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/dev_1.jpg?itok=7QJQWBKi (Ubuntu) +[4]: https://www.linux.com/licenses/category/used-permission +[5]: https://en.opensuse.org/Portal:Tumbleweed +[6]: https://en.opensuse.org/Portal:Leap +[7]: https://software.opensuse.org/distributions/tumbleweed +[8]: /files/images/dev2jpg +[9]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/dev_2.jpg?itok=1GJmpr1t (openSUSE) +[10]: /files/images/dev3jpg +[11]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/dev_3.jpg?itok=_6Ki4EOo (GNOME) +[12]: https://spins.fedoraproject.org/ +[13]: https://system76.com/ +[14]: /files/images/dev4jpg +[15]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/dev_4.jpg?itok=nNG2Ax24 (Pop!_OS) +[16]: https://manjaro.org/download/ +[17]: /files/images/dev5jpg +[18]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/dev_5.jpg?itok=RGfF2UEi (Manjaro) +[19]: https://unity3d.com/unity/editor +[20]: https://training.linuxfoundation.org/linux-courses/system-administration-training/introduction-to-linux diff --git a/sources/tech/20190125 Using Antora for your open source documentation.md b/sources/tech/20190125 Using Antora for your open source documentation.md new file mode 100644 index 0000000000..3df2862ba1 --- /dev/null +++ b/sources/tech/20190125 Using Antora for your open source documentation.md @@ -0,0 +1,208 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Using Antora for your open source documentation) +[#]: via: (https://fedoramagazine.org/using-antora-for-your-open-source-documentation/) +[#]: author: (Adam Šamalík https://fedoramagazine.org/author/asamalik/) + +Using Antora for your open source documentation +====== +![](https://fedoramagazine.org/wp-content/uploads/2019/01/antora-816x345.jpg) + +Are you looking for an easy way to write and publish technical documentation? Let me introduce [Antora][1] — an open source documentation site generator. Simple enough for a tiny project, but also complex enough to cover large documentation sites such as [Fedora Docs][2]. + +With sources stored in git, written in a simple yet powerful markup language AsciiDoc, and a static HTML as an output, Antora makes writing, collaborating on, and publishing your documentation a no-brainer. + +### The basic concepts + +Before we build a simple site, let’s have a look at some of the core concepts Antora uses to make the world a happier place. Or, at least, to build a documentation website. + +#### Organizing the content + +All sources that are used to build your documentation site are stored in a **git repository**. Or multiple ones — potentially owned by different people. For example, at the time of writing, the Fedora Docs had its sources stored in 24 different repositories owned by different groups having their own rules around contributions. + +The content in Antora is organized into **components** , usually representing different areas of your project, or, well, different components of the software you’re documenting — such as the backend, the UI, etc. Components can be independently versioned, and each component gets a separate space on the docs site with its own menu. + +Components can be optionally broken down into so-called **modules**. Modules are mostly invisible on the site, but they allow you to organize your sources into logical groups, and even store each in different git repository if that’s something you need to do. We use this in Fedora Docs to separate [the Release Notes, the Installation Guide, and the System Administrator Guide][3] into three different source repositories with their own rules, while preserving a single view in the UI. + +What’s great about this approach is that, to some extent, the way your sources are physically structured is not reflected on the site. + +#### Virtual catalog + +When assembling the site, Antora builds a **virtual catalog** of all pages, assigning a [unique ID][4] to each one based on its name and the component, the version, and module it belongs to. The page ID is then used to generate URLs for each page, and for internal links as well. So, to some extent, the source repository structure doesn’t really matter as far as the site is concerned. + +As an example, if we’d for some reason decided to merge all the 24 repositories of Fedora Docs into one, nothing on the site would change. Well, except the “Edit this page” link on every page that would suddenly point to this one repository. + +#### Independent UI + +We’ve covered the content, but how it’s going to look like? + +Documentation sites generated with Antora use a so-called [UI bundle][5] that defines the look and feel of your site. The UI bundle holds all graphical assets such as CSS, images, etc. to make your site look beautiful. + +It is expected that the UI will be developed independently of the documentation content, and that’s exactly what Antora supports. + +#### Putting it all together + +Having sources distributed in multiple repositories might raise a question: How do you build the site? The answer is: [Antora Playbook][6]. + +Antora Playbook is a file that points to all the source repositories and the UI bundle. It also defines additional metadata such as the name of your site. + +The Playbook is the only file you need to have locally available in order to build the site. Everything else gets fetched automatically as a part of the build process. + +### Building a site with Antora + +Demo time! To build a minimal site, you need three things: + + 1. At least one component holding your AsciiDoc sources. + 2. An Antora Playbook. + 3. A UI bundle + + + +Good news is the nice people behind Antora provide [example Antora sources][7] we can try right away. + +#### The Playbook + +Let’s first have a look at [the Playbook][8]: + +``` +site: + title: Antora Demo Site +# the 404 page and sitemap files only get generated when the url property is set + url: https://example.org/docs + start_page: component-b::index.adoc +content: + sources: + - url: https://gitlab.com/antora/demo/demo-component-a.git + branches: master + - url: https://gitlab.com/antora/demo/demo-component-b.git + branches: [v2.0, v1.0] + start_path: docs +ui: + bundle: + url: https://gitlab.com/antora/antora-ui-default/-/jobs/artifacts/master/raw/build/ui-bundle.zip?job=bundle-stable + snapshot: true +``` + +As we can see, the Playbook defines some information about the site, lists the content repositories, and points to the UI bundle. + +There are two repositories. The [demo-component-a][9] with a single branch, and the [demo-component-b][10] having two branches, each representing a different version. + +#### Components + +The minimal source repository structure is nicely demonstrated in the [demo-component-a][9] repository: + +``` +antora.yml <- component metadata +modules/ + ROOT/ <- the default module + nav.adoc <- menu definition + pages/ <- a directory with all the .adoc sources + source1.adoc + source2.adoc + ... +``` + +The following + +``` +antora.yml +``` + +``` +name: component-a +title: Component A +version: 1.5.6 +start_page: ROOT:inline-text-formatting.adoc +nav: + - modules/ROOT/nav.adoc +``` + +contains metadata for this component such as the name and the version of the component, the starting page, and it also points to a menu definition file. + +The menu definition file is a simple list that defines the structure of the menu and the content. It uses the [page ID][4] to identify each page. + +``` +* xref:inline-text-formatting.adoc[Basic Inline Text Formatting] +* xref:special-characters.adoc[Special Characters & Symbols] +* xref:admonition.adoc[Admonition] +* xref:sidebar.adoc[Sidebar] +* xref:ui-macros.adoc[UI Macros] +* Lists +** xref:lists/ordered-list.adoc[Ordered List] +** xref:lists/unordered-list.adoc[Unordered List] + +And finally, there's the actual content under modules/ROOT/pages/ — you can see the repository for examples, or the AsciiDoc syntax reference +``` + +#### The UI bundle + +For the UI, we’ll be using the example UI provided by the project. + +Going into the details of Antora UI would be above the scope of this article, but if you’re interested, please see the [Antora UI documentation][5] for more info. + +#### Building the site + +Note: We’ll be using Podman to run Antora in a container. You can [learn about Podman on the Fedora Magazine][11]. + +To build the site, we only need to call Antora on the Playbook file. + +The easiest way to get antora at the moment is to use the container image provided by the project. You can get it by running: + +``` +$ podman pull antora/antora +``` + +Let’s get the playbook repository: + +``` +$ git clone https://gitlab.com/antora/demo/demo-site.git +$ cd demo-site +``` + +And run Antora using the following command: + +``` +$ podman run --rm -it -v $(pwd):/antora:z antora/antora site.yml +``` + +The site will be available in the + +public + +``` +$ cd public +$ python3 -m http.server 8080 +``` + +directory. You can either open it in your web browser directly, or start a local web server using: + +Your site will be available on . + + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/using-antora-for-your-open-source-documentation/ + +作者：[Adam Šamalík][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/author/asamalik/ +[b]: https://github.com/lujun9972 +[1]: https://antora.org/ +[2]: http://docs.fedoraproject.org/ +[3]: https://docs.fedoraproject.org/en-US/fedora/f29/ +[4]: https://docs.antora.org/antora/2.0/page/page-id/#structure +[5]: https://docs.antora.org/antora-ui-default/ +[6]: https://docs.antora.org/antora/2.0/playbook/ +[7]: https://gitlab.com/antora/demo +[8]: https://gitlab.com/antora/demo/demo-site/blob/master/site.yml +[9]: https://gitlab.com/antora/demo/demo-component-a +[10]: https://gitlab.com/antora/demo/demo-component-b +[11]: https://fedoramagazine.org/running-containers-with-podman/ diff --git a/sources/tech/20190128 3 simple and useful GNOME Shell extensions.md b/sources/tech/20190128 3 simple and useful GNOME Shell extensions.md new file mode 100644 index 0000000000..d7384030c5 --- /dev/null +++ b/sources/tech/20190128 3 simple and useful GNOME Shell extensions.md @@ -0,0 +1,73 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (3 simple and useful GNOME Shell extensions) +[#]: via: (https://fedoramagazine.org/3-simple-and-useful-gnome-shell-extensions/) +[#]: author: (Ryan Lerch https://fedoramagazine.org/introducing-flatpak/) + +3 simple and useful GNOME Shell extensions +====== + +![](https://fedoramagazine.org/wp-content/uploads/2019/01/3simple-816x345.png) + +The default desktop of Fedora Workstation — GNOME Shell — is known and loved by many users for its minimal, clutter-free user interface. It is also known for the ability to add to the stock interface using extensions. In this article, we cover 3 simple, and useful extensions for GNOME Shell. These three extensions provide a simple extra behaviour to your desktop; simple tasks that you might do every day. + + +### Installing Extensions + +The quickest and easiest way to install GNOME Shell extensions is with the Software Application. Check out the previous post here on the Magazine for more details: + +![](https://fedoramagazine.org/wp-content/uploads/2018/11/installing-extensions-768x325.jpg) + +### Removable Drive Menu + +![][1] +Removable Drive Menu extension on Fedora 29 + +First up is the [Removable Drive Menu][2] extension. It is a simple tool that adds a small widget in the system tray if you have a removable drive inserted into your computer. This allows you easy access to open Files for your removable drive, or quickly and easily eject the drive for safe removal of the device. + +![][3] +Removable Drive Menu in the Software application + +### Extensions Extension. + +![][4] + +The [Extensions][5] extension is super useful if you are always installing and trying out new extensions. It provides a list of all the installed extensions, allowing you to enable or disable them. Additionally, if an extension has settings, it allows quick access to the settings dialog for each one. + +![][6] +the Extensions extension in the Software application + +### Frippery Move Clock + +![][7] + +Finally, there is the simplest extension in the list. [Frippery Move Clock][8], simply moves the position of the clock from the center of the top bar to the right, next to the status area. + +![][9] + + +-------------------------------------------------------------------------------- + +via: https://fedoramagazine.org/3-simple-and-useful-gnome-shell-extensions/ + +作者：[Ryan Lerch][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://fedoramagazine.org/introducing-flatpak/ +[b]: https://github.com/lujun9972 +[1]: https://fedoramagazine.org/wp-content/uploads/2019/01/removable-disk-1024x459.jpg +[2]: https://extensions.gnome.org/extension/7/removable-drive-menu/ +[3]: https://fedoramagazine.org/wp-content/uploads/2019/01/removable-software-1024x723.png +[4]: https://fedoramagazine.org/wp-content/uploads/2019/01/extensions-extension-1024x459.jpg +[5]: https://extensions.gnome.org/extension/1036/extensions/ +[6]: https://fedoramagazine.org/wp-content/uploads/2019/01/extensions-software-1024x723.png +[7]: https://fedoramagazine.org/wp-content/uploads/2019/01/move_clock-1024x189.jpg +[8]: https://extensions.gnome.org/extension/2/move-clock/ +[9]: https://fedoramagazine.org/wp-content/uploads/2019/01/Screenshot-from-2019-01-28-21-53-18-1024x723.png diff --git a/sources/tech/20190128 Top Hex Editors for Linux.md b/sources/tech/20190128 Top Hex Editors for Linux.md new file mode 100644 index 0000000000..5cd47704b4 --- /dev/null +++ b/sources/tech/20190128 Top Hex Editors for Linux.md @@ -0,0 +1,146 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Top Hex Editors for Linux) +[#]: via: (https://itsfoss.com/hex-editors-linux) +[#]: author: (Ankush Das https://itsfoss.com/author/ankush/) + +Top Hex Editors for Linux +====== + +Hex editor lets you view/edit the binary data of a file – which is in the form of “hexadecimal” values and hence the name “Hex” editor. Let’s be frank, not everyone needs it. Only a specific group of users who have to deal with the binary data use it. + +If you have no idea, what it is, let me give you an example. Suppose, you have the configuration files of a game, you can open them using a hex editor and change certain values to have more ammo/score and so on. To know more about Hex editors, you should start with the [Wikipedia page][1]. + +In case you already know what’s it used for – let us take a look at the best Hex editors available for Linux. + +### 5 Best Hex Editors Available + +![Best Hex Editors for Linux][2] + +**Note:** The hex editors mentioned are in no particular order of ranking. + +#### 1\. Bless Hex Editor + +![bless hex editor][3] + +**Key Features** : + + * Raw disk editing + * Multilevel undo/redo operations. + * Multiple tabs + * Conversion table + * Plugin support to extend the functionality + + + +Bless is one of the most popular Hex editor available for Linux. You can find it listed in your AppCenter or Software Center. If that is not the case, you can check out their [GitHub page][4] for the build and the instructions associated. + +It can easily handle editing big files without slowing down – so it’s a fast hex editor. + +#### 2\. GNOME Hex Editor + +![gnome hex editor][5] + +**Key Features:** + + * View/Edit in either Hex/Ascii + + * Edit large files + + * + + +Yet another amazing Hex editor – specifically tailored for GNOME. Well, I personally use Elementary OS, so I find it listed in the App Center. You should find it in the Software Center as well. If not, refer to the [GitHub page][6] for the source. + +You can use this editor to view/edit in either hex or ASCII. The user interface is quite simple – as you can see in the image above. + +#### 3\. Okteta + +![okteta][7] + +**Key Features:** + + * Customizable data views + * Multiple tabs + * Character encodings: All 8-bit encodings as supplied by Qt, EBCDIC + * Decoding table listing common simple data types. + + + +Okteta is a simple hex editor with not so fancy features. Although it can handle most of the tasks. There’s a separate module of it which you can use to embed this in other programs to view/edit files. + +Similar to all the above-mentioned editors, you can find this listed on your AppCenter and Software center as well. + +#### 4\. wxHexEditor + +![wxhexeditor][8] + +**Key Features:** + + * Easily handle big files + * Has x86 disassembly support + * **** Sector Indication **** on Disk devices + * Supports customizable hex panel formatting and colors. + + + +This is something interesting. It is primarily a Hex editor but you can also use it as a low level disk editor. For example, if you have a problem with your HDD, you can use this editor to edit the the sectors in raw hex and fix it. + +You can find it listed on your App Center and Software Center. If not, [Sourceforge][9] is the way to go. + +#### 5\. Hexedit (Command Line) + +![hexedit][10] + +**Key Features** : + + * Works via terminal + * It’s fast and simple + + + +If you want something to work on your terminal, you can go ahead and install Hexedit via the console. It’s my favorite Linux hex editor in command line. + +When you launch it, you will have to specify the location of the file, and it’ll then open it for you. + +To install it, just type in: + +``` +sudo apt install hexedit +``` + +### Wrapping Up + +Hex editors could come in handy to experiment and learn. If you are someone experienced, you should opt for the one with more feature – with a GUI. Although, it all comes down to personal preferences. + +What do you think about the usefulness of Hex editors? Which one do you use? Did we miss listing your favorite? Let us know in the comments! + +![][11] + +-------------------------------------------------------------------------------- + +via: https://itsfoss.com/hex-editors-linux + +作者：[Ankush Das][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://itsfoss.com/author/ankush/ +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/Hex_editor +[2]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/Linux-hex-editors-800x450.jpeg?resize=800%2C450&ssl=1 +[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/bless-hex-editor.jpg?ssl=1 +[4]: https://github.com/bwrsandman/Bless +[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/01/ghex-hex-editor.jpg?ssl=1 +[6]: https://github.com/GNOME/ghex +[7]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/okteta-hex-editor-800x466.jpg?resize=800%2C466&ssl=1 +[8]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2019/01/wxhexeditor.jpg?ssl=1 +[9]: https://sourceforge.net/projects/wxhexeditor/ +[10]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/hexedit-console.jpg?resize=800%2C566&ssl=1 +[11]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/01/Linux-hex-editors.jpeg?fit=800%2C450&ssl=1 diff --git a/sources/tech/20190129 7 Methods To Identify Disk Partition-FileSystem UUID On Linux.md b/sources/tech/20190129 7 Methods To Identify Disk Partition-FileSystem UUID On Linux.md new file mode 100644 index 0000000000..366e75846d --- /dev/null +++ b/sources/tech/20190129 7 Methods To Identify Disk Partition-FileSystem UUID On Linux.md @@ -0,0 +1,159 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (7 Methods To Identify Disk Partition/FileSystem UUID On Linux) +[#]: via: (https://www.2daygeek.com/check-partitions-uuid-filesystem-uuid-universally-unique-identifier-linux/) +[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) + +7 Methods To Identify Disk Partition/FileSystem UUID On Linux +====== + +As a Linux administrator you should aware of that how do you check partition UUID or filesystem UUID. + +Because most of the Linux systems are mount the partitions with UUID. The same has been verified in the `/etc/fstab` file. + +There are many utilities are available to check UUID. In this article we will show you how to check UUID in many ways and you can choose the one which is suitable for you. + +### What Is UUID? + +UUID stands for Universally Unique Identifier which helps Linux system to identify a hard drives partition instead of block device file. + +libuuid is part of the util-linux-ng package since kernel version 2.15.1 and it’s installed by default in Linux system. + +The UUIDs generated by this library can be reasonably expected to be unique within a system, and unique across all systems. + +It’s a 128 bit number used to identify information in computer systems. UUIDs were originally used in the Apollo Network Computing System (NCS) and later UUIDs are standardized by the Open Software Foundation (OSF) as part of the Distributed Computing Environment (DCE). + +UUIDs are represented as 32 hexadecimal (base 16) digits, displayed in five groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters (32 alphanumeric characters and four hyphens). + +For example: d92fa769-e00f-4fd7-b6ed-ecf7224af7fa + +Sample of my /etc/fstab file. + +``` +# cat /etc/fstab + +# /etc/fstab: static file system information. +# +# Use 'blkid' to print the universally unique identifier for a device; this may +# be used with UUID= as a more robust way to name devices that works even if +# disks are added and removed. See fstab(5). +# +# +UUID=69d9dd18-36be-4631-9ebb-78f05fe3217f / ext4 defaults,noatime 0 1 +UUID=a2092b92-af29-4760-8e68-7a201922573b swap swap defaults,noatime 0 2 +``` + +We can check this using the following seven commands. + + * **`blkid Command:`** locate/print block device attributes. + * **`lsblk Command:`** lsblk lists information about all available or the specified block devices. + * **`hwinfo Command:`** hwinfo stands for hardware information tool is another great utility that used to probe for the hardware present in the system. + * **`udevadm Command:`** udev management tool. + * **`tune2fs Command:`** adjust tunable filesystem parameters on ext2/ext3/ext4 filesystems. + * **`dumpe2fs Command:`** dump ext2/ext3/ext4 filesystem information. + * **`Using by-uuid Path:`** The directory contains UUID and real block device files, UUIDs were symlink with real block device files. + + + +### How To Check Disk Partition/FileSystem UUID In Linux Uusing blkid Command? + +blkid is a command-line utility to locate/print block device attributes. It uses libblkid library to get disk partition UUID in Linux system. + +``` +# blkid +/dev/sda1: UUID="d92fa769-e00f-4fd7-b6ed-ecf7224af7fa" TYPE="ext4" PARTUUID="eab59449-01" +/dev/sdc1: UUID="d17e3c31-e2c9-4f11-809c-94a549bc43b7" TYPE="ext2" PARTUUID="8cc8f9e5-01" +/dev/sdc3: UUID="ca307aa4-0866-49b1-8184-004025789e63" TYPE="ext4" PARTUUID="8cc8f9e5-03" +/dev/sdc5: PARTUUID="8cc8f9e5-05" +``` + +### How To Check Disk Partition/FileSystem UUID In Linux Uusing lsblk Command? + +lsblk lists information about all available or the specified block devices. The lsblk command reads the sysfs filesystem and udev db to gather information. + +If the udev db is not available or lsblk is compiled without udev support than it tries to read LABELs, UUIDs and filesystem types from the block device. In this case root permissions are necessary. The command prints all block devices (except RAM disks) in a tree-like format by default. + +``` +# lsblk -o name,mountpoint,size,uuid +NAME MOUNTPOINT SIZE UUID +sda 30G +└─sda1 / 20G d92fa769-e00f-4fd7-b6ed-ecf7224af7fa +sdb 10G +sdc 10G +├─sdc1 1G d17e3c31-e2c9-4f11-809c-94a549bc43b7 +├─sdc3 1G ca307aa4-0866-49b1-8184-004025789e63 +├─sdc4 1K +└─sdc5 1G +sdd 10G +sde 10G +sr0 1024M +``` + +### How To Check Disk Partition/FileSystem UUID In Linux Uusing by-uuid path? + +The directory contains UUID and real block device files, UUIDs were symlink with real block device files. + +``` +# ls -lh /dev/disk/by-uuid/ +total 0 +lrwxrwxrwx 1 root root 10 Jan 29 08:34 ca307aa4-0866-49b1-8184-004025789e63 -> ../../sdc3 +lrwxrwxrwx 1 root root 10 Jan 29 08:34 d17e3c31-e2c9-4f11-809c-94a549bc43b7 -> ../../sdc1 +lrwxrwxrwx 1 root root 10 Jan 29 08:34 d92fa769-e00f-4fd7-b6ed-ecf7224af7fa -> ../../sda1 +``` + +### How To Check Disk Partition/FileSystem UUID In Linux Uusing hwinfo Command? + +**[hwinfo][1]** stands for hardware information tool is another great utility that used to probe for the hardware present in the system and display detailed information about varies hardware components in human readable format. + +``` +# hwinfo --block | grep by-uuid | awk '{print $3,$7}' +/dev/sdc1, /dev/disk/by-uuid/d17e3c31-e2c9-4f11-809c-94a549bc43b7 +/dev/sdc3, /dev/disk/by-uuid/ca307aa4-0866-49b1-8184-004025789e63 +/dev/sda1, /dev/disk/by-uuid/d92fa769-e00f-4fd7-b6ed-ecf7224af7fa +``` + +### How To Check Disk Partition/FileSystem UUID In Linux Uusing udevadm Command? + +udevadm expects a command and command specific options. It controls the runtime behavior of systemd-udevd, requests kernel events, manages the event queue, and provides simple debugging mechanisms. + +``` +udevadm info -q all -n /dev/sdc1 | grep -i by-uuid | head -1 +S: disk/by-uuid/d17e3c31-e2c9-4f11-809c-94a549bc43b7 +``` + +### How To Check Disk Partition/FileSystem UUID In Linux Uusing tune2fs Command? + +tune2fs allows the system administrator to adjust various tunable filesystem parameters on Linux ext2, ext3, or ext4 filesystems. The current values of these options can be displayed by using the -l option. + +``` +# tune2fs -l /dev/sdc1 | grep UUID +Filesystem UUID: d17e3c31-e2c9-4f11-809c-94a549bc43b7 +``` + +### How To Check Disk Partition/FileSystem UUID In Linux Uusing dumpe2fs Command? + +dumpe2fs prints the super block and blocks group information for the filesystem present on device. + +``` +# dumpe2fs /dev/sdc1 | grep UUID +dumpe2fs 1.43.5 (04-Aug-2017) +Filesystem UUID: d17e3c31-e2c9-4f11-809c-94a549bc43b7 +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/check-partitions-uuid-filesystem-uuid-universally-unique-identifier-linux/ + +作者：[Magesh Maruthamuthu][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/magesh/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/hwinfo-check-display-detect-system-hardware-information-linux/ diff --git a/sources/tech/20190129 Create an online store with this Java-based framework.md b/sources/tech/20190129 Create an online store with this Java-based framework.md new file mode 100644 index 0000000000..b72a8551de --- /dev/null +++ b/sources/tech/20190129 Create an online store with this Java-based framework.md @@ -0,0 +1,235 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Create an online store with this Java-based framework) +[#]: via: (https://opensource.com/article/19/1/scipio-erp) +[#]: author: (Paul Piper https://opensource.com/users/madppiper) + +Create an online store with this Java-based framework +====== +Scipio ERP comes with a large range of applications and functionality. +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/osdc_whitehurst_money.png?itok=ls-SOzM0) + +So you want to sell products or services online, but either can't find a fitting software or think customization would be too costly? [Scipio ERP][1] may just be what you are looking for. + +Scipio ERP is a Java-based open source e-commerce framework that comes with a large range of applications and functionality. The project was forked from [Apache OFBiz][2] in 2014 with a clear focus on better customization and a more modern appeal. The e-commerce component is quite extensive and works in a multi-store setup, internationally, and with a wide range of product configurations, and it's also compatible with modern HTML frameworks. The software also provides standard applications for many other business cases, such as accounting, warehouse management, or sales force automation. It's all highly standardized and therefore easy to customize, which is great if you are looking for more than a virtual cart. + +The system makes it very easy to keep up with modern web standards, too. All screens are constructed using the system's "[templating toolkit][3]," an easy-to-learn macro set that separates HTML from all applications. Because of it, every application is already standardized to the core. Sounds confusing? It really isn't—it all looks a lot like HTML, but you write a lot less of it. + +### Initial setup + +Before you get started, make sure you have Java 1.8 (or greater) SDK and a Git client installed. Got it? Great! Next, check out the master branch from GitHub: + +``` +git clone https://github.com/ilscipio/scipio-erp.git +cd scipio-erp +git checkout master +``` + +To set up the system, simply run **./install.sh** and select either option from the command line. Throughout development, it is best to stick to an **installation for development** (Option 1), which will also install a range of demo data. For professional installations, you can modify the initial config data ("seed data") so it will automatically set up the company and catalog data for you. By default, the system will run with an internal database, but it [can also be configured][4] with a wide range of relational databases such as PostgreSQL and MariaDB. + +![Setup wizard][6] + +Follow the setup wizard to complete your initial configuration, + +Start the system with **./start.sh** and head over to **** to complete the configuration. If you installed with demo data, you can log in with username **admin** and password **scipio**. During the setup wizard, you can set up a company profile, accounting, a warehouse, your product catalog, your online store, and additional user profiles. Keep the website entries on the product store configuration screen for now. The system allows you to run multiple webstores with different underlying code; unless you want to do that, it is easiest to stick to the defaults. + +Congratulations, you just installed Scipio ERP! Play around with the screens for a minute or two to get a feel for the functionality. + +### Shortcuts + +Before you jump into the customization, here are a few handy commands that will help you along the way: + + * Create a shop-override: **./ant create-component-shop-override** + * Create a new component: **./ant create-component** + * Create a new theme component: **./ant create-theme** + * Create admin user: **./ant create-admin-user-login** + * Various other utility functions: **./ant -p** + * Utility to install & update add-ons: **./git-addons help** + + + +Also, make a mental note of the following locations: + + * Scripts to run Scipio as a service: **/tools/scripts/** + * Log output directory: **/runtime/logs** + * Admin application: **** + * E-commerce application: **** + + + +Last, Scipio ERP structures all code in the following five major directories: + + * Framework: framework-related sources, the application server, generic screens, and configurations + * Applications: core applications + * Addons: third-party extensions + * Themes: modifies the look and feel + * Hot-deploy: your own components + + + +Aside from a few configurations, you will be working within the hot-deploy and themes directories. + +### Webstore customizations + +To really make the system your own, start thinking about [components][7]. Components are a modular approach to override, extend, and add to the system. Think of components as self-contained web modules that capture information on databases ([entity][8]), functions ([services][9]), screens ([views][10]), [events and actions][11], and web applications. Thanks to components, you can add your own code while remaining compatible with the original sources. + +Run **./ant create-component-shop-override** and follow the steps to create your webstore component. A new directory will be created inside of the hot-deploy directory, which extends and overrides the original e-commerce application. + +![component directory structure][13] + +A typical component directory structure. + +Your component will have the following directory structure: + + * config: configurations + * data: seed data + * entitydef: database table definitions + * script: Groovy script location + * servicedef: service definitions + * src: Java classes + * webapp: your web application + * widget: screen definitions + + + +Additionally, the **ivy.xml** file allows you to add Maven libraries to the build process and the **ofbiz-component.xml** file defines the overall component and web application structure. Apart from the obvious, you will also find a **controller.xml** file inside the web apps' **WEB-INF** directory. This allows you to define request entries and connect them to events and screens. For screens alone, you can also use the built-in CMS functionality, but stick to the core mechanics first. Familiarize yourself with **/applications/shop/** before introducing changes. + +#### Adding custom screens + +Remember the [templating toolkit][3]? You will find it used on every screen. Think of it as a set of easy-to-learn macros that structure all content. Here's an example: + +``` +<@section title="Title"> +    <@heading id="slider">Slider +    <@row> +        <@cell columns=6> +            <@slider id="" class="" controls=true indicator=true> +                <@slide link="#" image="https://placehold.it/800x300">Just some content… +                <@slide title="This is a title" link="#" image="https://placehold.it/800x300"> +            +        +        <@cell columns=6>Second column +    + +``` + +Not too difficult, right? Meanwhile, themes contain the HTML definitions and styles. This hands the power over to your front-end developers, who can define the output of each macro and otherwise stick to their own build tools for development. + +Let's give it a quick try. First, define a request on your own webstore. You will modify the code for this. A built-in CMS is also available at **** , which allows you to create new templates and screens in a much more efficient way. It is fully compatible with the templating toolkit and comes with example templates that can be adopted to your preferences. But since we are trying to understand the system here, let's go with the more complicated way first. + +Open the **[controller.xml][14]** file inside of your shop's webapp directory. The controller keeps track of request events and performs actions accordingly. The following will create a new request under **/shop/test** : + +``` + + +      +      + +``` + +You can define multiple responses and, if you want, you could use an event or a service call inside the request to determine which response you may want to use. I opted for a response of type "view." A view is a rendered response; other types are request-redirects, forwards, and alike. The system comes with various renderers and allows you to determine the output later; to do so, add the following: + +``` + + +``` + +Replace **my-component** with your own component name. Then you can define your very first screen by adding the following inside the tags within the **widget/CommonScreens.xml** file: + +``` + +       
+            +            +            +                +                    +                        +                    +                +            +       
+    +``` + +Screens are actually quite modular and consist of multiple elements ([widgets, actions, and decorators][15]). For the sake of simplicity, leave this as it is for now, and complete the new webpage by adding your very first templating toolkit file. For that, create a new **webapp/mycomponent/test/test.ftl** file and add the following: + +``` +<@alert type="info">Success! +``` + +![Custom screen][17] + +A custom screen. + +Open **** and marvel at your own accomplishments. + +#### Custom themes + +Modify the look and feel of the shop by creating your very own theme. All themes can be found as components inside of the themes folder. Run **./ant create-theme** to add your own. + +![theme component layout][19] + +A typical theme component layout. + +Here's a list of the most important directories and files: + + * Theme configuration: **data/*ThemeData.xml** + * Theme-specific wrapping HTML: **includes/*.ftl** + * Templating Toolkit HTML definition: **includes/themeTemplate.ftl** + * CSS class definition: **includes/themeStyles.ftl** + * CSS framework: **webapp/theme-title/*** + + + +Take a quick look at the Metro theme in the toolkit; it uses the Foundation CSS framework and makes use of all the things above. Afterwards, set up your own theme inside your newly constructed **webapp/theme-title** directory and start developing. The Foundation-shop theme is a very simple shop-specific theme implementation that you can use as a basis for your own work. + +Voila! You have set up your own online store and are ready to customize! + +![Finished Scipio ERP shop][21] + +A finished shop based on Scipio ERP. + +### What's next? + +Scipio ERP is a powerful framework that simplifies the development of complex e-commerce applications. For a more complete understanding, check out the project [documentation][7], try the [online demo][22], or [join the community][23]. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/scipio-erp + +作者：[Paul Piper][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/madppiper +[b]: https://github.com/lujun9972 +[1]: https://www.scipioerp.com +[2]: https://ofbiz.apache.org/ +[3]: https://www.scipioerp.com/community/developer/freemarker-macros/ +[4]: https://www.scipioerp.com/community/developer/installation-configuration/configuration/#database-configuration +[5]: /file/419711 +[6]: https://opensource.com/sites/default/files/uploads/setup_step5_sm.jpg (Setup wizard) +[7]: https://www.scipioerp.com/community/developer/architecture/components/ +[8]: https://www.scipioerp.com/community/developer/entities/ +[9]: https://www.scipioerp.com/community/developer/services/ +[10]: https://www.scipioerp.com/community/developer/views-requests/ +[11]: https://www.scipioerp.com/community/developer/events-actions/ +[12]: /file/419716 +[13]: https://opensource.com/sites/default/files/uploads/component_structure.jpg (component directory structure) +[14]: https://www.scipioerp.com/community/developer/views-requests/request-controller/ +[15]: https://www.scipioerp.com/community/developer/views-requests/screen-widgets-decorators/ +[16]: /file/419721 +[17]: https://opensource.com/sites/default/files/uploads/success_screen_sm.jpg (Custom screen) +[18]: /file/419726 +[19]: https://opensource.com/sites/default/files/uploads/theme_structure.jpg (theme component layout) +[20]: /file/419731 +[21]: https://opensource.com/sites/default/files/uploads/finished_shop_1_sm.jpg (Finished Scipio ERP shop) +[22]: https://www.scipioerp.com/demo/ +[23]: https://forum.scipioerp.com/ diff --git a/sources/tech/20190129 Get started with gPodder, an open source podcast client.md b/sources/tech/20190129 Get started with gPodder, an open source podcast client.md new file mode 100644 index 0000000000..ca1556e16d --- /dev/null +++ b/sources/tech/20190129 Get started with gPodder, an open source podcast client.md @@ -0,0 +1,64 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Get started with gPodder, an open source podcast client) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-gpodder) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +Get started with gPodder, an open source podcast client +====== +Keep your podcasts synced across your devices with gPodder, the 17th in our series on open source tools that will make you more productive in 2019. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/podcast-record-microphone.png?itok=8yUDOywf) + +There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. + +Here's the 17th of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. + +### gPodder + +I like podcasts. Heck, I like them so much I record three of them (you can find links to them in [my profile][1]). I learn a lot from podcasts and play them in the background when I'm working. But keeping them in sync between multiple desktops and mobile devices can be a bit of a challenge. + +[gPodder][2] is a simple, cross-platform podcast downloader, player, and sync tool. It supports RSS feeds, [FeedBurner][3], [YouTube][4], and [SoundCloud][5], and it also has an open source sync service that you can run if you want. gPodder doesn't do podcast playback; instead, it uses your audio or video player of choice. + +![](https://opensource.com/sites/default/files/uploads/gpodder-1.png) + +Installing gPodder is very straightforward. Installers are available for Windows and MacOS, and packages are available for major Linux distributions. If it isn't available in your distribution, you can run it directly from a Git checkout. With the "Add Podcasts via URL" menu option, you can enter a podcast's RSS feed URL or one of the "special" URLs for the other services. gPodder will fetch a list of episodes and present a dialog where you can select which episodes to download or mark old episodes on the list. + +![](https://opensource.com/sites/default/files/uploads/gpodder-2.png) + +One of its nicer features is that if a URL is already in your clipboard, gPodder will automatically place it in its URL field, which makes it really easy to add a new podcast to your list. If you already have an OPML file of podcast feeds, you can upload and import it. There is also a discovery option that allows you to search for podcasts on [gPodder.net][6], the free and open source podcast listing site by the people who write and maintain gPodder. + +![](https://opensource.com/sites/default/files/uploads/gpodder-3.png) + +A [mygpo][7] server synchronizes podcasts between devices. By default, gPodder uses [gPodder.net][8]'s servers, but you can change this in the configuration files if want to run your own (be aware that you'll have to modify the configuration file directly). Syncing allows you to keep your lists consistent between desktops and mobile devices. This is very useful if you listen to podcasts on multiple devices (for example, I listen on my work computer, home computer, and mobile phone), as it means no matter where you are, you have the most recent lists of podcasts and episodes without having to set things up again and again. + +![](https://opensource.com/sites/default/files/uploads/gpodder-4.png) + +Clicking on a podcast episode will bring up the text post associated with it, and clicking "Play" will launch your device's default audio or video player. If you want to use something other than the default, you can change this in gPodder's configuration settings. + +gPodder makes it simple to find, download, and listen to podcasts, synchronize them across devices, and access a lot of other features in an easy-to-use interface. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-gpodder + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/users/ksonney +[2]: https://gpodder.github.io/ +[3]: https://feedburner.google.com/ +[4]: https://youtube.com +[5]: https://soundcloud.com/ +[6]: http://gpodder.net +[7]: https://github.com/gpodder/mygpo +[8]: http://gPodder.net diff --git a/sources/tech/20190129 How To Configure System-wide Proxy Settings Easily And Quickly.md b/sources/tech/20190129 How To Configure System-wide Proxy Settings Easily And Quickly.md new file mode 100644 index 0000000000..0848111d08 --- /dev/null +++ b/sources/tech/20190129 How To Configure System-wide Proxy Settings Easily And Quickly.md @@ -0,0 +1,309 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (How To Configure System-wide Proxy Settings Easily And Quickly) +[#]: via: (https://www.ostechnix.com/how-to-configure-system-wide-proxy-settings-easily-and-quickly/) +[#]: author: (SK https://www.ostechnix.com/author/sk/) + +How To Configure System-wide Proxy Settings Easily And Quickly +====== + +![](https://www.ostechnix.com/wp-content/uploads/2019/01/ProxyMan-720x340.png) + +Today, we will be discussing a simple, yet useful command line utility named **“ProxyMan”**. As the name says, it helps you to apply and manage proxy settings on our system easily and quickly. Using ProxyMan, we can set or unset proxy settings automatically at multiple points, without having to configure them manually one by one. It also allows you to save the settings for later use. In a nutshell, ProxyMan simplifies the task of configuring system-wide proxy settings with a single command. It is free, open source utility written in **Bash** and standard POSIX tools, no dependency required. ProxyMan can be helpful if you’re behind a proxy server and you want to apply the proxy settings system-wide in one go. + +### Installing ProxyMan + +Download the latest ProxyMan version from the [**releases page**][1]. It is available as zip and tar file. I am going to download zip file. + +``` +$ wget https://github.com/himanshub16/ProxyMan/archive/v3.1.1.zip +``` + +Extract the downloaded zip file: + +``` +$ unzip v3.1.1.zip +``` + +The above command will extract the contents in a folder named “ **ProxyMan-3.1.1** ” in your current working directory. Cd to that folder and install ProxyMan as shown below: + +``` +$ cd ProxyMan-3.1.1/ + +$ ./install +``` + +If you see **“Installed successfully”** message as output, congratulations! ProxyMan has been installed. + +Let us go ahead and see how to configure proxy settings. + +### Configure System-wide Proxy Settings + +ProxyMan usage is pretty simple and straight forward. Like I already said, It allows us to set/unset proxy settings, list current proxy settings, list available configs, save settings in a profile and load profile later. Proxyman currently manages proxy settings for **GNOME gsettings** , **bash** , **apt** , **dnf** , **git** , **npm** and **Dropbox**. + +**Set proxy settings** + +To set proxy settings system-wide, simply run: + +``` +$ proxyman set +``` + +You will asked to answer a series of simple questions such as, + + 1. HTTP Proxy host IP address, + 2. HTTP port, + 3. Use username/password authentication, + 4. Use same settings for HTTPS and FTP, + 5. Save profile for later use, + 6. Finally, choose the list of targets to apply the proxy settings. You can choose all at once or separate multiple choices with space. + + + +Sample output for the above command: + +``` +Enter details to set proxy +HTTP Proxy Host 192.168.225.22 +HTTP Proxy Port 8080 +Use auth - userid/password (y/n)? n +Use same for HTTPS and FTP (y/n)? y +No Proxy (default localhost,127.0.0.1,192.168.1.1,::1,*.local) +Save profile for later use (y/n)? y +Enter profile name : proxy1 +Saved to /home/sk/.config/proxyman/proxy1. + +Select targets to modify +| 1 | All of them ... Don't bother me +| 2 | Terminal / bash / zsh (current user) +| 3 | /etc/environment +| 4 | apt/dnf (Package manager) +| 5 | Desktop settings (GNOME/Ubuntu) +| 6 | npm & yarn +| 7 | Dropbox +| 8 | Git +| 9 | Docker + +Separate multiple choices with space +? 1 +Setting proxy... +To activate in current terminal window +run source ~/.bashrc +[sudo] password for sk: +Done +``` + +**List proxy settings** + +To view the current proxy settings, run: + +``` +$ proxyman list +``` + +Sample output: + +``` +Hmm... listing it all + +Shell proxy settings : /home/sk/.bashrc +export http_proxy="http://192.168.225.22:8080/" +export ftp_proxy="ftp://192.168.225.22:8080/" +export rsync_proxy="rsync://192.168.225.22:8080/" +export no_proxy="localhost,127.0.0.1,192.168.1.1,::1,*.local" +export HTTP_PROXY="http://192.168.225.22:8080/" +export FTP_PROXY="ftp://192.168.225.22:8080/" +export RSYNC_PROXY="rsync://192.168.225.22:8080/" +export NO_PROXY="localhost,127.0.0.1,192.168.1.1,::1,*.local" +export https_proxy="/" +export HTTPS_PROXY="/" + +git proxy settings : +http http://192.168.225.22:8080/ +https https://192.168.225.22:8080/ + +APT proxy settings : +3 +Done +``` + +**Unset proxy settings** + +To unset proxy settings, the command would be: + +``` +$ proxyman unset +``` + +You can unset proxy settings for all targets at once by entering number **1** or enter any given number to unset proxy settings for the respective target. + +``` +Select targets to modify +| 1 | All of them ... Don't bother me +| 2 | Terminal / bash / zsh (current user) +| 3 | /etc/environment +| 4 | apt/dnf (Package manager) +| 5 | Desktop settings (GNOME/Ubuntu) +| 6 | npm & yarn +| 7 | Dropbox +| 8 | Git +| 9 | Docker + +Separate multiple choices with space +? 1 +Unset all proxy settings +To activate in current terminal window +run source ~/.bashrc +Done +``` + +To apply the changes, simply run: + +``` +$ source ~/.bashrc +``` + +On ZSH, use this command instead: + +``` +$ source ~/.zshrc +``` + +To verify if the proxy settings have been removed, simply run “proxyman list” command: + +``` +$ proxyman list +Hmm... listing it all + +Shell proxy settings : /home/sk/.bashrc +None + +git proxy settings : +http +https + +APT proxy settings : +None +Done +``` + +As you can see, there is no proxy settings for all targets. + +**View list of configs (profiles)** + +Remember we saved proxy settings as a profile in the “Set proxy settings” section? You can view the list of available profiles with command: + +``` +$ proxyman configs +``` + +Sample output: + +``` +Here are available configs! +proxy1 +Done +``` + +As you can see, we have only one profile i.e **proxy1**. + +**Load profiles** + +The profiles will be available until you delete them permanently, so you can load a profile (E.g proxy1) at any time using command: + +``` +$ proxyman load proxy1 +``` + +This command will list the proxy settings for proxy1 profile. You can apply these settings to all or multiple targets by entering the respective number with space-separated. + +``` +Loading profile : proxy1 +HTTP > 192.168.225.22 8080 +HTTPS > 192.168.225.22 8080 +FTP > 192.168.225.22 8080 +no_proxy > localhost,127.0.0.1,192.168.1.1,::1,*.local +Use auth > n +Use same > y +Config > +Targets > +Select targets to modify +| 1 | All of them ... Don't bother me +| 2 | Terminal / bash / zsh (current user) +| 3 | /etc/environment +| 4 | apt/dnf (Package manager) +| 5 | Desktop settings (GNOME/Ubuntu) +| 6 | npm & yarn +| 7 | Dropbox +| 8 | Git +| 9 | Docker + +Separate multiple choices with space +? 1 +Setting proxy... +To activate in current terminal window +run source ~/.bashrc +Done +``` + +Finally, activate the changes using command: + +``` +$ source ~/.bashrc +``` + +For ZSH: + +``` +$ source ~/.zshrc +``` + +**Deleting profiles** + +To delete a profile, run: + +``` +$ proxyman delete proxy1 +``` + +Output: + +``` +Deleting profile : proxy1 +Done +``` + +To display help, run: + +``` +$ proxyman help +``` + + +### Conclusion + +Before I came to know about Proxyman, I used to apply proxy settings manually at multiple places, for example package manager, web browser etc. Not anymore! ProxyMan did this job automatically in couple seconds. + +And, that’s all for now. Hope this was useful. More good stuffs to come. Stay tuned. + +Cheers! + + + +-------------------------------------------------------------------------------- + +via: https://www.ostechnix.com/how-to-configure-system-wide-proxy-settings-easily-and-quickly/ + +作者：[SK][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.ostechnix.com/author/sk/ +[b]: https://github.com/lujun9972 +[1]: https://github.com/himanshub16/ProxyMan/releases/ diff --git a/sources/tech/20190130 Get started with Budgie Desktop, a Linux environment.md b/sources/tech/20190130 Get started with Budgie Desktop, a Linux environment.md new file mode 100644 index 0000000000..1c2389693f --- /dev/null +++ b/sources/tech/20190130 Get started with Budgie Desktop, a Linux environment.md @@ -0,0 +1,60 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Get started with Budgie Desktop, a Linux environment) +[#]: via: (https://opensource.com/article/19/1/productivity-tool-budgie-desktop) +[#]: author: (Kevin Sonney https://opensource.com/users/ksonney (Kevin Sonney)) + +Get started with Budgie Desktop, a Linux environment +====== +Configure your desktop as you want with Budgie, the 18th in our series on open source tools that will make you more productive in 2019. + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/data_metrics_analytics_desktop_laptop.png?itok=9QXd7AUr) + +There seems to be a mad rush at the beginning of every year to find ways to be more productive. New Year's resolutions, the itch to start the year off right, and of course, an "out with the old, in with the new" attitude all contribute to this. And the usual round of recommendations is heavily biased towards closed source and proprietary software. It doesn't have to be that way. + +Here's the 18th of my picks for 19 new (or new-to-you) open source tools to help you be more productive in 2019. + +### Budgie Desktop + +There are many, many desktop environments for Linux. From the easy to use and graphically stunning [GNOME desktop][1] (default on most major Linux distributions) and [KDE][2], to the minimalist [Openbox][3], to the highly configurable tiling [i3][4], there are a lot of options. What I look for in a good desktop environment is speed, unobtrusiveness, and a clean user experience. It is hard to be productive when a desktop works against you, not with or for you. + +![](https://opensource.com/sites/default/files/uploads/budgie-1.png) + +[Budgie Desktop][5] is the default desktop on the [Solus][6] Linux distribution and is available as an add-on package for most of the major Linux distributions. It is based on GNOME and uses many of the same tools and libraries you likely already have on your computer. + +The default desktop is exceptionally minimalistic, with just the panel and a blank desktop. Budgie includes an integrated sidebar (called Raven) that gives quick access to the calendar, audio controls, and settings menu. Raven also contains an integrated notification area with a unified display of system messages similar to MacOS's. + +![](https://opensource.com/sites/default/files/uploads/budgie-2.png) + +Clicking on the gear icon in Raven brings up Budgie's control panel with its configuration settings. Since Budgie is still in development, it is a little bare-bones compared to GNOME or KDE, and I hope it gets more options over time. The Top Panel option, which allows the user to configure the ordering, positioning, and contents of the top panel, is nice. + +![](https://opensource.com/sites/default/files/uploads/budgie-3.png) + +The Budgie Welcome application (presented at first login) contains options to install additional software, panel applets, snaps, and Flatpack packages. There are applets to handle networking, screenshots, additional clocks and timers, and much, much more. + +![](https://opensource.com/sites/default/files/uploads/budgie-4.png) + +Budgie provides a desktop that is clean and stable. It responds quickly and has many options that allow you to customize it as you see fit. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/productivity-tool-budgie-desktop + +作者：[Kevin Sonney][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/ksonney (Kevin Sonney) +[b]: https://github.com/lujun9972 +[1]: https://www.gnome.org/ +[2]: https://www.kde.org/ +[3]: http://openbox.org/wiki/Main_Page +[4]: https://i3wm.org/ +[5]: https://getsol.us/solus/experiences/ +[6]: https://getsol.us/home/ diff --git a/translated/talk/20180206 Building Slack for the Linux community and adopting snaps.md b/translated/talk/20180206 Building Slack for the Linux community and adopting snaps.md new file mode 100644 index 0000000000..ef97cf3485 --- /dev/null +++ b/translated/talk/20180206 Building Slack for the Linux community and adopting snaps.md @@ -0,0 +1,71 @@ +为 Linux 社区采用 snaps 搭建 Slack +====== +![][1] + +作为一个被数以百万计用户使用的企业级软件平台，[Slack][2] 允许任意规模的团队和企业有效地沟通。Slack 通过在一个单一集成环境中与其它软件工具无缝衔接，为一个组织内的通讯、信息和项目提供了一个易于接触的档案馆。尽管自从诞生后 Slack 就在过去四年中快速成长，但是他们负责该平台跨 Windows、MacOS 和 Linux 运行的桌面工程师团队仅由四人组成。我们通过与在这个团队中负责追踪[上月首发的 Slack snap][3] 的主任工程师 Felix Rieseberg 交谈，来探索更多有关该公司对于 Linux 社区的态度以及他们决定搭建一个 snap 的原因。 + +[安装 Slack snap][4] + +### 你们能告诉我们更多关于已发布的 Slack snap 的信息吗？ + +我们上月发布了我们的第一个 snap 作为我们为Linux 社区的一种新的发布形式。在企业界，我们发现人们更倾向于以一种相对于个人消费者较慢的速度来采用新科技， 因此我们将会在未来继续提供 .deb 形式的 snap。 + +### 你们觉得 Linux 社区会对 Slack 有多大的兴趣呢？ + +在所有的平台上人们对 Slack 的兴趣都正在增长，这一点使我感到十分兴奋。因此这对于我们来说，很难说源自 Linux 社区的兴趣和我们大体上所见到的兴趣有什么区别。当然，不管用户们在什么平台上面工作，满足他们对我们都是很重要的。我们有一个专门负责 Linux 的测试工程师并且我们同时也尽全力提供最好的用户体验。只是我们发现总体相对于 Windows 来说，为 Linux 搭建 snap 略微有点难度，因为我们是在一个较难以预测的平台上工作——而这正是 Linux 社区之光照耀的领域。在汇报程序缺陷以及寻找程序崩溃原因方面，我们有相当多数极富帮助的用户。 + +### 你们是如何得知 snap 的？ + +Canonical 公司的 Martin Wimpress 和我接触并向我解释了 snap 的概念。说实话尽管我也用 Ubuntu 但最初我还是迟疑的，因为它看起来像需要搭建与维护的另一套标准。尽管如此，一当我了解到其中的好处之后，我确信这是一笔有回报的投入。 + +### snap 的什么方面吸引了你们并使你们决定投入其中？ + +毫无疑问，我们决定搭建 snap 最重要的原因是它的更新特性。在 Slack 上我们大量运用网页技术，这些技术反过来也使得我们提供大量的特性——比如将 YouTube 视频或者 Spotify 播放列表集成在 Slack 中。与浏览器十分相似，这意味着我们需要频繁更新应用。 + +在 MacOS 和 Windows 上，我们已经有了一个甚至无需用户考虑更新的专门的自动更新器。我们发现哪怕是为了更新，任何形式的中断都是一种我们需要避免的烦恼。因此通过 snap 自动化的更新就显得无缝和便捷得多。 + +### 相比于其它形式的打包方式，搭建 snap 感觉如何？ 将它与现有的设施和进程集成在一起有多简便呢？ + +就 Linux 而言，我们尚未尝试其它新的打包方式，但我们迟早会的。鉴于我们的大多数用户都使用 Ubuntu，snap 是一个很简便的选项。同时 snap 在其它发行版上同样也可以使用，这也是一个巨大的加分项。Canonical 正将 snap 做到跨发行版而不是仅仅集中在 Ubuntu 上，这一点我认为是很好的。 + +搭建 snap 简单得出乎意料，我们有一个创建安装器和软件包的统一流程，我们的 snap 创建过程从一个 .deb 软件包炮制出一个 snap。对于其它技术而言，有时候我们不得不为了支持搭建链先造一个内部工具。但是 snapcraft 工具正是我们需要的东西。在整个过程中 Canonical 的团队不可思议般得有助，因为我们一路上确实碰到了一些问题。 + +### 你们觉得 snap 商店是如何改变用户们寻找、安装你们软件的方式的呢？ + +Slack 真正的独特之处在于人们不仅仅是碰巧发现它，他们从别的地方知道它并积极地试图找到它。因此尽管我们已经有了相当高的觉悟，我希望对于我们的用户来说，在商店中可以获得 snap 能够让安装过程变得简单一点。 + +### 你们对用 snap 而不是为了其它发行版不得不再发行软件包有什么期待，或者有什么已经是你们可见的节省呢？ + +我们希望 snap 可以给予我们的用户更多的便利并确保他们能够更加享受使用 Slack。在我们看来，鉴于用户们不必被困在之前的版本，这自然而然地解决了许多问题，因此 snap 可以让我们在客户支持方面节约时间。有 snap 对我们来说也是一个额外的加分项，因为我们能有一个可供搭建的平台而不是替换我们现有的东西。 + +### 如果存在的话，你们正使用或者准备使用边缘 (edge)、测试 (beta)、候选 (candidate)、稳定 (stable) 中的哪种发行频道？ + +我们仅仅在开发中使用边缘 (edge) 频道以与 Canonical 的团队共享。为 Linux 打造的 Slack 总体任在测试 (beta) 频道中。但是长远来看，拥有不同频道的选项十分有意思，同时能够提早一点为感兴趣的客户发行版本也肯定是有好处的。 + +### 你们认为将软件打包成一个 snap 是如何能够帮助用户的？你们从用户那边得到了什么反馈吗？ + +对我们的用户来说一个很大的好处是安装和更新总体来说都会变得简便一点。长远来看，问题在于“那些安装 snap 的用户是不是比其它用户少碰到一些困难？”，我十分期望 snap 自带的依赖关系能够使其变成可能。 + +### 你们有什么会和刚使用 snap 的新用户们分享的建议或知识呢？ + +我会推荐从 Debian 软件包来着手搭建你们的 snap——那出乎意料得简单。这同样也缩小了开始的范围避免变得不堪重负。这只需要投入相当少的时间，并且很大可能是一笔值得的投入。同样如果你们可以的话，尽量试着找到 Canonical 的人员来协作——他们拥有了不起的工程师。 + +### 对于开发来说，你们在什么地方看到了最大的机遇？ + +我们现在正一步步来，先是让人们用上 snap，再从那里开始搭建。正在使用 snap 的人们将会感到更加稳健因为他们将会得益于最新的更新。 + +-------------------------------------------------------------------------------- + +via: https://insights.ubuntu.com/2018/02/06/building-slack-for-the-linux-community-and-adopting-snaps/ + +作者：[Sarah][a] +译者：[tomjlw](https://github.com/tomjlw) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://insights.ubuntu.com/author/sarahfd/ +[1]:https://insights.ubuntu.com/wp-content/uploads/a115/Slack_linux_screenshot@2x-2.png +[2]:https://slack.com/ +[3]:https://insights.ubuntu.com/2018/01/18/canonical-brings-slack-to-the-snap-ecosystem/ +[4]:https://snapcraft.io/slack/ diff --git a/translated/talk/20180722 Dawn of the Microcomputer- The Altair 8800.md b/translated/talk/20180722 Dawn of the Microcomputer- The Altair 8800.md deleted file mode 100644 index d6ae8689bf..0000000000 --- a/translated/talk/20180722 Dawn of the Microcomputer- The Altair 8800.md +++ /dev/null @@ -1,141 +0,0 @@ -微型计算机的始祖：Altair 8800 -====== -《大众电子》的订阅者是个复杂的群体，杂志编辑 Arthur Salsberg 不得不在 [1974 年 12 月刊][1] 中的前言部分指出这点。此前，杂志编辑组曾收到了对《如何搭建家庭媒体中心》文章的抱怨，称这篇文章激励了许多业余电视爱好者走出去，削弱了专业修理人员存在的必要性，这对许多人的电视造成了极大伤害。Salsberg 认为，这个担忧的产生可能是因为大家不清楚《大众电子》读者们的真实水平。他解释道，杂志内部调查的数据显示，52 % 的订阅者都是某方面的电子专家，并且其中的 150,000 人在最近 60 天之内都修过电视。此外，订阅者们平均在电子产品上花费了 470 美金（2018 年则是 3578 美金），并且他们有对万用表、真空管伏特计、电子管测试仪、晶体管测试仪、射频讯号产生器和示波器的需求。“《大众电子》的读者们并不全都是新手。”Salsberg 总结道。 - -熟悉《大众电子》的人居然会质疑它的订阅者，这令我十分吃惊。不过最近 60 天我的确没修过电视。我的电脑对我来说就是一块铝，我甚至没把它拆开看过。1974 年 12 月的《大众电子》刊登的像《驻波比是什么以及如何处理它》和《对万用表的测试》之类的特色文章，甚至连广告都令人生畏。它们中有个看起来像某种立体声系统的东西大胆地写道“除了‘四通道单元（即内建的 SQ、RM 和 CD-4 解码接收器）’，没有任何音频设备是被期待的”。这也表明了《大众电子》的订阅者一定对电子有很多深入的了解。 - -不过在 [1975 年 1 月刊][2] 中，杂志为读者们带来了一些他们从没见过的东西。在标题“发现项目”下面，杂志的封面是一个黑灰色的盒子，它的前面板上有一组开关和灯。这便是 Altair 8800，“世界上首个有商业竞争力的迷你计算机”，它的售价低于 400 美元。尽管 Altair 作为“迷你计算机”被宣传，但其实大家都将它称为“微机”和PC，它是首个商业上成功的新型电脑。Altair 十分小巧而且很便宜，以至于它成为了当时家家户户都能用起的电脑。正如 Salsberg 所写道，它在《大众电子》上的出现意味着：“家用电脑的时代终于到来了。” - -![《大众电子》1975 年 1 月刊的封面][3] - -此前，我曾写过 [关于 Altair 的文章][4]，但我觉得 Altair 有让我再次介绍的价值。它在当时性能并不强（虽然它便宜很多），也不是首个装载微处理器（由至少三个微处理器组成）的通用计算机。但是 Altair 是一种可供我们所有人使用的计算机。它是历史上包括我们所拥有的设备中首台流行的计算机，早于 Altair 计算机都是完全不同的机器，它们由穿孔卡编程并且很少与用户交互。不过 Altair 也是台极其简单的计算机，它不附带任何操作系统甚至引导加载器。除非你购买其它外设，否则 Altair 就是一台装配 RAM 并且只有一组开关和灯泡的机器。由于 Altair 操作简单，学习计算的基本理论都成了十分简单的事情，就好像他们在数字世界冒险时遇上了旧世界的居民一样。 - -### Roberts 和他的公司 - -Altair 被一家名为 MITS 的公司设计和制造，这家公司位于美国新墨西哥州的阿尔布开克。MITS 由一个叫 H. Edward Roberts 运营。他们起初借 19 世纪 70 年代的热潮制造模型火箭的遥测系统。集成电路将计算器的成本降低到十分可观的数字，突然之间它就成了美国教授们的必需品。不幸的是，由于计算器市场竞争过于激烈，到了 1974 年，MITS 便负债累累。 - -1974 年在计算机界是奇迹迭出的一年annus mirabilis。一月的时候，惠普公司推出了世界首个可编程的手持计算器 HP-65。四月的时候，Intel 发布了 Intel 8080，他们的第二款 8 位微处理器，它也是首款受欢迎的微处理器。接着，六月的时候，《Radio Electronics》杂志介绍了 Mark-8 这个自制迷你计算机，它使用了 Intel 在 1972 年推出的 Intel 8008 微处理器。Mark-8 是使用微处理器搭建的第三台电脑，它的首次登场是在杂志的封面上。Mark-8 在《Radio Electronics》上的出现促使了《大众电子》寻找微机项目的出现。 - -《大众电子》的订阅者们其实早在 1974 年 12 月就通过电邮获得了 1975 年 1 月刊的副本。他们公布的 Altair 为这个奇迹迭出的一年annus mirabilis画上了圆满的句号。Altair 的出现是十分重要的，因为此前从未有过向公众提供的价格公道而又功能齐全的电脑。当时，作为最受欢迎的迷你计算机之一的 PDP-8 要几千美金才能买到。不过 Altair 搭载的 Intel 8080 芯片几乎能与 PDP-8 匹敌；8080 支持更广泛的指令集，而且 Altair 可以扩展到 64 kb 内存，显然强于仅有 4 kb 内存的 PDP-8。并且，Mark-8 也不是他的对手，因为它搭载的是只能处理 16 kb 内存的 Intel 8008。在 Mark-8 必须由用户按照说明书手动拼装的情况下，Altair 在购买时就已经被组装好了（不过由于后来 MITS 被大量订单淹没，最后真正能获得 Altair 的方式也只有买零件拼装了）。 - -对许多《大众电子》的读者来说，Altair 是他们了解数字计算的起点。1975 年 1 月刊上那篇介绍 Altair 的文章由 Roberts 和 Altair 的联合设计师 William Yates 所写。Roberts 和 Yates 煞费苦心地用电工和无线电狂热者们所熟悉的词汇来介绍了数字硬件和计算机编程的基本概念。他们写道：“一台计算机其实由一堆可变的硬件构成。仅需修改储存于内存之中的为组合形式，便可改变硬件设备的种类。”同时，Roberts 和 Yates 认为编程的基本概念是“足够简单并能在较短时间内掌握，但是想要成为一个高效的程序员必须经验丰富且富有创造力。”对此我十分认同。尽管已经组装好了，文章仍包含了用来讲解 Intel 8080 的组成的详细图表。文章解释了 CPU 和计算机内存单元的区别，堆栈指针的概念和汇编语言以及更高级的语言（例如 FORTRAN 和 BASIC）比起手动输入机器码所带来的巨大优势。 - -其实，《大众电子》在 1975 年 1 月刊之前就出版过 Roberts 撰写的系列文章。这一系列作为短期课程被收录在“数字逻辑”专栏中。在 1974 年 12 月刊中，Roberts 为读者们带来了关于构建“超低成本计算机终端”的文章，文章中介绍了可以用于 8 位电脑中输入值的八进制键盘。在介绍这个键盘时，Roberts 解释了晶体管到晶体管的逻辑工作原理，以及关于构建一种可以“记住”数字值的触发器的方法。Roberts 承诺说，这个键盘可以在下个月即将公布的 Altair 电脑中使用。 - -有多少《大众电子》的读者制作了这个键盘我们无从得知，但是那个键盘的确是个很有用的东西。如果没有键盘和其它输入设备，我们只能通过拨动 Altair 面板上的开关来输入值。Altair 的面板上有 16 行开关被用来设置地址，而下方的 8 个则是用来操作计算机的。16 行中最右边的开关是用来指定要储存在内存中的值的。这么做不无道理，因为 Intel 8080 使用 16 位的值来处理 8 位的信息。而这 16 个开关每一个都代表了一个位，当开关向上时代表 1，向下则代表 0。用这样的方式交互是个启示（一会儿我们就会讲到），因为 Altair 的面板是真正的二进制界面。这使得你可以触摸到裸露的金属。 - -尽管在当下 Altair 的界面对我们来说完全不像是人用的，不过在那个时候这可是不平凡的。比如 PDP-8 的面板上有个类似的但更漂亮的二进制输入装置，而且它被涂上了吸引人的黄色和橙色，不过讲真，它应该重新来过。然而 PDP-8 经常与纸带阅读器或电传打字机配合使用，这使得程序输入更加容易。这些 I/O 设备价格高昂，这意味着 Altair 的用户们大都会被面板卡住。正如你所想，通过这一堆开关进入一个大型程序是个繁重的工作。不过幸运的是，Altair 可以与盒式记录器连接，这样一来载入程序就不是什么难事了。Bill Gates 和 Paul Allen 进行了微软的首次商业合作，为 Altair 编写了 BASIC 语言，并在 1975 年以 MITS 许可证发行。此后，那些买得起电传打字机的用户就能 [通过纸带来将 BASIC 载入 Altair][5] 了，并能使得用户能够通过字符界面与 Altair 交互。之后，BASIC 便成为了学生们最爱的入门编程语言，并成了早期微机时代的标准接口。 - -### z80pack - -多亏了网络上一些人，特别是 Udo Munk 的努力，你可以在你的电脑上运行 Altair 的模拟器。这个模拟器是在 Zilog Z80 CPU 的虚拟套件上构建的，这个 CPU 可以运行 Intel 8080 的软件。Altair 模拟器允许你像 Altair 的用户们一样调整面板上的开关。尽管点击这些开关的感觉不如拨动真实开关，但是使用 Altair 模拟器仍是一个能让你知道二进制人机交互效率有多低的途径，不过我觉得这同时也很简明直观。 - -z80pack 是 Udo Munk 开发的 Z80 模拟器套件，你可以在 z80pack 的官网上找到它的下载链接。我在 [上一篇介绍 Altair 的文章中][4] 写到过在 macOS 上使用它的详细过程。如果你能编译 FrontPanel 库和 `altairsim` 可执行程序，你应该能直接运行 `altairsim` 并看到这个窗口： - -![模拟器中的 Altair 面板][6] - -在新版的 z80pack 中（比如我正在使用的 1.36 版本），你可以使用一个叫 Tarbell boot ROM 的功能，我觉得这是用来加载磁盘镜像的。经我测试，它的意思是你不能写入 RAM 中的前几个信息。在编辑 `/altairsim/conf/system.conf` 之后，你可以构建带有一个 16 页 RAM 且没有 ROM 或引导加载器的 Altair。除此之外，你还可以用这个配置文件来扩大运行模拟器的窗口，不得不说这还是挺方便的。 - -Altair 的面板看起来就很吓人，不过事实上并没有我们想象中的这么可怕。[Altair 说明书][7] 对解释开关和指示灯起到了很大的作用，这个 [YouTube 视频][8] 也是。若想运行一个简易的程序，你只需要了解一点点东西。Altair 右上方标签为 D0 到 D7 的指示灯代表当前处理地址的信息。标签为 A0 到 A15 的指示灯标识当前的地址。地址指示灯下的 16 个开关可以用来设置新地址；当 “EXAMINE” 开关被向上推动时，数据指示灯将会更新，并显示新地址上的内容。用这个功能，你便能观察到内存中所有的信息了。你也可以将 “EXAMINE” 推下来自动检查下一个位置上的信息，这使得检索信息更容易了。 - -要将模式保存到信息中，请使用最左边的 8 个标签为 0 到 7 的开关。然后，请向上推动 “DEPOSIT” 按钮。 - -在《大众电子》 的 [1975 年 2 月刊][9] 中，Roberts 和 Yates 制作了一小段程序来确保用户们的 Altair 正常工作。这个程序从内存中读取两个整型数据并添加之后将它们存回内存中。这个小程序仅由 6 条指令组成，但是这 6 条指令包含了 14 条在一起的内存信息，所以要正确地输入它们需要一点时间。这个程序也被写入了 Altair 的说明书，原文如下： - -| Address | Mnemonic | Bit Pattern | Octal Equivalent | -| :------: | :------: | :------: | :------: | -| 0 | LDA | 00 111 010 | 0 7 2 | -| 1 | (address) | 10 000 000 | 2 0 0 | -| 2 | (address) | 00 000 000 | 0 0 0 | -| 3 | MOV B, A | 01 000 111 | 1 0 7 | -| 4 | LDA | 00 111 010 | 0 7 2 | -| 5 | (address) | 10 000 001 | 2 0 1 | -| 6 | (address) | 00 000 000 | 0 0 0 | -| 7 | ADD B | 10 000 000 | 2 0 0 | -| 8 | STA | 00 110 010 | 0 6 2 | -| 9 | (address) | 10 000 010 | 2 0 2 | -| 10 | (address) | 00 000 000 | 0 0 0 | -| 11 | JMP | 11 000 011 | 3 0 3 | -| 12 | (address) | 00 000 000 | 0 0 0 | -| 13 | (address) | 00 000 000 | 0 0 0 | - -如果你通过开关来输入上面这些值，最终会得到一个程序，它会读取内存 128 中的值，并将其添加至 129 中，最终将其保存至 130 中。每条指令都会占用一个地址，它们最开始会被给予最低有效位，这便是第二个字节总会被清零（没有高于 255 的地址）的原因了。在输入这个程序并在 128 和 129 中输入了一些值之后，你可以向下推动 “RUN” ，之后再将它推到 “STOP” 位置。因为程序循环执行，以一秒内执行上千次的速度反复地添加并保存那些值。并且最后得到的值总是相同的，如果你暂停程序并检查 130，你应该能找到正确答案。 - -我不知道普通的 Altair 用户是否使用过，不过 z80pack 包括了一个汇编程序 —— `z80asm`，意思是适用于 Z80 的汇编程序Z80 assembly，所以它使用了不同的助记符。不过因为 Z80 是被设计来适配为 Intel 8080 写的软件的，所以即使助记符不一样，它们的操作码也是相同的。你可以直接将 `z80asm` 装载进 Altair： - -``` - ORG 0000H -START: LD A,(80H) ;Load from address 128. - LD B,A ;Move loaded value from accumulator (A) to reg B. - LD A,(81H) ;Load from address 129. - ADD A,B ;Add A and B. - LD (82H),A ;Store A at address 130. - JP START ;Jump to start. -``` - -编译之后，你可以调用汇编程序来将其转换为 Intel HEX 文件： - -```shell -$ ./z80asm -fh -oadd.hex add.asm -``` - -我们用带有 `h` 参数的 `-f` 标识来定义输出的 HEX 文件。你可以用 `-x` 标识来传递 HEX 文件，从而使得 Altair 能够加载程序： - -```shell -$ ./altairsim -x add.hex -``` - -这会在内存中自动设置前 14 个信息，就和你通过开关手动输入这些值一样。你可以直接使用 “RUN” 按钮来替代以前那些繁琐的步骤，这是如此的简单！ - -我不觉得有很多 Altair 用户以这种方式来编写软件。Altair BASIC 发布后，使得 BASIC 成为了 Altair 编程最简单的方法。z80pack 同时也包括了一些包含不同版本 Altair BASIC 的 HEX 文件；在模拟器中，你可以用这个方式加载 4.0 版本的 4K BASIC： - -```shell -$ ./altairsim -x basic4k40.hex -``` - -当你开启模拟器并按下 “RUN” 按钮之后，你就会看到 BASIC 开始执行了，同时它会在终端中与你交互。它首先会提示你输入你内存的可用量，我们输入 4000 字节。随后，在显示 “OK” 提示符之前，它会问你几个问题，Gates 和 Allen 用这个来代替标准的 “READY” 并以此节省内存。在这之后，你便可以使用 BASIC 了： - -``` -OK -PRINT 3 + 4 - 7 -``` - -尽管只有极小的 4 kb 空间来运行 BASIC，不过你仍迈出了使用面板操控电脑的重要一步。 - -很显然，Altair 远不及如今的家用电脑，并且比它晚十多年发布的 Mac 电脑看上去也是对 Altair 电脑的巨大飞跃。但是对亲手组装了 Altair 的《大众电子》的读者们来说，只用了低于 400 美金和一半的书柜空间的 Altair 才是第一个它们真正能拥有的全功能电脑。对那时只能用 [一叠卡片][10] 或一卷磁带来与计算机交互的人们来说，Altair 是个令人眼前一亮的玩意。这之后的微机基本都是在对 Altair 改进，使得它更易用。从某种意义上来说，我们甚至可以把它们看成更复杂的 Altair。Altair，一个野兽派的极简作品，却为之后的许多微机打下了铺垫。 - -如果你觉得这篇文章写的不错，你可以在推特上关注 [@TwoBitHistory][11] 或订阅 [RSS feed][12] 来获得我们文章的更新提醒。文章每两周就会更新一次！ - -TwoBitHistory 的上一篇文章是………… - -> “跟我一起来进行这振奋人心的冒险吧！只需要十分钟，你就能了解到 10 年都没人用过的软件。” -> -> — TwoBitHistory (@TwoBitHistory) [写于 2018 年 7 月 7 日][13] - --------------------------------------------------------------------------------- - -via: https://twobithistory.org/2018/07/22/dawn-of-the-microcomputer.html - -作者：[Two-Bit History][a] -选题：[lujun9972][b] -译者：[zhs852](https://github.com/zhs852) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://twobithistory.org -[b]: https://github.com/lujun9972 -[1]: https://www.americanradiohistory.com/Archive-Poptronics/70s/1974/Poptronics-1974-12.pdf -[2]: https://www.americanradiohistory.com/Archive-Poptronics/70s/1975/Poptronics-1975-01.pdf -[3]: https://twobithistory.org/images/jan1975-altair.jpg -[4]: https://twobithistory.org/2017/12/02/simulating-the-altair.html -[5]: https://www.youtube.com/watch?v=qv5b1Xowxdk -[6]: https://www.autometer.de/unix4fun/z80pack/altair.png -[7]: http://www.classiccmp.org/dunfield/altair/d/88opman.pdf -[8]: https://www.youtube.com/watch?v=suyiMfzmZKs -[9]: https://www.americanradiohistory.com/Archive-Poptronics/70s/1975/Poptronics-1975-02.pdf -[10]: https://twobithistory.org/2018/06/23/ibm-029-card-punch.html -[11]: https://twitter.com/TwoBitHistory -[12]: https://twobithistory.org/feed.xml -[13]: https://twitter.com/TwoBitHistory/status/1015647820353867776?ref_src=twsrc%5Etfw diff --git a/translated/talk/20190108 Hacking math education with Python.md b/translated/talk/20190108 Hacking math education with Python.md new file mode 100644 index 0000000000..120e56c521 --- /dev/null +++ b/translated/talk/20190108 Hacking math education with Python.md @@ -0,0 +1,86 @@ +[#]: collector: (lujun9972) +[#]: translator: (HankChow) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Hacking math education with Python) +[#]: via: (https://opensource.com/article/19/1/hacking-math) +[#]: author: (Don Watkins https://opensource.com/users/don-watkins) + +将 Python 结合到数学教育中 +====== +> 身兼教师、开发者、作家数职的 Peter Farrell 来讲述为什么使用 Python 来讲数学课会比传统方法更加好。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/getting_started_with_python.png?itok=MFEKm3gl) + +数学课一直都是很讨厌的一件事情，尤其对于在传统教学方法上吃过苦头的人（例如我）来说。传统教学方法强调的是死记硬背和理论知识，这种形式与学生们的现实世界似乎相去甚远。 + +[Peter Farrell][1] 作为一位 Python 开发者和数学教师，发现学生在数学课程中遇到了困难，于是决定尝试使用 Python 来帮助介绍数学概念。 + +Peter 的灵感来源于 Logo 语言之父 [Seymour Papert][2]，他的 Logo 语言现在还存在于 Python 的 [Turtle 模块][3]中。Logo 语言中的海龟形象让 Peter 喜欢上了 Python，并且进一步将 Python 应用到数学教学中。 + +Peter 在他的新书《[Python 数学奇遇记Math Adventures with Python][5]》中分享了他的方法：“图文并茂地指导如何用代码探索数学”。因此我最近对他进行了一次采访，向他了解更多这方面的情况。 + +**Don Watkins（译者注：本文作者）：** 你的教学背景是什么？ + +**Peter Farrell：** 我曾经当过八年的数学老师，之后又教了十年的数学。我还在当老师的时候，就阅读过 Papert 的 《[头脑风暴Mindstorms][6]》并从中受到了启发，将 Logo 语言和海龟引入到了我所有的数学课上。 + +**DW：** 你为什么开始使用 Python 呢？ + +**PF：** 在我当家教的时候，需要教学一门枯燥刻板的数学课程，这是一个痛苦的过程。后来我引入了 Logo 语言和海龟，我的学生刚好是一个编程爱好者，他非常喜欢这样的方式。在接触到函数和实际的编程之后，他还提议改用 Python。尽管当时我还不了解 Python，但看起来好像和 Logo 语言差别不大，我就同意了。后来我甚至坚持在 Python 上一条道走到黑了！ + +我还曾经寻找过 3D 图形方面的软件包，用来模拟太阳系行星的运动轨迹，让学生们理解行星是如何在牛顿的万有引力定律作用下运动的。很多图形软件包都需要用到 C 语言编程或者其它一些很复杂的内容，后来我发现了一个叫做 VisualPython 的软件包，它非常方便使用。于是在那之后的几年里，我就一直在用 [Vpython][7] 这个软件包。 + +所以，我是在和学生一起学习数学的时候被介绍使用 Python 的。在那段时间里，他是我的编程老师，而我则是他的数学老师。 + +**DW：** 是什么让你对数学感兴趣？ + +**PF：** 我是通过传统的方法学习数学的，那时候都是用手写、用纸记、在黑板上计算。我擅长代数和几何，在大学的时候也接触过 Basic 和 Fortran 编程，但那个时候也没有从中获取到灵感。直到后来在从编程中收到了启发，编程可以让你将数学课上一些晦涩难懂的内容变得简单直观，也能让你轻松地绘图、调整、探索，进而发现更多乐趣。 + +**DW：** 是什么启发了你使用 Python 教学？ + +**PF：** 还是在我当家教的时候，我惊奇地发现可以通过循环来计算对同一个函数输入不同参数的结果。如果用人手计算，可能要花半个小时的时间，但计算机瞬间就完成了。在这样的基础上，我们只要将一些计算的过程抽象成一个函数，再对其进行一些适当的扩展，就可以让计算机来计算了。 + +**DW：** 你的教学方法如何帮助学生，特别是在数学上感觉吃力的学生？如何将 Python 编程和数学结合起来 + +**PF：** 很多学生，尤其是高中生，都认为通过手工计算和画图来解决问题的方式在当今已经没有必要了，我并不反对这样的观点。例如，使用 Excel 来处理数据确实应该算是办公室工作的基本技能。学习任何一种编程语言，对公司来说都是一项非常有价值的技能。因此，使用计算机计算确实是有实际意义的。 + +而使用代码来为数学课创造艺术，则是一项革命性的改变。例如，仅仅是把某个形状显示到屏幕上，就需要使用到数学，因为位置需要用 x-y 坐标去表示，而尺寸、颜色等等都是数字。如果想要移动或者更改某些内容，会需要用到变量。更特殊地，如果需要改变位置，就需要更有效的向量来实现。这样的最终结果是，类似向量、矩阵这些难以捉摸的空洞概念会转变成实打实有意义的数学工具。 + +那些看起来在数学上吃力的学生，或许只是不太容易接受“书本上的数学”。因为“书本上的数学”过分强调了死记硬背和循规蹈矩，而有些忽视了创造力和实际应用能力。有些学生其实擅长数学，但并不适应学校的教学方式。我的方法会让父母们看到他们的孩子通过代码画出了很多有趣的图形，然后说：“我从来不知道正弦和余弦还能这样用！” + +**DW：** 你的教学方法是如何在学校里促进 STEM 教育的呢？ + +**PF：** 我喜欢将这几个学科统称为 STEM（科学、技术、工程、数学Science, Technology, Engineering and Mathematics） 或 STEAM（科学、技术、工程、艺术、数学Science, Technology, Engineering, Art and Mathematics）。但作为数学工作者，我很不希望其中的 M 被忽视。我经常看到很多很小的孩子在 STEM 实验室里参与一些有趣的项目，这表明他们已经在接受科学、技术和工程方面的教育。与此同时，我发现数学方面的材料和项目却很少。因此，我和[机电一体化][8]领域的优秀教师 Ken Hawthorn 正在着手解决这个问题。 + +希望我的书能够帮助鼓励学生们在技术上有所创新，无论在形式上是切实的还是虚拟的。同时书中还有很多漂亮的图形，希望能够激励大家去体验编程的过程，并且应用到实际中来。我使用的软件（[Python Processing][9]）是免费的，在树莓派等系统上都可以轻松安装。因为我认为，个人或者学校的成本问题不应该成为学生进入 STEM 世界的门槛。 + +**DW：** 你有什么想要跟其他的数学老师分享？ + +**PF：** 如果数学教学机构决定要向学生教导数字推理、逻辑、分析、建模、几何、数据解释这些内容，那么它们应该承认，可以通过编程来实现这些目标。正如我上面所说的，我的教学方法是在尝试使传统枯燥的方法变得直观，我认为任何一位老师都可以做到这一点。他们只需要知道其中的本质做法，就可以使用代码来完成大量重复的工作了。 + +我的教学方法依赖于一些免费的图形软件，因此只需要知道在哪里找到这些软件包，以及如何使用这些软件包，就可以开始引导学生使用 21 世纪的技术来解决实际问题，将整个过程和结果可视化，并找到更多可以以此实现的模式。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/hacking-math + +作者：[Don Watkins][a] +选题：[lujun9972][b] +译者：[HankChow](https://github.com/HankChow) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/don-watkins +[b]: https://github.com/lujun9972 +[1]: https://twitter.com/hackingmath +[2]: https://en.wikipedia.org/wiki/Seymour_Papert +[3]: https://en.wikipedia.org/wiki/Turtle_graphics +[4]: https://opensource.com/life/15/8/python-turtle-graphics +[5]: https://nostarch.com/mathadventures +[6]: https://en.wikipedia.org/wiki/Mindstorms_(book) +[7]: http://vpython.org/ +[8]: https://en.wikipedia.org/wiki/Mechatronics +[9]: https://processing.org/ + diff --git a/translated/talk/20190114 Remote Working Survival Guide.md b/translated/talk/20190114 Remote Working Survival Guide.md new file mode 100644 index 0000000000..54893cbdca --- /dev/null +++ b/translated/talk/20190114 Remote Working Survival Guide.md @@ -0,0 +1,129 @@ +[#]: collector: (lujun9972) +[#]: translator: (beamrolling) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Remote Working Survival Guide) +[#]: via: (https://www.jonobacon.com/2019/01/14/remote-working-survival/) +[#]: author: (Jono Bacon https://www.jonobacon.com/author/admin/) + +远程工作生存指南 +====== +![](https://www.jonobacon.com/wp-content/uploads/2019/01/5b5471d7eadb585ec8b8a0c3_featureimage-remotejob-1080x675.jpg) + +远程工作似乎是最近的一个热门话题。CNBC 报道称， [70% 的专业人士至少每周在家工作一次][1]。同样地，CoSo Cloud 调查发现， [77% 的人在远程工作时效率更高][2] ，而 aftercollege 的一份调查显示， [8% 的千禧一代会更多地考虑提供远程工作的公司][3]。 这看起来很合理：技术，网络以及文化似乎越来越推动远程工作的发展。哦，自制咖啡也比以前任何时候更好喝了。 + +目前，我准备写另一篇关于公司如何优化远程工作的文章（所以请确保你加入我们的会员以持续关注——这是免费的）。 + +但今天，我想 **分享一些个人如何做好远程工作的建议**。 不管你是全职远程工作者，或者是可以选择一周某几天在家工作的人，希望这篇文章对你有用。 + +眼下，你需要明白， **远程工作不是万能药**。当然，穿着睡衣满屋子乱逛，听听反社会音乐，喝一大杯咖啡看起来似乎挺完美的，但这不适合每个人。 + +有的人需要办公室的结构。有的人需要办公室的社会元素。有的人需要从家里走出来。有的人在家里缺乏保持关注的纪律。有的人因为好几年未缴退税而避免政府工作人员来住处敲门。 + +**远程工作就好像一块肌肉：如果你锻炼并且保持它，那么它能带来极大的力量和能力**。 如果不这么做，结果就不一样了。 + +在我职业生涯的大多数时间里，我在家工作。我喜欢这么做。当我在家工作的时候，我更有效率，更开心，更有能力。我并非不喜欢在办公室工作，我享受办公室的社会元素，但我更喜欢在家工作时我的“空间”。 我喜欢听重金属音乐，但当整个办公室的人不想听到 [After The Burial][5] 的时候，这会引起一些问题。 +![][6] +“Squirrel.” +[图片来源][7] + +已经学会了如何正确平衡工作，旅行以及其他元素来管理我的远程工作，以下是我的一些建议。 请务必**在评论中分享一些你的建议**。 + +### 1\.你需要训练和习惯（以及了解你的“波浪”） + +远程工作确实是需要训练的一块肌肉。就像构建真正的肌肉一样，它需要一个清楚的惯例和一小块健康的训练混合起来。 + +永远保持穿戴整齐（不要穿睡衣）。设置你一天工作的开始和结束时间（大多时候我从早上9点工作到下午6点）。选好你的午餐休息时间（我的是中午12点）。选好你的早晨仪式（我的是电子邮件，紧接着是全面审查客户需求）。决定你的主工作地在哪（我的主工作地是我家里的工作室）。决定好每天你什么时候运动（大多数时候我在下午5点运动）。 + +**设计一个实际的习惯并坚持66天**。构建一个习惯需要很长时间，不要尝试着背离你的习惯。你越坚持这个习惯，做下去所花费的功夫越少。在这66天的末尾，你想都不会想，自然而然地就按习惯去做了。 + +话虽这么说，我们又不住在真空里 ([更干净，或者别的什么][8])。我们都有自己的“波浪”。 + +“波浪”是你为了改变做事的方法时，对日常做出的一些改变。举个例子，夏天的时候我通常需要更多的阳光。那时我经常会在室外的花园工作。临近假期的时候我更容易分心，所以我在上班时间会更需要呆在室内。有时候我只想要多点人际接触，因此我会在咖啡馆工作几周。有时候我就是喜欢在厨房或者长椅上工作。你需要学习你的“波浪”并倾听你的身体。 **首先构建你自己的兴趣，然后在你认识到自己的“波浪”的时候再对它进行适当的修改**。 + +### 2\. 和你的同事以及上司一起设立预期 + +不是每个人都知道怎么远程工作，如果你的公司对远程工作没那么熟悉，你尤其需要和同事一起设立预期。 + +这件事十分简单：**当你要设计自己的工作日常的时候，清楚地跟你的上司和团队进行交流。**让他们知道如何找到你，紧急情况下如何联系你，以及你在家的时候如何保持合作。 + +这里的通信构件至关重要。有些远程工作者很怕离开他们的电脑，因为害怕当他们不在的时候有人给他们发消息（他们担心别人会觉得他们在边吃奇多边看 Netflix）。 + +你需要离开一会的时间。你需要吃午餐的时候眼睛不用一直盯着电脑屏幕。你又不是911接线员。 **设定预期以后，有时候你可能不能立刻回复，但你会尽快回复**。 + +同样地，设定你的一般可用性的预期。举个例子，我对客户设立的预期是我一般每天早上9点到下午6点工作。当然，如果某个客户急需某样东西，我很乐意在这段时间外回应他，但作为一个一般性规则，我通常只在这段时间内工作。这对于生活的平衡是必要的。 + +### 3\. 分心是你的敌人，它们需要管理 + +我们都会分心，这是人类的本能。让你分心的事情可能是你的孩子回家了，想玩变形金刚：救援机器人；可能是看看Facebook，Instagram，或者 Twitter 以确保你不会错过任何不受欢迎的政治观点，或者某人的午餐图片；可能是你生活中即将到来的某件事带走了你的注意力（例如，即将举办的婚礼，活动，或者一次大旅行）。 + +**你需要明白什么让你分心以及如何管理它**。举个例子，我知道我的电子邮件和 Twitter 会让我分心。我经常查看它们，并且每次查看都会让我脱离我正在工作的空间。拿水或者咖啡的时候我总会分心去吃零食，看 Youtube 的视频。 + +![][9] +我的分心克星 + +由电子产品造成的分心有一个简单对策：**锁起来**。直到你完成你手头的事情再关闭选项卡。有繁重的工作的时候我总这么干：我把让我分心的东西锁起来，直到做完手头的工作。这需要控制能力，但所有的一切都需要。 + +因为别人影响而分心的元素更难解决。如果你是有家庭的人，你需要在你工作的时候不被打扰，你通常需要独处。这也是为什么家庭办公室这么重要：你需要设一些“爸爸/妈妈正在工作”的界限。如果有急事才能进来，否则让孩子自个儿玩去。 + +把让你分心的事分开有许多方法：把你的电话静音；把自己的状态设成“离开”；换到一个没有让你分心的事的房间（或建筑物）。再重申一次，了解是什么让你分心并控制好它。如果不这么做，你会永远被分心的事摆布。 + +### 4\. （良好的）关系需要面对面的关注 + +有的角色比其他角色与远程工作更合拍。例如，我见过工程、质量保证、支持、安全以及其他团队（通常更专注于数字协作）的出色工作。其他团队，如设计或营销，往往在远程环境下更难熬（因为它们更注重触觉）。 + +但是，对于任何团队而言，建立牢固的关系至关重要，而现场讨论，协作和社交很有必要。我们的许多感官（例如肢体语言）在数字环境中被删除，这些在我们建立信任和关系的方式中发挥着关键作用。 + +![][10] +火箭也很有帮助 + +这尤为重要，如果（a）你初来这家公司，需要建立关系；（b）你是一个新角色，需要和你的团队建立关系；或者（c）你处于领导地位，建立买入和参与是你工作的关键部分。 + +**解决方法是？合理搭配远程工作与面对面的时间。** 如果你的公司就在附近，可以用一部分的时间在家工作，一部分时间在公司工作。如果你的公司比较远，安排定期前往办公室（并对你的上司设定你需要这么做的预期）。例如，当我在 XPRIZE 工作的时候，我每几周就会飞往洛杉矶几天。当我在 Canonical 工作时（总部在伦敦），我们每三个月来一次冲刺。 + +### 5\. 保持专注，不要松懈 + +本文所有内容的关键在于构建能力，并培养远程工作的肌肉。这就像建立你的日常，坚持它，并明白你的“波浪”和让你分心的事情以及如何管理它们一样简单。 + +我以一种相当具体的方式来看待这个世界：**我们所做的一切都有机会得到改进和完善**。举个例子，我已经公开演讲超过 15 年，但我总是能发现新的改进方法，以及修复新的错误（说到这些，请参阅我的 [提升你公众演讲的10个方法][11])。 + +发现新的改善方法，以及把每个绊脚石和错误视为一个开启新的不同的“啊哈！”时刻让人兴奋。远程工作和这没什么不同：寻找有助于解锁方式的模式，让你的远程工作时间更高效，更舒适，更有趣。 + +![][12] +看看这些书。它们非常适合个人发展。 +参阅我的 [150 美元个人发展工具包][13] 文章 + +...但别为此狂热。有的人花尽他们每一分钟来关注如何变得更好，他们经常以“做得还不够好”，“完成度不够高”等为由打击自己，无法达到他们内心关于完美的不切实际的观点。 + +我们都是人，我们是有生命的，不是机器人。始终致力于改进，但要明白不是所有东西都是完美的。你将会有一些休息日或休息周。你将会因为压力和倦怠而挣扎。你将会处理一些在办公室比远程工作更容易的情况。从这些时刻中学习，但不要沉迷于此。生命太短暂了。 + +**你有什么提示，技巧和建议吗？你如何管理远程工作？我的建议中还缺少什么吗？在评论区中与我分享！** + + +-------------------------------------------------------------------------------- + +via: https://www.jonobacon.com/2019/01/14/remote-working-survival/ + +作者：[Jono Bacon][a] +选题：[lujun9972][b] +译者：[beamrolling](https://github.com/beamrolling) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.jonobacon.com/author/admin/ +[b]: https://github.com/lujun9972 +[1]: https://www.cnbc.com/2018/05/30/70-percent-of-people-globally-work-remotely-at-least-once-a-week-iwg-study.html +[2]: http://www.cosocloud.com/press-release/connectsolutions-survey-shows-working-remotely-benefits-employers-and-employees +[3]: https://www.aftercollege.com/cf/2015-annual-survey +[4]: https://www.jonobacon.com/join/ +[5]: https://www.facebook.com/aftertheburial/ +[6]: https://www.jonobacon.com/wp-content/uploads/2019/01/aftertheburial2.jpg +[7]: https://skullsnbones.com/burial-live-photos-vans-warped-tour-denver-co/ +[8]: https://www.youtube.com/watch?v=wK1PNNEKZBY +[9]: https://www.jonobacon.com/wp-content/uploads/2019/01/IMG_20190114_102429-1024x768.jpg +[10]: https://www.jonobacon.com/wp-content/uploads/2019/01/15381733956_3325670fda_k-1024x576.jpg +[11]: https://www.jonobacon.com/2018/12/11/10-ways-to-up-your-public-speaking-game/ +[12]: https://www.jonobacon.com/wp-content/uploads/2019/01/DwVBxhjX4AgtJgV-1024x532.jpg +[13]: https://www.jonobacon.com/2017/11/13/150-dollar-personal-development-kit/ diff --git a/translated/tech/20120202 Computer Laboratory - Raspberry Pi- Lesson 2 OK02.md b/translated/tech/20120202 Computer Laboratory - Raspberry Pi- Lesson 2 OK02.md deleted file mode 100644 index 29fa885a4f..0000000000 --- a/translated/tech/20120202 Computer Laboratory - Raspberry Pi- Lesson 2 OK02.md +++ /dev/null @@ -1,70 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (qhwdw) -[#]: reviewer: () -[#]: publisher: () -[#]: url: () -[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 2 OK02) -[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok02.html) -[#]: author: (Robert Mullins http://www.cl.cam.ac.uk/~rdm34) - -计算机实验室 – 树莓派：课程 2 OK02 -====== - -OK02 课程是在 OK01 课程的基础上构建，通过不停地打开和关闭 `OK` 或 `ACT` LED 指示灯来实现闪烁。假设你已经有了 [课程 1：OK01][1] 操作系统的代码，它将是这一节课的基础。 - -### 1、等待 - -等待是操作系统开发中非常有用的部分。操作系统经常发现自己无事可做，以及必须要延迟。在这个例子中，我们想去做等待，为了能够让这种等待可以看得见，让 LED 灯打开关闭闪烁起来。如果你只是打开和关闭它，你什么都看不到，因为计算机每秒种可以打开和关闭它好几千次。在后面的课程中，我们将看到精确的等待，但是现在，我们只要简单地去消耗时间就足够了。 - -``` -mov r2,#0x3F0000 -wait1$: -sub r2,#1 -cmp r2,#0 -bne wait1$ -``` - -``` -sub reg,#val 从寄存器 reg 中的值上减去数字 val - -cmp reg,#val 将寄存器中的值与数字 val 进行比较。 - -如果最后的比较结果是不相等，那么执行后面的 ne 命令。 -``` - -上面是一个很常见的产生延迟的代码片段，由于每个树莓派基本上是相同的，所以产生的延迟大致也是相同的。它的工作原理是，使用一个 `mov` 命令将值 3F000016 推入到寄存器 r2 中，然后将这个值减 1，直到这个值减到 0 为止。在这里使用了三个新命令 `sub`、 `cmp` 和 `bne`。 - -`sub` 是减法命令，它只是简单地从第一个参数中的值减去第二个参数中的值。 - -`cmp` 是个很有趣的命令。它将第一个参数与第二个参数进行比较，然后将比较结果记录到一个称为当前处理器状态寄存器的专用寄存器中。你其实不用担心它，它记住的只是两个数谁大或谁小，或是相等而已。[^1] - -`bne` 其实是一个伪装的分支命令。在 ARM 汇编语言家族中，任何指令都可以有条件运行。这意味着如果上一个比较结果是某个确定的结果，那个指令才会运行。这是个非常有意思的技巧，我们在后面将大量使用到它，但在本案例中，我们在 `b` 命令后面的 ne 后缀意思是 “只有在上一个比较的结果是值不相等，才去运行分支”。`ne` 后缀可以使用在任何命令上，其它几个（总共 16 个）条件也是如此，比如 `eq` 表示等于，而 `lt` 表示小于。 - -### 2、组合到一起 - -上一节讲我提到过，通过将 GPIO 地址偏移量设置为 28（即：str r1,[r0,#28]）而不是 40 即可实现 LED 的关闭。因此，你需要去修改课程 OK01 的代码，在打开 LED 后，运行等待代码，然后再关闭 LED，再次运行等待代码，并包含一个回到开始位置的分支。注意，不需要重新启用 GPIO 的 16 号针脚的输出功能，这个操作只需要做一次就可以了。如果你想更高效，我建议你复用 r1 寄存器的值。所有课程都一样，你可以在 [下载页面][2] 找到所有的解决方案。需要注意的是，必须保证你的所有标签都是唯一的。当你写了 wait1\$: 你其它行上的标签就不能再使用 wait1\$ 了。 - -在我的树莓派上，它大约是每秒闪两次。通过改变我们所设置的 r2 寄存器中的值，可以很轻松地修改它。但是，不幸的是，我不能够精确地预测它的运行速度。如果你的树莓派未按预期正常工作，请查看我们的故障排除页面，如果它正常工作，恭喜你。 - -在这个课程中，我们学习了另外两个汇编命令：`sub` 和 `cmp`，同时学习了 ARM 中如何实现有条件运行。 - -在下一个课程，[课程 3：OK03][3] 中我们将学习如何编写代码，以及建立一些代码复用的标准，并且如果需要的话，可能会使用 C 或 C++ 来写代码。 - -[^1]:如果你点了这个链接，说明你一定想知道它的具体内容。CPSR 是一个由许多独立的比特位组成的 32 比特寄存器。它有一个位用于表示正数、零和负数。当一个 cmp 指令运行后，它从第一个参数上减去第二个参数，然后用这个位记下它的结果是正数、零还是负数。如果是零意味着它们相等（a-b=0 暗示着 a=b）如果为正数意味着 a 大于 b（a-b>0 暗示着 a>b），如果为负数意味着小于。还有其它比较指令，但 cmp 指令最直观。 - --------------------------------------------------------------------------------- - -via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok02.html - -作者：[Robert Mullins][a] -选题：[lujun9972][b] -译者：[qhwdw](https://github.com/qhwdw) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: http://www.cl.cam.ac.uk/~rdm34 -[b]: https://github.com/lujun9972 -[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok01.html -[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/downloads.html -[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html diff --git a/translated/tech/20120203 Computer Laboratory - Raspberry Pi- Lesson 3 OK03.md b/translated/tech/20120203 Computer Laboratory - Raspberry Pi- Lesson 3 OK03.md new file mode 100644 index 0000000000..21cdb40c2f --- /dev/null +++ b/translated/tech/20120203 Computer Laboratory - Raspberry Pi- Lesson 3 OK03.md @@ -0,0 +1,383 @@ +[#]: collector: (lujun9972) +[#]: translator: (qhwdw) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 3 OK03) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html) +[#]: author: (Robert Mullins http://www.cl.cam.ac.uk/~rdm34) + +计算机实验室 – 树莓派：课程 3 OK03 +====== + +OK03 课程基于 OK02 课程来构建，它教你在汇编中如何使用函数让代码可复用和可读性更好。假设你已经有了 [课程 2：OK02][1] 的操作系统，我们将以它为基础。 + +### 1、可复用的代码 + +到目前为止，我们所写的代码都是以我们希望发生的事为顺序来输入的。对于非常小的程序来说，这种做法很好，但是如果我们以这种方式去写一个完整的系统，所写的代码可读性将非常差。我们应该去使用函数。 + +``` +一个函数是一段可复用的代码片断，可以用于去计算某些答案，或执行某些动作。你也可以称它们为程序、整套动作或子动作。虽然它们都是不同的，但人们几乎都没有正确地使用这个术语。 + +你应该在数学上遇到了函数的概念。例如，余弦函数应用于一个给定的数时，会得到介于 -1 到 1 之间的另一个数，这个数就是角的余弦。一般我们写成 cos(x) 来表示应用到一个值 x 上的余弦函数。 + +在代码中，函数可以有多个输入（也可以没有输入），然后函数给出多个输出（也可以没有输出），并可能导致负面效应。例如一个函数可以在一个文件系统上创建一个文件，第一个输入是它的名字，第二个输入是文件的长度。 +``` + +![Function as black boxes][2] + +``` +函数可以认为是一个“黑匣子”。我们给它输入，然后它给我们输出，而我们不需要知道它是如何工作的。 +``` + +在像 C 或 C++ 这样的高级代码中，函数是语言的组成部分。在汇编代码中，函数只是我们的创意。 + +理想情况下，我们希望能够在我们的寄存器中设置一些值，分支地址，以及预期在某个时刻，分支将返回，并通过代码来设置输出值到寄存器。这就是我们所设想的汇编代码中的函数。困难之处在于我们用什么样的方式去设置寄存器。如果我们只是使用平时所接触到的任意方法去设置寄存器，每个程序可能使用不同的方法，这样你将会发现你很难理解其他程序员所写的代码。另外，编译器也不能像使用汇编代码那样轻松地工作，因为它们压根不知道如何去使用函数。为避免这种困惑，为每个汇编语言设计了一个称为应用程序二进制接口（ABI）的标准，由它来规范函数如何去运行。如果每个人都使用相同的方法去写函数，这样每个人都可以去使用其他人写的函数。在这里，我将教你们这个标准，而从现在开始，我所写的函数将全部遵循这个标准。 + +标准规定，寄存器 `r0`、`r1`、`r2` 和 `r3` 将被依此用于函数的输入。如果函数没有输入，那么它有没有值就无关紧要了。如果只需要一个输入，那么它应该总是在寄存器 `r0` 中，如果它需要两个输入，那么第一个输入在寄存器 `r0` 中，而第二个输入在寄存器 `r1` 中，依此类推。输出值也总是在寄存器 `r0` 中。如果函数没有输出，那么 `ro` 中是什么值就不重要了。 + +另外，标准要求当一个函数运行之后，寄存器 `r4` 到 `r12` 的值必须与函数启动时的值相同。这意味着当你调用一个函数时，你可以确保寄存器 `r4` 到 `r12` 中的值没有发生变化，但是不能确保寄存器 `r0` 到 `r3` 中的值也没有发生变化。 + +当一个函数运行完成后，它将返回到启动它的代码分支处。这意味着它必须知道启动它的代码的地址。为此，需要一个称为`lr`（链接寄存器）的专用寄存器，它总是在保存调用这个函数的指令的地址。 + +表 1.1 ARM ABI 寄存器用法 +| 寄存器 | 简介 | 保留 | 规则 | +| ------ | ---------- | ---- | ------------------------------------------------------------ | +| r0 | 参数和结果 | 否 | r0 和 r1 用于给函数传递前两个参数，以及函数返回的结果。如果函数返回值不使用它，那么在函数运行之后，它们可以携带任何值。 | +| r1 | 参数和结果 | 否 | | +| r2 | 参数 | 否 | r2 和 r3 用去给函数传递后两个参数。在函数运行之后，它们可以携带任何值。 | +| r3 | 参数 | 否 | | +| r4 | 通用寄存器 | 是 | r4 到 r12 用于保存函数运行过程中的值，它们的值在函数调用之后必须与调用之前相同。 | +| r5 | 通用寄存器 | 是 | | +| r6 | 通用寄存器 | 是 | | +| r7 | 通用寄存器 | 是 | | +| r8 | 通用寄存器 | 是 | | +| r9 | 通用寄存器 | 是 | | +| r10 | 通用寄存器 | 是 | | +| r11 | 通用寄存器 | 是 | | +| r12 | 通用寄存器 | 是 | | +| lr | 返回地址 | 否 | 当函数运行完成后，lr 中保存了分支的返回地址，但在函数运行完成之后，它将保存相同的地址。 | +| sp | 栈指针 | 是 | sp 是栈指针，在下面有详细描述。它的值在函数运行完成后，必须是相同的。 | + +通常，函数需要使用很多的寄存器，而不仅是 `r0` 到 `r3`。但是，由于 `r4` 到 `r12` 必须在系列动作完成之后值必须保持相同，因此它们需要被保存到某个地方。我们将它们保存到称为栈的地方。 + + +![Stack diagram][3] +``` +一个栈就是我们在计算中用来保存值的一个很形象的方法。就像是摞起来的一堆盘子，你可以从上到下来移除它们，而添加它们时，你只能从下到上来添加。 + +在函数运行时，使用栈来保存寄存器值是个非常好的创意。例如，如果我有一个函数需要去使用寄存器 r4 和 r5，它将在一个栈上存放这些寄存器的值。最后用这种方式，它可以再次将它拿回来。更高明的是，如果为完成运行我的函数，需要去运行另一个函数，并且那个函数需要保存一些寄存器，在它运行时，它将把寄存器保存在栈顶上，然后在结束后再将它们拿走。而这并不会影响我保存在寄存器 r4 和 r5 中的值，因为它们是在栈顶上添加的，拿走时也是从栈顶上取出的。 + +我们用专用的术语“栈帧”来表示使用特定的方法放到栈上的值。不是每种方法都使用一个栈帧，有些是不需要存储值的。 +``` + +因为栈非常有用，它被直接实现在 ARMv6 的指令集中。一个名为 `sp` （栈指针）的专用寄存器用来保存栈的地址。当需要有东西添加到栈上时，`sp` 寄存器被更新，这样就总是保证它保存的是栈上前一个东西的地址。`push {r4,r5}` 将推送 `r4` 和 `r5` 中的值到栈顶上，而 `pop {r4,r5}` 将（以正确的次序）取回它们。 + +### 2、我们的第一个函数 + +现在，关于函数的原理我们已经有了一些概念，我们尝试来写一个函数。由于是我们的第一个很基础的例子，我们写一个没有输入的函数，它将输出 GPIO 的地址。在上一节课程中，我们就是写到这个值上，但将它写成函数更好，因为我们在真实的操作系统中经常需要用到它，而我们不可能总是能够记住这个地址。 + +复制下列代码到一个名为 `gpio.s` 的新文件中。就像在`source` 目录中使用的 `main.s` 一样。我们将把与 GPIO 控制器相关的所有函数放到一个文件中，这样更好查找。 + +```assembly +.globl GetGpioAddress +GetGpioAddress: +ldr r0,=0x20200000 +mov pc,lr +``` + +```assembly +.globl lbl 使标签 lbl 从其它文件中可访问。 + +mov reg1,reg2 复制 reg2 中的值到 reg1 中。 +``` + +这就是一个很简单的完整的函数。`.globl GetGpioAddress` 命令是通知汇编器，让标签 `GetGpioAddress` 在所有文件中全局可访问。这意味着在我们的 `main.s` 文件中，我们可以使用分支指令到标签 `GetGpioAddress` 上，即便这个标签在那个文件中没有定义也没有问题。 + +你应该认得 `ldr r0,=0x20200000` 命令，它将 GPIO 控制器地址保存到 r0 中。由于这是一个函数，我们要让它输出寄存器 `r0` 中的值，因此我们不能再像以前那样随意使用任意一个寄存器了。 + +`mov pc,lr` 将寄存器 `lr` 中的值复制到 `pc` 中。正如前面所提到的，寄存器 `lr` 总是保存着方法完成后我们要返回的代码的地址。`pc` 是一个专用寄存器，它总是包含下一个要运行的指令的地址。一个普通的分支命令只需要改变这个寄存器的值即可。通过将 `lr` 中的值复制到 `pc` 中，我们就可以将运行的下一行命令改变成我们将要返回的那一行。 + +现在这里存在一个合乎常理的问题，那就是我们如何去运行这个代码？我们将需要一个特殊的分支类型 `bl`。它像一个普通的分支一样切换到一个标签，但它在切换之前先更新 `lr` 的值去包含一个分支之后的行的地址。这意味着当函数完成后，将返回到 `bl` 命令之后的那一行上。这就确保了函数能够像任何其它命令那样运行，它简单地运行，做任何需要做的事情，然后推进到下一行。这是函数最有用的方法。当我们使用它时，就将它们按“黑匣子”处理即可，不需要了解它是如何运行的，我们只了解它需要什么输入，以及它给我们什么输出即可。 + +到现在为止，我们已经明白了函数如何使用，下一节我们将使用它。 + +### 3、一个大的函数 + +现在，我们继续去实现一个更大的函数。我们的第一项任务是启用 GPIO 第 16 号针脚的输出。如果它是一个函数那就太好了。我们能够简单地指定针脚号作为函数的输入，然后函数将设置那个针脚的值。那样，我们就可以使用这个代码去控制任意的 GPIO 针脚，而不只是 LED 了。 + +将下列的命令复制到 `gpio.s` 文件中的 GetGpioAddress 函数中。 + +```assembly +.globl SetGpioFunction +SetGpioFunction: +cmp r0,#53 +cmpls r1,#7 +movhi pc,lr +``` + +``` +带后缀 ls 的命令只有在上一个比较命令的结果是第一个数字小于或等于第二个数字的情况下才会被运行。它是无符号的。 + +带后缀 hi 的命令只有上一个比较命令的结果是第一个数字大于第二个数字的情况下才会被运行。它是无符号的。 +``` + +在写一个函数时，我们首先要考虑的事情就是输入，如果输入错了我们怎么办？在这个函数中，我们有一个输入是 GPIO 针脚号，而它必须是介于 0 到 53 之间的数字，因为只有 54 个针脚。每个针脚有 8 个函数，被编号为 0 到 7，因此函数代码也必须是 0 到 7 之间的数字。我们可能假设输入应该是正确的，但是当在硬件上使用时，这种做法是非常危险的，因为不正确的值将导致极大的负面效应。所以，在这个案例中，我们希望确保输入值在正确的范围。 + +为了确保输入值在正确的范围，我们需要做一个检查，即 r0 <= 53 并且 r1 <= 7。首先我们使用前面看到的比较命令去将 `r0` 的值与 53 做比较。下一个指令 `cmpls` 仅在前一个比较指令结果是小于等于 53 时才会去运行。如果一切正常，它将寄存器 `r1` 的值与 7 进行比较，其它的部分都和前面的是一样的。如果最后的比较结果是寄存器值大于那个数字，最后我们将返回到运行函数的代码处。 + +这正是我们所希望的效果。如果 r0 中的值大于 53，那么 `cmpls` 命令将不会去运行，但是 `movhi` 会运行。如果 r0 中的值 <= 53，那么 `cmpls` 命令会运行，将 r1 中的值与 7 进行比较，如果它大于 7，`movhi` 会运行，函数结束，否则 `movhi` 不会运行，这样我们就确定 r0 <= 53 并且 r1 <= 7。 + +`ls`（低于或相同）与 `le`（小于或等于）有一些细微的差别，以及后缀 `hi` （高于）和 `gt` （大于）也一样有一些细微差别，我们在后面将会讲到。 + +将这些命令复制到上面的代码的下面位置。 + +```assembly +push {lr} +mov r2,r0 +bl GetGpioAddress +``` + +```assembly +push {reg1,reg2,...} 复制列出的寄存器 reg1、reg2、... 到栈顶。该命令仅能用于通用寄存器和 lr 寄存器。 + +bl lbl sets lr 设置下一个指令的地址并切换到标签 lbl。 +``` + +这三个命令用于调用我们第一个方法。`push {lr}` 命令复制 `lr` 中的值到栈顶，这样我们在后面可以检索到它。当我们调用 GetGpioAddress 时必须要这样做，我们将需要使用 `lr` 去保存我们函数的返回地址。 + +如果我们对 `GetGpioAddress` 函数一无所知，我们应该假设它改变了 `r0`、`r1`、`r2` 和 `r3` 的值 ，我们将移动我们的值到 r4 和 r5 中，以保持在它完成之后寄存器的值相同。幸运的是，我们知道 `GetGpioAddress` 做了什么，并且我们也知道它仅改变了 `r0` 到地址，它并没有影响 `r1`、`r2` 或 `r3` 的值。因此，我们仅去将 GPIO 针脚号从 `r0` 中移出，这样它就不会被覆盖掉，但我们知道，可以将它安全地移到 `r2` 中，因为 `GetGpioAddress` 并不去改变 `r2`。 + +最后我们使用 `bl` 指令去运行 `GetGpioAddress`。通常，运行一个函数，我们使用一个术语叫“调用”，从现在开始我们将一直使用这个术语。正如我们前面讨论过的，`bl` 通过更新 `lr` 中的下一个指令的地址，去调用一个函数，接着切换到函数。 + +当一个函数结束时，我们称为“返回”。当一个 `GetGpioAddress` 调用返回时，我们已经知道了 `r0` 中包含了 GPIO 的地址，`r1` 中包含了函数代码，而 `r2` 中包含了 GPIO 针脚号。我前面说过，GPIO 函数每 10 个保存在一个块中，因此首先我们需要去判断我们的针脚在哪个块中。这似乎听起来像是要使用一个除法，但是除法做起来非常慢，因此对于这些比较小的数来说，不停地做减法要比除法更好。 + +将下面的代码复制到上面的代码中最下面的位置。 + +```assembly +functionLoop$: + +cmp r2,#9 +subhi r2,#10 +addhi r0,#4 +bhi functionLoop$ +``` + +```assembly +add reg,#val 将数字 val 加到寄存器 reg 的内容上。 +``` + +这个简单的循环代码将针脚号与 9 进行比较。如果它大于 9，它将从针脚号上减去 10，并且将 GPIO 控制器地址加上 4，然后再次运行检查。 + +这样做的效果就是，现在，`r2` 中将包含一个 0 到 9 之间的数字，它是针脚号除以 9 的余数。`r0` 将包含这个针脚的函数所设置的 GPIO 控制器的地址。它就如同是 “GPIO 控制器地址 + 4 × (GPIO Pin Number ÷ 10)”。 + +最后，将下面的代码复制到上面的代码中最下面的位置。 + +```assembly +add r2, r2,lsl #1 +lsl r1,r2 +str r1,[r0] +pop {pc} +``` + +```assembly +移位参数 reg,lsl #val 表示将寄存器 reg 中二进制表示的数逻辑左移 val 位之后的结果作为与前面运算的操作数。 + +lsl reg,amt 将寄存器 reg 中的二进制数逻辑左移 amt 中的位数。 + +str reg,[dst] 与 str reg,[dst,#0] 相同。 + +pop {reg1,reg2,...} 从栈顶复制值到寄存器列表 reg1、reg2、.... 仅有通用寄存器与 pc 可以这样弹出值。 +``` + +这个代码完成了这个方法。第一行其实是乘以 3 的变体。乘法在汇编中是一个大而慢的指令，因为电路需要很长时间才能给出答案。有时使用一些能够很快给出答案的指令会让它变得更快。在本案例中，我们知道 r2 × 3 与 r2 × 2 + r2 是相同的。一个寄存器乘以 2 是非常容易的，因为它可以通过将二进制表示的数左移一位来很方便地实现。 + +ARMv6 汇编语言其中一个非常有用的特性就是，在使用它之前可以先移动参数所表示的位数。在本案例中，我将 `r2` 加上 `r2` 中二进制表示的数左移一位的结果。在汇编代码中，你可以经常使用这个技巧去更快更容易地计算出答案，但如果你觉得这个技巧使用起来不方便，你也可以写成类似 `mov r3,r2`； `add r2,r3`； `add r2,r3` 这样的代码。 + +现在，我们可以将一个函数的值左移 `r2` 中所表示的位数。大多数对数量的指令（比如加法和减法）都有一个可以使用寄存器而不是数字的变体。我们执行这个移位是因为我们想去设置表示针脚号的位，并且每个针脚有三个位。 + +然后，我们将函数计算后的值保存到 GPIO 控制器的地址上。我们在循环中已经算出了那个地址，因此我们不需要像 OK01 和 OK02 中那样在一个偏移量上保存它。 + +最后，我们从这个方法调用中返回。由于我们将 `lr` 推送到了栈上，因此我们 `pop pc`，它将复制 `lr` 中的值并将它推送到 `pc` 中。这个操作类似于 `mov pc,lr`，因此函数调用将返回到运行它的那一行上。 + +敏锐的人可能会注意到，这个函数其实并不能正确工作。虽然它将 GPIO 针脚函数设置为所要求的值，但它会导致在同一个块中的 10 个函数的所有针脚都归 0！在一个大量使用 GPIO 针脚的系统中，这将是一个很恼人的问题。我将这个问题留给有兴趣去修复这个函数的人，以确保只设置相关的 3 个位而不去覆写其它位，其它的所有位都保持不变。关于这个问题的解决方案可以在本课程的下载页面上找到。你可能会发现非常有用的几个函数是 `and`，它是计算两个寄存器的布尔与函数，`mvns` 是计算布尔非函数，而 `orr` 是计算布尔或函数。 + +### 4、另一个函数 + +现在，我们已经有了能够设置 GPIO 针脚的函数。我们还需要写一个能够打开或关闭 GPIO 针脚的函数。我们不需要写一个打开的函数和一个关闭的函数，只需要一个函数就可以做这两件事情。 + +我们将写一个名为 `SetGpio` 的函数，它用 `r0` 中的值作为第一个输入，`r1` 中的值作为第二个输入。如果值为 `0`，我们将关闭针脚，而如果为非零则打开针脚。 + +将下列的代码复制粘贴到 `gpio.s` 文件的结尾部分。 + +```assembly +.globl SetGpio +SetGpio: +pinNum .req r0 +pinVal .req r1 +``` + +```assembly +alias .req reg 设置寄存器 reg 的别名为 alias。 +``` + +我们再次需要 `.globl` 命令，标记它为其它文件可访问的全局函数。这次我们将使用寄存器别名。寄存器别名允许我们为寄存器使用名字而不仅是 `r0` 或 `r1`。到目前为止，寄存器别名还不是很重要，但随着我们后面写的方法越来越大，它将被证明非常有用，现在开始我们将尝试使用别名。当在指令中使用到 `pinNum .req r0` 时，它的意思是 `pinNum` 表示 `r0`。 + +将下面的代码复制粘贴到上述的代码下面位置。 + +```assembly +cmp pinNum,#53 +movhi pc,lr +push {lr} +mov r2,pinNum +.unreq pinNum +pinNum .req r2 +bl GetGpioAddress +gpioAddr .req r0 +``` + +```assembly +.unreq alias 删除别名 alias。 +``` + +就像在函数 `SetGpio` 中所做的第一件事情是检查给定的针脚号是否有效一样。我们需要同样的方式去将 `pinNum (r0)` 与 53 进行比较，如果它大于 53 将立即返回。一旦我们再次调用 `GetGpioAddress`，我们就需要将 `lr`推送到栈上来保护它，将将 `pinNum` 移动到 `r2` 中。然后我们使用 `.unreq` 语句来删除我们给 `r0` 定义的别名。因为针脚号现在保存在寄存器 `r2` 中，我们希望通过别名能够映射到它，因此我们重新定义到 `r2` 的别名。你应该每次在别名使用结束后，立即删除它，这样当它不再存在时，你就不会在后面的代码中因它而产生错误。 + +然后，我们调用了 `GetGpioAddress`，并且我们创建了一个指向 `r0`的别名。 + +将下面的代码复制粘贴到上述代码的后面位置。 + +```assembly +pinBank .req r3 +lsr pinBank,pinNum,#5a +lsl pinBank,#2 +add gpioAddr,pinBank +.unreq pinBank +``` + +```assembly +lsr dst,src,#val 将 src 中二进制表示的数右移 val 位，并将结果保存到 dst。 +``` + +对于打开和关闭 GPIO 针脚，每个针脚在 GPIO 控制器上有两个 4 字节组。在每个场景下，第一个 4 字节组控制前 32 个针脚，而第二个 4 字节组控制剩下的 22 个针脚。为了判断我们要设置的针脚在哪个 4 字节组中，我们需要将针脚号除以 32。幸运的是，这很容易，因为它等价于将二进制表示的针脚号右移 5 位。因此，在本案例中，我们将 `r3` 命名为 `pinBank`，然后计算 `pinNum ÷ 32`。因为它是一个 4 字节组，我们需要将它与 4 相乘的结果。它与二进制表示的数左移 2 位的相同的，这就是下一行的命令。你可能想知道我们能否将它右移 3 位呢，这样我们就可以先右移再左移。但是这样做是不行的，因为当我们做 ÷ 32 时有些答案可能是四舍五入的，而如果我们做 ÷ 8 时却不会这样。 + +现在，`gpioAddr` 的结果有可能是 20200000~16~（如果针脚号介于 0 到 31 之间），也有可能是 20200004~16~（如果针脚号介于 32 到 53 之间）。这意味着如果加上 28~10~ ，我们将得到打开针脚的地址，而如果加上 40~10~ ，我们将得到关闭针脚的地址。由于我们使用了 `pinBank` ，所以在它之后立即使用 `.unreq` 去删除它。、 + +将下面的代码复制粘贴到上述代码的下面位置。 + +```assembly +and pinNum,#31 +setBit .req r3 +mov setBit,#1 +lsl setBit,pinNum +.unreq pinNum +``` + +```assembly +and reg,#val 计算寄存器中的数与 val 的布尔与。 +``` + +函数的下一个部分是产生一个正确的设置数的位。至于 GPIO 控制器去打开或关闭针脚，我们在针脚号除以 32 的余数的位置，给它一个设置数字的位。例如，设置 16 号针脚，我们需要第 16 位设置数字为 1 。设置 45 号针脚，我们需要设置第 13 位数字为 1，因为 45 ÷ 32 = 1 余数 13。 + +这个 `and` 命令计算我们需要的余数。它是这样计算的，在输入中所有的二进制位都是 1 时，这个 `and` 运算的结果就是 1，否则就是 0。这是一个很基础的二进制操作，`and` 操作非常快。我们给定的输入是 “pinNum and 31~10~ = 11111~2~”。这意味着答案的后 5 位中只有 1，因此它肯定是在 0 到 31 之间。尤其是在 `pinNum` 的后 5 位的位置是 1 的地方它只有 1。这就如同被 32 整除的余数部分。就像 31 = 32 - 1 并不是巧合。 + +![binary division example][4] + +代码的其余部分使用这个值去左移 1 位。这就有了创建我们所需要的二进制数的效果。 + +将下面的代码复制粘贴到上述代码的下面位置。 + +```assembly +teq pinVal,#0 +.unreq pinVal +streq setBit,[gpioAddr,#40] +strne setBit,[gpioAddr,#28] +.unreq setBit +.unreq gpioAddr +pop {pc} +``` + +```assembly +teq reg,#val 检查寄存器 reg 中的数字与 val 是否相等。 +``` + +这个代码是方法的结束部分。如前面所说，当 `pinVal` 为 0 时，我们关闭它，否则就打开它。`teq`（等于测试）是另一个比较操作，它仅能够测试是否相等。它类似于 `cmp` ，但它并不能算出哪个数大。如果你只是希望测试数字是否相同，你可以使用 `teq`。 + +如果 `pinVal` 是 0，我们将 `setBit` 保存在 GPIO 地址偏移 40 的位置，我们已经知道，这样会关闭那个针脚。否则将它保存在 GPIO 地址偏移 28 的位置，它将打开那个针脚。最后，我们通过弹出 `pc` 返回，这将设置它为我们推送链接寄存器时保存的值。 + +### 5、一个新的开始 + +在完成上述工作后，我们终于有了我们的 GPIO 函数。现在，我们需要去修改 `main.s` 去使用它们。因为 `main.s` 现在已经有点大了，也更复杂了。将它分成两节将是一个很好的设计。到目前为止，我们一直使用的 `.init` 应该尽可能的让它保持小。我们可以更改代码来很容易地反映出这一点。 + +将下列的代码插入到 `main.s` 文件中 `_start: ` 的后面： + +``` +b main + +.section .text +main: +mov sp,#0x8000 +``` + +在这里重要的改变是引入了 `.text` 节。我设计了 `makefile` 和链接器脚本，它将 `.text` 节（它是默认节）中的代码放在地址为 8000~16~ 的 `.init` 节之后。这是默认加载地址，并且它给我们提供了一些空间去保存栈。由于栈存在于内存中，它也有一个地址。栈向下增长内存，因此每个新值都低于前一个地址，所以，这便得栈顶是最低的一个地址。 + +``` +图中的 'ATAGs' 节的位置保存了有关树莓派的信息，比如它有多少内存，默认屏幕分辨率是多少。 +``` + +![Layout diagram of operating system][5] + +用下面的代码替换掉所有设置 GPIO 函数针脚的代码： + +```assembly +pinNum .req r0 +pinFunc .req r1 +mov pinNum,#16 +mov pinFunc,#1 +bl SetGpioFunction +.unreq pinNum +.unreq pinFunc +``` + +这个代码将使用针脚号 16 和函数代码 1 去调用 `SetGpioFunction`。它的效果就是启用了 OK LED 灯的输出。 + +用下面的代码去替换打开 OK LED 灯的代码： + +```assembly +pinNum .req r0 +pinVal .req r1 +mov pinNum,#16 +mov pinVal,#0 +bl SetGpio +.unreq pinNum +.unreq pinVal +``` + +这个代码使用 `SetGpio` 去关闭 GPIO 第 16 号针脚，因此将打开 OK LED。如果我们（将第 4 行）替换成 `mov pinVal,#1` 它将关闭 LED 灯。用以上的代码去替换掉你关闭 LED 灯的旧代码。 + +### 6、继续向目标前进 + +但愿你能够顺利地在你的树莓派上测试我们所做的这一切。到目前为止，我们已经写了一大段代码，因此不可避免会出现错误。如果有错误，可以去查看我们的排错页面。 + +如果你的代码已经正常工作，恭喜你。虽然我们的操作系统除了做 [课程 2：OK02][1] 中的事情之外，还做不了别的任何事情，但我们已经学会了函数和格式有关的知识，并且我们现在可以更好更快地编写新特性了。现在，我们在操作系统上修改 GPIO 寄存器将变得非常简单，而它就是用于控制硬件的！ + +在 [课程 4：OK04][6] 中，我们将处理我们的 `wait` 函数，目前，它的时间控制还不精确，这样我们就可以更好地控制我们的 LED 灯了，进而最终控制所有的 GPIO 针脚。 + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html + +作者：[Robert Mullins][a] +选题：[lujun9972][b] +译者：[qhwdw](https://github.com/qhwdw ) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.cl.cam.ac.uk/~rdm34 +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok02.html +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/functions.png +[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/stack.png +[4]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/binary3.png +[5]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/osLayout.png +[6]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok04.html diff --git a/translated/tech/20120204 Computer Laboratory - Raspberry Pi- Lesson 4 OK04.md b/translated/tech/20120204 Computer Laboratory - Raspberry Pi- Lesson 4 OK04.md new file mode 100644 index 0000000000..69a56f3e72 --- /dev/null +++ b/translated/tech/20120204 Computer Laboratory - Raspberry Pi- Lesson 4 OK04.md @@ -0,0 +1,173 @@ +[#]: collector: (lujun9972) +[#]: translator: (qhwdw) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Computer Laboratory – Raspberry Pi: Lesson 4 OK04) +[#]: via: (https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok04.html) +[#]: author: (Robert Mullins http://www.cl.cam.ac.uk/~rdm34) + +计算机实验室 – 树莓派：课程 4 OK04 +====== + +OK04 课程在 OK03 的基础上进行构建，它教你如何使用定时器让 `OK` 或 `ACT` LED 灯按精确的时间间隔来闪烁。假设你已经有了 [课程 3：OK03][1] 的操作系统，我们将以它为基础来构建。 + +### 1、一个新设备 + +定时器是树莓派保持时间的唯一方法。大多数计算机都有一个电池供电的时钟，这样当计算机关机后仍然能保持时间。 + +到目前为止，我们仅看了树莓派硬件的一小部分，即 GPIO 控制器。我只是简单地告诉你做什么，然后它会发生什么事情。现在，我们继续看定时器，并继续带你去了解它的工作原理。 + +和 GPIO 控制器一样，定时器也有地址。在本案例中，定时器的基地址在 20003000~16~。阅读手册我们可以找到下面的表： + +表 1.1 GPIO 控制器寄存器 +| 地址 | 大小 / 字节 | 名字 | 描述 | 读或写 | +| -------- | ------------ | ---------------- | ---------------------------------------------------------- | ---------------- | +| 20003000 | 4 | Control / Status | 用于控制和清除定时器通道比较器匹配的寄存器 | RW | +| 20003004 | 8 | Counter | 按 1 MHz 的频率递增的计数器 | R | +| 2000300C | 4 | Compare 0 | 0 号比较器寄存器 | RW | +| 20003010 | 4 | Compare 1 | 1 号比较器寄存器 | RW | +| 20003014 | 4 | Compare 2 | 2 号比较器寄存器 | RW | +| 20003018 | 4 | Compare 3 | 3 号比较器寄存器 | RW | + +![Flowchart of the system timer's operation][2] + +这个表只告诉我们一部分内容，在手册中描述了更多的字段。手册上解释说，定时器本质上是按每微秒将计数器递增 1 的方式来运行。每次它是这样做的，它将计数器的低 32 位（4 字节）与 4 个比较器寄存器进行比较，如果匹配它们中的任何一个，它更新 `Control/Status` 以反映出其中有一个是匹配的。 + +关于位bit、字节、位字段bit field、以及数据大小的更多内容如下： + +> +> 一个位是一个单个的二进制数的名称。你可能还记得，一个单个的二进制数即可能是一个 1，也可能是一个 0。 +> +> 一个字节是一个 8 位集合的名称。由于每个位可能是 1 或 0 这两个值的其中之一，因此，一个字节有 2^8^ = 256 个不同的可能值。我们一般解释一个字节为一个介于 0 到 255（含）之间的二进制数。 +> +> ![Diagram of GPIO function select controller register 0.][3] +> +> 一个位字段是解释二进制的另一种方式。二进制可以解释为许多不同的东西，而不仅仅是一个数字。一个位字段可以将二进制看做为一系列的 1（开） 或 0（关）的开关。对于每个小开关，我们都有一个意义，我们可以使用它们去控制一些东西。我们已经遇到了 GPIO 控制器使用的位字段，使用它设置一个针脚的开或关。位为 1 时 GPIO 针脚将准确地打开或关闭。有时我们需要更多的选项，而不仅仅是开或关，因此我们将几个开关组合到一起，比如 GPIO 控制器的函数设置（如上图），每 3 位为一组控制一个 GPIO 针脚的函数。 +> + + +我们的目标是实现一个函数，这个函数能够以一个时间数量为输入来调用它，这个输入的时间数量将作为等待的时间，然后返回。想一想如何去做，想想我们都拥有什么。 + +我认为这将有两个选择： + + 1. 从计数器中读取一个值，然后保持分支返回到相同的代码，直到计数器的等待时间数量大于它。 + 2. 从计数器中读取一个值，加时间数量去等待，保存它到比较器寄存器，然后保持分支返回到相同的代码处，直到 `Control / Status` 寄存器更新。 + + +``` +像这样存在被称为"并发问题"的问题，并且几乎无法解决。 +``` + +这两种策略都工作的很好，但在本教程中，我们将只实现第一个。原因是比较器寄存器更容易出错，因为在增加等待时间并保存它到比较器的寄存器期间，计数器可能已经增加了，并因此可能会不匹配。如果请求的是 1 微秒（或更糟糕的情况是 0 微秒）的等待，这样可能导致非常长的意外延迟。 + +### 2、实现 + +``` +大型的操作系统通常使用等待函数来抓住机会在后台执行任务。 +``` + +我将把这个创建完美的等待方法的挑战留给你。我建议你将所有与定时器相关的代码都放在一个名为 `systemTimer.s` 的文件中（理由很明显）。关于这个方法的复杂部分是，计数器是一个 8 字节值，而每个寄存器仅能保存 4 字节。所以，计数器值将分到 2 个寄存器中。 + +下列的代码块是一个示例。 + +```assembly +ldrd r0,r1,[r2,#4] +``` + +```assembly +ldrd regLow,regHigh,[src,#val] 从 src 加上 val 数的地址上加载 8 字节到寄存器 regLow 和 regHigh 中。 +``` + +上面的代码中你可以发现一个很有用的指令是 `ldrd`。它从两个寄存器中加载 8 字节的内存。在本案例中，这 8 字节内存从寄存器 `r2` 中的地址开始，将被复制进寄存器 `r0` 和 `r1`。这种安排的稍微复杂之处在于 `r1` 实际上只持有了高位 4 字节。换句话说就是，如果如果计数器的值是 999,999,999,999~10~ = 1110100011010100101001010000111111111111~2~ ，那么寄存器 `r1` 中只有 11101000~2~，而寄存器 `r0` 中则是 11010100101001010000111111111111~2~。 + +实现它的更明智的方式应该是，去计算当前计数器值与来自方法启动后的那一个值的差，然后将它与要求的等待时间数量进行比较。除非恰好你希望的等待时间是支持 8 字节的，否则上面示例中寄存器 `r1` 中的值将会丢失，而计数器仅需要使用低位 4 字节。 + +当等待开始时，你应该总是确保使用大于比较，而不是使用等于比较，因为如果你尝试去等待一个时间，而这个时间正好等于方法开始的时间与结束的时间之差，那么你就错过这个值而永远等待下去。 + +如果你不明白如何编写等待函数的代码，可以参考下面的指南。 + +> +> 借鉴 GPIO 控制器的创意，第一个函数我们应该去写如何取得系统定时器的地址。示例如下： +> +> ```assembly +> .globl GetSystemTimerBase +> GetSystemTimerBase: +> ldr r0,=0x20003000 +> mov pc,lr +> ``` +> +> 另一个被证明非常有用的函数是在寄存器 `r0` 和 `r1` 中返回当前计数器值： +> +> ```assembly +> .globl GetTimeStamp +> GetTimeStamp: +> push {lr} +> bl GetSystemTimerBase +> ldrd r0,r1,[r0,#4] +> pop {pc} +> ``` +> +> 这个函数简单地使用了 `GetSystemTimerBase` 函数，并像我们前面学过的那样，使用 `ldrd` 去加载当前计数器值。 +> +> 现在，我们可以去写我们的等待方法的代码了。首先，在方法启动后，我们需要知道计数器值，当前计数器值我们现在已经可以使用 `GetTimeStamp` 来取得了。 +> +> ```assembly +> delay .req r2 +> mov delay,r0 +> push {lr} +> bl GetTimeStamp +> start .req r3 +> mov start,r0 +> ``` +> +> 这个代码复制我们的方法的输入，将延迟时间的数量放到寄存器 `r2` 中，然后调用 `GetTimeStamp`，这个函数将会在寄存器 `r0` 和 `r1` 中返回当前计数器值。接着复制计数器值的低位 4 字节到寄存器 `r3` 中。 +> +> 接下来，我们需要计算当前计数器值与读入的值的差，然后持续这样做，直到它们的差至少是延迟大小为止。 +> +> ```assembly +> loop$: +> +> bl GetTimeStamp +> elapsed .req r1 +> sub elapsed,r0,start +> cmp elapsed,delay +> .unreq elapsed +> bls loop$ +> ``` +> +> 这个代码将一直等待，一直到等待到传递给它的时间数量为止。它从计数器中读取数值，减去最初从计数器中读取的值，然后与要求的延迟时间进行比较。如果过去的时间数量小于要求的延迟，它切换到 `loop$`。 +> +> ```assembly +> .unreq delay +> .unreq start +> pop {pc} +> ``` +> +> 代码完成后，函数返回。 +> + + +### 3、另一个闪灯程序 + +你一旦明白了等待函数的工作原理，修改 `main.s` 去使用它。修改各处 `r0` 的等待设置值为某个很大的数量（记住它的单位是微秒），然后在树莓派上测试。如果函数不能正常工作，请查看我们的排错页面。 + +如果正常工作，恭喜你学会控制另一个设备了，会使用它，则时间由你控制。在下一节课程中，我们将完成 OK 系列课程的最后一节 [课程 5：OK05][4]，我们将使用我们已经学习过的知识让 LED 按我们的模式进行闪烁。 + +-------------------------------------------------------------------------------- + +via: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok04.html + +作者：[Robert Mullins][a] +选题：[lujun9972][b] +译者：[qhwdw](https://github.com/qhwdw) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: http://www.cl.cam.ac.uk/~rdm34 +[b]: https://github.com/lujun9972 +[1]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok03.html +[2]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/systemTimer.png +[3]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/images/gpioControllerFunctionSelect.png +[4]: https://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok05.html diff --git a/translated/tech/20180604 4 Firefox extensions worth checking out.md b/translated/tech/20180604 4 Firefox extensions worth checking out.md deleted file mode 100644 index d434a01af7..0000000000 --- a/translated/tech/20180604 4 Firefox extensions worth checking out.md +++ /dev/null @@ -1,109 +0,0 @@ -4个值得一提的 Firefox 拓展插件 -====== - -![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/firefox_blue_lead.jpg?itok=gYaubJUv) - -自从大约12年前 V2.0 推出以来, 我一直是 Firefox （火狐浏览器）的用户。那时它不是最好的网络浏览器，但我仍旧因为一个理由使用它：我最喜爱的无可比拟的浏览器拓展插件 - -如今, 我喜欢 Firefox 的当前状态，因为它快速、可定制和开源，但我也很欣赏扩展插件来体现原开发人员从未想到的特点： 如果您想在没有鼠标的情况下浏览呢？如果您不喜欢盯着晚上从显示器里出来的强光呢？对于 YouTube 和其他视频托管网站为了更好的性能和扩展使用一个更专业的播放器又如何呢？如果您需要更复杂的方法来禁用跟踪器和加快加载页面, 该怎么办？ - -幸运的是， 这些问题都有答案， 我将展现给你我最喜爱的拓展--所有这些都是免费软件或开源的 (即, 在 [GNU GPL][1]， [MPL][2]，或 [Apache][3] 许可下) 并使一个优秀的浏览器更好。 - -尽管术语加载项和扩展具有微微不同的含义,，但我将在本文中交替使用它们。 - -### Tridactyl - -![Tridactyl screenshot][5] - -Tridactyl 的新选项卡页面，展示隐藏连接。 - -[Tridactyl][6] 使您能够在大多数浏览活动中使用键盘。它的灵感来自于现已解散的 [Vimperator][7] 和 [Pentadactyl][8] ，这是由 [Vim][9] 默认绑定值启发的。由于我已经习惯了 Vim 和其他命令行应用程序，我发现了一些功能，比如能够使用键值 `h/j/k/l` 进行导航，用 `f/F` 与超链接进行交互，并创建非常方便的自定义键绑定和命令。 - -Tridactyl 的可选本地信代理（目前，仅适用于GNU/Linux 和 Mac OSX）， 最近才实现的，提供了更酷的功能来启动。例如， 有了它， 您可以隐藏 Firefox GUI 的一些元素（à la Vimperator 和 Pentadactyl），在外部程序中打开链接或当前页 （我经常用 [mpv][10] 和 [youtube-dl][11] 在视频上）通过按 `Ctrl-I` 用您喜爱的编辑器编辑文本内容（或者任意您选择的组合键）。 - -话虽如此， 但要记住，这是一个相对早期的项目，细节可能还是很粗糙。 另一方面，它的发展非常活跃， 当你回顾它早期的缺陷时， 使用它可能是一种乐趣。 - -### Open With - -![Open With Screenshot][13] - -Open With 提供的菜单。我可以在当前页面打开一个额外的列表。 - -说到与外部程序的互动，有时很高兴有能力用鼠标来做到这一点。这是 [Open With][14] 想法的来源. - -除了添加的上下文菜单 （如屏幕截图所示） 外，您还可以通过单击加载项栏上的扩展图标来找到自己定义的命令。 [its page on Mozilla Add-ons][14] 建议作为它的图标和描述，它主要是为了与其他 web 浏览器一起工作， 但我也可以轻松地使用它与 mpv 和 youtube-dl 。 - -这里也提供键盘快捷方式，但它们受到严重限制。可以在扩展设置的下拉列表中选择的组合不超过三种。相反， Tridactyl 允许我将命令分配给几乎任何没有被 Firefox 阻止的东西。打开与是目前为鼠标，真的。 - -### Stylus - -![Stylus Screenshot][16] - -在这个屏幕截图中， 我刚刚搜索并安装了一个黑暗的主题, 我正在上 Stylus 的网站。即使是弹出窗口也可以定制风格 （称为 Deepdark Stylus）！ - -[Stylus][17] 是一个用户样式管理器，这意味着通过编写自定义 CSS 规则并将其加载到 Stylus 中，您可以更改任何网页的外观。如果你不知道 CSS ，有大量的风格在其他网站上，如 [userstyles.org][18] 。 - -现在，你可能会问，“这不正是什么 [Stylish][19] 么？” 你是对的！你看 Stylus 是基于 Stylish 并提供了更多的改进：它不包含任何遥测数据， 尊重您的隐私，所有开发都是公开的(尽管 Stylish 仍在积极开发， 我一直未能找到最新版本的源代码）， 而且它还支持 [UserCSS][20]。 - -UserCSS 是一种有趣的格式，尤其是对于开发人员。我已经为不同的网站写了几种用户样式（主要是黑暗的主题和调整，以提高可读性），虽然 Stylus 的内部编辑器很好，我还是喜欢用 Neovim 编辑代码。为了做到这样我所需要做的就是用 ".user.css" 作为本地加载文件的后缀名，在 Stylus 里启动 "Live Reload" 选项，所有更改都会被应用只要我在 Neovim 中启保存和更改文件。远程 UserCSS 文件也支持，因此，每当我将更改推送到 Github 或任何基于 git 的开发平台时，它们将自动对用户可用。（我提供了指向该文件的原始版本的链接， 以便他们可以轻松地访问它。） - -### uMatrix - -![uMatrix Screenshot][22] - -uMatrix 的用户使用界面，显示当前访问过的网页的当前规则。 - -Jeremy Garcia 提到了 uBlock Origin 在 [his article][23] 在 Opensource.com 作为一个优秀的 blocker 。我想推荐另一个拓展插件作者是 [gorhill][24]: uMatrix 。 - -[uMatrix][25] 允许您为网页上的某些请求设置阻止规则，可以通过点击加载项的弹出窗口来切换（在上面的屏幕截图中可以看到）。 这些请求的区别在于脚本的类别、 scripts, cookies, CSS rules, images, media content, frames，和其他被 uMatrix 标记为 "other" 的 。 例如，您可以设置全局规则， 以便在默认情况下允许所有请求， 并将特定请求添加到黑名单中（更方便的方法），或在默认情况下阻止所有内容， 并手动将某些请求列入白名单 （更安全的方法）。如果您一直在使用NoScript 或 RequestPolicy，你可以 [import][26] 你的白名单规则。 - -另外 uMatrix 支持 [hosts files ][27]，可用于阻止来自某些网站的请求。 不能与原始 uBlock 的筛选列表相比， 其使用的语法是 Adblock Plus 。默认情况下， uMatrix 会在几个文件的帮助下阻止已知分发广告、跟踪器和恶意软件的服务器， 如果需要， 您可以添加更多外部源。 - -那么你将选择哪一个-- uBlock Origin 或 uMatrix ？就个人而言，我在电脑上两个都用，只在安卓手机上用 uMatrix 。两者之间会有重叠的部分 [according to gorhill][28] ，但他们有不同的用户和目标群，如果你想要的只是阻止跟踪器和广告的简单方法， uBlock Origine 是更好的选择， 另一方面，如果您希望对网页在浏览器中可以执行或不能执行的操作进行精细的控制， 即使需要一些时间来进行配置， 并且可能会阻止网站按预期运行， uMatrix 是更好的选择。 - -### 结论 - -目前, 这些是 Firefox 里我最喜欢的扩展。Tridactyl 是依靠键盘和与外部程序交互， 加快浏览导航速度；Open With 能让我用鼠标点击程序操作， Stylus 是明确的用户风格的管理器， 对用户和开发人员都有吸引力； uMatrix 本质上是 Firefox 的防火墙用于过滤未知的请求。 - -尽管我几乎完全讨论了这些加载项的好处，但没有一个软件是完美的。如果你喜欢他们中的任何一个，并认为他们可以以任何方式改进， 我建议你去他们的 Github 页面，并寻找他们的贡献指南。通常情况下，免费和开源软件的开发人员欢迎错误报告和提交请求。告诉你的朋友或道谢也是帮助开发者的好方法， 特别是如果他们在业余时间从事他们的项目。 - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/18/6/firefox-open-source-extensions - -作者：[Zsolt Szakács][a] -选题：[lujun9972](https://github.com/lujun9972) -译者：[lixinyuxx](https://github.com/lixinyuxx) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:https://opensource.com/users/zsolt -[1]:https://www.gnu.org/licenses/gpl-3.0.en.html -[2]:https://www.mozilla.org/en-US/MPL/ -[3]:https://www.apache.org/licenses/LICENSE-2.0 -[4]:/file/398411 -[5]:https://opensource.com/sites/default/files/uploads/tridactyl.png "Tridactyl's new tab page, showcasing link hinting" -[6]:https://addons.mozilla.org/en-US/firefox/addon/tridactyl-vim/ -[7]:https://github.com/vimperator/vimperator-labs -[8]:https://addons.mozilla.org/en-US/firefox/addon/pentadactyl/ -[9]:https://www.vim.org/ -[10]:https://mpv.io/ -[11]:https://rg3.github.io/youtube-dl/index.html -[12]:/file/398416 -[13]:https://opensource.com/sites/default/files/uploads/openwith.png "A context menu provided by Open With. I can open the current page with one of the external programs listed here." -[14]:https://addons.mozilla.org/en-US/firefox/addon/open-with/ -[15]:/file/398421 -[16]:https://opensource.com/sites/default/files/uploads/stylus.png "In this screenshot, I've just searched for and installed a dark theme for the site I'm currently on with Stylus. Even the popup has custom style (called Deepdark Stylus)!" -[17]:https://addons.mozilla.org/en-US/firefox/addon/styl-us/ -[18]:https://userstyles.org/ -[19]:https://addons.mozilla.org/en-US/firefox/addon/stylish/ -[20]:https://github.com/openstyles/stylus/wiki/Usercss -[21]:/file/398426 -[22]:https://opensource.com/sites/default/files/uploads/umatrix.png "The user interface of uMatrix, showing the current rules for the currently visited webpage." -[23]:https://opensource.com/article/18/5/firefox-extensions -[24]:https://addons.mozilla.org/en-US/firefox/user/gorhill/ -[25]:https://addons.mozilla.org/en-US/firefox/addon/umatrix -[26]:https://github.com/gorhill/uMatrix/wiki/FAQ -[27]:https://en.wikipedia.org/wiki/Hosts_(file) -[28]:https://github.com/gorhill/uMatrix/issues/32#issuecomment-61372436 diff --git a/translated/tech/20181224 An Introduction to Go.md b/translated/tech/20181224 An Introduction to Go.md new file mode 100644 index 0000000000..04adb076dc --- /dev/null +++ b/translated/tech/20181224 An Introduction to Go.md @@ -0,0 +1,274 @@ +[#]: collector: (lujun9972) +[#]: translator: (LazyWolfLin) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (An Introduction to Go) +[#]: via: (https://blog.jak-linux.org/2018/12/24/introduction-to-go/) +[#]: author: (Julian Andres Klode https://blog.jak-linux.org/) + +Go 简介 +====== + +（以下内容是我的硕士论文的摘录，几乎整个 2.1 章节，向具有 CS 背景的人快速介绍 Go） + +Go 是一门用于并发编程的命令式编程语言，它主要由创造者 Google 进行开发，最初主要由 Robert Griesemer、Rob Pike 和 Ken Thompson开发。这门语言的设计起始于 2017 年，并在 2019 年推出最初版本；而第一个稳定版本是 2012 年发布的 1.0 版本。 + +Go 有 C 风格的语法（没有预处理器），垃圾回收机制，而且类似它在贝尔实验室里被开发出来的前辈们：Newsqueak (Rob Pike)、Alef (Phil Winterbottom) 和 Inferno (Pike, Ritchie, et al.)，使用所谓的 goroutines 和信道（一种基于 Hoare 的“通信顺序进程”理论的协程）提供内建的并发支持。 + +Go 程序以包的形式组织。包本质是一个包含 Go 文件的文件夹。包内的所有文件共享相同的命名空间，而包内的符号有两种可见性：以大写字母开头的符号对于其他包是可见，而其他符号则是该包私有的： + +``` +func PublicFunction() { + fmt.Println("Hello world") +} + +func privateFunction() { + fmt.Println("Hello package") +} +``` + +### 类型 + +Go 有一个相当简单的类型系统：没有子类型（但有类型转换），没有泛型，没有多态函数，只有一些基本的类型： + + 1. 基本类型：`int`、`int64`、`int8`、`uint`、`float32`、`float64` 等。 + + 2. `struct` + + 3. `interface` \- 一组方法的集合 + + 4. `map[K, V]` \- 一个从键类型到值类型的映射 + + 5. `[number]Type` \- 一些 Type 类型的元素组成的数组 + + 6. `[]Type` \- 某种类型的切片（指向具有长度和功能的数组） + + 7. `chan Type` \- 一个线程安全的队列 + + 8. 指针 `*T` 指向其他类型 + + 9. 函数 + + 10. 具名类型 - 可能具有关联方法的其他类型的别名（译者注：这里的别名并非指 Go 1.9 中的新特性“类型别名”）： + + ``` + type T struct { foo int } + type T *T + type T OtherNamedType + ``` + + 具名类型完全不同于他们的底层类型，所以你不能让他们互相赋值，但一些运输符，例如 `+`，能够处理同一底层数值类型的具名类型对象们（所以你可以在上面的示例中把两个 `T` 加起来）。 + +Maps、slices 和 channels 是类似于引用的类型——他们实际上是包含指针的结构。包括数组（具有固定长度并可被拷贝）在内的其他类型则是值（拷贝）传递。 + +#### 类型转换 + +类型转换类似于 C 或其他语言中的类型转换。它们写成这样子： + +``` +TypeName(value) +``` + +#### 常量 + +Go 有“无类型”字面量和常量。 + +``` +1 // 无类型整数字面量 +const foo = 1 // 无类型整数常量 +const foo int = 1 // int 类型常量 +``` + +无类型值可以分为以下几类：`UntypedBool`、`UntypedInt`、`UntypedRune`、`UntypedFloat`、`UntypedComplex`、`UntypedString` 以及 `UntypedNil`（Go 称它们为基础类型，其他基础种类可用于具体类型，如 `uint8`）。一个无类型值可以赋值给一个从基础类型中派生的具名类型；例如： + +``` +type someType int + +const untyped = 2 // UntypedInt +const bar someType = untyped // OK: untyped 可以被赋值给 someType +const typed int = 2 // int +const bar2 someType = typed // error: int 不能被赋值给 someType +``` + +### 接口和对象 + +正如上面所说的，接口是一组方法的集合。Go 本身不是一种面向对象的语言，但它支持将方法关联到命名类型上：当声明一个函数时，可以提供一个接收者。接收者是函数的一个额外参数，可以在函数之前传递并参与函数查找，就像这样： + +``` +type SomeType struct { ... } + +func (s *SomeType) MyMethod() { +} + +func main() { + var s SomeType + s.MyMethod() +} +``` + +如果对象实现了所有方法，那么它就实现了接口；例如，`*SomeType`（注意指针）实现了下面的接口 `MyMethoder`，因此 `*SomeType` 类型的值就能作为 `MyMethoder` 类型的值使用。最基本的接口类型是 `interface{}`，它是一个带空方法集的接口——任何对象都满足该接口。 + +``` +type MyMethoder interface { + MyMethod() +} +``` + +合法的接收者类型是有些限制的；例如，命名类型可以是指针类型（例如，`type MyIntPointer *int`），但这种类型不是合法的接收者类型。 + +### 控制流 + +Go 提供了三个主要的控制了语句：`if`、`switch` 和 `for`。这些语句同其他 C 风格语言内的语句非常类似，但有一些不同： + + * 条件语句没有括号，所以条件语句是 `if a == b {}` 而不是 `if (a == b) {}`。大括号是必须的。 + + * 所有的语句都可以有初始化，比如这个 + + `if result, err := someFunction(); err == nil { // use result }` + + * `switch` 语句在 cases 里可以使用任何表达式 + + * `switch` 语句可以处理空的表达式（等于 true） + + * 默认情况下，Go 不会从一个 case 进入下一个 case（不需要 `break`语句），在程序块的末尾使用 `fallthrough` 则会进入下一个 case。 + + * 循环语句 `for` 不仅能循环值域：`for key, val := range map { do something }` + +### Goroutines + +关键词 `go` 会产生一个新的 goroutine，一个可以并行执行的函数。它可以用于任何函数调用，甚至一个匿名函数： + +``` +func main() { + ... + go func() { + ... + }() + + go some_function(some_argument) +} +``` + +### 信道 + +Goroutines 通常和信道结合，用来提供一种通信顺序进程的扩展。信道是一个并发安全的队列，而且可以选择是否缓冲数据： + +``` +var unbuffered = make(chan int) // 直到数据被读取时完成数据块发送 +var buffered = make(chan int, 5) // 最多有 5 个未读取的数据块 +``` + +运算符 `<-` 用于和单个信道进行通信。 + +``` +valueReadFromChannel := <- channel +otherChannel <- valueToSend +``` + +语句 `select` 允许多个信道进行通信： + +``` +select { + case incoming := <- inboundChannel: + // 一条新消息 + case outgoingChannel <- outgoing: + // 可以发送消息 +} +``` + +### `defer` 声明 + +Go 提供语句 `defer` 允许函数退出时调用执行预定的函数。它可以用于进行资源释放操作，例如： + +``` +func myFunc(someFile io.ReadCloser) { + defer someFile.close() + /* 文件相关操作 */ +} +``` + +当然，它允许使用匿名函数作为被调函数，而且编写被调函数时可以像平常一样使用任何变量。 + +### 错误处理 + +Go 没有提供异常类或者结构化的错误处理。然而，它通过第二个及后续的返回值来返回错误从而处理错误： + +``` +func Read(p []byte) (n int, err error) + +// 内建类型： +type error interface { + Error() string +} +``` + +必须在代码中检查错误或者赋值给 `_`： + +``` +n0, _ := Read(Buffer) // 忽略错误 +n, err := Read(buffer) +if err != nil { + return err +} +``` + +有两个函数可以快速跳出和恢复调用栈：`panic()` 和 `recover()`。当 `panic()` 被调用时，调用栈开始弹出，同时每个 `defer` 函数都会正常运行。当一个 `defer` 函数调用 `recover()`时，调用栈停止弹出，同时返回函数 `panic()` 给出的值。如果我们让调用栈正常弹出而不是由于调用 `panic()` 函数，`recover()` 将只返回 `nil`。在下面的例子中，`defer` 函数将捕获 `panic()` 抛出的任何 `error` 类型的值并储存在错误返回值中。第三方库中有时会使用这个方法增强递归代码的可读性，如解析器，同时保持公有函数仍使用普通错误返回值。 + +``` +func Function() (err error) { + defer func() { + s := recover() + switch s := s.(type) { // type switch + case error: + err = s // s has type error now + default: + panic(s) + } + } +} +``` + +### 数组和切片 + +正如前边说的，数组是值类型而切片是指向数组的指针。切片可以由现有的数组切片产生，也可以使用 `make()` 创建切片，这会创建一个匿名数组以保存元素。 + +``` +slice1 := make([]int, 2, 5) // 分配 5 个元素，其中 2 个初始化为0 +slice2 := array[:] // 整个数组的切片 +slice3 := array[1:] // 除了首元素的切片 +``` + +除了上述例子，还有更多可行的切片运算组合，但需要明了直观。 + +使用 `append()` 函数，切片可以作为一个变长数组使用。 + +``` +slice = append(slice, value1, value2) +slice = append(slice, arrayOrSlice...) +``` + +切片也可以用于函数的变长参数。 + +### Maps + +Maps 是简单的键值对储存容器并支持索引和分配。但它们不是线程安全的。 + +``` +someValue := someMap[someKey] +someValue, ok := someMap[someKey] // 如果键值不在 someMap 中，变量 ok 会赋值为 `false` +someMap[someKey] = someValue +``` +-------------------------------------------------------------------------------- + +via: https://blog.jak-linux.org/2018/12/24/introduction-to-go/ + +作者：[Julian Andres Klode][a] +选题：[lujun9972][b] +译者：[LazyWolfLin](https://github.com/LazyWolfLin) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://blog.jak-linux.org/ +[b]: https://github.com/lujun9972 diff --git a/translated/tech/20190115 Comparing 3 open source databases- PostgreSQL, MariaDB, and SQLite.md b/translated/tech/20190115 Comparing 3 open source databases- PostgreSQL, MariaDB, and SQLite.md new file mode 100644 index 0000000000..6638fb8fb7 --- /dev/null +++ b/translated/tech/20190115 Comparing 3 open source databases- PostgreSQL, MariaDB, and SQLite.md @@ -0,0 +1,149 @@ +[#]: collector: (lujun9972) +[#]: translator: (HankChow) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Comparing 3 open source databases: PostgreSQL, MariaDB, and SQLite) +[#]: via: (https://opensource.com/article/19/1/open-source-databases) +[#]: author: (Sam Bocetta https://opensource.com/users/sambocetta) + +开源数据库 PostgreSQL、MariaDB 和 SQLite 的对比 +====== +> 要知道如何选择最适合你的需求的开源数据库。 + +![](https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/data_container_block.png?itok=S8MbXEYw) + +在现代企业的技术领域中，开源软件已经成为了一股不可忽视的重要力量。借助[开源运动open source movement][1]的东风，很多重大的技术已经得到了长足的发展。 + +个中原因显而易见，尽管一些基于 Linux 的开源网络标准可能不如著名厂商的产品那么受欢迎，但是不同制造商的智能设备之间能够互相通信，开源技术功不可没。当然也有不少人认为开源应用比厂商提供的产品更加好，所以无论如何，使用开源数据库进行开发确实是相当有利的。 + +和其它类型的应用软件一样，[不同的开源数据库管理系统之间在功能和特性上可能会存在着比较大的差异][2]。因此，如果要为整个团队选择一个开源数据库，那么应该重点考察数据库是否对用户友好、是否能够持续适应团队需求、是否能够提供足够安全的功能等方面的因素。 + +出于这方面考虑，我们在这篇文章中对一些开源数据库进行了概述和对比。但也有可能略过了一些常用的数据库。需要提到的是，MongoDB 最近更改了它的许可证，因此它已经不是完全的开源产品了。从商业角度来看，这个决定是很有意义的，因为 MongoDB 已经成为了[约 27000 家公司][3]在数据库托管方面的实际解决方案，这也意味着 MongoDB 已经不再被视为真正的开源产品。 + +另外，在 MySQL 被 Oracle 收购之后，这个产品就已经不再具有开源性质了。MySQL 在过去相当长的一段时间里都是很多项目的首选数据库，因此它的案例也是摆在其它开源数据库面前的一个巨大挑战。 + +下面讨论一下我们提到的三个开源数据库。 + +### PostgreSQL + +[PostgreSQL][4] 可以说是开源数据库中的一个重要成员。无论是哪种规模的企业，PostgreSQL 可能都是它们的首选解决方案。Oracle 对 MySQL 的收购在当时来说可能具有一定的商业意义，但是随着云存储的日益壮大，[开发者对 MySQL 的依赖程度或许并不如以前那么大了][5]。 + +尽管 PostgreSQL 不是一个最近几年才面世的新产品，但它却是借助了 [MySQL 衰落][6]的机会才逐渐成为最受欢迎的开源数据库之一。由于它和 MySQL 的工作方式非常相似，因此很多热衷于使用开源软件的开发者都纷纷转向 PostgreSQL。 + +#### 优势 + + * 目前 PostgreSQL 最显著的优点是它的算法效率高，因此它的性能就比其它的数据库也高一些。这一点在处理大型数据集的时候就可以很明显地体现出来了，否则在运算过程中 I/O 会成为瓶颈。 + * PostgreSQL 也是最灵活的开源数据库之一，使用 Python、Perl、Java、Ruby、C 或者 R 都能够很方便地调用数据库。 + * 作为最常用的几个开源数据库之中，PostgreSQL 的社区支持是做得最好的。 + + + + +#### 劣势 + + * 在数据量比较大的时候，PostgreSQL 的效率毋庸置疑是很高的，但对于数据量较小的情况，使用 PostgreSQL 就显得不如其它的一些工具轻量级了。 + + * 尽管拥有一个很优秀的社区支持，但 PostgreSQL 的核心文档仍然需要作出改进。 + + * 如果你需要使用并行计算或者集群化等高级工具，就需要安装 PostgreSQL 的第三方插件。尽管官方有计划将这些功能逐步添加到主要版本当中，但可能会需要再等待好几年才能实现。 + + + + +### MariaDB + +[MariaDB][7] 是 MySQL 的真正开源发行版本（在 [GNU GPLv2][8] 下发布）。在 Oracle 收购 MySQL 之后，MySQL 的一些核心开发人员认为 Oracle 会破坏 MySQL 的开源理念，因此建立了 MariaDB 这个独立的分支。 + +MariaDB 在开发过程中替换了 MySQL 的几个关键组件，但仍然尽可能地保持兼容 MySQL。MariaDB 使用了 Aria 作为存储引擎，这个存储引擎既可以作为事务式引擎，也可以作为非事务式引擎。在 MariaDB 独立出来之前，就[有一些人推测][10] Aria 会成为 MySQL 未来版本中的标准引擎。 + +#### 优势 + + * 由于 MariaDB [频繁进行安全发布][11]，很多用户选择使用 MariaDB 而不选择 MySQL。尽管这不一定代表 MariaDB 会比 MySQL 更加安全，但确实表明它的开发社区对安全性十分重视。 + + * 有一些人认为，MariaDB 的主要优点就是它在坚持开源的同时会与 MySQL 保持高度兼容，这就表示从 MySQL 向 MariaDB 的迁移会非常容易。 + + * 也正是由于这种兼容性，MariaDB 也可以和其它常用于 MySQL 的语言配合使用，因此从 MySQL 迁移到 MariaDB 之后，学习和调试代码的时间成本会非常低。 + + * 你可以将 WordPress 和 MariaDB（而不是 MySQL）[配合使用][12]从而获得更好的性能和更丰富的功能。WordPress 是[最受欢迎的内容管理系统Content Management System][13]（CMS），并且拥有活跃的开源开发者社区。各种第三方插件在 WordPress 和 MariaDB 配合使用时都能够正常工作。 + + + + +#### 劣势 + + * MariaDB 有时会变得比较臃肿，尤其是它的 IDX 日志文件在长期使用之后会变得非常大，最终导致性能下降。 + + * MariaDB 的缓存并没有期望中那么快，这可能会让人有所失望。 + + * 尽管 MariaDB 最初承诺兼容 MySQL，但目前 MariaDB 已经不是完全兼容 MySQL。如果要从 MySQL 迁移到 MariaDB，就需要额外做一些兼容工作。 + + + + +### SQLite + +[SQLite][14] 可以说是世界上实现最多的数据库引擎，因为它被很多流行的 web 浏览器、操作系统和手机所采用。它最初是作为 MySQL 的轻量级分支所开发的。SQLite 和很多其它的数据库不同，它不采用客户端-服务端的引擎架构，而是将整个软件嵌入到每个实现当中。 + +这样的架构让 SQLite 拥有一个强大的优势，就是在嵌入式系统或者分布式系统中，每台机器都搭载了数据库的整个实现。这样的做法减少了系统间的调用，从而大大提高了数据库的性能。 + +#### 优势 + + * 如果你需要构建和实现一个小型数据库，SQLite [可能是最好的选择][15]。它小而灵活，不需要费工夫寻求各种变通方案，就可以在嵌入式系统中实现。 + + * SQLite 体积很小，因此速度也很快。其它的一些高级数据库可能会使用复杂的优化方式来提高效率，但不如SQLite 这样减小数据库大小更为直接。 + + * SQLite 被广泛采用也导致它可能是兼容性最高的数据库。如果你希望将应用程序集成到智能手机上，只要有第三方应用程序使用到了 SQLite，就能够正常运行数据库了。 + + + + +#### 劣势 + + * SQLite 的轻量意味着它缺少了很多其它大型数据库的常见功能。例如数据加密就是[抵御网络攻击][16]的标准功能，而 SQLite 却没有内置这个功能。 + + * SQLite 的广泛流行和源码公开使它易于使用，但是也让它更容易遭受攻击。这是它最大的劣势。SQLite 经常被发现高位的漏洞，例如最近的 [Magellan][17]。 + + * 尽管 SQLite 单文件的方式拥有速度上的优势，但是要使用它实现多用户环境却比较困难。 + + + + +### 哪个开源数据库才是最好的？ + +当然，对于开源数据库的选择还是取决于业务的需求以及系统的体量。对于小型数据库或者是使用量比较小的数据库，可以使用比较轻量级的解决方案，这样不仅可以加快实现的速度，而且由于系统的复杂程度不算太高，花在调试上的时间成本也不会太高。 + +而对于大型的系统，尤其是业务增长速度较快的业务，最好还是花时间使用更复杂的数据库（例如 PostgreSQL）。这是一个磨刀不误砍柴工的选择，能够让你不至于在后期再重新选择另一款数据库。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/open-source-databases + +作者：[Sam Bocetta][a] +选题：[lujun9972][b] +译者：[HankChow](https://github.com/HankChow) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/sambocetta +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/article/18/2/pivotal-moments-history-open-source +[2]: https://blog.capterra.com/free-database-software/ +[3]: https://idatalabs.com/tech/products/mongodb +[4]: https://www.postgresql.org/ +[5]: https://www.theregister.co.uk/2018/05/31/rise_of_the_open_source_data_strategies/ +[6]: https://www.itworld.com/article/2721995/big-data/signs-of-mysql-decline-on-horizon.html +[7]: https://mariadb.org/ +[8]: https://github.com/MariaDB/server/blob/10.4/COPYING +[9]: https://mariadb.com/about-us/ +[10]: http://kb.askmonty.org/en/aria-faq +[11]: https://mariadb.org/tag/security/ +[12]: https://mariadb.com/resources/blog/how-to-install-and-run-wordpress-with-mariadb/ +[13]: https://websitesetup.org/popular-cms/ +[14]: https://www.sqlite.org/index.html +[15]: https://www.sqlite.org/aff_short.html +[16]: https://hostingcanada.org/most-common-website-vulnerabilities/ +[17]: https://www.securitynewspaper.com/2018/12/18/critical-vulnerability-in-sqlite-you-should-update-now/ + + diff --git a/translated/tech/20190117 How to Update-Change Users Password in Linux Using Different Ways.md b/translated/tech/20190117 How to Update-Change Users Password in Linux Using Different Ways.md new file mode 100644 index 0000000000..2c8cc10e3c --- /dev/null +++ b/translated/tech/20190117 How to Update-Change Users Password in Linux Using Different Ways.md @@ -0,0 +1,251 @@ +[#]: collector: (lujun9972) +[#]: translator: (MjSeven) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (How to Update/Change Users Password in Linux Using Different Ways) +[#]: via: (https://www.2daygeek.com/linux-passwd-chpasswd-command-set-update-change-users-password-in-linux-using-shell-script/) +[#]: author: (Vinoth Kumar https://www.2daygeek.com/author/vinoth/) + +如何使用不同的方式更新或更改 Linux 用户密码 +====== + +在 Linux 中创建用户账号时，设置用户密码是一件基本的事情。 + +每个人都使用 passwd 命令和用户名，比如 `passwd USERNAME` 来为用户设置密码。 + +确保你一定设置一个难以猜测的密码，这可以帮助你使系统更安全。 + +我的意思是，密码应该是字母，符合和数字的组合。 + +此外，出于安全原因，我建议你至少每月更改一次密码。 + +当你使用 passwd 命令时，它会要求你输入两次密码来设置。这是一种设置用户密码的原生方法。 + +如果你不想两次更新密码，并希望以不同的方式进行更新，怎么办呢？ + +当然，这可以的，有可能做到。 + +如果你是 Linux 管理员，你可能已经多次问过下面的问题。 + +你们可能，也可能没有得到这些问题的答案。 + +无论如何，不要担心，我们会回答你所有的问题。 + + * 如何用一条命令更新或更改用户密码？ + * 如何在 Linux 中为多个用户更新或更改相同的密码？ + * 如何在 Linux 中更新或更改多个用户的密码？ + * 如何在 Linux 中更新或更改多个用户的密码？（to 校正：这句和上一句有不同？） + * 如何在 Linux 中更新或更改多个用户的不同密码？ + * 如何在多个 Linux 服务器中更新或更改用户的密码？ + * 如何在多个 Linux 服务器中更新或更改多个用户的密码？ + + + +### 方法-1: 使用 passwd 命令 + +passwd 命令是在 Linux 中为用户设置，更新或更改密码的标准方法。以下是标准方法。 + +``` +# passwd renu +Changing password for user renu. +New password: +BAD PASSWORD: The password contains the user name in some form +Retype new password: +passwd: all authentication tokens updated successfully. +``` + +如果希望在一条命令中设置或更改密码，运行以下命令。它允许用户在一条命令中更新密码。 + +``` +# echo "new_password" | passwd --stdin thanu +Changing password for user thanu. +passwd: all authentication tokens updated successfully. +``` + +### 方法-2: 使用 chpasswd 命令 + +chpasswd 是另一个命令，允许我们为 Linux 中的用户设置，更新或更改密码。如果希望在一条命令中使用 chpasswd 命令更改用户密码，用以下格式。 + +``` +# echo "thanu:new_password" | chpasswd +``` + +### 方法-3: 如何为多个用户设置不同的密码 + +如果你要为 Linux 中的多个用户设置，更新或更改密码，并且使用不同的密码，使用以下脚本。 + +为此，首先我们需要使用以下命令获取用户列表。下面的命令将列出拥有 `/home` 目录的用户，并将输出重定向到 `user-list.txt` 文件。 + +``` +# cat /etc/passwd | grep "/home" | cut -d":" -f1 > user-list.txt +``` + +使用 cat 命令列出用户。如果你不想重置特定用户的密码，那么从列表中移除该用户。 + +``` +# cat user-list.txt +centos +magi +daygeek +thanu +renu +``` + +创建以下小 shell 脚本来实现此目的。 + +``` +# vi password-update.sh + +#!/bin/sh +for user in `more user-list.txt` +do +echo "[email protected]" | passwd --stdin "$user" +chage -d 0 $user +done +``` + +给 `password-update.sh` 文件设置可执行权限。 + +``` +# chmod +x password-update.sh +``` + +最后运行脚本来实现这一目标。 + +``` +# ./password-up.sh + +magi +Changing password for user magi. +passwd: all authentication tokens updated successfully. +daygeek +Changing password for user daygeek. +passwd: all authentication tokens updated successfully. +thanu +Changing password for user thanu. +passwd: all authentication tokens updated successfully. +renu +Changing password for user renu. +passwd: all authentication tokens updated successfully. +``` + +### 方法-4: 如何为多个用户设置相同的密码 + +如果要在 Linux 中为多个用户设置，更新或更改相同的密码，使用以下脚本。 + +``` +# vi password-update.sh + +#!/bin/sh +for user in `more user-list.txt` +do +echo "new_password" | passwd --stdin "$user" +chage -d 0 $user +done +``` + +### 方法-5: 如何在多个服务器中更改用户密码 + +如果希望更改多个服务器中的用户密码，使用以下脚本。在本例中，我们将更改 `renu` 用户的密码，确保你必须提供你希望更新密码的用户名而不是我们的用户名。 + +确保你必须将服务器列表保存在 `server-list.txt` 文件中，每个服务器应该在单独一行中。 + +``` +# vi password-update.sh + +#!/bin/bash +for server in `cat server-list.txt` +do +ssh [email protected]$server 'passwd --stdin renu < +``` + +例如， + +```shell +$ more jekyll-article.md +``` + +![](https://opensource.com/sites/default/files/uploads/more-viewing-file.png) + +使用空格键可以向下翻页，输入 **q** 可以退出。 + +如果你想在这个文件中搜索一些文本，输入 **/** 字符并在其后加上你想要查找的文字。例如你要查看的字段是 terminal，只需输入： + +``` +/terminal +``` + +![](https://opensource.com/sites/default/files/uploads/more-searching.png) + +搜索的内容是区分大小写的，所以输入 /terminal 跟 /Terminal 会出现不同的结果。 + +### 和其他实用工具组合使用 +你可以通过管道将其他命令行工具得到的文本传输到 **more**。你问为什么这样做？因为有时这些工具获取的文本会超过终端一页可以显示的限度。 + +想要做到这个，先输入你想要使用的完整命令，后面跟上管道符（**|**），管道符后跟 **more**。假设现在有一个有很多文件的目录。你就可以组合 **more** 跟 **ls** 命令完整查看这个目录当中的内容。 + +```shell +$ ls | more +``` + +![](https://opensource.com/sites/default/files/uploads/more-with_ls_cmd.png) + +你可以组合 **more** 和 **grep** 命令，从而实现在多个文件中找到指定的文本。下面是我在多篇文章的源文件中查找 productivity 的例子。 + +```shell +$ grep ‘productivity’ core.md Dict.md lctt2014.md lctt2016.md lctt2018.md README.md | more +``` + +![](https://opensource.com/sites/default/files/uploads/more-with_grep_cmd.png) + +另外一个可以和 **more** 组合的实用工具是 **ps**（列出你系统上正在运行的进程）。当你的系统上运行了很多的进程，你现在想要查看他们的时候，这个组合将会派上用场。例如你想找到一个你需要杀死的进程，只需输入下面的命令： + +```shell +$ ps -u scott | more +``` + +注意用你的用户名替换掉 scott。 + +![](https://opensource.com/sites/default/files/uploads/more-with_ps_cmd.png) + +就像我文章开篇提到的， **more** 很容易使用。尽管不如它的双胞胎兄弟 **less** 那般灵活，但是仍然值得了解一下。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/19/1/more-text-files-linux + +作者：[Scott Nesbitt][a] +选题：[lujun9972][b] +译者：[dianbanjiu](https://github.com/dianbanjiu) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/scottnesbitt +[b]: https://github.com/lujun9972 +[1]: https://en.wikipedia.org/wiki/More_(command) +[2]: https://opensource.com/article/18/4/using-less-view-text-files-command-line diff --git a/translated/tech/20190129 More About Angle Brackets in Bash.md b/translated/tech/20190129 More About Angle Brackets in Bash.md new file mode 100644 index 0000000000..de4f8331ca --- /dev/null +++ b/translated/tech/20190129 More About Angle Brackets in Bash.md @@ -0,0 +1,87 @@ +[#]: collector: (lujun9972) +[#]: translator: (HankChow) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (More About Angle Brackets in Bash) +[#]: via: (https://www.linux.com/blog/learn/2019/1/more-about-angle-brackets-bash) +[#]: author: (Paul Brown https://www.linux.com/users/bro66) + +Bash 中尖括号的更多用法 +====== + +![](https://www.linux.com/sites/lcom/files/styles/rendered_file/public/bash-angles.png?itok=mVFnxPzF) + +在[上一篇文章][1]当中，我们介绍了尖括号（`<>`）以及它们的一些用法。在这篇文章，我们继续来深入探讨尖括号的更多其它用法。 + +通过使用 `<`，可以实现“欺骗”的效果，让其它命令认为某个命令的输出是一个文件。 + +例如，在进行备份文件的时候不确定备份是否完整，就需要去确认某个目录是否已经包含从原目录中复制过去的所有文件。你可以试一下这样操作： + +``` +diff <(ls /original/dir/) <(ls /backup/dir/) +``` + +[`diff`][2] 命令是一个逐行比较两个文件之间差异的工具。在上面的例子中，就使用了 `<` 让 `diff` 认为两个 `ls` 命令输出的结果都是文件，从而能够比较它们之间的差异。 + +要注意，在 `<` 和 `(...)` 之间是没有空格的。 + +我尝试在我的图片目录和它的备份目录执行上面的命令，输出的是以下结果： + +``` +diff <(ls /My/Pictures/) <(ls /My/backup/Pictures/) 5d4 < Dv7bIIeUUAAD1Fc.jpg:large.jpg +``` + +输出结果中的 `<` 表示 `Dv7bIIeUUAAD1Fc.jpg:large.jpg` 这个文件存在于左边的目录（`/My/Pictures`）但不存在于右边的目录（`/My/backup/Pictures`）中。也就是说，在备份过程中可能发生了问题，导致这个文件没有被成功备份。如果 `diff` 没有显示出任何输出结果，就表明两个目录中的文件是一致的。 + +看到这里你可能会想到，既然可以通过 `<` 将一些命令行的输出内容作为一个文件，提供给一个需要接受文件格式的命令，那么在上一篇文章的“最喜欢的演员排序”例子中，就可以省去中间的一些步骤，直接对输出内容执行 `sort` 操作了。 + +确实如此，这个例子可以简化成这样： + +``` +sort -r <(while read -r name surname films;do echo $films $name $surname ; done < CBactors) +``` + +### Here string + +除此以外，尖括号的重定向功能还有另一种使用方式。 + +使用 `echo` 和管道（`|`）来传递变量的用法，相信大家都不陌生。假如想要把一个字符串变量转换为全大写形式，你可以这样做： + +``` +myvar="Hello World" echo $myvar | tr '[:lower:]' '[:upper:]' HELLO WORLD +``` + +[`tr`][3] 命令可以将一个字符串转换为某种格式。在上面的例子中，就使用了 `tr` 将字符串中的所有小写字母都转换为大写字母。 + +要理解的是，这个传递过程的重点不是变量，而是变量的值，也就是字符串 `Hello World`。这样的字符串叫做 here string，含义是“这就是我们要处理的字符串”。但对于上面的例子，还可以用更直观的方式的处理，就像下面这样： + +``` +tr '[:lower:]' '[:upper:]' <<< $myvar +``` + +这种简便方式并不需要使用到 `echo` 或者管道，而是使用了我们一直在说的尖括号。 + +### 总结 + +使用 `<` 和 `>` 这两个简单的符号，原来可以实现这么多功能，Bash 又一次为工作的灵活性提供了很多选择。 + +当然，我们的介绍还远远没有完结，因为还有很多别的符号可以为 Bash 命令带来更多便利。不过如果没有充分理解它们，充满符号的 Bash 命令看起来只会像是一堆乱码。接下来我会解读更多类似的 Bash 符号，下次见！ + +-------------------------------------------------------------------------------- + +via: https://www.linux.com/blog/learn/2019/1/more-about-angle-brackets-bash + +作者：[Paul Brown][a] +选题：[lujun9972][b] +译者：[HankChow](https://github.com/HankChow) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.linux.com/users/bro66 +[b]: https://github.com/lujun9972 +[1]: https://www.linux.com/blog/learn/2019/1/understanding-angle-brackets-bash +[2]: https://linux.die.net/man/1/diff +[3]: https://linux.die.net/man/1/tr +