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[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Raspberry Pi 4 is here!)
[#]: via: (https://opensource.com/article/19/6/raspberry-pi-4)
[#]: author: (Ben Nuttall https://opensource.com/users/bennuttall)
Raspberry Pi 4 is here!
======
A new version of the $35 computer features a 1.5GHz Arm chip and support
for dual-HDMI 4K displays, Gigabit Ethernet, and much more.
![Raspberry Pi 4 board][1]
The latest version of the Raspberry Pi—Raspberry Pi 4—was released today, earlier than anticipated, featuring a new 1.5GHz Arm chip and VideoCore GPU with some brand new additions: dual-HDMI 4K display output; USB3 ports; Gigabit Ethernet; and multiple RAM options up to 4GB.
![Raspberry Pi 4 case][2]
The Raspberry Pi 4 is a very powerful single-board computer and starts at the usual price of $35. That gets you the standard 1GB RAM, or you can pay $45 for the 2GB model or $55 for the 4GB model—premium-priced models are a first for Raspberry Pi.
The specs at-a-glance:
* 64-bit BCM2711 quad-core A72 CPU @ 1.5GHz
* VideoCore VI GPU
* Gigabit Ethernet port
* 1GB, 2GB, or 4GB LPDDR4 RAM
* Two Micro-HDMI ports
* Two USB3 ports
* Two USB2 ports
* Dual-band (2.4GHz and 5GHz) WiFi
* Bluetooth 5.0
* USB Type C power port
* CSI camera interface
* DSI display interface
* MicroSD card slot
* Power-over-Ethernet pins
* Full compatibility with all previous Raspberry Pi models
### USB and networking
The Raspberry Pi 4 has the benefit of having USB3; it's powered by a USB Type C cable and provides two USB3 ports and two USB2 ports. You can now connect USB3 hard drives and other peripherals and get faster connectivity.
![Raspberry Pi 4 USBs][3]
The BCM2835-based chip in Raspberry Pi 1 to 3 provided just one native USB port and no Ethernet, so a USB hub on the board provided more USB ports and an Ethernet port. The 3B+ added a dedicated LAN chip, which gave it Gigabit Ethernet, but this was limited to USB2 speeds. The Pi 4 has dedicated Gigabit Ethernet, and because it's no longer throttled over USB, its networking speeds are much faster.
The Pi 4 takes advantage of the technology built into the 3B+ that made it the first single-board computer with dual-band WiFi. This means you can connect to both 2.4GHz and 5GHz networks.
### Displays
When the first Raspberry Pi launched, the balance of its CPU and GPU performance was tipped heavily in favor of the GPU. The VideoCore IV was a very powerful graphics processor, capable of full-HD 1080p multimedia, which is why the Pi has always been popular as a home media center. The Pi 2 rebalanced things somewhat and brought the CPU in line, taking the Pi from a single-core to a quad-core Arm chip. The Pi 4 takes both factors a big step forward. The new VideoCore VI GPU gives the Pi 4K video and allows two displays via the board's two Micro-HDMI ports (selected to keep the board the same size), so you'll need an adapter or a Micro-to-full HDMI cable to use an HDMI monitor.
Dual displays are a godsend when you need more screen real estate to keep eye contact with multiple windows—if you're programming you might have your code on one screen and the website or app you're building; your database; your web browser; your emails, or anything else on the other. For the first time, development on Raspberry Pi won't be limited to a single monitor. It's also handy if you want to build a Pi-based project with different things on different screens.
The Pi also has a Display Serial Interface (DSI) port to drive another special display—not another monitor per se, but the official Raspberry Pi touch screen display connected via a flex cable.
### Raspbian Buster
This Raspberry Pi 4's launch coincides with a major Debian release, and the fact the new Pi supports OpenGL ES 3 means it makes sense for any software developed for the Pi 4 to target Raspbian Buster. Buster brings a few user interface tweaks and a whole host of software upgrades, including Python 3.7.
![Raspbian Buster][4]
### Open source graphics drivers
Over the last five years, Eric Anholt has been working to write open source graphics drivers for the Raspberry Pi. Now, Raspbian can use this driver to deliver accelerated web browsing, desktop graphics, and 3D applications on the Pi. This replaces a large chunk of closed-source code that was previously required. Huge thanks to Eric and Broadcom for this effort.
Previously, the Raspberry Pi 4 was expected to be yet another year away, but the chip design turned out to be ready for production much earlier than anticipated, so here it is!
* * *
_The Raspberry Pi 4 is on sale now. Which model will you opt for? Let us know your plans in the comments!_
--------------------------------------------------------------------------------
via: https://opensource.com/article/19/6/raspberry-pi-4
作者：[Ben Nuttall][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/bennuttall
[b]: https://github.com/lujun9972
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/raspberry-pi-4_lead.jpg?itok=2bkk43om (Raspberry Pi 4 board)
[2]: https://opensource.com/sites/default/files/uploads/raspberry-pi-4-case.jpg (Raspberry Pi 4 case)
[3]: https://opensource.com/sites/default/files/uploads/raspberry-pi-4-usb.jpg (Raspberry Pi 4 USBs)
[4]: https://opensource.com/sites/default/files/uploads/raspbian-buster.png (Raspbian Buster)

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sources/tech/20190531 Use Firefox Send with ffsend in Fedora.md
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[#]: collector: (lujun9972)
[#]: translator: (geekpi)
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Use Firefox Send with ffsend in Fedora)
[#]: via: (https://fedoramagazine.org/use-firefox-send-with-ffsend-in-fedora/)
[#]: author: (Sylvia Sánchez https://fedoramagazine.org/author/lailah/)
Use Firefox Send with ffsend in Fedora
======
![][1]
_ffsend_ is the command line client of Firefox Send. This article will show how Firefox Send and _ffsend_ work. It’ll also detail how it can be installed and used in Fedora.
### What are Firefox Send and ffsend ?
Firefox Send is a file sharing tool from Mozilla that allows sending encrypted files to other users. You can install Send on your own server, or use the Mozilla-hosted link [send.firefox.com][2]. The hosted version officially supports files up to 1 GB, and links that expire after a configurable download count (default of 1) or 24 hours, and then all the files on the Send server are deleted. This tool is still _in experimental phase_ , and therefore shouldn’t be used in production or to share important or sensitive data.
While Firefox Send is the tool itself and can be used with a web interface, _ffsend_ is a command-line utility you can use with scripts and arguments. It has a wide range of configuration options and can be left working in the background without any human intervention.
### How does it work?
FFSend can both upload and download files. The remote host can use either the Firefox tool or another web browser to download the file. Neither Firefox Send nor _ffsend_ require the use of Firefox.
It’s important to highlight that _ffsend_ uses client-side encryption. This means that files are encrypted _before_ they’re uploaded. You share secrets together with the link, so be careful when sharing, because anyone with the link will be able to download the file. As an extra layer of protection, you can protect the file with a password by using the following argument:
```
ffsend password URL -p PASSWORD
```
### Other features
There are a few other features worth mentioning. Here’s a list:
* Configurable download limit, between 1 and 20 times, before the link expires
* Built-in extract and archiving functions
* Track history of shared files
* Inspect or delete shared files
* Folders can be shared as well, either as they are or as compressed files
* Generate a QR code, for easier download on a mobile phone
### How to install in Fedora
While Fedora Send works with Firefox without installing anything extra, you’ll need to install the CLI tool to use _ffsend_. This tool is in the official repositories, so you only need a simple _dnf_ command [with][3] _[sudo][3]_.
```
$ sudo dnf install ffsend
```
After that, you can use _ffsend_ from the terminal .
### Upload a file
Uploading a file is a simple as
```
$ ffsend upload /etc/os-release
Upload complete
Share link: https://send.firefox.com/download/05826227d70b9a4b/#RM_HSBq6kuyeBem8Z013mg
```
The file now can be easily share using the Share link URL.
## Downloading a file
Downloading a file is as simple as uploading.
```
$ ffsend download https://send.firefox.com/download/05826227d70b9a4b/#RM_HSBq6kuyeBem8Z013mg
Download complete
```
Before downloading a file it might be useful to check if the file exist and get information about it. _ffsend_ provides 2 handy commands for that.
```
$ ffsend exists https://send.firefox.com/download/88a6324e2a99ebb6/#YRJDh8ZDQsnZL2KZIA-PaQ
Exists: true
Password: false
$ ffsend info https://send.firefox.com/download/88a6324e2a99ebb6/#YRJDh8ZDQsnZL2KZIA-PaQ
ID: 88a6324e2a99ebb6
Downloads: 0 of 1
Expiry: 23h59m (86388s
```
## Upload history
_ffsend_ also provides a way to check the history of the uploads made with the tools. This can be really useful if you upload a lot of files during a scripted tasks for example and you want to keep track of each files download status.
```
$ ffsend history
LINK EXPIRY
1 https://send.firefox.com/download/#8TJ9QNw 23h59m
2 https://send.firefox.com/download/KZIA-PaQ 23h54m
```
## Delete a file
Another useful feature is the possibility to delete a file.
```
ffsend delete https://send.firefox.com/download/2d9faa7f34bb1478/#phITKvaYBjCGSRI8TJ9QNw
```
Firefox Send is a great service and the _ffsend_ tools makes it really convenient to use from the terminal. More examples and documentation is available on _ffsend_ ‘s [Gitlab repository][4].
--------------------------------------------------------------------------------
via: https://fedoramagazine.org/use-firefox-send-with-ffsend-in-fedora/
作者：[Sylvia Sánchez][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/lailah/
[b]: https://github.com/lujun9972
[1]: https://fedoramagazine.org/wp-content/uploads/2019/04/firefox-send-816x345.png
[2]: http://send.firefox.com/
[3]: https://fedoramagazine.org/howto-use-sudo/
[4]: https://gitlab.com/timvisee/ffsend

2
sources/tech/20190609 How to set ulimit and file descriptors limit on Linux Servers.md
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[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: translator: (zgj1024)
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )

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sources/tech/20190610 Applications for writing Markdown.md
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[#]: collector: (lujun9972)
[#]: translator: (murphyzhao)
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Applications for writing Markdown)
[#]: via: (https://fedoramagazine.org/applications-for-writing-markdown/)
[#]: author: (Ryan Lerch https://fedoramagazine.org/author/ryanlerch/)
Applications for writing Markdown
======
![][1]
Markdown is a lightweight markup language that is useful for adding formatting while still maintaining readability when viewing as plain text. Markdown (and Markdown derivatives) are used extensively as the priumary form of markup of documents on services like GitHub and pagure. By design, Markdown is easily created and edited in a text editor, however, there are a multitude of editors available that provide a formatted preview of Markdown markup, and / or provide a text editor that highlights the markdown syntax.
This article covers 3 desktop applications for Fedora Workstation that help out when editing Markdown.
### UberWriter
[UberWriter][2] is a minimal Markdown editor and previewer that allows you to edit in text, and preview the rendered document.
![][3]
The editor itself has inline previews built in, so text marked up as bold is displayed bold. The editor also provides inline previews for images, formulas, footnotes, and more. Ctrl-clicking one of these items in the markup provides an instant preview of that element to appear.
In addition to the editor features, UberWriter also features a full screen mode and a focus mode to help minimise distractions. Focus mode greys out all but the current paragraph to help you focus on that element in your document
Install UberWriter on Fedora from the 3rd-party Flathub repositories. It can be installed directly from the Software application after [setting up your system to install from Flathub][4]
### Marker
Marker is a Markdown editor that provides a simple text editor to write Markdown in, and provides a live preview of the rendered document. The interface is designed with a split screen layout with the editor on the left, and the live preview on the right.
![][5]
Additionally, Marker allows you to export you document in a range of different formats, including HTML, PDF, and the Open Document Format (ODF).
Install Marker on Fedora from the 3rd-party Flathub repositories. It can be installed directly from the Software application after [setting up your system to install from Flathub][4]
### Ghostwriter
Where the previous editors are more focussed on a minimal user experice, Ghostwriter provides many more features and options to play with. Ghostwriter provides a text editor that is partially styled as you write in Markdown format. Bold text is bold, and headings are in a larger font to assist in writing the markup.
![][6]
It also provides a split screen with a live updating preview of the rendered document.
![][7]
Ghostwriter also includes a range of other features, including the ability to choose the Markdown flavour that the preview is rendered in, as well as the stylesheet used to render the preview too.
Additionally, it provides a format menu (and keyboard shortcuts) to insert some of the frequent markdown ‘tags’ like bold, bullets, and italics.
Install Ghostwriter on Fedora from the 3rd-party Flathub repositories. It can be installed directly from the Software application after [setting up your system to install from Flathub][4]
--------------------------------------------------------------------------------
via: https://fedoramagazine.org/applications-for-writing-markdown/
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/author/ryanlerch/
[b]: https://github.com/lujun9972
[1]: https://fedoramagazine.org/wp-content/uploads/2019/06/markdownapps.png-816x345.jpg
[2]: https://uberwriter.github.io/uberwriter/#1
[3]: https://fedoramagazine.org/wp-content/uploads/2019/06/uberwriter-editor-1.png
[4]: https://fedoramagazine.org/install-flathub-apps-fedora/
[5]: https://fedoramagazine.org/wp-content/uploads/2019/06/marker-screenshot-1024x500.png
[6]: https://fedoramagazine.org/wp-content/uploads/2019/06/ghostwriter-1024x732.png
[7]: https://fedoramagazine.org/wp-content/uploads/2019/06/ghostwriter2-1024x566.png

2
sources/tech/20190613 IPython is still the heart of Jupyter Notebooks for Python developers.md
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[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: translator: (chen-ni)
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )

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sources/tech/20190624 Book Review- A Byte of Vim.md Normal file
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[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Book Review: A Byte of Vim)
[#]: via: (https://itsfoss.com/book-review-a-byte-of-vim/)
[#]: author: (John Paul https://itsfoss.com/author/john/)
Book Review: A Byte of Vim
======
[Vim][1] is a tool that is both simple and very powerful. Most new users will be intimidated by it because it doesn’t ‘work’ like regular graphical text editors. The ‘unusual’ keyboard shortcuts makes people wonder about [how to save and exit Vim][2]. But once you master Vim, there is nothing like it.
There are numerous [Vim resources available online][3]. We have covered some Vim tricks on It’s FOSS as well. Apart from online resources, plenty of books have been dedicated to this editor as well. Today, we will look at one of such book that is designed to make Vim easy for most users to understand. The book we will be discussing is [A Byte of Vim][4] by [Swaroop C H][5].
The author [Swaroop C H][6] has worked in computing for over a decade. He previously worked at Yahoo and Adobe. Out of college, he made money by selling Linux CDs. He started a number of businesses, including an iPod charger named ion. He is currently an engineering manager for the AI team at [Helpshift][7].
### A Byte of Vim
![][8]
Like all good books, A Byte of Vim starts by talking about what Vim is: “a computer program used for writing any kind of text”. He does on to say, “What makes Vim special is that it is one of those few software which is both simple and powerful.”
Before diving into telling how to use Vim, Swaroop tells the reader how to install Vim for Windows, Mac, Linux, and BSD. Once the installation is complete, he runs you through how to launch Vim and how to create your first file.
Next, Swaroop discusses the different modes of Vim and how to navigate around your document using Vim’s keyboard shortcuts. This is followed by the basics of editing a document with Vim, including the Vim version of cut/copy/paste and undo/redo.
Once the editing basics are covered, Swaroop talks about using Vim to edit multiple parts of a single document. You can also multiple tabs and windows to edit multiple documents at the same time.
[][9]
Suggested read  Bring Your Old Computer Back to Life With 4MLinux
The book also covers extending the functionality of Vim through scripting and installing plugins. There are two ways to using scripts in Vim, use Vim’s built-in scripting language or using a programming language like Python or Perl to access Vim’s internals. There are five types of Vim plugins that can be written or downloaded: vimrc, global plugin, filetype plugin, syntax highlighting plugin, and compiler plugin.
In a separate section, Swaroop C H covers the features of Vim that make it good for programming. These features include syntax highlighting, smart indentation, support for shell commands, omnicompletion, and the ability to be used as an IDE.
#### Getting the ‘A Byte of Vim’ book and contributing to it
A Byte of Book is licensed under [Creative Commons 4.0][10]. You can read an online version of the book for free on [the author’s website][4]. You can also download a [PDF][11], [Epub][12], or [Mobi][13] for free.
[Get A Byte of Vim for FREE][4]
If you prefer reading a [hard copy][14], you have that option, as well.
Please note that the _**original version of A Byte of Vim was written in 2008**_ and converted to PDf. Unfortunately, Swaroop C H lost the original source files and he is working to convert the book to [Markdown][15]. If you would like to help, please visit the [book’s GitHub page][16].
Preview | Product | Price |
---|---|---|---
![Mastering Vim Quickly: From WTF to OMG in no time][17] ![Mastering Vim Quickly: From WTF to OMG in no time][17] | [Mastering Vim Quickly: From WTF to OMG in no time][18] | $34.00[][19] | [Buy on Amazon][20]
#### Conclusion
When I first stared into the angry maw that is Vim, I did not have a clue what to do. I wish that I had known about A Byte of Vim then. This book is a good resource for anyone learning about Linux, especially if you are getting into the command line.
Have you read [A Byte of Vim][4] by Swaroop C H? If yes, how do you find it? If not, what is your favorite book on an open source topic? Let us know in the comments below.
[][21]
Suggested read  Iridium Browser: A Browser for the Privacy Conscious
If you found this article interesting, please take a minute to share it on social media, Hacker News or [Reddit][22].
--------------------------------------------------------------------------------
via: https://itsfoss.com/book-review-a-byte-of-vim/
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.vim.org/
[2]: https://itsfoss.com/how-to-exit-vim/
[3]: https://linuxhandbook.com/basic-vim-commands/
[4]: https://vim.swaroopch.com/
[5]: https://swaroopch.com/
[6]: https://swaroopch.com/about/
[7]: https://www.helpshift.com/
[8]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/06/Byte-of-vim-book.png?resize=800%2C450&ssl=1
[9]: https://itsfoss.com/4mlinux-review/
[10]: https://creativecommons.org/licenses/by/4.0/
[11]: https://www.gitbook.com/download/pdf/book/swaroopch/byte-of-vim
[12]: https://www.gitbook.com/download/epub/book/swaroopch/byte-of-vim
[13]: https://www.gitbook.com/download/mobi/book/swaroopch/byte-of-vim
[14]: https://swaroopch.com/buybook/
[15]: https://itsfoss.com/best-markdown-editors-linux/
[16]: https://github.com/swaroopch/byte-of-vim#status-incomplete
[17]: https://i2.wp.com/images-na.ssl-images-amazon.com/images/I/41itW8furUL._SL160_.jpg?ssl=1
[18]: https://www.amazon.com/Mastering-Vim-Quickly-WTF-time/dp/1983325740?SubscriptionId=AKIAJ3N3QBK3ZHDGU54Q&tag=chmod7mediate-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=1983325740 (Mastering Vim Quickly: From WTF to OMG in no time)
[19]: https://www.amazon.com/gp/prime/?tag=chmod7mediate-20 (Amazon Prime)
[20]: https://www.amazon.com/Mastering-Vim-Quickly-WTF-time/dp/1983325740?SubscriptionId=AKIAJ3N3QBK3ZHDGU54Q&tag=chmod7mediate-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=1983325740 (Buy on Amazon)
[21]: https://itsfoss.com/iridium-browser-review/
[22]: http://reddit.com/r/linuxusersgroup

113
sources/tech/20190624 Check your password security with Have I Been Pwned- and pass.md Normal file
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[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Check your password security with Have I Been Pwned? and pass)
[#]: via: (https://opensource.com/article/19/6/check-passwords)
[#]: author: (Brian "bex" Exelbierd https://opensource.com/users/bexelbie/users/jason-baker/users/admin/users/mtsouk)
Check your password security with Have I Been Pwned? and pass
======
Periodically checking for password compromise is an excellent way to
help ward off most attackers in most threat models.
![Password lock][1]
Password security involves a broad set of practices, and not all of them are appropriate or possible for everyone. Therefore, the best strategy is to develop a threat model by thinking through your most significant risks—who and what you are protecting against—then model your security approach on the activities that are most effective against those specific threats. The Electronic Frontier Foundation (EFF) has a [great series on threat modeling][2] that I encourage everyone to read.
In my threat model, I am very concerned about the security of my passwords against (among other things) [dictionary attacks][3], in which an attacker uses a list of likely or known passwords to try to break into a system. One way to stop dictionary attacks is to have your service provider rate-limit or deny login attempts after a certain number of failures. Another way is not to use passwords in the "known passwords" dataset.
### Check password security with HIBP
[Troy Hunt][4] created [Have I Been Pwned?][5] (HIBP) to notify people when their information is found in leaked data dumps and breaches. If you haven't already registered, you should, as the mere act of registering exposes nothing. Troy has built a collection of over 550 million real-world passwords from this data. These are passwords that real people used and were exposed by data that was stolen or accidentally made public.
The site _does not_ publish the plaintext password list, but it doesn't have to. By definition, this data is already out there. If you've ever reused a password or used a "common" password, then you are at risk because someone is building a dictionary of these passwords to try right now.
Recently, Firefox and HIBP announced they are [teaming up][6] to make breach searches easier. And the National Institutes of Standards and Technology (NIST) recommends that you [check passwords][7] against those known to be compromised and change them if they are found. HIBP supports this via a password-checking feature that is exposed via an API, so it is easy to use.
Now, it would be a bad idea to send the website a full list of your passwords. While I trust [HaveIBeenPwned.com][5], it could be compromised one day. Instead, the site uses a process called [k-Anonymity][8] that allows you to check your passwords without exposing them. This is a three-step process. First, let's review the steps, and then we can use the **pass-pwned** plugin to do it for us:
1. Create a hash value of your password. A hash value is just a way of turning arbitrary data—your password—into a fixed data representation—the hash value. A cryptographic hash function is collision-resistant, meaning it creates a unique hash value for every input. The algorithm used for the hash is a one-way transformation, which makes it hard to know the input value if you only have the hash value. For example, using the SHA-1 algorithm that HIBP uses, the password **hunter2** becomes **F3BBBD66A63D4BF1747940578EC3D0103530E21D**.
2. Send the first five characters (**F3BBB** in our example) to the site, and the site will send back a list of all the hash values that start with those five characters. This way, the site can't know which hash values you are interested in. The k-Anonymity process ensures there is so much statistical noise that it is hard for a compromised site to determine which password you inquired about. For example, our query returns a list of 527 potential matches from HIBP.
3. Search through the list of results to see if your hash is there. If it is, your password has been compromised. If it isn't, the password isn't in a publicly known data breach. HIBP returns a bonus in its data: a count of how many times the password has been seen in data breaches. Astoundingly, **hunter2** has been seen 17,043 times!
### Check password security with pass
I use [**pass**][9], a [GNU Privacy Guard][10]-based password manager. It has many extensions, which are available on the [**pass** website][11] and as a separately maintained [awesome-style list][12]. One of these extensions is [**pass-pwned**][13], which will check your passwords with HIBP. Both **pass** and **pass-pwned** are packaged for Fedora 29, 30, and Rawhide. You can install the extension with:
```
`sudo dnf install pass pass-pwned`
```
or you can follow the manual instructions on their respective websites.
If you're just getting started with **pass**, read [Managing passwords the open source way][14] for a great overview.
The following will quickly set up **pass** and check a stored password. This example assumes you already have a GPG key.
```
# Setup a pass password store
$ pass init <GPG key email>
# Add the password, "hunter2" to the store
$ pass insert awesome-site.com
# Install the pass-pwned extension
# Download the bash script from the upstream and then review it
$ mkdir ~/.password-store/.extensions
$ wget <https://raw.githubusercontent.com/alzeih/pass-pwned/master/pwned.bash> -O ~/.password-store/.extensions/pwned.bash
$ vim ~/.password-store/.extensions/pwned.bash
# If everything is OK, set it executable and enable pass extensions
$ chmod u+x ~/.password-store/.extensions/pwned.bash
$ echo 'export PASSWORD_STORE_ENABLE_EXTENSIONS="true"' &gt;&gt; ~/.bash_profile
$ source ~/.bash_profile
# Check the password
$ pass pwned awesome-site.com
Password found in haveibeenpwned 17043 times
# Change this password to something randomly generated and verify it
$ pass generate -i awesoem-site.com
The generated password for awesome-site.com is:
&lt;REDACTED&gt;
$ pass pwned awesome-site.com
Password not found in haveibeenpwned
```
Congratulations, your password is now more secure than it was before! You can also [use wildcards to check multiple passwords][15] at once.
Periodically checking for password compromise is an excellent way to help ward off most attackers in most threat models. If your password management system doesn't make it this easy, you may want to upgrade to something like **pass**.
--------------------------------------------------------------------------------
via: https://opensource.com/article/19/6/check-passwords
作者：[Brian "bex" Exelbierd][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/bexelbie/users/jason-baker/users/admin/users/mtsouk
[b]: https://github.com/lujun9972
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/password.jpg?itok=ec6z6YgZ (Password lock)
[2]: https://ssd.eff.org/en/module/your-security-plan
[3]: https://en.wikipedia.org/wiki/Dictionary_attack
[4]: https://www.troyhunt.com/
[5]: https://haveibeenpwned.com/
[6]: https://www.troyhunt.com/were-baking-have-i-been-pwned-into-firefox-and-1password/
[7]: https://pages.nist.gov/800-63-FAQ/#q-b5
[8]: https://blog.cloudflare.com/validating-leaked-passwords-with-k-anonymity/
[9]: https://www.passwordstore.org/
[10]: https://gnupg.org/
[11]: https://www.passwordstore.org/#extensions
[12]: https://github.com/tijn/awesome-password-store
[13]: https://github.com/alzeih/pass-pwned
[14]: https://opensource.com/life/14/7/managing-passwords-open-source-way
[15]: https://github.com/alzeih/pass-pwned/issues/3

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[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (How to Install and Configure KVM on RHEL 8)
[#]: via: (https://www.linuxtechi.com/install-configure-kvm-on-rhel-8/)
[#]: author: (Pradeep Kumar https://www.linuxtechi.com/author/pradeep/)
How to Install and Configure KVM on RHEL 8
======
**KVM** is an open source virtualization technology which converts your Linux machine into a type-1 bare-metal hypervisor that allows you to run multiple virtual machines (VMs) or guest VMs
<https://www.linuxtechi.com/wp-content/uploads/2019/06/Install-KVM-RHEL8.jpg>
KVM stands for **Kernel based Virtual machine**, as the name suggests KVM is a kernel module, once it is loaded into the kernel , then your Linux machine will start working as a KVM hypervisor. In this article we will demonstrate how to install KVM on RHEL 8 system but before start installing KVM on your RHEL 8 system first we have to make sure that your system’s processor supports hardware virtualization extensions like **Intel VT** or **AMD-V** and enabled it from BIOS.
**RHEL 8 KVM Lab Details:**
* OS = RHEL 8
* Hostname = rhel8-kvm
* Ethernet Cards = ens32 –  192.168.1.4 &amp; ens36 – 192.168..1.12
* RAM = 4 GB
* CPU = 2
* Disk = 40 GB Free Space (/var/libvirtd)
Let’s Jump into the KVM installation steps
### Step:1) Verify Hardware Virtualization is enabled or not
Open the terminal and execute the beneath egrep command
```
[root@linuxtechi ~]# egrep -c '(vmx|svm)' /proc/cpuinfo
2
[root@linuxtechi ~]#
```
If output of above egrep command is equal to 1 or more than 1 then this confirms that hardware virtualization is enabled and supported.
Alternate way to check whether hardware virtualization is enabled or not , execute the beneath command,
```
[root@linuxtechi ~]# lscpu | grep Virtualization:
Virtualization: VT-x
[root@linuxtechi opt]#
```
If there is no output in above command then it confirms that Virtualization is not enabled from BIOS.
**Note:** To enable hardware virtualization reboot your system, go to bios settings and then look for Intel VT or AMD virtualization option and enable one of this option which which suits to your system architecture.
### Step:2) Install KVM and its dependent packages using dnf
Run the following dnf command to install KVM and its dependent packages,
```
[root@linuxtechi ~]# dnf install qemu-kvm qemu-img libvirt virt-install libvirt-client virt-manager -y
```
Once above packages has been installed successfully, then run the below command to confirm whether KVM module has been loaded into the kernel or not,
```
root@linuxtechi ~]# lsmod | grep -i kvm
kvm_intel 245760 0
kvm 745472 1 kvm_intel
irqbypass 16384 1 kvm
[root@linuxtechi ~]#
```
### Step:3) Enable and Start libvirtd service
Run the following systemctl command to enable and start libvirtd service,
```
[root@linuxtechi ~]# systemctl enable libvirtd
[root@linuxtechi ~]# systemctl start libvirtd
```
### Step:4) Create Network bridge and attach Interface to it 
In RHEL 8, network scripts are deprecated, We have to use Network Manager (nmcli / nmtui) to configure network and network bridges.
I have two Ethernet cards on my server, ens36 will attached to bridge br0 and ens32 will be used for management .
```
[root@linuxtechi ~]# nmcli connection show
NAME UUID TYPE DEVICE
ens32 1d21959d-e2ea-4129-bb89-163486c8d7bc ethernet ens32
ens36 1af408b6-c98e-47ce-bca7-5141b721f8d4 ethernet ens36
virbr0 d0f05de4-4b3b-4710-b904-2524b5ad11bf bridge virbr0
[root@linuxtechi ~]#
```
Delete the existing connection of interface “ens36”
```
[root@linuxtechi ~]# nmcli connection delete ens36
Connection 'ens36' (1af408b6-c98e-47ce-bca7-5141b721f8d4) successfully deleted.
[root@linuxtechi ~]#
```
Create a Network Bridge with name “**br0**” using mcli command,
```
[root@linuxtechi ~]# nmcli connection add type bridge autoconnect yes con-name br0 ifname br0
Connection 'br0' (62c14e9d-3e72-41c2-8ecf-d17978ad02da) successfully added.
[root@linuxtechi ~]#
```
Assign the same IP of ens36 to the bridge interface using following nmcli commands,
```
[root@linuxtechi ~]# nmcli connection modify br0 ipv4.addresses 192.168.1.12/24 ipv4.method manual
[root@linuxtechi ~]# nmcli connection modify br0 ipv4.gateway 192.168.1.1
[root@linuxtechi ~]# nmcli connection modify br0 ipv4.dns 192.168.1.1
```
Add ens36 interface as bridge salve to the network bridge br0,
```
[root@linuxtechi ~]# nmcli connection add type bridge-slave autoconnect yes con-name ens36 ifname ens36 master br0
Connection 'ens36' (0c2065bc-ad39-47a7-9a3e-85c80cd73c94) successfully added.
[root@linuxtechi ~]#
```
Now bring up the network bridge using beneath nmcli command,
```
[root@linuxtechi ~]# nmcli connection up br0
Connection successfully activated (master waiting for slaves) (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/9)
[root@linuxtechi ~]#
```
Verify the connections using following command,
```
[root@linuxtechi ~]# nmcli connection show
NAME UUID TYPE DEVICE
br0 00bcff8f-af85-49ad-9196-974de2d9d9d1 bridge br0
ens32 1d21959d-e2ea-4129-bb89-163486c8d7bc ethernet ens32
ens36 eaef13c9-c24e-4a3f-ae85-21bf0610471e ethernet ens36
virbr0 d0f05de4-4b3b-4710-b904-2524b5ad11bf bridge virbr0
[root@linuxtechi ~]#
```
View the bridge (br0) details and status using ip command,
![rhel-8-bridge-details][1]
**Note:** If you want to use network-scripts in RHEL 8 system then install network-scripts packages,
```
~ ]# dnf install network-scripts -y
```
### Step:5) Creating and Managing KVM Virtual Machines
In RHEL 8 there are different ways to create and manage KVM virtual machines,
* virt-manager (GUI)
* Command Line tools (**virt-install** &amp; **virsh**)
During the KVM installation we have already installed virt-manager and virt-install packages.
### Creating Virtual Machines using virt-manager GUI tool:
Run the virt-manager command from command line or Access virt-manager from RHEL 8 Desktop
[![Access-Virt-Manager-RHEL8][2]][3]
Click on Monitor Icon to create a new guest VM (Virtual Machine),
Choose Local Installation Media as ISO,
[![Choose-ISO-KVM-RHEL8][4]][5]
Click on forward,
In the next screen, browse the OS installation ISO file , in my case i have placed Ubuntu 18.04 LTS server ISO file under /opt folder,
[![Installation-ISO-File-RHEL8-KVM][6]][7]
click on Forward to Proceed further,
In the next window you will be prompted to specify RAM and vCPU for your virtual machine, so specify the values that suits your installation and then click on Forward,
[![Specify-RAM-CPU-KVM-RHEL8][8]][9]
In next window specify disk size for your Virtual Machine and the click on Forward, in my case i am giving disk space for my VM as 20 GB,
[![Disk-Image-RHEL8-KVM-VM][10]][11]
In the next window, specify the name of VM and choose the Network that you want to attach to VM’s Ethernet card, as we had created network bridge “br0” for vms networking, so choose bridge“br0”.
[![Network-Selection-KVM-RHEL8][12]][13]
Click on Finish to proceed with VM creation and its OS installation,
[![OS-Installation-KVM-VM-RHEL8][14]][15]
Follow the screen Instructions and complete the Installation.
**Creating KVM Virtual Machine from Command Line**
if you are fan of command line then there is a command line tool for you called “**virt-install**” to create virtual machines. Once the Virtual machines are provisioned then vms can be managed via command line tool “[virsh][16]“.
Let’s assume we want to create CentOS 7 VM using virt-install, i have already placed CentOS 7 ISO file under /opt folder,
Execute beneath command to provision a VM
```
[root@linuxtechi ~]# virt-install -n CentOS7-Server --description "CentOS 7 Virtual Machine" --os-type=Linux --os-variant=rhel7 --ram=1096 --vcpus=1 --disk path=/var/lib/libvirt/images/centos7-server.img,bus=virtio,size=20 --network bridge:br0 --graphics none --location /opt/CentOS-7-x86_64-DVD-1511.iso --extra-args console=ttyS0
```
Output of command would be something like below,
![Virt-Install-KVM-RHEL8][17]
Follow screen instructions to complete CentOS 7 Installation. That’s all from this tutorial, i hope these steps helped you to setup KVM on your RHEL 8 system, please do share your feedback and comments.
--------------------------------------------------------------------------------
via: https://www.linuxtechi.com/install-configure-kvm-on-rhel-8/
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]: https://www.linuxtechi.com/author/pradeep/
[b]: https://github.com/lujun9972
[1]: https://www.linuxtechi.com/wp-content/uploads/2019/06/rhel-8-bridge-details-1024x628.jpg
[2]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Access-Virt-Manager-RHEL8-1024x471.jpg
[3]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Access-Virt-Manager-RHEL8.jpg
[4]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Choose-ISO-KVM-RHEL8-1024x479.jpg
[5]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Choose-ISO-KVM-RHEL8.jpg
[6]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Installation-ISO-File-RHEL8-KVM-1024x477.jpg
[7]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Installation-ISO-File-RHEL8-KVM.jpg
[8]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Specify-RAM-CPU-KVM-RHEL8-1024x478.jpg
[9]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Specify-RAM-CPU-KVM-RHEL8.jpg
[10]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Disk-Image-RHEL8-KVM-VM-1024x483.jpg
[11]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Disk-Image-RHEL8-KVM-VM.jpg
[12]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Network-Selection-KVM-RHEL8-1024x482.jpg
[13]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Network-Selection-KVM-RHEL8.jpg
[14]: https://www.linuxtechi.com/wp-content/uploads/2019/06/OS-Installation-KVM-VM-RHEL8-1024x479.jpg
[15]: https://www.linuxtechi.com/wp-content/uploads/2019/06/OS-Installation-KVM-VM-RHEL8.jpg
[16]: https://www.linuxtechi.com/create-revert-delete-kvm-virtual-machine-snapshot-virsh-command/
[17]: https://www.linuxtechi.com/wp-content/uploads/2019/06/Virt-Install-KVM-RHEL8.jpg

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[#]: collector: (lujun9972)
[#]: translator: (geekpi)
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Using i3 with multiple monitors)
[#]: via: (https://fedoramagazine.org/using-i3-with-multiple-monitors/)
[#]: author: (Adam Šamalík https://fedoramagazine.org/author/asamalik/)
Using i3 with multiple monitors
======
![][1]
Are you using multiple monitors with your Linux workstation? Seeing many things at once might be beneficial. But there are often much more windows in our workflows than physical monitors — and that’s a good thing, because seeing too many things at once might be distracting. So being able to switch what we see on individual monitors seems crucial.
Let’s talk about i3 — a popular tiling window manager that works great with multiple monitors. And there is one handy feature that many other window managers don’t have — the ability to switch workspaces on individual monitors independently.
### Quick introduction to i3
The [Fedora Magazine has already covered i3][2] about three years ago. And it was one of the most popular articles ever published! Even though that’s not always the case, i3 is pretty stable and that article is still very accurate today. So — not to repeat ourselves too much — this article only covers the very minimum to get i3 up and running, and you’re welcome to go ahead and read it if you’re new to i3 and want to learn more about the basics.
To install i3 on your system, run the following command:
```
$ sudo dnf install i3
```
When that’s done, log out, and on the log in screen choose i3 as your window manager and log back in again.
When you run i3 for the first time, you’ll be asked if you wish to proceed with automatic configuration — answer yes here. After that, you’ll be asked to choose a “mod key”. If you’re not sure here, just accept the default which sets you Windows/Super key as the mod key. You’ll use this key for mostly all the shortcuts within the window manager.
At this point, you should see a little bar at the bottom and an empty screen. Let’s have a look at some of the basic shortcuts.
Open a terminal using:
```
$mod + enter
```
Switch to a second workspace using:
```
$mod + 2
```
Open firefox in two steps, first by:
```
$mod + d
```
… and then by typing “firefox” and pressing enter.
Move it to the first workspace by:
```
$mod + shift + 1
```
… and switch to the first workspace by:
```
$mod + 1
```
At this point, you’ll see a terminal and a firefox window side by side. To close a window, press:
```
$mod + shift + q
```
There are more shortcuts, but these should give you the minimum to get started with i3.
Ah! And to exit i3 (to log out) press:
```
$mod + shift + e
```
… and then confirm using your mouse at the top-right corner.
### Getting multiple screens to work
Now that we have i3 up and running, let’s put all those screens to work!
To do that, we’ll need to use the command line as i3 is very lightweight and doesn’t have gui to manage additional screens. But don’t worry if that sounds difficult — it’s actually quite straightforward!
The command we’ll use is called xrandr. If you don’t have xrandr on your system, install it by running:
```
$ sudo dnf install xrandr
```
When that’s installed, let’s just go ahead and run it:
```
$ xrandr
```
The output lists all the available outputs, and also indicated which have a screen attached to them (a monitor connected with a cable) by showing supported resolutions. Good news is that we don’t need to really care about the specific resolutions to make the them work.
This specific example shows a primary screen of a laptop (named eDP1), and a second monitor connected to the HDMI-2 output, physically positioned right of the laptop. To turn it on, run the following command:
```
$ xrandr --output HDMI-2 --auto --right-of eDP1
```
And that’s it! Your screen is now active.
![Second screen active. The commands shown on this screenshot are slightly different than in the article, as they set a smaller resolution to make the screenshots more readable.][3]
### Managing workspaces on multiple screens
Switching workspaces and creating new ones on multiple screens is very similar to having just one screen. New workspaces get created on the screen that’s currently active — the one that has your mouse cursor on it.
So, to switch to a specific workspace (or to create a new one in case it doesn’t exist), press:
```
$mod + NUMBER
```
And you can switch workspaces on individual monitors independently!
![Workspace 2 on the left screen, workspace 4 on the right screen.][4]
![Left screen switched to workspace 3, right screen still showing workspace 4.][5]
![Right screen switched to workspace 4, left screen still showing workspace 3.][6]
### Moving workspaces between monitors
The same way we can move windows to different workspaces by the following command:
```
$mod + shift + NUMBER
```
… we can move workspaces to different screens as well. However, there is no default shortcut for this action — so we have to create it first.
To create a custom shortcut, you’ll need to open the configuration file in a text editor of your choice (this article uses _vim_):
```
$ vim ~/.config/i3/config
```
And add the following lines to the very bottom of the configuration file:
```
# Moving workspaces between screens
bindsym $mod+p move workspace to output right
```
Save, close, and to reload and apply the configuration, press:
```
$mod + shift + r
```
Now you’ll be able to move your active workspace to the second monitor by:
```
$mod + p
```
![Workspace 2 with Firefox on the left screen][7]
![Workspace 2 with Firefox moved to the second screen][8]
And that’s it! Enjoy your new multi-monitor experience, and to learn more about i3, you’re welcome to read the previous article about i3 on the Fedora Magazine, or consult the official i3 documentation.
--------------------------------------------------------------------------------
via: https://fedoramagazine.org/using-i3-with-multiple-monitors/
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://fedoramagazine.org/wp-content/uploads/2019/06/i3-title-816x345.jpg
[2]: https://fedoramagazine.org/getting-started-i3-window-manager/
[3]: https://fedoramagazine.org/wp-content/uploads/2019/06/0-1-1024x384.png
[4]: https://fedoramagazine.org/wp-content/uploads/2019/06/1-1-1024x384.png
[5]: https://fedoramagazine.org/wp-content/uploads/2019/06/1-2-1024x384.png
[6]: https://fedoramagazine.org/wp-content/uploads/2019/06/1-3-1024x384.png
[7]: https://fedoramagazine.org/wp-content/uploads/2019/06/2-1-1024x384.png
[8]: https://fedoramagazine.org/wp-content/uploads/2019/06/2-2-1024x384.png

110
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[#]: collector: (lujun9972)
[#]: translator: ( )
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (With Upgraded Specs, Raspberry Pi 4 Takes Aim at Desktop Segment)
[#]: via: (https://itsfoss.com/raspberry-pi-4/)
[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
With Upgraded Specs, Raspberry Pi 4 Takes Aim at Desktop Segment
======
_**Brief: Raspberry Pi 4 is here with the upgraded technical specifications. You get up to 4 GB of RAM and you can connect two 4K displays with it. With the new hardware, you should be more comfortable using it as a desktop. Starting price remains the $35 like the previous models.**_
The Raspberry Pi Foundation has just launched the new [Raspberry Pi 4 Model B][1].
It comes with some impressive upgrades which makes one of the most powerful [single board computers][2] under $40.
![Raspberry Pi 4][3]
### What’s new in Raspberry Pi 4?
The Raspberry Pi 4 now supports a dual 4K monitor setup – if that is what you are looking for. In addition to this, you get a more powerful processor which can be coupled with up to 4 GB of RAM. That’s almost equivalent to a mid-end laptop.
The upgraded specification makes it a competitor in the [Linux mini-PC][4] segment while the same price tag of $35 gives it an edge over [other single board computers][2].
Right after the launch, it’s almost out of stock at major online stores. So, let us take a look at what makes it so impressive.
#### Raspberry Pi 4 key specifications
![Raspberry Pi 4 Tech Specs][5]
* Broadcom BCM2711, Quad core Cortex-A72 (ARM v8) 64-bit SoC @ 1.5GHz
* Up to 4GB RAM (choices are 1 GB, 2 GB and 4 GB)
* WiFi and Bluetooth 5.0
* 2 USB 3.0 and a USB 2.0 ports
* 40 pin GPIO header (backward compatible)
* 2 micro-HDMI ports (supports 4K displays)
* USB-C (power supply)
* Gigabit Ethernet
If you are curious to know more, do check out the [official tech specs][6] on their website.
### Pricing and availability
The pricing for just the Raspberry Pi 4 board starts from $35 and depending on the choice of RAM (1-4 GB), the cost shall vary.
* Raspberry Pi 4 with 1 GB RAM: $35
* Raspberry Pi 4 with 2 GB RAM: $45
* Raspberry Pi 4 with 4 GB RAM: $55
Raspberry Pi 4 is available from different vendors depending on your country. It’s getting out of stock so you should either hurry up or wait for a few days/weeks. You can get purchase information on its official webpage.
[Buy Raspberry Pi 4][1]
You should note that [you need to have additional accessories in order to run Raspberry Pi][7]. This is why there are several starter kits available to give you all the necessary supporting accessories.
[][8]
Suggested read  Raspberry Pi Gets RAM Upgrade, In The Same Price
#### Raspberry Pi 4 desktop Kit
![Raspberry Pi 4 Desktop Kit][9]
You can also purchase the official Raspberry Pi 4 desktop kit that comes with a Raspberry Pi 4, its case, keyboard, mouse, micro HDMI cables, USB-C power supply, user guide and 16GB [microSD card with Raspbian installed][10].
![Raspberry Pi Branded Desktop Kit][11]
The entire kit is in red and white color and it looks pretty (if you care for the looks). You can get the purchase information on Raspberry Pi website.
[Raspberry Pi 4 Desktop Kit][12]
#### Raspberry Pi 4 is promising
With all that spec buff, it is definitely going to be one of the best out there. Also, instead of getting an entry-level desktop, Raspberry Pi 4 will be a better choice. You can easily access your documents, manage your spreadsheets, and do a lot of things at a cheaper price tag.
I’m definitely considering to purchase the Raspberry Pi 4 as a spare (but a powerful) entry-level desktop. Well, I won’t be going for the 4K dual monitor setup, but it surely is capable of that, at least on paper.
What do you think about the new Raspberry Pi 4 Model B? Let us know your thoughts in the comments below.
--------------------------------------------------------------------------------
via: https://itsfoss.com/raspberry-pi-4/
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.raspberrypi.org/products/raspberry-pi-4-model-b/
[2]: https://itsfoss.com/raspberry-pi-alternatives/
[3]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/06/raspberry-pi-4.jpeg?resize=800%2C449&ssl=1
[4]: https://itsfoss.com/linux-based-mini-pc/
[5]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/06/raspberry-pi-4-tech-specs.jpg?ssl=1
[6]: https://www.raspberrypi.org/products/raspberry-pi-4-model-b/specifications/
[7]: https://itsfoss.com/things-you-need-to-get-your-raspberry-pi-working/
[8]: https://itsfoss.com/raspberry-pi-gets-ram-upgrade-in-the-same-price/
[9]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2019/06/raspberry-pi-4-desktop-kit.jpg?resize=800%2C427&ssl=1
[10]: https://itsfoss.com/tutorial-how-to-install-raspberry-pi-os-raspbian-wheezy/
[11]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2019/06/raspberry-pi-desktop-kit-official.jpg?ssl=1
[12]: https://www.raspberrypi.org/products/raspberry-pi-4-desktop-kit/

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[#]: collector: (lujun9972)
[#]: translator: (geekpi)
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Use Firefox Send with ffsend in Fedora)
[#]: via: (https://fedoramagazine.org/use-firefox-send-with-ffsend-in-fedora/)
[#]: author: (Sylvia Sánchez https://fedoramagazine.org/author/lailah/)
在 Fedora 中利用 ffsend 使用 Firefox Send
======
![][1]
_ffsend_ 是 Firefox Send 的命令行客户端。本文将展示 Firefox Send 和 _ffsend_ 如何工作。还会详细介绍如何在 Fedora 中安装和使用它。
### 什么是 Firefox Send 和 ffsend？
Firefox Send 是 Mozilla 的一个文件共享工具，它能将加密文件发送给其他用户。你可以在自己的服务器上安装 Send，也可以使用 Mozilla 托管的链接 [send.firefox.com][2]。它最大支持 1GB 的文件，链接会在可配置的下载次数（默认值为 1）或 24 小时后过期，然后会删除发送服务器上的所有文件。此工具仍_处于实验阶段_，因此不应在生产中使用或共享重要或敏感数据。
虽然 Firefox Send 本身就是工具，并且可以在 Web 中使用，但 _ffsend_ 是一个可以与脚本和参数一起使用的命令行程序。它有多种配置选项，并且可以在后台工作而无需任何人为干预。
### 它如何工作？
ffsend 可以上传和下载文件。远程主机可以使用 Firefox 工具或其他 Web 浏览器来下载文件。 Firefox Send 和 _ffsend_ 都不需要使用 Firefox。
值得一提 _ffsend_ 使用了客户端加密。这意味着文件在上传_前_被加密。链接中就有密钥，因此在共享时要小心，因为任何有链接的人都可以下载该文件。作为额外的保护，你可以使用以下参数使用密码保护文件：
```
ffsend password URL -p PASSWORD
```
### 其他功能
还有一些值得一提的其他功能：
* 链接到期前可配置的下载限制，范围从 1 到 20 次之间
  * 内置解压和归档功能
  * 跟踪共享文件的历史记录
  * 检查或删除共享文件
  * 文件夹也可以按原样共享，也可以作为压缩文件共享
  * 生成 QR 码，便于在手机上下载
### 如何在 Fedora 中安装
虽然 Fedora Send 可以在 Firefox 中使用而无需安装其他，但你需要安装 CLI 工具才能使用 _ffsend_。此工具在官方仓库中，因此你只需使用 _dnf_ 命令，并使用 _[sudo][3]_。
```
$ sudo dnf install ffsend
```
之后，你可以在终端使用 _ffsend_。
### 上传文件
上传文件很简单。
```
$ ffsend upload /etc/os-release
Upload complete
Share link: https://send.firefox.com/download/05826227d70b9a4b/#RM_HSBq6kuyeBem8Z013mg
```
现在可以使用 “Share link” URL 轻松共享该文件。
## 下载文件
下载文件和上传一样简单。
```
$ ffsend download https://send.firefox.com/download/05826227d70b9a4b/#RM_HSBq6kuyeBem8Z013mg
Download complete
```
在下载之前，检查文件是否存在并获取有关它的信息会有用。 _ffsend_ 为此提供了 2 个方便的命令。
```
$ ffsend exists https://send.firefox.com/download/88a6324e2a99ebb6/#YRJDh8ZDQsnZL2KZIA-PaQ
Exists: true
Password: false
$ ffsend info https://send.firefox.com/download/88a6324e2a99ebb6/#YRJDh8ZDQsnZL2KZIA-PaQ
ID: 88a6324e2a99ebb6
Downloads: 0 of 1
Expiry: 23h59m (86388s
```
## 上传历史
_ffsend_ 还提供了一种查看使用工具上传的历史记录的方法。例如，如果你用脚本上传了大量文件并且想要跟踪每个文件的下载状态，那么这非常有用。
```
$ ffsend history
LINK EXPIRY
1 https://send.firefox.com/download/#8TJ9QNw 23h59m
2 https://send.firefox.com/download/KZIA-PaQ 23h54m
```
## 删除文件
另一个有用的功能是删除文件。
```
ffsend delete https://send.firefox.com/download/2d9faa7f34bb1478/#phITKvaYBjCGSRI8TJ9QNw
```
Firefox Send 是一项很棒的服务，_ffsend_ 使得它在终端使用起来非常方便。[Gitlab 仓库[4]中有关于 _ffsend_ 的的更多示例和文档。
--------------------------------------------------------------------------------
via: https://fedoramagazine.org/use-firefox-send-with-ffsend-in-fedora/
作者：[Sylvia Sánchez][a]
选题：[lujun9972][b]
译者：[geekpi](https://github.com/geekpi)
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/lailah/
[b]: https://github.com/lujun9972
[1]: https://fedoramagazine.org/wp-content/uploads/2019/04/firefox-send-816x345.png
[2]: http://send.firefox.com/
[3]: https://fedoramagazine.org/howto-use-sudo/
[4]: https://gitlab.com/timvisee/ffsend

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[#]: collector: (lujun9972)
[#]: translator: (murphyzhao)
[#]: reviewer: ( )
[#]: publisher: ( )
[#]: url: ( )
[#]: subject: (Applications for writing Markdown)
[#]: via: (https://fedoramagazine.org/applications-for-writing-markdown/)
[#]: author: (Ryan Lerch https://fedoramagazine.org/author/ryanlerch/)
撰写 Markdown 的软件
======
![][1]
Markdown 是一种轻量级标记语言，添加格式后，以纯文本格式查看时依然保持可读性。Markdown（和 Markdown 衍生物）被广泛用作 GitHub 和 pagure 等服务上文档标记的主要形式。根据设计，可以在文本编辑器中轻松创建和编辑 Markdown，但是，有许多编辑器可以提供 Markdown 标记的格式化预览，或提供 markdown 语法高亮显示。
本文介绍了针对 Fedora 平台的 3 个桌面应用程序，以帮助编辑 Markdown。
### UberWriter
[UberWriter][2] 是一个小巧的 Markdown 编辑器和预览器，允许您编辑文本，并预览渲染的文档。
![][3]
编辑器本身具有内置的内联预览，因此标记为粗体的文本以粗体显示。编辑器还提供图像、公式、脚注等标记的内联预览。按住 Ctrl 键单击其中的一个标记可以即时预览要显示的元素。
除了编辑器功能外，UberWriter 还具有全屏模式和聚焦模式，有助于最大限度地减少干扰。焦点模式将以灰色显示除当前段落以外的所有内容，以帮助您专注于文档中当前元素。
从第三方 Flathub 存储库安装 UberWriter 到 Fedora 平台。在将系统[设置为从 Flathub 安装][4]后，可以直接从 Software 应用程序中安装它。
### Marker
Marker 是一个 Markdown 编辑器，它提供了一个简单的文本编辑器来编写 Markdown，并提供渲染文档的实时预览。界面采用分屏设计，左侧为编辑器，右侧为实时预览。
![][5]
此外，Marker 允许您以各种格式导出文档，包括 HTML、PDF 和开放文档格式（ODF）。
从第三方 Flathub 存储库安装 Marker 到 Fedora 平台。在将系统[设置为从 Flathub 安装][4]后，可以直接从 Software 应用程序中安装它。
### Ghostwriter
以前的编辑更专注于最小的用户体验，Ghostwriter 提供了更多的功能和选项。Ghostwriter 提供了一个文本编辑器，当您以 Markdown 格式书写时，编辑器将 Markdown 部分样式化。粗体标记文本显示为粗体，标题标记显示为较大的字体，以帮助编写 Markdown 标记。
![][6]
它还提供了一个分屏，包含渲染文档的实时更新预览。
![][7]
Ghostwriter 还包括一系列其他功能，包括能够选择渲染预览的 Markdown 风格，以及用于渲染预览的样式表。
此外，它还提供了一个格式菜单（和键盘快捷键）来插入一些频繁的 Markdown 标记，如粗体、项目符号和斜体。
从第三方 Flathub 存储库安装 Ghostwriter 到 Fedora 平台。在将系统[设置为从 Flathub 安装][4]后，可以直接从 Software 应用程序中安装它。
--------------------------------------------------------------------------------
via: https://fedoramagazine.org/applications-for-writing-markdown/
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/author/ryanlerch/
[b]: https://github.com/lujun9972
[1]: https://fedoramagazine.org/wp-content/uploads/2019/06/markdownapps.png-816x345.jpg
[2]: https://uberwriter.github.io/uberwriter/#1
[3]: https://fedoramagazine.org/wp-content/uploads/2019/06/uberwriter-editor-1.png
[4]: https://fedoramagazine.org/install-flathub-apps-fedora/
[5]: https://fedoramagazine.org/wp-content/uploads/2019/06/marker-screenshot-1024x500.png
[6]: https://fedoramagazine.org/wp-content/uploads/2019/06/ghostwriter-1024x732.png
[7]: https://fedoramagazine.org/wp-content/uploads/2019/06/ghostwriter2-1024x566.png