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published/20140607 Five things that make Go fast.md
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published/20140607 Five things that make Go fast.md
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五种加速 Go 的特性
|
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========
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_Anthony Starks 使用他出色的 Deck 演示工具重构了我原来的基于 Google Slides 的幻灯片。你可以在他的博客上查看他重构后的幻灯片,
|
||||
[mindchunk.blogspot.com.au/2014/06/remixing-with-deck][5]。_
|
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|
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我最近被邀请在 Gocon 发表演讲，这是一个每半年在日本东京举行的 Go 的精彩大会。[Gocon 2014][6] 是一个完全由社区驱动的为期一天的活动，由培训和一整个下午的围绕着生产环境中的 Go</q> 这个主题的演讲组成.（LCTT 译注：本文发表于 2014 年）
|
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|
||||
以下是我的讲义。原文的结构能让我缓慢而清晰的演讲，因此我已经编辑了它使其更可读。
|
||||
|
||||
我要感谢 [Bill Kennedy][7] 和 Minux Ma，特别是 [Josh Bleecher Snyder][8]，感谢他们在我准备这次演讲中的帮助。
|
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|
||||
* * *
|
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|
||||
大家下午好。
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|
||||
我叫 David.
|
||||
|
||||
我很高兴今天能来到 Gocon。我想参加这个会议已经两年了，我很感谢主办方能提供给我向你们演讲的机会。
|
||||
|
||||
[][9]
|
||||
|
||||
我想以一个问题开始我的演讲。
|
||||
|
||||
为什么选择 Go？
|
||||
|
||||
当大家讨论学习或在生产环境中使用 Go 的原因时，答案不一而足，但因为以下三个原因的最多。
|
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|
||||
[][10]
|
||||
|
||||
这就是 TOP3 的原因。
|
||||
|
||||
第一，并发。
|
||||
|
||||
Go 的 <ruby>并发原语<rt>Concurrency Primitives</rt></ruby> 对于来自 Nodejs，Ruby 或 Python 等单线程脚本语言的程序员，或者来自 C++ 或 Java 等重量级线程模型的语言都很有吸引力。
|
||||
|
||||
易于部署。
|
||||
|
||||
我们今天从经验丰富的 Gophers 那里听说过，他们非常欣赏部署 Go 应用的简单性。
|
||||
|
||||
[][11]
|
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|
||||
然后是性能。
|
||||
|
||||
我相信人们选择 Go 的一个重要原因是它 _快_。
|
||||
|
||||
[][12]
|
||||
|
||||
在今天的演讲中，我想讨论五个有助于提高 Go 性能的特性。
|
||||
|
||||
我还将与大家分享 Go 如何实现这些特性的细节。
|
||||
|
||||
[][13]
|
||||
|
||||
我要谈的第一个特性是 Go 对于值的高效处理和存储。
|
||||
|
||||
[][14]
|
||||
|
||||
这是 Go 中一个值的例子。编译时，`gocon` 正好消耗四个字节的内存。
|
||||
|
||||
让我们将 Go 与其他一些语言进行比较
|
||||
|
||||
[][15]
|
||||
|
||||
由于 Python 表示变量的方式的开销，使用 Python 存储相同的值会消耗六倍的内存。
|
||||
|
||||
Python 使用额外的内存来跟踪类型信息，进行 <ruby>引用计数<rt>Reference Counting</rt></ruby> 等。
|
||||
|
||||
让我们看另一个例子：
|
||||
|
||||
[][16]
|
||||
|
||||
与 Go 类似，Java 消耗 4 个字节的内存来存储 `int` 型。
|
||||
|
||||
但是，要在像 `List` 或 `Map` 这样的集合中使用此值，编译器必须将其转换为 `Integer` 对象。
|
||||
|
||||
[][17]
|
||||
|
||||
因此，Java 中的整数通常消耗 16 到 24 个字节的内存。
|
||||
|
||||
为什么这很重要？ 内存便宜且充足，为什么这个开销很重要？
|
||||
|
||||
[][18]
|
||||
|
||||
这是一张显示 CPU 时钟速度与内存总线速度的图表。
|
||||
|
||||
请注意 CPU 时钟速度和内存总线速度之间的差距如何继续扩大。
|
||||
|
||||
两者之间的差异实际上是 CPU 花费多少时间等待内存。
|
||||
|
||||
[][19]
|
||||
|
||||
自 1960 年代后期以来，CPU 设计师已经意识到了这个问题。
|
||||
|
||||
他们的解决方案是一个缓存，一个更小、更快的内存区域，介入 CPU 和主存之间。
|
||||
|
||||
[][20]
|
||||
|
||||
这是一个 `Location` 类型，它保存物体在三维空间中的位置。它是用 Go 编写的，因此每个 `Location` 只消耗 24 个字节的存储空间。
|
||||
|
||||
我们可以使用这种类型来构造一个容纳 1000 个 `Location` 的数组类型，它只消耗 24000 字节的内存。
|
||||
|
||||
在数组内部，`Location` 结构体是顺序存储的，而不是随机存储的 1000 个 `Location` 结构体的指针。
|
||||
|
||||
这很重要，因为现在所有 1000 个 `Location` 结构体都按顺序放在缓存中，紧密排列在一起。
|
||||
|
||||
[][21]
|
||||
|
||||
Go 允许您创建紧凑的数据结构，避免不必要的填充字节。
|
||||
|
||||
紧凑的数据结构能更好地利用缓存。
|
||||
|
||||
更好的缓存利用率可带来更好的性能。
|
||||
|
||||
[][22]
|
||||
|
||||
函数调用不是无开销的。
|
||||
|
||||
[][23]
|
||||
|
||||
调用函数时会发生三件事。
|
||||
|
||||
创建一个新的 <ruby>栈帧<rt>Stack Frame</rt></ruby>，并记录调用者的详细信息。
|
||||
|
||||
在函数调用期间可能被覆盖的任何寄存器都将保存到栈中。
|
||||
|
||||
处理器计算函数的地址并执行到该新地址的分支。
|
||||
|
||||
[][24]
|
||||
|
||||
由于函数调用是非常常见的操作，因此 CPU 设计师一直在努力优化此过程，但他们无法消除开销。
|
||||
|
||||
函调固有开销，或重于泰山，或轻于鸿毛，这取决于函数做了什么。
|
||||
|
||||
减少函数调用开销的解决方案是 <ruby>内联<rt>Inlining</rt></ruby>。
|
||||
|
||||
[][25]
|
||||
|
||||
Go 编译器通过将函数体视为调用者的一部分来内联函数。
|
||||
|
||||
内联也有成本，它增加了二进制文件大小。
|
||||
|
||||
只有当调用开销与函数所做工作关联度的很大时内联才有意义，因此只有简单的函数才能用于内联。
|
||||
|
||||
复杂的函数通常不受调用它们的开销所支配，因此不会内联。
|
||||
|
||||
[][26]
|
||||
|
||||
这个例子显示函数 `Double` 调用 `util.Max`。
|
||||
|
||||
为了减少调用 `util.Max` 的开销，编译器可以将 `util.Max` 内联到 `Double` 中，就象这样
|
||||
|
||||
[][27]
|
||||
|
||||
内联后不再调用 `util.Max`，但是 `Double` 的行为没有改变。
|
||||
|
||||
内联并不是 Go 独有的。几乎每种编译或及时编译的语言都执行此优化。但是 Go 的内联是如何实现的？
|
||||
|
||||
Go 实现非常简单。编译包时，会标记任何适合内联的小函数，然后照常编译。
|
||||
|
||||
然后函数的源代码和编译后版本都会被存储。
|
||||
|
||||
[][28]
|
||||
|
||||
此幻灯片显示了 `util.a` 的内容。源代码已经过一些转换，以便编译器更容易快速处理。
|
||||
|
||||
当编译器编译 `Double` 时，它看到 `util.Max` 可内联的，并且 `util.Max` 的源代码是可用的。
|
||||
|
||||
就会替换原函数中的代码，而不是插入对 `util.Max` 的编译版本的调用。
|
||||
|
||||
拥有该函数的源代码可以实现其他优化。
|
||||
|
||||
[][29]
|
||||
|
||||
在这个例子中，尽管函数 `Test` 总是返回 `false`，但 `Expensive` 在不执行它的情况下无法知道结果。
|
||||
|
||||
当 `Test` 被内联时，我们得到这样的东西。
|
||||
|
||||
[][30]
|
||||
|
||||
编译器现在知道 `Expensive` 的代码无法访问。
|
||||
|
||||
这不仅节省了调用 `Test` 的成本，还节省了编译或运行任何现在无法访问的 `Expensive` 代码。
|
||||
|
||||
Go 编译器可以跨文件甚至跨包自动内联函数。还包括从标准库调用的可内联函数的代码。
|
||||
|
||||
[][31]
|
||||
|
||||
<ruby>强制垃圾回收<rt>Mandatory Garbage Collection</rt></ruby> 使 Go 成为一种更简单，更安全的语言。
|
||||
|
||||
这并不意味着垃圾回收会使 Go 变慢，或者垃圾回收是程序速度的瓶颈。
|
||||
|
||||
这意味着在堆上分配的内存是有代价的。每次 GC 运行时都会花费 CPU 时间，直到释放内存为止。
|
||||
|
||||
[][32]
|
||||
|
||||
然而，有另一个地方分配内存，那就是栈。
|
||||
|
||||
与 C 不同，它强制您选择是否将值通过 `malloc` 将其存储在堆上，还是通过在函数范围内声明将其储存在栈上；Go 实现了一个名为 <ruby>逃逸分析<rt>Escape Analysis</rt></ruby> 的优化。
|
||||
|
||||
[][33]
|
||||
|
||||
逃逸分析决定了对一个值的任何引用是否会从被声明的函数中逃逸。
|
||||
|
||||
如果没有引用逃逸，则该值可以安全地存储在栈中。
|
||||
|
||||
存储在栈中的值不需要分配或释放。
|
||||
|
||||
让我们看一些例子
|
||||
|
||||
[][34]
|
||||
|
||||
`Sum` 返回 1 到 100 的整数的和。这是一种相当不寻常的做法，但它说明了逃逸分析的工作原理。
|
||||
|
||||
因为切片 `numbers` 仅在 `Sum` 内引用，所以编译器将安排到栈上来存储的 100 个整数，而不是安排到堆上。
|
||||
|
||||
没有必要回收 `numbers`，它会在 `Sum` 返回时自动释放。
|
||||
|
||||
[][35]
|
||||
|
||||
第二个例子也有点尬。在 `CenterCursor` 中，我们创建一个新的 `Cursor` 对象并在 `c` 中存储指向它的指针。
|
||||
|
||||
然后我们将 `c` 传递给 `Center()` 函数，它将 `Cursor` 移动到屏幕的中心。
|
||||
|
||||
最后我们打印出那个 'Cursor` 的 X 和 Y 坐标。
|
||||
|
||||
即使 `c` 被 `new` 函数分配了空间，它也不会存储在堆上，因为没有引用 `c` 的变量逃逸 `CenterCursor` 函数。
|
||||
|
||||
[][36]
|
||||
|
||||
默认情况下，Go 的优化始终处于启用状态。可以使用 `-gcflags = -m` 开关查看编译器的逃逸分析和内联决策。
|
||||
|
||||
因为逃逸分析是在编译时执行的，而不是运行时，所以无论垃圾回收的效率如何，栈分配总是比堆分配快。
|
||||
|
||||
我将在本演讲的其余部分详细讨论栈。
|
||||
|
||||
[][37]
|
||||
|
||||
Go 有 goroutine。 这是 Go 并发的基石。
|
||||
|
||||
我想退一步，探索 goroutine 的历史。
|
||||
|
||||
最初，计算机一次运行一个进程。在 60 年代，多进程或 <ruby>分时<rt>Time Sharing</rt></ruby> 的想法变得流行起来。
|
||||
|
||||
在分时系统中，操作系统必须通过保护当前进程的现场，然后恢复另一个进程的现场，不断地在这些进程之间切换 CPU 的注意力。
|
||||
|
||||
这称为 _进程切换_。
|
||||
|
||||
[][38]
|
||||
|
||||
进程切换有三个主要开销。
|
||||
|
||||
首先，内核需要保护该进程的所有 CPU 寄存器的现场，然后恢复另一个进程的现场。
|
||||
|
||||
内核还需要将 CPU 的映射从虚拟内存刷新到物理内存，因为这些映射仅对当前进程有效。
|
||||
|
||||
最后是操作系统 <ruby>上下文切换<rt>Context Switch</rt></ruby> 的成本，以及 <ruby>调度函数<rt>Scheduler Function</rt></ruby> 选择占用 CPU 的下一个进程的开销。
|
||||
|
||||
[][39]
|
||||
|
||||
现代处理器中有数量惊人的寄存器。我很难在一张幻灯片上排开它们，这可以让你知道保护和恢复它们需要多少时间。
|
||||
|
||||
由于进程切换可以在进程执行的任何时刻发生，因此操作系统需要存储所有寄存器的内容，因为它不知道当前正在使用哪些寄存器。
|
||||
|
||||
[][40]
|
||||
|
||||
这导致了线程的出生，这些线程在概念上与进程相同，但共享相同的内存空间。
|
||||
|
||||
由于线程共享地址空间，因此它们比进程更轻，因此创建速度更快，切换速度更快。
|
||||
|
||||
[][41]
|
||||
|
||||
Goroutine 升华了线程的思想。
|
||||
|
||||
Goroutine 是 <ruby>协作式调度<rt>Cooperative Scheduled
|
||||
</rt></ruby>的，而不是依靠内核来调度。
|
||||
|
||||
当对 Go <ruby>运行时调度器<rt>Runtime Scheduler</rt></ruby> 进行显式调用时，goroutine 之间的切换仅发生在明确定义的点上。
|
||||
|
||||
编译器知道正在使用的寄存器并自动保存它们。
|
||||
|
||||
[][42]
|
||||
|
||||
虽然 goroutine 是协作式调度的，但运行时会为你处理。
|
||||
|
||||
Goroutine 可能会给禅让给其他协程时刻是：
|
||||
|
||||
* 阻塞式通道发送和接收。
|
||||
* Go 声明，虽然不能保证会立即调度新的 goroutine。
|
||||
* 文件和网络操作式的阻塞式系统调用。
|
||||
* 在被垃圾回收循环停止后。
|
||||
|
||||
[][43]
|
||||
|
||||
这个例子说明了上一张幻灯片中描述的一些调度点。
|
||||
|
||||
箭头所示的线程从左侧的 `ReadFile` 函数开始。遇到 `os.Open`，它在等待文件操作完成时阻塞线程，因此调度器将线程切换到右侧的 goroutine。
|
||||
|
||||
继续执行直到从通道 `c` 中读，并且此时 `os.Open` 调用已完成，因此调度器将线程切换回左侧并继续执行 `file.Read` 函数，然后又被文件 IO 阻塞。
|
||||
|
||||
调度器将线程切换回右侧以进行另一个通道操作，该操作在左侧运行期间已解锁，但在通道发送时再次阻塞。
|
||||
|
||||
最后，当 `Read` 操作完成并且数据可用时，线程切换回左侧。
|
||||
|
||||
[][44]
|
||||
|
||||
这张幻灯片显示了低级语言描述的 `runtime.Syscall` 函数，它是 `os` 包中所有函数的基础。
|
||||
|
||||
只要你的代码调用操作系统，就会通过此函数。
|
||||
|
||||
对 `entersyscall` 的调用通知运行时该线程即将阻塞。
|
||||
|
||||
这允许运行时启动一个新线程，该线程将在当前线程被阻塞时为其他 goroutine 提供服务。
|
||||
|
||||
这导致每 Go 进程的操作系统线程相对较少，Go 运行时负责将可运行的 Goroutine 分配给空闲的操作系统线程。
|
||||
|
||||
[][45]
|
||||
|
||||
在上一节中，我讨论了 goroutine 如何减少管理许多（有时是数十万个并发执行线程）的开销。
|
||||
|
||||
Goroutine故事还有另一面，那就是栈管理，它引导我进入我的最后一个话题。
|
||||
|
||||
[][46]
|
||||
|
||||
这是一个进程的内存布局图。我们感兴趣的关键是堆和栈的位置。
|
||||
|
||||
传统上，在进程的地址空间内，堆位于内存的底部，位于程序（代码）的上方并向上增长。
|
||||
|
||||
栈位于虚拟地址空间的顶部，并向下增长。
|
||||
|
||||
[][47]
|
||||
|
||||
因为堆和栈相互覆盖的结果会是灾难性的，操作系统通常会安排在栈和堆之间放置一个不可写内存区域，以确保如果它们发生碰撞，程序将中止。
|
||||
|
||||
这称为保护页，有效地限制了进程的栈大小，通常大约为几兆字节。
|
||||
|
||||
[][48]
|
||||
|
||||
我们已经讨论过线程共享相同的地址空间，因此对于每个线程，它必须有自己的栈。
|
||||
|
||||
由于很难预测特定线程的栈需求，因此为每个线程的栈和保护页面保留了大量内存。
|
||||
|
||||
希望是这些区域永远不被使用，而且防护页永远不会被击中。
|
||||
|
||||
缺点是随着程序中线程数的增加，可用地址空间的数量会减少。
|
||||
|
||||
[][49]
|
||||
|
||||
我们已经看到 Go 运行时将大量的 goroutine 调度到少量线程上，但那些 goroutines 的栈需求呢？
|
||||
|
||||
Go 编译器不使用保护页，而是在每个函数调用时插入一个检查，以检查是否有足够的栈来运行该函数。如果没有，运行时可以分配更多的栈空间。
|
||||
|
||||
由于这种检查，goroutines 初始栈可以做得更小，这反过来允许 Go 程序员将 goroutines 视为廉价资源。
|
||||
|
||||
[][50]
|
||||
|
||||
这是一张显示了 Go 1.2 如何管理栈的幻灯片。
|
||||
|
||||
当 `G` 调用 `H` 时，没有足够的空间让 `H` 运行，所以运行时从堆中分配一个新的栈帧，然后在新的栈段上运行 `H`。当 `H` 返回时，栈区域返回到堆，然后返回到 `G`。
|
||||
|
||||
[][51]
|
||||
|
||||
这种管理栈的方法通常很好用，但对于某些类型的代码，通常是递归代码，它可能导致程序的内部循环跨越这些栈边界之一。
|
||||
|
||||
例如，在程序的内部循环中，函数 `G` 可以在循环中多次调用 `H`，
|
||||
|
||||
每次都会导致栈拆分。 这被称为 <ruby>热分裂<rt>Hot Split</rt></ruby> 问题。
|
||||
|
||||
[][52]
|
||||
|
||||
为了解决热分裂问题，Go 1.3 采用了一种新的栈管理方法。
|
||||
|
||||
如果 goroutine 的栈太小，则不会添加和删除其他栈段，而是分配新的更大的栈。
|
||||
|
||||
旧栈的内容被复制到新栈，然后 goroutine 使用新的更大的栈继续运行。
|
||||
|
||||
在第一次调用 `H` 之后，栈将足够大，对可用栈空间的检查将始终成功。
|
||||
|
||||
这解决了热分裂问题。
|
||||
|
||||
[][53]
|
||||
|
||||
值，内联，逃逸分析，Goroutines 和分段/复制栈。
|
||||
|
||||
这些是我今天选择谈论的五个特性，但它们绝不是使 Go 成为快速的语言的唯一因素，就像人们引用他们学习 Go 的理由的三个原因一样。
|
||||
|
||||
这五个特性一样强大，它们不是孤立存在的。
|
||||
|
||||
例如，运行时将 goroutine 复用到线程上的方式在没有可扩展栈的情况下几乎没有效率。
|
||||
|
||||
内联通过将较小的函数组合成较大的函数来降低栈大小检查的成本。
|
||||
|
||||
逃逸分析通过自动将从实例从堆移动到栈来减少垃圾回收器的压力。
|
||||
|
||||
逃逸分析还提供了更好的 <ruby>缓存局部性<rt>Cache Locality</rt></ruby>。
|
||||
|
||||
如果没有可增长的栈，逃逸分析可能会对栈施加太大的压力。
|
||||
|
||||
[][54]
|
||||
|
||||
* 感谢 Gocon 主办方允许我今天发言
|
||||
* twitter / web / email details
|
||||
* 感谢 @offbymany，@billkennedy_go 和 Minux 在准备这个演讲的过程中所提供的帮助。
|
||||
|
||||
### 相关文章：
|
||||
|
||||
1. [听我在 OSCON 上关于 Go 性能的演讲][1]
|
||||
2. [为什么 Goroutine 的栈是无限大的？][2]
|
||||
3. [Go 的运行时环境变量的旋风之旅][3]
|
||||
4. [没有事件循环的性能][4]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
作者简介：
|
||||
|
||||
David 是来自澳大利亚悉尼的程序员和作者。
|
||||
|
||||
自 2011 年 2 月起成为 Go 的 contributor，自 2012 年 4 月起成为 committer。
|
||||
|
||||
联系信息
|
||||
|
||||
* dave@cheney.net
|
||||
* twitter: @davecheney
|
||||
|
||||
----------------------
|
||||
|
||||
via: https://dave.cheney.net/2014/06/07/five-things-that-make-go-fast
|
||||
|
||||
作者：[Dave Cheney][a]
|
||||
译者：[houbaron](https://github.com/houbaron)
|
||||
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://dave.cheney.net/
|
||||
[1]:https://dave.cheney.net/2015/05/31/hear-me-speak-about-go-performance-at-oscon
|
||||
[2]:https://dave.cheney.net/2013/06/02/why-is-a-goroutines-stack-infinite
|
||||
[3]:https://dave.cheney.net/2015/11/29/a-whirlwind-tour-of-gos-runtime-environment-variables
|
||||
[4]:https://dave.cheney.net/2015/08/08/performance-without-the-event-loop
|
||||
[5]:http://mindchunk.blogspot.com.au/2014/06/remixing-with-deck.html
|
||||
[6]:http://ymotongpoo.hatenablog.com/entry/2014/06/01/124350
|
||||
[7]:http://www.goinggo.net/
|
||||
[8]:https://twitter.com/offbymany
|
||||
[9]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-1.jpg
|
||||
[10]:https://dave.cheney.net/2014/06/07/five-things-that-make-go-fast/gocon-2014-2
|
||||
[11]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-3.jpg
|
||||
[12]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-4.jpg
|
||||
[13]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-5.jpg
|
||||
[14]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-6.jpg
|
||||
[15]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-7.jpg
|
||||
[16]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-8.jpg
|
||||
[17]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-9.jpg
|
||||
[18]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-10.jpg
|
||||
[19]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-11.jpg
|
||||
[20]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-12.jpg
|
||||
[21]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-13.jpg
|
||||
[22]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-14.jpg
|
||||
[23]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-15.jpg
|
||||
[24]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-16.jpg
|
||||
[25]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-17.jpg
|
||||
[26]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-18.jpg
|
||||
[27]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-19.jpg
|
||||
[28]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-20.jpg
|
||||
[29]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-21.jpg
|
||||
[30]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-22.jpg
|
||||
[31]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-23.jpg
|
||||
[32]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-24.jpg
|
||||
[33]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-25.jpg
|
||||
[34]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-26.jpg
|
||||
[35]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-27.jpg
|
||||
[36]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-28.jpg
|
||||
[37]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-30.jpg
|
||||
[38]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-29.jpg
|
||||
[39]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-31.jpg
|
||||
[40]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-32.jpg
|
||||
[41]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-33.jpg
|
||||
[42]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-34.jpg
|
||||
[43]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-35.jpg
|
||||
[44]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-36.jpg
|
||||
[45]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-37.jpg
|
||||
[46]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-39.jpg
|
||||
[47]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-40.jpg
|
||||
[48]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-41.jpg
|
||||
[49]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-42.jpg
|
||||
[50]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-43.jpg
|
||||
[51]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-44.jpg
|
||||
[52]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-45.jpg
|
||||
[53]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-46.jpg
|
||||
[54]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-47.jpg
|
||||
@ -0,0 +1,181 @@
|
||||
三周内构建 JavaScript 全栈 web 应用
|
||||
===========
|
||||
|
||||
|
||||
|
||||
*应用 Align 中，用户主页的控制面板*
|
||||
|
||||
### 从构思到部署应用程序的简单分步指南
|
||||
|
||||
我在 Grace Hopper Program 为期三个月的编码训练营即将结束，实际上这篇文章的标题有些纰漏 —— 现在我已经构建了 _三个_ 全栈应用：[从零开始的电子商店][3]、我个人的 [私人黑客马拉松项目][4]，还有这个“三周的结业项目”。这个项目是迄今为止强度最大的 —— 我和另外两名队友共同花费三周的时光 —— 而它也是我在训练营中最引以为豪的成就。这是我目前所构建和涉及的第一款稳定且复杂的应用。
|
||||
|
||||
如大多数开发者所知，即使你“知道怎么编写代码”，但真正要制作第一款全栈的应用却是非常困难的。JavaScript 生态系统出奇的大：有包管理器、模块、构建工具、转译器、数据库、库文件，还要对上述所有东西进行选择，难怪如此多的编程新手除了 Codecademy 的教程外，做不了任何东西。这就是为什么我想让你体验这个决策的分布教程，跟着我们队伍的脚印，构建可用的应用。
|
||||
|
||||
* * *
|
||||
|
||||
首先，简单的说两句。Align 是一个 web 应用，它使用直观的时间线界面帮助用户管理时间、设定长期目标。我们的技术栈有：用于后端服务的 Firebase 和用于前端的 React。我和我的队友在这个短视频中解释的更详细：
|
||||
|
||||
[video](https://youtu.be/YacM6uYP2Jo)
|
||||
|
||||
展示 Align @ Demo Day Live // 2017 年 7 月 10 日
|
||||
|
||||
从第 1 天（我们组建团队的那天）开始，直到最终应用的完成，我们是如何做的？这里是我们采取的步骤纲要：
|
||||
|
||||
* * *
|
||||
|
||||
### 第 1 步：构思
|
||||
|
||||
第一步是弄清楚我们到底要构建什么东西。过去我在 IBM 中当咨询师的时候，我和合作组长一同带领着构思工作组。从那之后，我一直建议小组使用经典的头脑风暴策略，在会议中我们能够提出尽可能多的想法 —— 即使是 “愚蠢的想法” —— 这样每个人的大脑都在思考，没有人因顾虑而不敢发表意见。
|
||||
|
||||
|
||||
|
||||
在产生了好几个关于应用的想法时，我们把这些想法分类记录下来，以便更好的理解我们大家都感兴趣的主题。在我们这个小组中，我们看到实现想法的清晰趋势，需要自我改进、设定目标、情怀，还有个人发展。我们最后从中决定了具体的想法：做一个用于设置和管理长期目标的控制面板，有保存记忆的元素，可以根据时间将数据可视化。
|
||||
|
||||
从此，我们创作出了一系列用户故事（从一个终端用户的视角，对我们想要拥有的功能进行描述），阐明我们到底想要应用实现什么功能。
|
||||
|
||||
### 第 2 步：UX/UI 示意图
|
||||
|
||||
接下来，在一块白板上，我们画出了想象中应用的基本视图。结合了用户故事，以便理解在应用基本框架中这些视图将会如何工作。
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
这些骨架确保我们意见统一，提供了可预见的蓝图，让我们向着计划的方向努力。
|
||||
|
||||
### 第 3 步：选好数据结构和数据库类型
|
||||
|
||||
到了设计数据结构的时候。基于我们的示意图和用户故事，我们在 Google doc 中制作了一个清单，它包含我们将会需要的模型和每个模型应该包含的属性。我们知道需要 “目标（goal）” 模型、“用户（user）”模型、“里程碑（milestone）”模型、“记录（checkin）”模型还有最后的“资源（resource）”模型和“上传（upload）”模型，
|
||||
|
||||
|
||||
|
||||
*最初的数据模型结构*
|
||||
|
||||
在正式确定好这些模型后，我们需要选择某种 _类型_ 的数据库：“关系型的”还是“非关系型的”（也就是“SQL”还是“NoSQL”）。由于基于表的 SQL 数据库需要预定义的格式，而基于文档的 NoSQL 数据库却可以用动态格式描述非结构化数据。
|
||||
|
||||
对于我们这个情况，用 SQL 型还是 No-SQL 型的数据库没多大影响，由于下列原因，我们最终选择了 Google 的 NoSQL 云数据库 Firebase：
|
||||
|
||||
1. 它能够把用户上传的图片保存在云端并存储起来
|
||||
2. 它包含 WebSocket 功能，能够实时更新
|
||||
3. 它能够处理用户验证，并且提供简单的 OAuth 功能。
|
||||
|
||||
我们确定了数据库后，就要理解数据模型之间的关系了。由于 Firebase 是 NoSQL 类型，我们无法创建联合表或者设置像 _“记录 （Checkins）属于目标（Goals）”_ 的从属关系。因此我们需要弄清楚 JSON 树是什么样的，对象是怎样嵌套的（或者不是嵌套的关系）。最终，我们构建了像这样的模型：
|
||||
|
||||
|
||||
|
||||
*我们最终为目标（Goal）对象确定的 Firebase 数据格式。注意里程碑（Milestones）和记录（Checkins）对象嵌套在 Goals 中。*
|
||||
|
||||
_（注意: 出于性能考虑，Firebase 更倾向于简单、常规的数据结构, 但对于我们这种情况，需要在数据中进行嵌套，因为我们不会从数据库中获取目标（Goal）却不获取相应的子对象里程碑（Milestones）和记录（Checkins）。）_
|
||||
|
||||
### 第 4 步：设置好 Github 和敏捷开发工作流
|
||||
|
||||
我们知道，从一开始就保持井然有序、执行敏捷开发对我们有极大好处。我们设置好 Github 上的仓库，我们无法直接将代码合并到主（master）分支，这迫使我们互相审阅代码。
|
||||
|
||||
|
||||
|
||||
我们还在 [Waffle.io][5] 网站上创建了敏捷开发的面板，它是免费的，很容易集成到 Github。我们在 Waffle 面板上罗列出所有用户故事以及需要我们去修复的 bug。之后当我们开始编码时，我们每个人会为自己正在研究的每一个用户故事创建一个 git 分支，在完成工作后合并这一条条的分支。
|
||||
|
||||
|
||||
|
||||
我们还开始保持晨会的习惯，讨论前一天的工作和每一个人遇到的阻碍。会议常常决定了当天的流程 —— 哪些人要结对编程，哪些人要独自处理问题。
|
||||
|
||||
我认为这种类型的工作流程非常好，因为它让我们能够清楚地找到自己的定位，不用顾虑人际矛盾地高效执行工作。
|
||||
|
||||
### 第 5 步： 选择、下载样板文件
|
||||
|
||||
由于 JavaScript 的生态系统过于复杂，我们不打算从最底层开始构建应用。把宝贵的时间花在连通 Webpack 构建脚本和加载器，把符号链接指向项目工程这些事情上感觉很没必要。我的团队选择了 [Firebones][6] 框架，因为它恰好适用于我们这个情况，当然还有很多可供选择的开源框架。
|
||||
|
||||
### 第 6 步：编写后端 API 路由（或者 Firebase 监听器）
|
||||
|
||||
如果我们没有用基于云的数据库，这时就应该开始编写执行数据库查询的后端高速路由了。但是由于我们用的是 Firebase，它本身就是云端的，可以用不同的方式进行代码交互，因此我们只需要设置好一个可用的数据库监听器。
|
||||
|
||||
为了确保监听器在工作，我们用代码做出了用于创建目标（Goal）的基本用户表格，实际上当我们完成表格时，就看到数据库执行可更新。数据库就成功连接了！
|
||||
|
||||
### 第 7 步：构建 “概念证明”
|
||||
|
||||
接下来是为应用创建 “概念证明”，也可以说是实现起来最复杂的基本功能的原型，证明我们的应用 _可以_ 实现。对我们而言，这意味着要找个前端库来实现时间线的渲染，成功连接到 Firebase，显示数据库中的一些种子数据。
|
||||
|
||||
|
||||
|
||||
*Victory.JS 绘制的简单时间线*
|
||||
|
||||
我们找到了基于 D3 构建的响应式库 Victory.JS，花了一天时间阅读文档，用 _VictoryLine_ 和 _VictoryScatter_ 组件实现了非常基础的示例，能够可视化地显示数据库中的数据。实际上，这很有用！我们可以开始构建了。
|
||||
|
||||
### 第 8 步：用代码实现功能
|
||||
|
||||
最后，是时候构建出应用中那些令人期待的功能了。取决于你要构建的应用，这一重要步骤会有些明显差异。我们根据所用的框架，编码出不同的用户故事并保存在 Waffle 上。常常需要同时接触前端和后端代码（比如，创建一个前端表格同时要连接到数据库）。我们实现了包含以下这些大大小小的功能：
|
||||
|
||||
* 能够创建新目标、里程碑和记录
|
||||
* 能够删除目标，里程碑和记录
|
||||
* 能够更改时间线的名称，颜色和详细内容
|
||||
* 能够缩放时间线
|
||||
* 能够为资源添加链接
|
||||
* 能够上传视频
|
||||
* 在达到相关目标的里程碑和记录时弹出资源和视频
|
||||
* 集成富文本编辑器
|
||||
* 用户注册、验证、OAuth 验证
|
||||
* 弹出查看时间线选项
|
||||
* 加载画面
|
||||
|
||||
有各种原因，这一步花了我们很多时间 —— 这一阶段是产生最多优质代码的阶段，每当我们实现了一个功能，就会有更多的事情要完善。
|
||||
|
||||
### 第 9 步： 选择并实现设计方案
|
||||
|
||||
当我们使用 MVP 架构实现了想要的功能，就可以开始清理，对它进行美化了。像表单，菜单和登陆栏等组件，我的团队用的是 Material-UI，不需要很多深层次的设计知识，它也能确保每个组件看上去都很圆润光滑。
|
||||
|
||||
|
||||
|
||||
*这是我制作的最喜爱功能之一了。它美得令人心旷神怡。*
|
||||
|
||||
我们花了一点时间来选择颜色方案和编写 CSS ，这让我们在编程中休息了一段美妙的时间。期间我们还设计了 logo 图标，还上传了网站图标。
|
||||
|
||||
### 第 10 步： 找出并减少 bug
|
||||
|
||||
我们一开始就应该使用测试驱动开发的模式，但时间有限，我们那点时间只够用来实现功能。这意味着最后的两天时间我们花在了模拟我们能够想到的每一种用户流，并从应用中找出 bug。
|
||||
|
||||
|
||||
|
||||
这一步是最不具系统性的，但是我们发现了一堆够我们忙乎的 bug，其中一个是在某些情况下加载动画不会结束的 bug，还有一个是资源组件会完全停止运行的 bug。修复 bug 是件令人恼火的事情，但当软件可以运行时，又特别令人满足。
|
||||
|
||||
### 第 11 步：应用上线
|
||||
|
||||
最后一步是上线应用，这样才可以让用户使用它！由于我们使用 Firebase 存储数据，因此我们使用了 Firebase Hosting，它很直观也很简单。如果你要选择其它的数据库，你可以使用 Heroku 或者 DigitalOcean。一般来讲，可以在主机网站中查看使用说明。
|
||||
|
||||
我们还在 Namecheap.com 上购买了一个便宜的域名，这让我们的应用更加完善，很容易被找到。
|
||||
|
||||
|
||||
|
||||
* * *
|
||||
|
||||
好了，这就是全部的过程 —— 我们都是这款实用的全栈应用的合作开发者。如果要继续讲，那么第 12 步将会是对用户进行 A/B 测试，这样我们才能更好地理解：实际用户与这款应用交互的方式和他们想在 V2 版本中看到的新功能。
|
||||
|
||||
但是，现在我们感到非常开心，不仅是因为成品，还因为我们从这个过程中获得了难以估量的知识和理解。点击 [这里][7] 查看 Align 应用！
|
||||
|
||||
|
||||
|
||||
*Align 团队：Sara Kladky（左），Melanie Mohn（中），还有我自己。*
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://medium.com/ladies-storm-hackathons/how-we-built-our-first-full-stack-javascript-web-app-in-three-weeks-8a4668dbd67c?imm_mid=0f581a&cmp=em-web-na-na-newsltr_20170816
|
||||
|
||||
作者：[Sophia Ciocca][a]
|
||||
译者：[BriFuture](https://github.com/BriFuture)
|
||||
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://medium.com/@sophiaciocca?source=post_header_lockup
|
||||
[1]:https://medium.com/@sophiaciocca?source=post_header_lockup
|
||||
[2]:https://medium.com/@sophiaciocca?source=post_header_lockup
|
||||
[3]:https://github.com/limitless-leggings/limitless-leggings
|
||||
[4]:https://www.youtube.com/watch?v=qyLoInHNjoc
|
||||
[5]:http://www.waffle.io/
|
||||
[6]:https://github.com/FullstackAcademy/firebones
|
||||
[7]:https://align.fun/
|
||||
[8]:https://github.com/align-capstone/align
|
||||
[9]:https://github.com/sophiaciocca
|
||||
[10]:https://github.com/Kladky
|
||||
[11]:https://github.com/melaniemohn
|
||||
224
published/20170926 Managing users on Linux systems.md
Normal file
224
published/20170926 Managing users on Linux systems.md
Normal file
@ -0,0 +1,224 @@
|
||||
管理 Linux 系统中的用户
|
||||
======
|
||||
|
||||
|
||||
|
||||
也许你的 Linux 用户并不是愤怒的公牛，但是当涉及管理他们的账户的时候，能让他们一直满意也是一种挑战。你需要监控他们的访问权限，跟进他们遇到问题时的解决方案，并且把他们在使用系统时出现的重要变动记录下来。这里有一些方法和工具可以让这个工作轻松一点。
|
||||
|
||||
### 配置账户
|
||||
|
||||
添加和删除账户是管理用户中比较简单的一项，但是这里面仍然有很多需要考虑的方面。无论你是用桌面工具或是命令行选项，这都是一个非常自动化的过程。你可以使用 `adduser jdoe` 命令添加一个新用户，同时会触发一系列的反应。在创建 John 这个账户时会自动使用下一个可用的 UID，并有很多自动生成的文件来完成这个工作。当你运行 `adduser` 后跟一个参数时（要创建的用户名），它会提示一些额外的信息，同时解释这是在干什么。
|
||||
|
||||
```
|
||||
$ sudo adduser jdoe
|
||||
Adding user 'jdoe' ...
|
||||
Adding new group `jdoe' (1001) ...
|
||||
Adding new user `jdoe' (1001) with group `jdoe' ...
|
||||
Creating home directory `/home/jdoe' ...
|
||||
Copying files from `/etc/skel' …
|
||||
Enter new UNIX password:
|
||||
Retype new UNIX password:
|
||||
passwd: password updated successfully
|
||||
Changing the user information for jdoe
|
||||
Enter the new value, or press ENTER for the default
|
||||
Full Name []: John Doe
|
||||
Room Number []:
|
||||
Work Phone []:
|
||||
Home Phone []:
|
||||
Other []:
|
||||
Is the information correct? [Y/n] Y
|
||||
```
|
||||
|
||||
如你所见，`adduser` 会添加用户的信息（到 `/etc/passwd` 和 `/etc/shadow` 文件中），创建新的<ruby>家目录<rt>home directory</rt></ruby>，并用 `/etc/skel` 里设置的文件填充家目录，提示你分配初始密码和认证信息，然后确认这些信息都是正确的，如果你在最后的提示 “Is the information correct?” 处的回答是 “n”，它会回溯你之前所有的回答，允许修改任何你想要修改的地方。
|
||||
|
||||
创建好一个用户后，你可能会想要确认一下它是否是你期望的样子，更好的方法是确保在添加第一个帐户**之前**，“自动”选择与你想要查看的内容是否匹配。默认有默认的好处，它对于你想知道他们定义在哪里很有用，以便你想做出一些变动 —— 例如，你不想让用户的家目录在 `/home` 里，你不想让用户 UID 从 1000 开始，或是你不想让家目录下的文件被系统中的**每个人**都可读。
|
||||
|
||||
`adduser` 的一些配置细节设置在 `/etc/adduser.conf` 文件里。这个文件包含的一些配置项决定了一个新的账户如何配置，以及它之后的样子。注意，注释和空白行将会在输出中被忽略，因此我们更关注配置项。
|
||||
|
||||
```
|
||||
$ cat /etc/adduser.conf | grep -v "^#" | grep -v "^$"
|
||||
DSHELL=/bin/bash
|
||||
DHOME=/home
|
||||
GROUPHOMES=no
|
||||
LETTERHOMES=no
|
||||
SKEL=/etc/skel
|
||||
FIRST_SYSTEM_UID=100
|
||||
LAST_SYSTEM_UID=999
|
||||
FIRST_SYSTEM_GID=100
|
||||
LAST_SYSTEM_GID=999
|
||||
FIRST_UID=1000
|
||||
LAST_UID=29999
|
||||
FIRST_GID=1000
|
||||
LAST_GID=29999
|
||||
USERGROUPS=yes
|
||||
USERS_GID=100
|
||||
DIR_MODE=0755
|
||||
SETGID_HOME=no
|
||||
QUOTAUSER=""
|
||||
SKEL_IGNORE_REGEX="dpkg-(old|new|dist|save)"
|
||||
```
|
||||
|
||||
可以看到，我们有了一个默认的 shell（`DSHELL`），UID（`FIRST_UID`）的起始值，家目录（`DHOME`）的位置，以及启动文件（`SKEL`）的来源位置。这个文件也会指定分配给家目录（`DIR_HOME`）的权限。
|
||||
|
||||
其中 `DIR_HOME` 是最重要的设置，它决定了每个家目录被使用的权限。这个设置分配给用户创建的目录权限是 755，家目录的权限将会设置为 `rwxr-xr-x`。用户可以读其他用户的文件，但是不能修改和移除它们。如果你想要更多的限制，你可以更改这个设置为 750（用户组外的任何人都不可访问）甚至是 700（除用户自己外的人都不可访问）。
|
||||
|
||||
任何用户账号在创建之前都可以进行手动修改。例如，你可以编辑 `/etc/passwd` 或者修改家目录的权限，开始在新服务器上添加用户之前配置 `/etc/adduser.conf` 可以确保一定的一致性，从长远来看可以节省时间和避免一些麻烦。
|
||||
|
||||
`/etc/adduser.conf` 的修改将会在之后创建的用户上生效。如果你想以不同的方式设置某个特定账户，除了用户名之外，你还可以选择使用 `adduser` 命令提供账户配置选项。或许你想为某些账户分配不同的 shell，分配特殊的 UID，或完全禁用该账户登录。`adduser` 的帮助页将会为你显示一些配置个人账户的选择。
|
||||
|
||||
```
|
||||
adduser [options] [--home DIR] [--shell SHELL] [--no-create-home]
|
||||
[--uid ID] [--firstuid ID] [--lastuid ID] [--ingroup GROUP | --gid ID]
|
||||
[--disabled-password] [--disabled-login] [--gecos GECOS]
|
||||
[--add_extra_groups] [--encrypt-home] user
|
||||
```
|
||||
|
||||
每个 Linux 系统现在都会默认把每个用户放入对应的组中。作为一个管理员，你可能会选择以不同的方式。你也许会发现把用户放在一个共享组中更适合你的站点，你就可以选择使用 `adduser` 的 `--gid` 选项指定一个特定的组。当然，用户总是许多组的成员，因此也有一些选项来管理主要和次要的组。
|
||||
|
||||
### 处理用户密码
|
||||
|
||||
一直以来，知道其他人的密码都不是一件好事，在设置账户时，管理员通常使用一个临时密码，然后在用户第一次登录时运行一条命令强制他修改密码。这里是一个例子：
|
||||
|
||||
```
|
||||
$ sudo chage -d 0 jdoe
|
||||
```
|
||||
|
||||
当用户第一次登录时，会看到类似下面的提示：
|
||||
|
||||
```
|
||||
WARNING: Your password has expired.
|
||||
You must change your password now and login again!
|
||||
Changing password for jdoe.
|
||||
(current) UNIX password:
|
||||
```
|
||||
|
||||
### 添加用户到副组
|
||||
|
||||
添加用户到副组中，你可能会用如下所示的 `usermod` 命令添加用户到组中并确认已经做出变动。
|
||||
|
||||
```
|
||||
$ sudo usermod -a -G sudo jdoe
|
||||
$ sudo grep sudo /etc/group
|
||||
sudo:x:27:shs,jdoe
|
||||
```
|
||||
|
||||
记住在一些组意味着特别的权限，如 sudo 或者 wheel 组，一定要特别注意这一点。
|
||||
|
||||
### 移除用户，添加组等
|
||||
|
||||
Linux 系统也提供了移除账户，添加新的组，移除组等一些命令。例如，`deluser` 命令，将会从 `/etc/passwd` 和 `/etc/shadow` 中移除用户记录，但是会完整保留其家目录，除非你添加了 `--remove-home` 或者 `--remove-all-files` 选项。`addgroup` 命令会添加一个组，默认按目前组的次序分配下一个 id（在用户组范围内），除非你使用 `--gid` 选项指定 id。
|
||||
|
||||
```
|
||||
$ sudo addgroup testgroup --gid=131
|
||||
Adding group `testgroup' (GID 131) ...
|
||||
Done.
|
||||
```
|
||||
|
||||
### 管理特权账户
|
||||
|
||||
一些 Linux 系统中有一个 wheel 组，它给组中成员赋予了像 root 一样运行命令的权限。在这种情况下，`/etc/sudoers` 将会引用该组。在 Debian 系统中，这个组被叫做 sudo，但是原理是相同的，你在 `/etc/sudoers` 中可以看到像这样的信息：
|
||||
|
||||
```
|
||||
%sudo ALL=(ALL:ALL) ALL
|
||||
```
|
||||
|
||||
这行基本的配置意味着任何在 wheel 或者 sudo 组中的成员只要在他们运行的命令之前添加 `sudo`，就可以以 root 的权限去运行命令。
|
||||
|
||||
你可以向 sudoers 文件中添加更多有限的权限 —— 也许给特定用户几个能以 root 运行的命令。如果你是这样做的，你应该定期查看 `/etc/sudoers` 文件以评估用户拥有的权限，以及仍然需要提供的权限。
|
||||
|
||||
在下面显示的命令中，我们过滤了 `/etc/sudoers` 中有效的配置行。其中最有意思的是，它包含了能使用 `sudo` 运行命令的路径设置，以及两个允许通过 `sudo` 运行命令的组。像刚才提到的那样，单个用户可以通过包含在 sudoers 文件中来获得权限，但是更有实际意义的方法是通过组成员来定义各自的权限。
|
||||
|
||||
```
|
||||
# cat /etc/sudoers | grep -v "^#" | grep -v "^$"
|
||||
Defaults env_reset
|
||||
Defaults mail_badpass
|
||||
Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"
|
||||
root ALL=(ALL:ALL) ALL
|
||||
%admin ALL=(ALL) ALL <== admin group
|
||||
%sudo ALL=(ALL:ALL) ALL <== sudo group
|
||||
```
|
||||
|
||||
### 登录检查
|
||||
|
||||
你可以通过以下命令查看用户的上一次登录：
|
||||
|
||||
```
|
||||
# last jdoe
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 08:44 - 11:48 (00:04)
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 13:43 - 18:44 (00:00)
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 19:42 - 19:43 (00:00)
|
||||
```
|
||||
|
||||
如果你想查看每一个用户上一次的登录情况，你可以通过一个像这样的循环来运行 `last` 命令：
|
||||
|
||||
```
|
||||
$ for user in `ls /home`; do last $user | head -1; done
|
||||
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 19:42 - 19:43 (00:03)
|
||||
|
||||
rocket pts/18 192.168.0.11 Thu Sep 14 13:02 - 13:02 (00:00)
|
||||
shs pts/17 192.168.0.11 Thu Sep 14 12:45 still logged in
|
||||
```
|
||||
|
||||
此命令仅显示自当前 wtmp 文件登录过的用户。空白行表示用户自那以后从未登录过，但没有将他们显示出来。一个更好的命令可以明确地显示这期间从未登录过的用户：
|
||||
|
||||
```
|
||||
$ for user in `ls /home`; do echo -n "$user"; last $user | head -1 | awk '{print substr($0,40)}'; done
|
||||
dhayes
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 19:42 - 19:43
|
||||
peanut pts/19 192.168.0.29 Mon Sep 11 09:15 - 17:11
|
||||
rocket pts/18 192.168.0.11 Thu Sep 14 13:02 - 13:02
|
||||
shs pts/17 192.168.0.11 Thu Sep 14 12:45 still logged
|
||||
tsmith
|
||||
```
|
||||
|
||||
这个命令要打很多字，但是可以通过一个脚本使它更加清晰易用。
|
||||
|
||||
```
|
||||
#!/bin/bash
|
||||
|
||||
for user in `ls /home`
|
||||
do
|
||||
echo -n "$user ";last $user | head -1 | awk '{print substr($0,40)}'
|
||||
done
|
||||
```
|
||||
|
||||
有时这些信息可以提醒你用户角色的变动，表明他们可能不再需要相关帐户了。
|
||||
|
||||
### 与用户沟通
|
||||
|
||||
Linux 提供了许多和用户沟通的方法。你可以向 `/etc/motd` 文件中添加信息，当用户从终端登录到服务器时，将会显示这些信息。你也可以通过例如 `write`（通知单个用户）或者 `wall`（write 给所有已登录的用户）命令发送通知。
|
||||
|
||||
```
|
||||
$ wall System will go down in one hour
|
||||
|
||||
Broadcast message from shs@stinkbug (pts/17) (Thu Sep 14 14:04:16 2017):
|
||||
|
||||
System will go down in one hour
|
||||
```
|
||||
|
||||
重要的通知应该通过多个渠道传达，因为很难预测用户实际会注意到什么。mesage-of-the-day（motd），`wall` 和 email 通知可以吸引用户大部分的注意力。
|
||||
|
||||
### 注意日志文件
|
||||
|
||||
多注意日志文件也可以帮你理解用户的活动情况。尤其 `/var/log/auth.log` 文件将会显示用户的登录和注销活动，组的创建记录等。`/var/log/message` 或者 `/var/log/syslog` 文件将会告诉你更多有关系统活动的日志。
|
||||
|
||||
### 追踪问题和需求
|
||||
|
||||
无论你是否在 Linux 系统上安装了事件跟踪系统，跟踪用户遇到的问题以及他们提出的需求都非常重要。如果需求的一部分久久不见回应，用户必然不会高兴。即使是记录在纸上也是有用的，或者最好有个电子表格，这可以让你注意到哪些问题仍然悬而未决，以及问题的根本原因是什么。确认问题和需求非常重要，记录还可以帮助你记住你必须采取的措施来解决几个月甚至几年后重新出现的问题。
|
||||
|
||||
### 总结
|
||||
|
||||
在繁忙的服务器上管理用户帐号，部分取决于配置良好的默认值，部分取决于监控用户活动和遇到的问题。如果用户觉得你对他们的顾虑有所回应并且知道在需要系统升级时会发生什么，他们可能会很高兴。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3225109/linux/managing-users-on-linux-systems.html
|
||||
|
||||
作者：[Sandra Henry-Stocker][a]
|
||||
译者：[dianbanjiu](https://github.com/dianbanjiu)
|
||||
校对：[wxy](https://github.com/wxy)、[pityonline](https://github.com/pityonline)
|
||||
|
||||
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/
|
||||
@ -1,27 +1,20 @@
|
||||
在 Debian 9 / Ubuntu 16.04 / 17.10 中如何安装并使用 Wireshark
|
||||
如何安装并使用 Wireshark
|
||||
======
|
||||
|
||||
作者 [Pradeep Kumar][1]，首发于 2017 年 11 月 29 日，更新于 2017 年 11 月 29 日
|
||||
|
||||
[][2]
|
||||
|
||||
Wireshark 是免费的，开源的，跨平台的基于 GUI 的网络数据包分析器，可用于 Linux, Windows, MacOS, Solaris 等。它可以实时捕获网络数据包，并以人性化的格式呈现。Wireshark 允许我们监控网络数据包上升到微观层面。Wireshark 还有一个名为 `tshark` 的命令行实用程序，它与 Wireshark 执行相同的功能，但它是通过终端而不是 GUI。
|
||||
Wireshark 是自由开源的、跨平台的基于 GUI 的网络数据包分析器，可用于 Linux、Windows、MacOS、Solaris 等。它可以实时捕获网络数据包，并以人性化的格式呈现。Wireshark 允许我们监控网络数据包直到其微观层面。Wireshark 还有一个名为 `tshark` 的命令行实用程序，它与 Wireshark 执行相同的功能，但它是通过终端而不是 GUI。
|
||||
|
||||
Wireshark 可用于网络故障排除，分析，软件和通信协议开发以及用于教育目的。Wireshark 使用 `pcap` 库来捕获网络数据包。
|
||||
Wireshark 可用于网络故障排除、分析、软件和通信协议开发以及用于教育目的。Wireshark 使用 `pcap` 库来捕获网络数据包。
|
||||
|
||||
Wireshark 具有许多功能：
|
||||
|
||||
* 支持数百项协议检查
|
||||
|
||||
* 能够实时捕获数据包并保存，以便以后进行离线分析
|
||||
|
||||
* 许多用于分析数据的过滤器
|
||||
|
||||
* 捕获的数据可以被压缩和解压缩（to 校正：on the fly 什么意思？）
|
||||
|
||||
* 支持各种文件格式的数据分析，输出也可以保存为 XML, CSV 和纯文本格式
|
||||
|
||||
* 数据可以从以太网，wifi，蓝牙，USB，帧中继，令牌环等多个接口中捕获
|
||||
* 捕获的数据可以即时压缩和解压缩
|
||||
* 支持各种文件格式的数据分析，输出也可以保存为 XML、CSV 和纯文本格式
|
||||
* 数据可以从以太网、wifi、蓝牙、USB、帧中继、令牌环等多个接口中捕获
|
||||
|
||||
在本文中，我们将讨论如何在 Ubuntu/Debian 上安装 Wireshark，并将学习如何使用 Wireshark 捕获网络数据包。
|
||||
|
||||
@ -102,7 +95,7 @@ linuxtechi@nixhome:/tmp/wireshark-2.4.2$ sudo make install
|
||||
linuxtechi@nixhome:/tmp/wireshark-2.4.2$ sudo ldconfig
|
||||
```
|
||||
|
||||
在安装后，它将创建一个单独的 Wireshark 组，我们现在将我们的用户添加到组中，以便它可以与 Wireshark 一起使用，否则在启动 wireshark 时可能会出现 `permission denied（权限被拒绝）`错误。
|
||||
在安装后，它将创建一个单独的 Wireshark 组，我们现在将我们的用户添加到组中，以便它可以与 Wireshark 一起使用，否则在启动 wireshark 时可能会出现 “permission denied（权限被拒绝）”错误。
|
||||
|
||||
要将用户添加到 wireshark 组，执行以下命令：
|
||||
|
||||
@ -120,7 +113,7 @@ linuxtechi@nixhome:~$ wireshark
|
||||
|
||||
[][4]
|
||||
|
||||
点击 Wireshark 图标
|
||||
点击 Wireshark 图标。
|
||||
|
||||
[][5]
|
||||
|
||||
@ -128,7 +121,7 @@ linuxtechi@nixhome:~$ wireshark
|
||||
|
||||
[][6]
|
||||
|
||||
点击 Wireshark 图标
|
||||
点击 Wireshark 图标。
|
||||
|
||||
[][7]
|
||||
|
||||
@ -138,7 +131,7 @@ linuxtechi@nixhome:~$ wireshark
|
||||
|
||||
[][8]
|
||||
|
||||
所有这些都是我们可以捕获网络数据包的接口。根据你系统上的界面，此屏幕可能与你的不同。
|
||||
所有这些都是我们可以捕获网络数据包的接口。根据你系统上的接口，此屏幕可能与你的不同。
|
||||
|
||||
我们选择 `enp0s3` 来捕获该接口的网络流量。选择接口后，在我们网络上所有设备的网络数据包开始填充（参考下面的屏幕截图）：
|
||||
|
||||
@ -146,11 +139,11 @@ linuxtechi@nixhome:~$ wireshark
|
||||
|
||||
第一次看到这个屏幕，我们可能会被这个屏幕上显示的数据所淹没，并且可能已经想过如何整理这些数据，但不用担心，Wireshark 的最佳功能之一就是它的过滤器。
|
||||
|
||||
我们可以根据 IP 地址，端口号，也可以使用来源和目标过滤器，数据包大小等对数据进行排序和过滤，也可以将两个或多个过滤器组合在一起以创建更全面的搜索。我们也可以在 `Apply a Display Filter(应用显示过滤器)`选项卡中编写过滤规则，也可以选择已创建的规则。要选择之前构建的过滤器，请单击 `Apply a Display Filter(应用显示过滤器)`选项卡旁边的 `flag` 图标。
|
||||
我们可以根据 IP 地址、端口号，也可以使用来源和目标过滤器、数据包大小等对数据进行排序和过滤，也可以将两个或多个过滤器组合在一起以创建更全面的搜索。我们也可以在 “Apply a Display Filter（应用显示过滤器）”选项卡中编写过滤规则，也可以选择已创建的规则。要选择之前构建的过滤器，请单击 “Apply a Display Filter（应用显示过滤器）”选项卡旁边的旗帜图标。
|
||||
|
||||
[][10]
|
||||
|
||||
我们还可以根据颜色编码过滤数据，默认情况下，浅紫色是 TCP 流量，浅蓝色是 UDP 流量，黑色标识有错误的数据包，看看这些编码是什么意思，点击 `View -> Coloring Rules`，我们也可以改变这些编码。
|
||||
我们还可以根据颜色编码过滤数据，默认情况下，浅紫色是 TCP 流量，浅蓝色是 UDP 流量，黑色标识有错误的数据包，看看这些编码是什么意思，点击 “View -> Coloring Rules”，我们也可以改变这些编码。
|
||||
|
||||
[][11]
|
||||
|
||||
@ -161,11 +154,11 @@ Wireshark 是一个非常强大的工具，需要一些时间来习惯并对其
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linuxtechi.com
|
||||
via: https://www.linuxtechi.com/install-use-wireshark-debian-9-ubuntu/
|
||||
|
||||
作者：[Pradeep Kumar][a]
|
||||
译者：[MjSeven](https://github.com/MjSeven)
|
||||
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
|
||||
|
||||
@ -1,5 +1,6 @@
|
||||
DevOps 实践指南
|
||||
======
|
||||
> 这些技巧或许对那些想要践行 DevOps 的系统运维和开发者能有所帮助。
|
||||
|
||||
|
||||
|
||||
@ -11,19 +12,19 @@ DevOps 实践指南
|
||||
|
||||
了解历史是搞清楚未来的关键，DevOps 也不例外。想搞清楚 DevOps 运动的普及和流行，去了解一下上世纪 90 年代后期和 21 世纪前十年 IT 的情况会有帮助。这是我的经验。
|
||||
|
||||
我的第一份工作是在一家大型跨国金融服务公司做 Windows 系统管理员。当时给计算资源扩容需要给 Dell 打电话（或者像我们公司那样打给 CDW），并下一个价值数十万美元的订单，包含服务器、网络设备、电缆和软件，所有这些都要运到生产或线下的数据中心去。虽然 VMware 仍在尝试说服企业使用虚拟机运行他们的“性能敏感”型程序是更划算的，但是包括我们在内的很多公司都还忠于使用他们的物理机运行应用。
|
||||
我的第一份工作是在一家大型跨国金融服务公司做 Windows 系统管理员。当时给计算资源扩容需要给 Dell 打电话（或者像我们公司那样打给 CDW），并下一个价值数十万美元的订单，包含服务器、网络设备、电缆和软件，所有这些都要运到生产或线下的数据中心去。虽然 VMware 仍在尝试说服企业使用虚拟机运行他们的“性能敏感”型程序是更划算的，但是包括我们在内的很多公司都还是愿意使用他们的物理机运行应用。
|
||||
|
||||
在我们技术部门，有一个专门做数据中心工程和运营的团队，他们的工作包括价格谈判，让荒唐的月租能够降一点点，还包括保证我们的系统能够正常冷却（如果设备太多，这个事情的难度会呈指数增长）。如果这个团队足够幸运足够有钱，境外数据中心的工作人员对我们所有的服务器型号又都有足够的了解，就能避免在盘后交易中不小心搞错东西。那时候亚马逊 AWS 和 Rackspace 逐渐开始加速扩张，但还远远没到临界规模。
|
||||
|
||||
当时我们还有专门的团队来保证硬件上运行着的操作系统和软件能够按照预期工作。这些工程师负责设计可靠的架构以方便给系统打补丁，监控和报警，还要定义<ruby>基础镜像<rt>gold image</rt></ruby>的内容。这些大都是通过很多手工实验完成的，很多手工实验是为了编写一个<ruby>运行说明书<rt>runbook</rt></ruby>来描述要做的事情，并确保按照它执行后的结果确实在预期内。在我们这么大的组织里，这样做很重要，因为一线和二线的技术支持都是境外的，而他们的培训内容只覆盖到了这些运行说明而已。
|
||||
当时我们还有专门的团队来保证硬件上运行着的操作系统和软件能够按照预期工作。这些工程师负责设计可靠的架构以方便给系统打补丁、监控和报警，还要定义<ruby>基础镜像<rt>gold image</rt></ruby>的内容。这些大都是通过很多手工实验完成的，很多手工实验是为了编写一个<ruby>运行说明书<rt>runbook</rt></ruby>来描述要做的事情，并确保按照它执行后的结果确实在预期内。在我们这么大的组织里，这样做很重要，因为一线和二线的技术支持都是境外的，而他们的培训内容只覆盖到了这些运行说明而已。
|
||||
|
||||
(这是我职业生涯前三年的世界。我那时候的梦想是成为制定金本位制的人！)
|
||||
（这是我职业生涯前三年的世界。我那时候的梦想是成为制定最高标准的人！）
|
||||
|
||||
软件发布则完全是另外一头怪兽。无可否认，我在这方面并没有积累太多经验。但是，从我收集的故事（和最近的经历）来看，当时大部分软件开发的日常大概是这样：
|
||||
|
||||
* 开发人员按照技术和功能需求来编写代码，这些需求来自于业务分析人员的会议，但是会议并没有邀请开发人员参加。
|
||||
* 开发人员可以选择为他们的代码编写单元测试，以确保在代码里没有任何明显的疯狂行为，比如除以 0 但不抛出异常。
|
||||
* 然后开发者会把他们的代码标记为“Ready for QA”（准备好了接受测试），质量保障的成员会把这个版本的代码发布到他们自己的环境中，这个环境和生产环境可能相似，也可能不，甚至和开发环境相比也不一定相似。
|
||||
* 然后开发者会把他们的代码标记为 “Ready for QA”（准备好了接受测试），质量保障的成员会把这个版本的代码发布到他们自己的环境中，这个环境和生产环境可能相似，也可能不，甚至和开发环境相比也不一定相似。
|
||||
* 故障会在几天或者几个星期内反馈到开发人员那里，这个时长取决于其它业务活动和优先事项。
|
||||
|
||||
虽然系统管理员和开发人员经常有不一致的意见，但是对“变更管理”却一致痛恨。变更管理由高度规范的（就我当时的雇主而言）和非常必要的规则和程序组成，用来管理一家公司应该什么时候做技术变更，以及如何做。很多公司都按照 [ITIL][4] 来操作，简单的说，ITIL 问了很多和事情发生的原因、时间、地点和方式相关的问题，而且提供了一个过程，对产生最终答案的决定做审计跟踪。
|
||||
@ -54,20 +55,20 @@ DevOps 不是一个团队，CI/CD 也不是 JIRA 系统的一个用户组。DevO
|
||||
|
||||
我经常被问到这个问题，它的答案和同属于开放式的其它大部分问题一样：视情况而定。
|
||||
|
||||
现在“DevOps 工程师”在不同的公司有不同的含义。在软件开发人员比较多但是很少有人懂基础设施的小公司，他们很可能是在找有更多系统管理经验的人。而其他公司，通常是大公司或老公司，已经有一个稳固的系统管理团队了，他们在向类似于谷歌 [SRE][7] 的方向做优化，也就是“设计操作功能的软件工程师”。但是，这并不是金科玉律，就像其它技术类工作一样，这个决定很大程度上取决于他的招聘经理。
|
||||
现在“DevOps 工程师”在不同的公司有不同的含义。在软件开发人员比较多但是很少有人懂基础设施的小公司，他们很可能是在找有更多系统管理经验的人。而其他公司，通常是大公司或老公司，已经有一个稳固的系统管理团队了，他们在向类似于谷歌 [SRE][7] 的方向做优化，也就是“设计运维功能的软件工程师”。但是，这并不是金科玉律，就像其它技术类工作一样，这个决定很大程度上取决于他的招聘经理。
|
||||
|
||||
也就是说，我们一般是在找对深入学习以下内容感兴趣的工程师：
|
||||
|
||||
* 如何管理和设计安全、可扩展的云平台（通常是在 AWS 上，不过微软的 Azure，Google Cloud Platform，还有 DigitalOcean 和 Heroku 这样的 PaaS 提供商，也都很流行）。
|
||||
* 如何用流行的 [CI/CD][8] 工具，比如 Jenkins，GoCD，还有基于云的 Travis CI 或者 CircleCI，来构造一条优化的发布部署流水线和发布部署策略。
|
||||
* 如何在你的系统中使用基于时间序列的工具，比如 Kibana，Grafana，Splunk，Loggly 或者 Logstash 来监控，记录，并在变化的时候报警。
|
||||
* 如何使用配置管理工具，例如 Chef，Puppet 或者 Ansible 做到“基础设施即代码”，以及如何使用像 Terraform 或 CloudFormation 的工具发布这些基础设施。
|
||||
* 如何管理和设计安全、可扩展的云平台（通常是在 AWS 上，不过微软的 Azure、Google Cloud Platform，还有 DigitalOcean 和 Heroku 这样的 PaaS 提供商，也都很流行）。
|
||||
* 如何用流行的 [CI/CD][8] 工具，比如 Jenkins、GoCD，还有基于云的 Travis CI 或者 CircleCI，来构造一条优化的发布部署流水线和发布部署策略。
|
||||
* 如何在你的系统中使用基于时间序列的工具，比如 Kibana、Grafana、Splunk、Loggly 或者 Logstash 来监控、记录，并在变化的时候报警。
|
||||
* 如何使用配置管理工具，例如 Chef、Puppet 或者 Ansible 做到“基础设施即代码”，以及如何使用像 Terraform 或 CloudFormation 的工具发布这些基础设施。
|
||||
|
||||
容器也变得越来越受欢迎。尽管有人对大规模使用 Docker 的现状[表示不满][9]，但容器正迅速地成为一种很好的方式来实现在更少的操作系统上运行超高密度的服务和应用，同时提高它们的可靠性。（像 Kubernetes 或者 Mesos 这样的容器编排工具，能在宿主机故障的时候，几秒钟之内重新启动新的容器。）考虑到这些，掌握 Docker 或者 rkt 以及容器编排平台的知识会对你大有帮助。
|
||||
|
||||
如果你是希望做 DevOps 实践的系统管理员，你还需要知道如何写代码。Python 和 Ruby 是 DevOps 领域的流行语言，因为它们是可移植的（也就是说可以在任何操作系统上运行），快速的，而且易读易学。它们还支撑着这个行业最流行的配置管理工具（Ansible 是使用 Python 写的，Chef 和 Puppet 是使用 Ruby 写的）以及云平台的 API 客户端（亚马逊 AWS，微软 Azure，Google Cloud Platform 的客户端通常会提供 Python 和 Ruby 语言的版本）。
|
||||
如果你是希望做 DevOps 实践的系统管理员，你还需要知道如何写代码。Python 和 Ruby 是 DevOps 领域的流行语言，因为它们是可移植的（也就是说可以在任何操作系统上运行）、快速的，而且易读易学。它们还支撑着这个行业最流行的配置管理工具（Ansible 是使用 Python 写的，Chef 和 Puppet 是使用 Ruby 写的）以及云平台的 API 客户端（亚马逊 AWS、微软 Azure、Google Cloud Platform 的客户端通常会提供 Python 和 Ruby 语言的版本）。
|
||||
|
||||
如果你是开发人员，也希望做 DevOps 的实践，我强烈建议你去学习 Unix，Windows 操作系统以及网络基础知识。虽然云计算把很多系统管理的难题抽象化了，但是对应用的性能做 debug 的时候，如果你知道操作系统如何工作的就会有很大的帮助。下文包含了一些这个主题的图书。
|
||||
如果你是开发人员，也希望做 DevOps 的实践，我强烈建议你去学习 Unix、Windows 操作系统以及网络基础知识。虽然云计算把很多系统管理的难题抽象化了，但是对应用的性能做调试的时候，如果你知道操作系统如何工作的就会有很大的帮助。下文包含了一些这个主题的图书。
|
||||
|
||||
如果你觉得这些东西听起来内容太多，没关系，大家都是这么想的。幸运的是，有很多小项目可以让你开始探索。其中一个项目是 Gary Stafford 的[选举服务](https://github.com/garystafford/voter-service)，一个基于 Java 的简单投票平台。我们要求面试候选人通过一个流水线将该服务从 GitHub 部署到生产环境基础设施上。你可以把这个服务与 Rob Mile 写的了不起的 DevOps [入门教程](https://github.com/maxamg/cd-office-hours)结合起来学习。
|
||||
|
||||
@ -79,22 +80,22 @@ DevOps 不是一个团队，CI/CD 也不是 JIRA 系统的一个用户组。DevO
|
||||
|
||||
#### 理论书籍
|
||||
|
||||
* Gene Kim 写的 [The Phoenix Project（凤凰项目）][10]。这是一本很不错的书，内容涵盖了我上文解释过的历史（写的更生动形象），描述了一个运行在敏捷和 DevOps 之上的公司向精益前进的过程。
|
||||
* Terrance Ryan 写的 [Driving Technical Change（布道之道）][11]。非常好的一小本书，讲了大多数技术型组织内的常见性格特点以及如何和他们打交道。这本书对我的帮助比我想象的更多。
|
||||
* Tom DeMarco 和 Tim Lister 合著的 [Peopleware（人件）][12]。管理工程师团队的经典图书，有一点过时，但仍然很有价值。
|
||||
* Tom Limoncelli 写的 [Time Management for System Administrators（时间管理：给系统管理员）][13]。这本书主要面向系统管理员，它对很多大型组织内的系统管理员生活做了深入的展示。如果你想了解更多系统管理员和开发人员之间的冲突，这本书可能解释了更多。
|
||||
* Eric Ries 写的 [The Lean Startup（精益创业）][14]。描述了 Eric 自己的 3D 虚拟形象公司，IMVU，发现了如何精益工作，快速失败和更快盈利。
|
||||
* Jez Humble 和他的朋友写的 [Lean Enterprise（精益企业）][15]。这本书是对精益创业做的改编，以更适应企业，两本书都很棒，都很好地解释了 DevOps 背后的商业动机。
|
||||
* Kief Morris 写的 [Infrastructure As Code（基础设施即代码）][16]。关于“基础设施即代码”的非常好的入门读物！很好的解释了为什么所有公司都有必要采纳这种做法。
|
||||
* Betsy Beyer、Chris Jones、Jennifer Petoff 和 Niall Richard Murphy 合著的 [Site Reliability Engineering（站点可靠性工程师）][17]。一本解释谷歌 SRE 实践的书，也因为是“DevOps 诞生之前的 DevOps”被人熟知。在如何处理运行时间、时延和保持工程师快乐方面提供了有意思的看法。
|
||||
* Gene Kim 写的 《<ruby>[凤凰项目][10]<rt>The Phoenix Project</rt></ruby>》。这是一本很不错的书，内容涵盖了我上文解释过的历史（写的更生动形象），描述了一个运行在敏捷和 DevOps 之上的公司向精益前进的过程。
|
||||
* Terrance Ryan 写的 《<ruby>[布道之道][11]<rt>Driving Technical Change</rt></ruby>》。非常好的一小本书，讲了大多数技术型组织内的常见性格特点以及如何和他们打交道。这本书对我的帮助比我想象的更多。
|
||||
* Tom DeMarco 和 Tim Lister 合著的 《<ruby>[人件][12]<rt>Peopleware</rt></ruby>》。管理工程师团队的经典图书，有一点过时，但仍然很有价值。
|
||||
* Tom Limoncelli 写的 《<ruby>[时间管理：给系统管理员][13]<rt>Time Management for System Administrators</rt></ruby>》。这本书主要面向系统管理员，它对很多大型组织内的系统管理员生活做了深入的展示。如果你想了解更多系统管理员和开发人员之间的冲突，这本书可能解释了更多。
|
||||
* Eric Ries 写的 《<ruby>[精益创业][14]<rt>The Lean Startup</rt></ruby>》。描述了 Eric 自己的 3D 虚拟形象公司，IMVU，发现了如何精益工作，快速失败和更快盈利。
|
||||
* Jez Humble 和他的朋友写的 《<ruby>[精益企业][15]<rt>Lean Enterprise</rt></ruby>》。这本书是对精益创业做的改编，以更适应企业，两本书都很棒，都很好地解释了 DevOps 背后的商业动机。
|
||||
* Kief Morris 写的 《<ruby>[基础设施即代码][16]<rt>Infrastructure As Code</rt></ruby>》。关于“基础设施即代码”的非常好的入门读物！很好的解释了为什么所有公司都有必要采纳这种做法。
|
||||
* Betsy Beyer、Chris Jones、Jennifer Petoff 和 Niall Richard Murphy 合著的 《<ruby>[站点可靠性工程师][17]<rt>Site Reliability Engineering</rt></ruby>》。一本解释谷歌 SRE 实践的书，也因为是“DevOps 诞生之前的 DevOps”被人熟知。在如何处理运行时间、时延和保持工程师快乐方面提供了有意思的看法。
|
||||
|
||||
#### 技术书籍
|
||||
|
||||
如果你想找的是让你直接跟代码打交道的书，看这里就对了。
|
||||
|
||||
* W. Richard Stevens 的 [TCP/IP Illustrated（TCP/IP 详解）][18]。这是一套经典的（也可以说是最全面的）讲解网络协议基础的巨著，重点介绍了 TCP/IP 协议族。如果你听说过 1，2，3，4 层网络，而且对深入学习它们感兴趣，那么你需要这本书。
|
||||
* Evi Nemeth、Trent Hein 和 Ben Whaley 合著的 [UNIX and Linux System Administration Handbook（UNIX/Linux 系统管理员手册）][19]。一本很好的入门书，介绍 Linux/Unix 如何工作以及如何使用。
|
||||
* Don Jones 和 Jeffrey Hicks 合著的 [Learn Windows Powershell In A Month of Lunches（Windows PowerShell 实战指南）][20]。如果你在 Windows 系统下做自动化任务，你需要学习怎么使用 Powershell。这本书能够帮助你。Don Jones 是这方面著名的 MVP。
|
||||
* W. Richard Stevens 的 《<ruby>[TCP/IP 详解][18]<rt>TCP/IP Illustrated</rt></ruby>》。这是一套经典的（也可以说是最全面的）讲解网络协议基础的巨著，重点介绍了 TCP/IP 协议族。如果你听说过 1、2、3、4 层网络，而且对深入学习它们感兴趣，那么你需要这本书。
|
||||
* Evi Nemeth、Trent Hein 和 Ben Whaley 合著的 《<ruby>[UNIX/Linux 系统管理员手册][19]<rt>UNIX and Linux System Administration Handbook</rt></ruby>》。一本很好的入门书，介绍 Linux/Unix 如何工作以及如何使用。
|
||||
* Don Jones 和 Jeffrey Hicks 合著的 《<ruby>[Windows PowerShell 实战指南][20]<rt>Learn Windows Powershell In A Month of Lunches</rt></ruby>》。如果你在 Windows 系统下做自动化任务，你需要学习怎么使用 Powershell。这本书能够帮助你。Don Jones 是这方面著名的 MVP。
|
||||
* 几乎所有 [James Turnbull][21] 写的东西，针对流行的 DevOps 工具，他发表了很好的技术入门读物。
|
||||
|
||||
不管是在那些把所有应用都直接部署在物理机上的公司，（现在很多公司仍然有充分的理由这样做）还是在那些把所有应用都做成 serverless 的先驱公司，DevOps 都很可能会持续下去。这部分工作很有趣，产出也很有影响力，而且最重要的是，它搭起桥梁衔接了技术和业务之间的缺口。DevOps 是一个值得期待的美好事物。
|
||||
@ -0,0 +1,49 @@
|
||||
从过时的 Windows 机器迁移到 Linux
|
||||
======
|
||||
> 这是一个当老旧的 Windows 机器退役时，决定迁移到 Linux 的故事。
|
||||
|
||||
|
||||
|
||||
我在 ONLYOFFICE 的市场部门工作的每一天，我都能看到 Linux 用户在网上讨论我们的办公软件。我们的产品在 Linux 用户中很受欢迎，这使得我对使用 Linux 作为日常工具的体验非常好奇。我的老旧的 Windows XP 机器在性能上非常差，因此我决定了解 Linux 系统（特别是 Ubuntu）并且决定去尝试使用它。我的两个同事也加入了我的计划。
|
||||
|
||||
### 为何选择 Linux ？
|
||||
|
||||
我们必须做出改变，首先，我们的老系统在性能方面不够用：我们经历过频繁的崩溃，每当运行超过两个应用时，机器就会负载过度，关闭机器时有一半的几率冻结等等。这很容易让我们从工作中分心，意味着我们没有我们应有的工作效率了。
|
||||
|
||||
升级到 Windows 的新版本也是一种选择，但这样可能会带来额外的开销，而且我们的软件本身也是要与 Microsoft 的办公软件竞争。因此我们在这方面也存在意识形态的问题。
|
||||
|
||||
其次，就像我之前提过的， ONLYOFFICE 产品在 Linux 社区内非常受欢迎。通过阅读 Linux 用户在使用我们的软件时的体验，我们也对加入他们很感兴趣。
|
||||
|
||||
在我们要求转换到 Linux 系统一周后，我们拿到了崭新的装好了 [Kubuntu][1] 的机器。我们选择了 16.04 版本，因为这个版本支持 KDE Plasma 5.5 和包括 Dolphin 在内的很多 KDE 应用，同时也包括 LibreOffice 5.1 和 Firefox 45 。
|
||||
|
||||
### Linux 让人喜欢的地方
|
||||
|
||||
我相信 Linux 最大的优势是它的运行速度，比如，从按下机器的电源按钮到开始工作只需要几秒钟时间。从一开始，一切看起来都超乎寻常地快：总体的响应速度，图形界面，甚至包括系统更新的速度。
|
||||
|
||||
另一个使我惊奇的事情是跟 Windows 相比， Linux 几乎能让你配置任何东西，包括整个桌面的外观。在设置里面，我发现了如何修改各种栏目、按钮和字体的颜色和形状，也可以重新布置任意桌面组件的位置，组合桌面小工具（甚至包括漫画和颜色选择器）。我相信我还仅仅只是了解了基本的选项，之后还需要探索这个系统更多著名的定制化选项。
|
||||
|
||||
Linux 发行版通常是一个非常安全的环境。人们很少在 Linux 系统中使用防病毒的软件，因为很少有人会写病毒程序来攻击 Linux 系统。因此你可以拥有很好的系统速度，并且节省了时间和金钱。
|
||||
|
||||
总之， Linux 已经改变了我们的日常生活，用一系列的新选项和功能大大震惊了我们。仅仅通过短时间的使用，我们已经可以给它总结出以下特性：
|
||||
|
||||
* 操作很快很顺畅
|
||||
* 高度可定制
|
||||
* 对新手很友好
|
||||
* 了解基本组件很有挑战性，但回报丰厚
|
||||
* 安全可靠
|
||||
* 对所有想改变工作场所的人来说都是一次绝佳的体验
|
||||
|
||||
你已经从 Windows 或 MacOS 系统换到 Kubuntu 或其他 Linux 变种了么？或者你是否正在考虑做出改变？请分享你想要采用 Linux 系统的原因，连同你对开源的印象一起写在评论中。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/1/move-to-linux-old-windows
|
||||
|
||||
作者：[Michael Korotaev][a]
|
||||
译者：[bookug](https://github.com/bookug)
|
||||
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/michaelk
|
||||
[1]:https://kubuntu.org/
|
||||
@ -1,16 +1,15 @@
|
||||
在 React 条件渲染中使用三元表达式和 “&&”
|
||||
============================================================
|
||||
=======
|
||||
|
||||
|
||||
Photo by [Brendan Church][1] on [Unsplash][2]
|
||||
|
||||
React 组件可以通过多种方式决定渲染内容。你可以使用传统的 if 语句或 switch 语句。在本文中，我们将探讨一些替代方案。但要注意，如果你不小心，有些方案会带来自己的陷阱。
|
||||
React 组件可以通过多种方式决定渲染内容。你可以使用传统的 `if` 语句或 `switch` 语句。在本文中，我们将探讨一些替代方案。但要注意，如果你不小心，有些方案会带来自己的陷阱。
|
||||
|
||||
### 三元表达式 vs if/else
|
||||
|
||||
假设我们有一个组件被传进来一个 `name` prop。 如果这个字符串非空，我们会显示一个问候语。否则，我们会告诉用户他们需要登录。
|
||||
假设我们有一个组件被传进来一个 `name` 属性。 如果这个字符串非空，我们会显示一个问候语。否则，我们会告诉用户他们需要登录。
|
||||
|
||||
这是一个只实现了如上功能的无状态函数式组件。
|
||||
这是一个只实现了如上功能的无状态函数式组件（SFC）。
|
||||
|
||||
```
|
||||
const MyComponent = ({ name }) => {
|
||||
@ -29,7 +28,7 @@ const MyComponent = ({ name }) => {
|
||||
};
|
||||
```
|
||||
|
||||
这个很简单但是我们可以做得更好。这是使用三元运算符编写的相同组件。
|
||||
这个很简单但是我们可以做得更好。这是使用<ruby>三元运算符<rt>conditional ternary operator</rt></ruby>编写的相同组件。
|
||||
|
||||
```
|
||||
const MyComponent = ({ name }) => (
|
||||
@ -41,86 +40,85 @@ const MyComponent = ({ name }) => (
|
||||
|
||||
请注意这段代码与上面的例子相比是多么简洁。
|
||||
|
||||
有几点需要注意。因为我们使用了箭头函数的单语句形式，所以隐含了return语句。另外，使用三元运算符允许我们省略掉重复的 `<div className="hello">` 标记。🎉
|
||||
有几点需要注意。因为我们使用了箭头函数的单语句形式，所以隐含了`return` 语句。另外，使用三元运算符允许我们省略掉重复的 `<div className="hello">` 标记。
|
||||
|
||||
### 三元表达式 vs &&
|
||||
|
||||
正如您所看到的，三元表达式用于表达 if/else 条件式非常好。但是对于简单的 if 条件式怎么样呢？
|
||||
正如您所看到的，三元表达式用于表达 `if`/`else` 条件式非常好。但是对于简单的 `if` 条件式怎么样呢？
|
||||
|
||||
让我们看另一个例子。如果 isPro（一个布尔值）为真，我们将显示一个奖杯表情符号。我们也要渲染星星的数量（如果不是0）。我们可以这样写。
|
||||
让我们看另一个例子。如果 `isPro`（一个布尔值）为真，我们将显示一个奖杯表情符号。我们也要渲染星星的数量（如果不是 0）。我们可以这样写。
|
||||
|
||||
```
|
||||
const MyComponent = ({ name, isPro, stars}) => (
|
||||
<div className="hello">
|
||||
<div>
|
||||
Hello {name}
|
||||
{isPro ? '🏆' : null}
|
||||
{isPro ? '♨' : null}
|
||||
</div>
|
||||
{stars ? (
|
||||
<div>
|
||||
Stars:{'⭐️'.repeat(stars)}
|
||||
Stars:{'☆'.repeat(stars)}
|
||||
</div>
|
||||
) : null}
|
||||
</div>
|
||||
);
|
||||
```
|
||||
|
||||
请注意 “else” 条件返回 null 。 这是因为三元表达式要有"否则"条件。
|
||||
请注意 `else` 条件返回 `null` 。 这是因为三元表达式要有“否则”条件。
|
||||
|
||||
对于简单的 “if” 条件式，我们可以使用更合适的东西：&& 运算符。这是使用 “&&” 编写的相同代码。
|
||||
对于简单的 `if` 条件式，我们可以使用更合适的东西：`&&` 运算符。这是使用 `&&` 编写的相同代码。
|
||||
|
||||
```
|
||||
const MyComponent = ({ name, isPro, stars}) => (
|
||||
<div className="hello">
|
||||
<div>
|
||||
Hello {name}
|
||||
{isPro && '🏆'}
|
||||
{isPro && '♨'}
|
||||
</div>
|
||||
{stars && (
|
||||
<div>
|
||||
Stars:{'⭐️'.repeat(stars)}
|
||||
Stars:{'☆'.repeat(stars)}
|
||||
</div>
|
||||
)}
|
||||
</div>
|
||||
);
|
||||
```
|
||||
|
||||
没有太多区别，但是注意我们消除了每个三元表达式最后面的 `: null` （else 条件式）。一切都应该像以前一样渲染。
|
||||
没有太多区别，但是注意我们消除了每个三元表达式最后面的 `: null` （`else` 条件式）。一切都应该像以前一样渲染。
|
||||
|
||||
嘿！约翰得到了什么？当什么都不应该渲染时，只有一个 `0`。这就是我上面提到的陷阱。这里有解释为什么：
|
||||
|
||||
嘿！约翰得到了什么？当什么都不应该渲染时，只有一个0。这就是我上面提到的陷阱。这里有解释为什么。
|
||||
|
||||
[根据 MDN][3]，一个逻辑运算符“和”（也就是`&&`）：
|
||||
[根据 MDN][3]，一个逻辑运算符“和”（也就是 `&&`）：
|
||||
|
||||
> `expr1 && expr2`
|
||||
|
||||
> 如果 `expr1` 可以被转换成 `false` ，返回 `expr1`；否则返回 `expr2`。 如此，当与布尔值一起使用时，如果两个操作数都是 true，`&&` 返回 `true` ；否则，返回 `false`。
|
||||
> 如果 `expr1` 可以被转换成 `false` ，返回 `expr1`；否则返回 `expr2`。 如此，当与布尔值一起使用时，如果两个操作数都是 `true`，`&&` 返回 `true` ；否则，返回 `false`。
|
||||
|
||||
好的，在你开始拔头发之前，让我为你解释它。
|
||||
|
||||
在我们这个例子里， `expr1` 是变量 `stars`，它的值是 `0`，因为0是 falsey 的值, `0` 会被返回和渲染。看，这还不算太坏。
|
||||
在我们这个例子里， `expr1` 是变量 `stars`，它的值是 `0`，因为 0 是假值，`0` 会被返回和渲染。看，这还不算太坏。
|
||||
|
||||
我会简单地这么写。
|
||||
|
||||
> 如果 `expr1` 是 falsey，返回 `expr1` ，否则返回 `expr2`
|
||||
> 如果 `expr1` 是假值，返回 `expr1` ，否则返回 `expr2`。
|
||||
|
||||
所以，当对非布尔值使用 “&&” 时，我们必须让 falsy 的值返回 React 无法渲染的东西，比如说，`false` 这个值。
|
||||
所以，当对非布尔值使用 `&&` 时，我们必须让这个假值返回 React 无法渲染的东西，比如说，`false` 这个值。
|
||||
|
||||
我们可以通过几种方式实现这一目标。让我们试试吧。
|
||||
|
||||
```
|
||||
{!!stars && (
|
||||
<div>
|
||||
{'⭐️'.repeat(stars)}
|
||||
{'☆'.repeat(stars)}
|
||||
</div>
|
||||
)}
|
||||
```
|
||||
|
||||
注意 `stars` 前的双感叹操作符（ `!!`）（呃，其实没有双感叹操作符。我们只是用了感叹操作符两次）。
|
||||
注意 `stars` 前的双感叹操作符（`!!`）（呃，其实没有双感叹操作符。我们只是用了感叹操作符两次）。
|
||||
|
||||
第一个感叹操作符会强迫 `stars` 的值变成布尔值并且进行一次“非”操作。如果 `stars` 是 `0` ，那么 `!stars` 会 是 `true`。
|
||||
第一个感叹操作符会强迫 `stars` 的值变成布尔值并且进行一次“非”操作。如果 `stars` 是 `0` ，那么 `!stars` 会是 `true`。
|
||||
|
||||
然后我们执行第二个`非`操作，所以如果 `stars` 是0，`!!stars` 会是 `false`。正好是我们想要的。
|
||||
然后我们执行第二个`非`操作，所以如果 `stars` 是 `0`，`!!stars` 会是 `false`。正好是我们想要的。
|
||||
|
||||
如果你不喜欢 `!!`，那么你也可以强制转换出一个布尔数比如这样（这种方式我觉得有点冗长）。
|
||||
|
||||
@ -136,11 +134,11 @@ const MyComponent = ({ name, isPro, stars}) => (
|
||||
|
||||
#### 关于字符串
|
||||
|
||||
空字符串与数字有一样的毛病。但是因为渲染后的空字符串是不可见的，所以这不是那种你很可能会去处理的难题，甚至可能不会注意到它。然而，如果你是完美主义者并且不希望DOM上有空字符串，你应采取我们上面对数字采取的预防措施。
|
||||
空字符串与数字有一样的毛病。但是因为渲染后的空字符串是不可见的，所以这不是那种你很可能会去处理的难题，甚至可能不会注意到它。然而，如果你是完美主义者并且不希望 DOM 上有空字符串，你应采取我们上面对数字采取的预防措施。
|
||||
|
||||
### 其它解决方案
|
||||
|
||||
一种可能的将来可扩展到其他变量的解决方案，是创建一个单独的 `shouldRenderStars` 变量。然后你用“&&”处理布尔值。
|
||||
一种可能的将来可扩展到其他变量的解决方案，是创建一个单独的 `shouldRenderStars` 变量。然后你用 `&&` 处理布尔值。
|
||||
|
||||
```
|
||||
const shouldRenderStars = stars > 0;
|
||||
@ -151,7 +149,7 @@ return (
|
||||
<div>
|
||||
{shouldRenderStars && (
|
||||
<div>
|
||||
{'⭐️'.repeat(stars)}
|
||||
{'☆'.repeat(stars)}
|
||||
</div>
|
||||
)}
|
||||
</div>
|
||||
@ -170,7 +168,7 @@ return (
|
||||
<div>
|
||||
{shouldRenderStars && (
|
||||
<div>
|
||||
{'⭐️'.repeat(stars)}
|
||||
{'☆'.repeat(stars)}
|
||||
</div>
|
||||
)}
|
||||
</div>
|
||||
@ -181,7 +179,7 @@ return (
|
||||
|
||||
我认为你应该充分利用这种语言。对于 JavaScript，这意味着为 `if/else` 条件式使用三元表达式，以及为 `if` 条件式使用 `&&` 操作符。
|
||||
|
||||
我们可以回到每处都使用三元运算符的舒适区，但你现在消化了这些知识和力量，可以继续前进 && 取得成功了。
|
||||
我们可以回到每处都使用三元运算符的舒适区，但你现在消化了这些知识和力量，可以继续前进 `&&` 取得成功了。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -195,7 +193,7 @@ via: https://medium.freecodecamp.org/conditional-rendering-in-react-using-ternar
|
||||
|
||||
作者：[Donavon West][a]
|
||||
译者：[GraveAccent](https://github.com/GraveAccent)
|
||||
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
|
||||
|
||||
140
published/20180412 A Desktop GUI Application For NPM.md
Normal file
140
published/20180412 A Desktop GUI Application For NPM.md
Normal file
@ -0,0 +1,140 @@
|
||||
ndm：NPM 的桌面 GUI 程序
|
||||
======
|
||||
|
||||
|
||||
|
||||
NPM 是 **N**ode **P**ackage **M**anager （node 包管理器）的缩写，它是用于安装 NodeJS 软件包或模块的命令行软件包管理器。我们发布过一个指南描述了如何[使用 NPM 管理 NodeJS 包][1]。你可能已经注意到，使用 Npm 管理 NodeJS 包或模块并不是什么大问题。但是，如果你不习惯用 CLI 的方式，这有一个名为 **NDM** 的桌面 GUI 程序，它可用于管理 NodeJS 程序/模块。 NDM，代表 **N**PM **D**esktop **M**anager （npm 桌面管理器），是 NPM 的自由开源图形前端，它允许我们通过简单图形桌面安装、更新、删除 NodeJS 包。
|
||||
|
||||
在这个简短的教程中，我们将了解 Linux 中的 Ndm。
|
||||
|
||||
### 安装 NDM
|
||||
|
||||
NDM 在 AUR 中可用，因此你可以在 Arch Linux 及其衍生版（如 Antergos 和 Manjaro Linux）上使用任何 AUR 助手程序安装。
|
||||
|
||||
使用 [Pacaur][2]：
|
||||
|
||||
```
|
||||
$ pacaur -S ndm
|
||||
```
|
||||
|
||||
使用 [Packer][3]：
|
||||
|
||||
```
|
||||
$ packer -S ndm
|
||||
```
|
||||
|
||||
使用 [Trizen][4]：
|
||||
|
||||
```
|
||||
$ trizen -S ndm
|
||||
```
|
||||
|
||||
使用 [Yay][5]：
|
||||
|
||||
```
|
||||
$ yay -S ndm
|
||||
```
|
||||
|
||||
使用 [Yaourt][6]：
|
||||
|
||||
```
|
||||
$ yaourt -S ndm
|
||||
```
|
||||
|
||||
在基于 RHEL 的系统（如 CentOS）上，运行以下命令以安装 NDM。
|
||||
|
||||
```
|
||||
$ echo "[fury] name=ndm repository baseurl=https://repo.fury.io/720kb/ enabled=1 gpgcheck=0" | sudo tee /etc/yum.repos.d/ndm.repo && sudo yum update &&
|
||||
```
|
||||
|
||||
在 Debian、Ubuntu、Linux Mint：
|
||||
|
||||
```
|
||||
$ echo "deb [trusted=yes] https://apt.fury.io/720kb/ /" | sudo tee /etc/apt/sources.list.d/ndm.list && sudo apt-get update && sudo apt-get install ndm
|
||||
```
|
||||
|
||||
也可以使用 **Linuxbrew** 安装 NDM。首先，按照以下链接中的说明安装 Linuxbrew。
|
||||
|
||||
安装 Linuxbrew 后，可以使用以下命令安装 NDM：
|
||||
|
||||
```
|
||||
$ brew update
|
||||
$ brew install ndm
|
||||
```
|
||||
|
||||
在其他 Linux 发行版上，进入 [NDM 发布页面][7]，下载最新版本，自行编译和安装。
|
||||
|
||||
### NDM 使用
|
||||
|
||||
从菜单或使用应用启动器启动 NDM。这就是 NDM 的默认界面。
|
||||
|
||||
![][9]
|
||||
|
||||
在这里你可以本地或全局安装 NodeJS 包/模块。
|
||||
|
||||
#### 本地安装 NodeJS 包
|
||||
|
||||
要在本地安装软件包，首先通过单击主屏幕上的 “Add projects” 按钮选择项目目录，然后选择要保留项目文件的目录。例如，我选择了一个名为 “demo” 的目录作为我的项目目录。
|
||||
|
||||
单击项目目录（即 demo），然后单击 “Add packages” 按钮。
|
||||
|
||||
![][10]
|
||||
|
||||
输入要安装的软件包名称，然后单击 “Install” 按钮。
|
||||
|
||||
![][11]
|
||||
|
||||
安装后，软件包将列在项目目录下。只需单击该目录即可在本地查看已安装软件包的列表。
|
||||
|
||||
![][12]
|
||||
|
||||
同样，你可以创建单独的项目目录并在其中安装 NodeJS 模块。要查看项目中已安装模块的列表，请单击项目目录，右侧将显示软件包。
|
||||
|
||||
#### 全局安装 NodeJS 包
|
||||
|
||||
要全局安装 NodeJS 包，请单击主界面左侧的 “Globals” 按钮。然后，单击 “Add packages” 按钮，输入包的名称并单击 “Install” 按钮。
|
||||
|
||||
#### 管理包
|
||||
|
||||
单击任何已安装的包，不将在顶部看到各种选项，例如：
|
||||
|
||||
1. 版本（查看已安装的版本），
|
||||
2. 最新（安装最新版本），
|
||||
3. 更新（更新当前选定的包），
|
||||
4. 卸载（删除所选包）等。
|
||||
|
||||
![][13]
|
||||
|
||||
NDM 还有两个选项，即 “Update npm” 用于将 node 包管理器更新成最新可用版本， 而 “Doctor” 会运行一组检查以确保你的 npm 安装有所需的功能管理你的包/模块。
|
||||
|
||||
### 总结
|
||||
|
||||
NDM 使安装、更新、删除 NodeJS 包的过程更加容易！你无需记住执行这些任务的命令。NDM 让我们在简单的图形界面中点击几下鼠标即可完成所有操作。对于那些懒得输入命令的人来说，NDM 是管理 NodeJS 包的完美伴侣。
|
||||
|
||||
干杯!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/ndm-a-desktop-gui-application-for-npm/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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.ostechnix.com/author/sk/
|
||||
[1]:https://www.ostechnix.com/manage-nodejs-packages-using-npm/
|
||||
[2]:https://www.ostechnix.com/install-pacaur-arch-linux/
|
||||
[3]:https://www.ostechnix.com/install-packer-arch-linux-2/
|
||||
[4]:https://www.ostechnix.com/trizen-lightweight-aur-package-manager-arch-based-systems/
|
||||
[5]:https://www.ostechnix.com/yay-found-yet-another-reliable-aur-helper/
|
||||
[6]:https://www.ostechnix.com/install-yaourt-arch-linux/
|
||||
[7]:https://github.com/720kb/ndm/releases
|
||||
[8]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[9]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-1.png
|
||||
[10]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-5-1.png
|
||||
[11]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-6.png
|
||||
[12]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-7.png
|
||||
[13]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-8.png
|
||||
@ -1,21 +1,22 @@
|
||||
The df Command Tutorial With Examples For Beginners
|
||||
df 命令新手教程
|
||||
======
|
||||
|
||||
|
||||
|
||||
In this guide, we are going to learn to use **df** command. The df command, stands for **D** isk **F** ree, reports file system disk space usage. It displays the amount of disk space available on the file system in a Linux system. The df command is not to be confused with **du** command. Both serves different purposes. The df command reports **how much disk space we have** (i.e free space) whereas the du command reports **how much disk space is being consumed** by the files and folders. Hope I made myself clear. Let us go ahead and see some practical examples of df command, so you can understand it better.
|
||||
在本指南中，我们将学习如何使用 `df` 命令。df 命令是 “Disk Free” 的首字母组合，它报告文件系统磁盘空间的使用情况。它显示一个 Linux 系统中文件系统上可用磁盘空间的数量。`df` 命令很容易与 `du` 命令混淆。它们的用途不同。`df` 命令报告我们拥有多少磁盘空间（空闲磁盘空间），而 `du` 命令报告被文件和目录占用了多少磁盘空间。希望我这样的解释你能更清楚。在继续之前，我们来看一些 `df` 命令的实例，以便于你更好地理解它。
|
||||
|
||||
### The df Command Tutorial With Examples
|
||||
### df 命令使用举例
|
||||
|
||||
**1\. View entire file system disk space usage**
|
||||
#### 1、查看整个文件系统磁盘空间使用情况
|
||||
|
||||
无需任何参数来运行 `df` 命令，以显示整个文件系统磁盘空间使用情况。
|
||||
|
||||
Run df command without any arguments to display the entire file system disk space.
|
||||
```
|
||||
$ df
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
示例输出：
|
||||
|
||||
```
|
||||
Filesystem 1K-blocks Used Available Use% Mounted on
|
||||
dev 4033216 0 4033216 0% /dev
|
||||
@ -27,25 +28,23 @@ tmpfs 4038880 11636 4027244 1% /tmp
|
||||
/dev/loop0 84096 84096 0 100% /var/lib/snapd/snap/core/4327
|
||||
/dev/sda1 95054 55724 32162 64% /boot
|
||||
tmpfs 807776 28 807748 1% /run/user/1000
|
||||
|
||||
```
|
||||
|
||||
![][2]
|
||||
|
||||
As you can see, the result is divided into six columns. Let us see what each column means.
|
||||
正如你所见，输出结果分为六列。我们来看一下每一列的含义。
|
||||
|
||||
* **Filesystem** – the filesystem on the system.
|
||||
* **1K-blocks** – the size of the filesystem, measured in 1K blocks.
|
||||
* **Used** – the amount of space used in 1K blocks.
|
||||
* **Available** – the amount of available space in 1K blocks.
|
||||
* **Use%** – the percentage that the filesystem is in use.
|
||||
* **Mounted on** – the mount point where the filesystem is mounted.
|
||||
* `Filesystem` – Linux 系统中的文件系统
|
||||
* `1K-blocks` – 文件系统的大小，用 1K 大小的块来表示。
|
||||
* `Used` – 以 1K 大小的块所表示的已使用数量。
|
||||
* `Available` – 以 1K 大小的块所表示的可用空间的数量。
|
||||
* `Use%` – 文件系统中已使用的百分比。
|
||||
* `Mounted on` – 已挂载的文件系统的挂载点。
|
||||
|
||||
#### 2、以人类友好格式显示文件系统硬盘空间使用情况
|
||||
|
||||
在上面的示例中你可能已经注意到了，它使用 1K 大小的块为单位来表示使用情况，如果你以人类友好格式来显示它们，可以使用 `-h` 标志。
|
||||
|
||||
**2\. Display file system disk usage in human readable format**
|
||||
|
||||
As you may noticed in the above examples, the usage is showed in 1k blocks. If you want to display them in human readable format, use **-h** flag.
|
||||
```
|
||||
$ df -h
|
||||
Filesystem Size Used Avail Use% Mounted on
|
||||
@ -61,11 +60,12 @@ tmpfs 789M 28K 789M 1% /run/user/1000
|
||||
|
||||
```
|
||||
|
||||
Now look at the **Size** and **Avail** columns, the usage is shown in GB and MB.
|
||||
现在，在 `Size` 列和 `Avail` 列，使用情况是以 GB 和 MB 为单位来显示的。
|
||||
|
||||
**3\. Display disk space usage only in MB**
|
||||
#### 3、仅以 MB 为单位来显示文件系统磁盘空间使用情况
|
||||
|
||||
如果仅以 MB 为单位来显示文件系统磁盘空间使用情况，使用 `-m` 标志。
|
||||
|
||||
To view file system disk space usage only in Megabytes, use **-m** flag.
|
||||
```
|
||||
$ df -m
|
||||
Filesystem 1M-blocks Used Available Use% Mounted on
|
||||
@ -78,12 +78,12 @@ tmpfs 3945 12 3933 1% /tmp
|
||||
/dev/loop0 83 83 0 100% /var/lib/snapd/snap/core/4327
|
||||
/dev/sda1 93 55 32 64% /boot
|
||||
tmpfs 789 1 789 1% /run/user/1000
|
||||
|
||||
```
|
||||
|
||||
**4\. List inode information instead of block usage**
|
||||
#### 4、列出节点而不是块的使用情况
|
||||
|
||||
如下所示，我们可以通过使用 `-i` 标记来列出节点而不是块的使用情况。
|
||||
|
||||
We can list inode information instead of block usage by using **-i** flag as shown below.
|
||||
```
|
||||
$ df -i
|
||||
Filesystem Inodes IUsed IFree IUse% Mounted on
|
||||
@ -96,12 +96,12 @@ tmpfs 1009720 3008 1006712 1% /tmp
|
||||
/dev/loop0 12829 12829 0 100% /var/lib/snapd/snap/core/4327
|
||||
/dev/sda1 25688 390 25298 2% /boot
|
||||
tmpfs 1009720 29 1009691 1% /run/user/1000
|
||||
|
||||
```
|
||||
|
||||
**5\. Display the file system type**
|
||||
#### 5、显示文件系统类型
|
||||
|
||||
使用 `-T` 标志显示文件系统类型。
|
||||
|
||||
To display the file system type, use **-T** flag.
|
||||
```
|
||||
$ df -T
|
||||
Filesystem Type 1K-blocks Used Available Use% Mounted on
|
||||
@ -114,27 +114,27 @@ tmpfs tmpfs 4038880 11984 4026896 1% /tmp
|
||||
/dev/loop0 squashfs 84096 84096 0 100% /var/lib/snapd/snap/core/4327
|
||||
/dev/sda1 ext4 95054 55724 32162 64% /boot
|
||||
tmpfs tmpfs 807776 28 807748 1% /run/user/1000
|
||||
|
||||
```
|
||||
|
||||
As you see, there is an extra column (second from left) that shows the file system type.
|
||||
正如你所见，现在出现了显示文件系统类型的额外的列（从左数的第二列）。
|
||||
|
||||
**6\. Display only the specific file system type**
|
||||
#### 6、仅显示指定类型的文件系统
|
||||
|
||||
我们可以限制仅列出某些文件系统。比如，只列出 ext4 文件系统。我们使用 `-t` 标志。
|
||||
|
||||
We can limit the listing to a certain file systems. for example **ext4**. To do so, we use **-t** flag.
|
||||
```
|
||||
$ df -t ext4
|
||||
Filesystem 1K-blocks Used Available Use% Mounted on
|
||||
/dev/sda2 478425016 428790896 25308436 95% /
|
||||
/dev/sda1 95054 55724 32162 64% /boot
|
||||
|
||||
```
|
||||
|
||||
See? This command shows only the ext4 file system disk space usage.
|
||||
看到了吗？这个命令仅显示了 ext4 文件系统的磁盘空间使用情况。
|
||||
|
||||
**7\. Exclude specific file system type**
|
||||
#### 7、不列出指定类型的文件系统
|
||||
|
||||
有时，我们可能需要从结果中去排除指定类型的文件系统。我们可以使用 `-x` 标记达到我们的目的。
|
||||
|
||||
Some times, you may want to exclude a specific file system from the result. This can be achieved by using **-x** flag.
|
||||
```
|
||||
$ df -x ext4
|
||||
Filesystem 1K-blocks Used Available Use% Mounted on
|
||||
@ -145,34 +145,32 @@ tmpfs 4038880 0 4038880 0% /sys/fs/cgroup
|
||||
tmpfs 4038880 11984 4026896 1% /tmp
|
||||
/dev/loop0 84096 84096 0 100% /var/lib/snapd/snap/core/4327
|
||||
tmpfs 807776 28 807748 1% /run/user/1000
|
||||
|
||||
```
|
||||
|
||||
The above command will display all file systems usage, except **ext4**.
|
||||
上面的命令列出了除 ext4 类型以外的全部文件系统。
|
||||
|
||||
**8\. Display usage for a folder**
|
||||
#### 8、显示一个目录的磁盘使用情况
|
||||
|
||||
去显示某个目录的硬盘空间使用情况以及它的挂载点，例如 `/home/sk/` 目录，可以使用如下的命令：
|
||||
|
||||
To display the disk space available and where it is mounted for a folder, for example **/home/sk/** , use this command:
|
||||
```
|
||||
$ df -hT /home/sk/
|
||||
Filesystem Type Size Used Avail Use% Mounted on
|
||||
/dev/sda2 ext4 457G 409G 25G 95% /
|
||||
|
||||
```
|
||||
|
||||
This command shows the file system type, used and available space in human readable form and where it is mounted. If you don’t to display the file system type, just ignore the **-t** flag.
|
||||
这个命令显示文件系统类型、以人类友好格式显示已使用和可用磁盘空间、以及它的挂载点。如果你不想去显示文件系统类型，只需要忽略 `-t` 标志即可。
|
||||
|
||||
更详细的使用情况，请参阅 man 手册页。
|
||||
|
||||
For more details, refer the man pages.
|
||||
```
|
||||
$ man df
|
||||
|
||||
```
|
||||
|
||||
**Recommended read:**
|
||||
|
||||
And, that’s all for today! I hope this was useful. More good stuffs to come. Stay tuned!
|
||||
今天就到此这止！我希望对你有用。还有更多更好玩的东西即将奉上。请继续关注！
|
||||
|
||||
Cheers!
|
||||
再见！
|
||||
|
||||
|
||||
|
||||
@ -181,12 +179,13 @@ Cheers!
|
||||
via: https://www.ostechnix.com/the-df-command-tutorial-with-examples-for-beginners/
|
||||
|
||||
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)
|
||||
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://www.ostechnix.com/author/sk/
|
||||
[1]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[2]:http://www.ostechnix.com/wp-content/uploads/2018/04/df-command.png
|
||||
|
||||
@ -0,0 +1,313 @@
|
||||
在 Ubuntu 18.04 LTS 无头服务器上安装 Oracle VirtualBox
|
||||
======
|
||||
|
||||
|
||||
|
||||
本教程将指导你在 Ubuntu 18.04 LTS 无头服务器上，一步一步地安装 **Oracle VirtualBox**。同时，本教程也将介绍如何使用 **phpVirtualBox** 去管理安装在无头服务器上的 **VirtualBox** 实例。**phpVirtualBox** 是 VirtualBox 的一个基于 Web 的前端工具。这个教程也可以工作在 Debian 和其它 Ubuntu 衍生版本上，如 Linux Mint。现在，我们开始。
|
||||
|
||||
### 前提条件
|
||||
|
||||
在安装 Oracle VirtualBox 之前，我们的 Ubuntu 18.04 LTS 服务器上需要满足如下的前提条件。
|
||||
|
||||
首先，逐个运行如下的命令来更新 Ubuntu 服务器。
|
||||
|
||||
```
|
||||
$ sudo apt update
|
||||
$ sudo apt upgrade
|
||||
$ sudo apt dist-upgrade
|
||||
```
|
||||
|
||||
接下来，安装如下的必需的包：
|
||||
|
||||
```
|
||||
$ sudo apt install build-essential dkms unzip wget
|
||||
```
|
||||
|
||||
安装完成所有的更新和必需的包之后，重启动 Ubuntu 服务器。
|
||||
|
||||
```
|
||||
$ sudo reboot
|
||||
```
|
||||
|
||||
### 在 Ubuntu 18.04 LTS 服务器上安装 VirtualBox
|
||||
|
||||
添加 Oracle VirtualBox 官方仓库。为此你需要去编辑 `/etc/apt/sources.list` 文件：
|
||||
|
||||
```
|
||||
$ sudo nano /etc/apt/sources.list
|
||||
```
|
||||
|
||||
添加下列的行。
|
||||
|
||||
在这里，我将使用 Ubuntu 18.04 LTS，因此我添加下列的仓库。
|
||||
|
||||
```
|
||||
deb http://download.virtualbox.org/virtualbox/debian bionic contrib
|
||||
```
|
||||
|
||||
![][2]
|
||||
|
||||
用你的 Ubuntu 发行版的代码名字替换关键字 ‘bionic’，比如，‘xenial’、‘vivid’、‘utopic’、‘trusty’、‘raring’、‘quantal’、‘precise’、‘lucid’、‘jessie’、‘wheezy’、或 ‘squeeze‘。
|
||||
|
||||
然后，运行下列的命令去添加 Oracle 公钥：
|
||||
|
||||
```
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
|
||||
```
|
||||
|
||||
对于 VirtualBox 的老版本，添加如下的公钥：
|
||||
|
||||
```
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
|
||||
```
|
||||
|
||||
接下来，使用如下的命令去更新软件源：
|
||||
|
||||
```
|
||||
$ sudo apt update
|
||||
```
|
||||
|
||||
最后，使用如下的命令去安装最新版本的 Oracle VirtualBox：
|
||||
|
||||
```
|
||||
$ sudo apt install virtualbox-5.2
|
||||
```
|
||||
|
||||
### 添加用户到 VirtualBox 组
|
||||
|
||||
我们需要去创建并添加我们的系统用户到 `vboxusers` 组中。你也可以单独创建用户，然后将它分配到 `vboxusers` 组中，也可以使用已有的用户。我不想去创建新用户，因此，我添加已存在的用户到这个组中。请注意，如果你为 virtualbox 使用一个单独的用户，那么你必须注销当前用户，并使用那个特定的用户去登入，来完成剩余的步骤。
|
||||
|
||||
我使用的是我的用户名 `sk`，因此，我运行如下的命令将它添加到 `vboxusers` 组中。
|
||||
|
||||
```
|
||||
$ sudo usermod -aG vboxusers sk
|
||||
```
|
||||
|
||||
现在，运行如下的命令去检查 virtualbox 内核模块是否已加载。
|
||||
|
||||
```
|
||||
$ sudo systemctl status vboxdrv
|
||||
```
|
||||
|
||||
![][3]
|
||||
|
||||
正如你在上面的截屏中所看到的，vboxdrv 模块已加载，并且是已运行的状态！
|
||||
|
||||
对于老的 Ubuntu 版本，运行：
|
||||
|
||||
```
|
||||
$ sudo /etc/init.d/vboxdrv status
|
||||
```
|
||||
|
||||
如果 virtualbox 模块没有启动，运行如下的命令去启动它。
|
||||
|
||||
```
|
||||
$ sudo /etc/init.d/vboxdrv setup
|
||||
```
|
||||
|
||||
很好！我们已经成功安装了 VirtualBox 并启动了 virtualbox 模块。现在，我们继续来安装 Oracle VirtualBox 的扩展包。
|
||||
|
||||
### 安装 VirtualBox 扩展包
|
||||
|
||||
VirtualBox 扩展包为 VirtualBox 访客系统提供了如下的功能。
|
||||
|
||||
* 虚拟的 USB 2.0 (EHCI) 驱动
|
||||
* VirtualBox 远程桌面协议（VRDP）支持
|
||||
* 宿主机网络摄像头直通
|
||||
* Intel PXE 引导 ROM
|
||||
* 对 Linux 宿主机上的 PCI 直通提供支持
|
||||
|
||||
从[这里][4]为 VirtualBox 5.2.x 下载最新版的扩展包。
|
||||
|
||||
```
|
||||
$ wget https://download.virtualbox.org/virtualbox/5.2.14/Oracle_VM_VirtualBox_Extension_Pack-5.2.14.vbox-extpack
|
||||
```
|
||||
|
||||
使用如下的命令去安装扩展包：
|
||||
|
||||
```
|
||||
$ sudo VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-5.2.14.vbox-extpack
|
||||
```
|
||||
|
||||
恭喜！我们已经成功地在 Ubuntu 18.04 LTS 服务器上安装了 Oracle VirtualBox 的扩展包。现在已经可以去部署虚拟机了。参考 [virtualbox 官方指南][5]，在命令行中开始创建和管理虚拟机。
|
||||
|
||||
然而，并不是每个人都擅长使用命令行。有些人可能希望在图形界面中去创建和使用虚拟机。不用担心！下面我们为你带来非常好用的 **phpVirtualBox** 工具！
|
||||
|
||||
### 关于 phpVirtualBox
|
||||
|
||||
**phpVirtualBox** 是一个免费的、基于 web 的 Oracle VirtualBox 后端。它是使用 PHP 开发的。用 phpVirtualBox 我们可以通过 web 浏览器从网络上的任意一个系统上，很轻松地创建、删除、管理、和执行虚拟机。
|
||||
|
||||
### 在 Ubuntu 18.04 LTS 上安装 phpVirtualBox
|
||||
|
||||
由于它是基于 web 的工具，我们需要安装 Apache web 服务器、PHP 和一些 php 模块。
|
||||
|
||||
为此，运行如下命令：
|
||||
|
||||
```
|
||||
$ sudo apt install apache2 php php-mysql libapache2-mod-php php-soap php-xml
|
||||
```
|
||||
|
||||
然后，从 [下载页面][6] 上下载 phpVirtualBox 5.2.x 版。请注意，由于我们已经安装了 VirtualBox 5.2 版，因此，同样的我们必须去安装 phpVirtualBox 的 5.2 版本。
|
||||
|
||||
运行如下的命令去下载它：
|
||||
|
||||
```
|
||||
$ wget https://github.com/phpvirtualbox/phpvirtualbox/archive/5.2-0.zip
|
||||
```
|
||||
|
||||
使用如下命令解压下载的安装包：
|
||||
|
||||
```
|
||||
$ unzip 5.2-0.zip
|
||||
```
|
||||
|
||||
这个命令将解压 5.2.0.zip 文件的内容到一个名为 `phpvirtualbox-5.2-0` 的文件夹中。现在，复制或移动这个文件夹的内容到你的 apache web 服务器的根文件夹中。
|
||||
|
||||
```
|
||||
$ sudo mv phpvirtualbox-5.2-0/ /var/www/html/phpvirtualbox
|
||||
```
|
||||
|
||||
给 phpvirtualbox 文件夹分配适当的权限。
|
||||
|
||||
```
|
||||
$ sudo chmod 777 /var/www/html/phpvirtualbox/
|
||||
```
|
||||
|
||||
接下来，我们开始配置 phpVirtualBox。
|
||||
|
||||
像下面这样复制示例配置文件。
|
||||
|
||||
```
|
||||
$ sudo cp /var/www/html/phpvirtualbox/config.php-example /var/www/html/phpvirtualbox/config.php
|
||||
```
|
||||
|
||||
编辑 phpVirtualBox 的 `config.php` 文件：
|
||||
|
||||
```
|
||||
$ sudo nano /var/www/html/phpvirtualbox/config.php
|
||||
```
|
||||
|
||||
找到下列行，并且用你的系统用户名和密码去替换它（就是前面的“添加用户到 VirtualBox 组中”节中使用的用户名）。
|
||||
|
||||
在我的案例中，我的 Ubuntu 系统用户名是 `sk` ，它的密码是 `ubuntu`。
|
||||
|
||||
```
|
||||
var $username = 'sk';
|
||||
var $password = 'ubuntu';
|
||||
```
|
||||
|
||||
![][7]
|
||||
|
||||
保存并关闭这个文件。
|
||||
|
||||
接下来，创建一个名为 `/etc/default/virtualbox` 的新文件：
|
||||
|
||||
```
|
||||
$ sudo nano /etc/default/virtualbox
|
||||
```
|
||||
|
||||
添加下列行。用你自己的系统用户替换 `sk`。
|
||||
|
||||
```
|
||||
VBOXWEB_USER=sk
|
||||
```
|
||||
|
||||
最后，重引导你的系统或重启下列服务去完成整个配置工作。
|
||||
|
||||
```
|
||||
$ sudo systemctl restart vboxweb-service
|
||||
$ sudo systemctl restart vboxdrv
|
||||
$ sudo systemctl restart apache2
|
||||
```
|
||||
|
||||
### 调整防火墙允许连接 Apache web 服务器
|
||||
|
||||
如果你在 Ubuntu 18.04 LTS 上启用了 UFW，那么在默认情况下，apache web 服务器是不能被任何远程系统访问的。你必须通过下列的步骤让 http 和 https 流量允许通过 UFW。
|
||||
|
||||
首先，我们使用如下的命令来查看在策略中已经安装了哪些应用：
|
||||
|
||||
```
|
||||
$ sudo ufw app list
|
||||
Available applications:
|
||||
Apache
|
||||
Apache Full
|
||||
Apache Secure
|
||||
OpenSSH
|
||||
```
|
||||
|
||||
正如你所见，Apache 和 OpenSSH 应该已经在 UFW 的策略文件中安装了。
|
||||
|
||||
如果你在策略中看到的是 `Apache Full`，说明它允许流量到达 80 和 443 端口：
|
||||
|
||||
```
|
||||
$ sudo ufw app info "Apache Full"
|
||||
Profile: Apache Full
|
||||
Title: Web Server (HTTP,HTTPS)
|
||||
Description: Apache v2 is the next generation of the omnipresent Apache web
|
||||
server.
|
||||
|
||||
Ports:
|
||||
80,443/tcp
|
||||
```
|
||||
|
||||
现在，运行如下的命令去启用这个策略中的 HTTP 和 HTTPS 的入站流量：
|
||||
|
||||
```
|
||||
$ sudo ufw allow in "Apache Full"
|
||||
Rules updated
|
||||
Rules updated (v6)
|
||||
```
|
||||
|
||||
如果你希望允许 https 流量，但是仅是 http (80) 的流量，运行如下的命令：
|
||||
|
||||
```
|
||||
$ sudo ufw app info "Apache"
|
||||
```
|
||||
|
||||
### 访问 phpVirtualBox 的 Web 控制台
|
||||
|
||||
现在，用任意一台远程系统的 web 浏览器来访问。
|
||||
|
||||
在地址栏中，输入：`http://IP-address-of-virtualbox-headless-server/phpvirtualbox`。
|
||||
|
||||
在我的案例中，我导航到这个链接 – `http://192.168.225.22/phpvirtualbox`。
|
||||
|
||||
你将看到如下的屏幕输出。输入 phpVirtualBox 管理员用户凭据。
|
||||
|
||||
phpVirtualBox 的默认管理员用户名和密码是 `admin` / `admin`。
|
||||
|
||||
![][8]
|
||||
|
||||
恭喜！你现在已经进入了 phpVirtualBox 管理面板了。
|
||||
|
||||
![][9]
|
||||
|
||||
现在，你可以从 phpvirtualbox 的管理面板上，开始去创建你的 VM 了。正如我在前面提到的，你可以从同一网络上的任意一台系统上访问 phpVirtualBox 了，而所需要的仅仅是一个 web 浏览器和 phpVirtualBox 的用户名和密码。
|
||||
|
||||
如果在你的宿主机系统（不是访客机）的 BIOS 中没有启用虚拟化支持，phpVirtualBox 将只允许你去创建 32 位的访客系统。要安装 64 位的访客系统，你必须在你的宿主机的 BIOS 中启用虚拟化支持。在你的宿主机的 BIOS 中你可以找到一些类似于 “virtualization” 或 “hypervisor” 字眼的选项，然后确保它是启用的。
|
||||
|
||||
本文到此结束了，希望能帮到你。如果你找到了更有用的指南，共享出来吧。
|
||||
|
||||
还有一大波更好玩的东西即将到来，请继续关注！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/install-oracle-virtualbox-ubuntu-16-04-headless-server/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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://www.ostechnix.com/author/sk/
|
||||
[1]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[2]:http://www.ostechnix.com/wp-content/uploads/2016/07/Add-VirtualBox-repository.png
|
||||
[3]:http://www.ostechnix.com/wp-content/uploads/2016/07/vboxdrv-service.png
|
||||
[4]:https://www.virtualbox.org/wiki/Downloads
|
||||
[5]:http://www.virtualbox.org/manual/ch08.html
|
||||
[6]:https://github.com/phpvirtualbox/phpvirtualbox/releases
|
||||
[7]:http://www.ostechnix.com/wp-content/uploads/2016/07/phpvirtualbox-config.png
|
||||
[8]:http://www.ostechnix.com/wp-content/uploads/2016/07/phpvirtualbox-1.png
|
||||
[9]:http://www.ostechnix.com/wp-content/uploads/2016/07/phpvirtualbox-2.png
|
||||
@ -1,33 +1,35 @@
|
||||
如何在 Linux 中配置基于密钥认证的 SSH
|
||||
如何在 Linux 中配置基于密钥认证的 SSH
|
||||
======
|
||||
|
||||
|
||||
|
||||
### 什么是基于 SSH密钥的认证？
|
||||
### 什么是基于 SSH 密钥的认证？
|
||||
|
||||
众所周知，**Secure Shell**，又称 **SSH**，是允许你通过无安全网络(例如 Internet)和远程系统之间安全访问/通信的加密网络协议。无论何时使用 SSH 在无安全网络上发送数据，它都会在源系统上自动地被加密，并且在目的系统上解密。SSH 提供了四种加密方式，**基于密码认证**，**基于密钥认证**，**基于主机认证**和**键盘认证**。最常用的认证方式是基于密码认证和基于密钥认证。
|
||||
众所周知，**Secure Shell**，又称 **SSH**，是允许你通过无安全网络（例如 Internet）和远程系统之间安全访问/通信的加密网络协议。无论何时使用 SSH 在无安全网络上发送数据，它都会在源系统上自动地被加密，并且在目的系统上解密。SSH 提供了四种加密方式，**基于密码认证**，**基于密钥认证**，**基于主机认证**和**键盘认证**。最常用的认证方式是基于密码认证和基于密钥认证。
|
||||
|
||||
在基于密码认证中，你需要的仅仅是远程系统上用户的密码。如果你知道远程用户的密码，你可以使用**“ssh[[email protected]][1]”**访问各自的系统。另一方面，在基于密钥认证中，为了通过 SSH 通信，你需要生成 SSH 密钥对，并且为远程系统上传 SSH 公钥。每个 SSH 密钥对由私钥与公钥组成。私钥应该保存在客户系统上，公钥应该上传给远程系统。你不应该将私钥透露给任何人。希望你已经对 SSH 和它的认证方式有了基本的概念。
|
||||
在基于密码认证中，你需要的仅仅是远程系统上用户的密码。如果你知道远程用户的密码，你可以使用 `ssh user@remote-system-name` 访问各自的系统。另一方面，在基于密钥认证中，为了通过 SSH 通信，你需要生成 SSH 密钥对，并且为远程系统上传 SSH 公钥。每个 SSH 密钥对由私钥与公钥组成。私钥应该保存在客户系统上，公钥应该上传给远程系统。你不应该将私钥透露给任何人。希望你已经对 SSH 和它的认证方式有了基本的概念。
|
||||
|
||||
这篇教程，我们将讨论如何在 linux 上配置基于密钥认证的 SSH。
|
||||
这篇教程，我们将讨论如何在 Linux 上配置基于密钥认证的 SSH。
|
||||
|
||||
### 在 Linux 上配置基于密钥认证的SSH
|
||||
### 在 Linux 上配置基于密钥认证的 SSH
|
||||
|
||||
为本篇教程起见，我将使用 Arch Linux 为本地系统，Ubuntu 18.04 LTS 为远程系统。
|
||||
为方便演示，我将使用 Arch Linux 为本地系统，Ubuntu 18.04 LTS 为远程系统。
|
||||
|
||||
本地系统详情：
|
||||
* **OS** : Arch Linux Desktop
|
||||
* **IP address** : 192.168.225.37 /24
|
||||
|
||||
* OS: Arch Linux Desktop
|
||||
* IP address: 192.168.225.37/24
|
||||
|
||||
远程系统详情：
|
||||
* **OS** : Ubuntu 18.04 LTS Server
|
||||
* **IP address** : 192.168.225.22/24
|
||||
|
||||
* OS: Ubuntu 18.04 LTS Server
|
||||
* IP address: 192.168.225.22/24
|
||||
|
||||
### 本地系统配置
|
||||
|
||||
就像我之前所说，在基于密钥认证的方法中，想要通过 SSH 访问远程系统，就应该将公钥上传给它。公钥通常会被保存在远程系统的一个文件**~/.ssh/authorized_keys** 中。
|
||||
就像我之前所说，在基于密钥认证的方法中，想要通过 SSH 访问远程系统，需要将公钥上传到远程系统。公钥通常会被保存在远程系统的一个 `~/.ssh/authorized_keys` 文件中。
|
||||
|
||||
**注意事项：**不要使用**root** 用户生成密钥对，这样只有 root 用户才可以使用。使用普通用户创建密钥对。
|
||||
**注意事项**：不要使用 **root** 用户生成密钥对，这样只有 root 用户才可以使用。使用普通用户创建密钥对。
|
||||
|
||||
现在，让我们在本地系统上创建一个 SSH 密钥对。只需要在客户端系统上运行下面的命令。
|
||||
|
||||
@ -35,9 +37,9 @@
|
||||
$ ssh-keygen
|
||||
```
|
||||
|
||||
上面的命令将会创建一个 2048 位的 RSA 密钥对。输入两次密码。更重要的是，记住你的密码。后面将会用到它。
|
||||
上面的命令将会创建一个 2048 位的 RSA 密钥对。你需要输入两次密码。更重要的是，记住你的密码。后面将会用到它。
|
||||
|
||||
**样例输出**
|
||||
**样例输出**：
|
||||
|
||||
```
|
||||
Generating public/private rsa key pair.
|
||||
@ -62,22 +64,22 @@ The key's randomart image is:
|
||||
+----[SHA256]-----+
|
||||
```
|
||||
|
||||
如果你已经创建了密钥对，你将看到以下信息。输入 ‘y’ 就会覆盖已存在的密钥。
|
||||
如果你已经创建了密钥对，你将看到以下信息。输入 `y` 就会覆盖已存在的密钥。
|
||||
|
||||
```
|
||||
/home/username/.ssh/id_rsa already exists.
|
||||
Overwrite (y/n)?
|
||||
```
|
||||
|
||||
请注意**密码是可选的**。如果你输入了密码，那么每次通过 SSH 访问远程系统时都要求输入密码，除非你使用了 SSH 代理保存了密码。如果你不想要密码（虽然不安全），简单地输入两次 ENTER。不过，我们建议你使用密码。从安全的角度来看，使用无密码的 ssh 密钥对大体上不是一个很好的主意。 这种方式应该限定在特殊的情况下使用，例如，没有用户介入的服务访问远程系统。（例如，用 rsync 远程备份...）
|
||||
请注意**密码是可选的**。如果你输入了密码，那么每次通过 SSH 访问远程系统时都要求输入密码，除非你使用了 SSH 代理保存了密码。如果你不想要密码（虽然不安全），简单地敲两次回车。不过，我建议你使用密码。从安全的角度来看，使用无密码的 ssh 密钥对不是什么好主意。这种方式应该限定在特殊的情况下使用，例如，没有用户介入的服务访问远程系统。（例如，用 `rsync` 远程备份……）
|
||||
|
||||
如果你已经在个人文件 **~/.ssh/id_rsa** 中有了无密码的密钥对，但想要更新为带密码的密钥。使用下面的命令：
|
||||
如果你已经在个人文件 `~/.ssh/id_rsa` 中有了无密码的密钥，但想要更新为带密码的密钥。使用下面的命令：
|
||||
|
||||
```
|
||||
$ ssh-keygen -p -f ~/.ssh/id_rsa
|
||||
```
|
||||
|
||||
样例输出：
|
||||
**样例输出**：
|
||||
|
||||
```
|
||||
Enter new passphrase (empty for no passphrase):
|
||||
@ -91,40 +93,40 @@ Your identification has been saved with the new passphrase.
|
||||
$ ssh-copy-id sk@192.168.225.22
|
||||
```
|
||||
|
||||
在这，我把本地（Arch Linux）系统上的公钥拷贝到了远程系统（Ubuntu 18.04 LTS）上。从技术上讲，上面的命令会把本地系统 **~/.ssh/id_rsa.pub key** 文件中的内容拷贝到远程系统**~/.ssh/authorized_keys** 中。明白了吗？非常棒。
|
||||
在这里，我把本地（Arch Linux）系统上的公钥拷贝到了远程系统（Ubuntu 18.04 LTS）上。从技术上讲，上面的命令会把本地系统 `~/.ssh/id_rsa.pub` 文件中的内容拷贝到远程系统 `~/.ssh/authorized_keys` 中。明白了吗？非常棒。
|
||||
|
||||
输入 **yes** 来继续连接你的远程 SSH 服务端。接着，输入远程系统 root 用户的密码。
|
||||
输入 `yes` 来继续连接你的远程 SSH 服务端。接着，输入远程系统用户 `sk` 的密码。
|
||||
|
||||
```
|
||||
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
|
||||
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
|
||||
[email protected]2.168.225.22's password:
|
||||
sk@192.168.225.22's password:
|
||||
|
||||
Number of key(s) added: 1
|
||||
|
||||
Now try logging into the machine, with: "ssh '[email protected]'"
|
||||
Now try logging into the machine, with: "ssh 'sk@192.168.225.22'"
|
||||
and check to make sure that only the key(s) you wanted were added.
|
||||
```
|
||||
|
||||
如果你已经拷贝了密钥，但想要替换为新的密码，使用 **-f** 选项覆盖已有的密钥。
|
||||
如果你已经拷贝了密钥，但想要替换为新的密码，使用 `-f` 选项覆盖已有的密钥。
|
||||
|
||||
```
|
||||
$ ssh-copy-id -f sk@192.168.225.22
|
||||
```
|
||||
|
||||
我们现在已经成功地将本地系统的 SSH 公钥添加进了远程系统。现在，让我们在远程系统上完全禁用掉基于密码认证的方式。因为，我们已经配置了密钥认证，因此我们不再需要密码认证了。
|
||||
我们现在已经成功地将本地系统的 SSH 公钥添加进了远程系统。现在，让我们在远程系统上完全禁用掉基于密码认证的方式。因为我们已经配置了密钥认证，因此不再需要密码认证了。
|
||||
|
||||
### 在远程系统上禁用基于密码认证的 SSH
|
||||
|
||||
你需要在 root 或者 sudo 用户下执行下面的命令。
|
||||
你需要在 root 用户或者 `sudo` 执行下面的命令。
|
||||
|
||||
为了禁用基于密码的认证，你需要在远程系统的控制台上编辑 **/etc/ssh/sshd_config** 配置文件：
|
||||
禁用基于密码的认证，你需要在远程系统的终端里编辑 `/etc/ssh/sshd_config` 配置文件：
|
||||
|
||||
```
|
||||
$ sudo vi /etc/ssh/sshd_config
|
||||
```
|
||||
|
||||
找到下面这一行，去掉注释然后将值设为 **no**
|
||||
找到下面这一行，去掉注释然后将值设为 `no`：
|
||||
|
||||
```
|
||||
PasswordAuthentication no
|
||||
@ -146,19 +148,19 @@ $ ssh sk@192.168.225.22
|
||||
|
||||
输入密码。
|
||||
|
||||
**样例输出：**
|
||||
**样例输出**：
|
||||
|
||||
```
|
||||
Enter passphrase for key '/home/sk/.ssh/id_rsa':
|
||||
Last login: Mon Jul 9 09:59:51 2018 from 192.168.225.37
|
||||
[email protected]:~$
|
||||
sk@ubuntuserver:~$
|
||||
```
|
||||
|
||||
现在，你就能 SSH 你的远程系统了。如你所见，我们已经使用之前 **ssh-keygen** 创建的密码登录进了远程系统的账户，而不是使用账户实际的密码。
|
||||
现在，你就能 SSH 你的远程系统了。如你所见，我们已经使用之前 `ssh-keygen` 创建的密码登录进了远程系统的账户，而不是使用当前账户实际的密码。
|
||||
|
||||
如果你试图从其他客户端系统 ssh （远程系统），你将会得到这条错误信息。比如，我试图通过命令从 CentOS SSH 访问 Ubuntu 系统：
|
||||
如果你试图从其它客户端系统 ssh（远程系统），你将会得到这条错误信息。比如，我试图通过命令从 CentOS SSH 访问 Ubuntu 系统：
|
||||
|
||||
**样例输出:**
|
||||
**样例输出**：
|
||||
|
||||
```
|
||||
The authenticity of host '192.168.225.22 (192.168.225.22)' can't be established.
|
||||
@ -168,7 +170,7 @@ Warning: Permanently added '192.168.225.22' (ECDSA) to the list of known hosts.
|
||||
Permission denied (publickey).
|
||||
```
|
||||
|
||||
如你所见，除了 CentOS （译注：根据上文，这里应该是 Arch） 系统外，我不能通过其他任何系统 SSH 访问我的远程系统 Ubuntu 18.04。
|
||||
如你所见，除了 CentOS（LCTT 译注：根据上文，这里应该是 Arch）系统外，我不能通过其它任何系统 SSH 访问我的远程系统 Ubuntu 18.04。
|
||||
|
||||
### 为 SSH 服务端添加更多客户端系统的密钥
|
||||
|
||||
@ -180,21 +182,21 @@ Permission denied (publickey).
|
||||
$ ssh-keygen
|
||||
```
|
||||
|
||||
输入两次密码。现在， ssh 密钥对已经生成了。你需要手动把公钥（不是私钥）拷贝到远程服务端上。
|
||||
输入两次密码。现在，ssh 密钥对已经生成了。你需要手动把公钥（不是私钥）拷贝到远程服务端上。
|
||||
|
||||
使用命令查看公钥：
|
||||
使用以下命令查看公钥：
|
||||
|
||||
```
|
||||
$ cat ~/.ssh/id_rsa.pub
|
||||
```
|
||||
|
||||
应该会输出如下信息：
|
||||
应该会输出类似下面的信息：
|
||||
|
||||
```
|
||||
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCt3a9tIeK5rPx9p74/KjEVXa6/OODyRp0QLS/sLp8W6iTxFL+UgALZlupVNgFjvRR5luJ9dLHWwc+d4umavAWz708e6Na9ftEPQtC28rTFsHwmyLKvLkzcGkC5+A0NdbiDZLaK3K3wgq1jzYYKT5k+IaNS6vtrx5LDObcPNPEBDt4vTixQ7GZHrDUUk5586IKeFfwMCWguHveTN7ykmo2EyL2rV7TmYq+eY2ZqqcsoK0fzXMK7iifGXVmuqTkAmZLGZK8a3bPb6VZd7KFum3Ezbu4BXZGp7FVhnOMgau2kYeOH/ItKPzpCAn+dg3NAAziCCxnII9b4nSSGz3mMY4Y7 ostechnix@centosserver
|
||||
```
|
||||
|
||||
拷贝所有内容（通过 USB 驱动器或者其它任何介质），然后去你的远程服务端的控制台。像下面那样，在 home 下创建文件夹叫做 **ssh**。你需要以 root 身份执行命令。
|
||||
拷贝所有内容（通过 USB 驱动器或者其它任何介质），然后去你的远程服务端的终端，像下面那样，在 `$HOME` 下创建文件夹叫做 `.ssh`。你需要以 root 身份执行命令（注：不一定需要 root）。
|
||||
|
||||
```
|
||||
$ mkdir -p ~/.ssh
|
||||
@ -208,15 +210,16 @@ echo {Your_public_key_contents_here} >> ~/.ssh/authorized_keys
|
||||
|
||||
在远程系统上重启 ssh 服务。现在，你可以在新的客户端上 SSH 远程服务端了。
|
||||
|
||||
如果觉得手动添加 ssh 公钥有些困难，在远程系统上暂时性启用密码认证，使用 “ssh-copy-id“ 命令从本地系统上拷贝密钥，最后关闭密码认证。
|
||||
如果觉得手动添加 ssh 公钥有些困难，在远程系统上暂时性启用密码认证，使用 `ssh-copy-id` 命令从本地系统上拷贝密钥，最后禁用密码认证。
|
||||
|
||||
**推荐阅读：**
|
||||
|
||||
（译者注：在原文中此处有超链接）
|
||||
* [SSLH – Share A Same Port For HTTPS And SSH][1]
|
||||
* [ScanSSH – Fast SSH Server And Open Proxy Scanner][2]
|
||||
|
||||
好了，到此为止。基于密钥认证的 SSH 提供了一层防止暴力破解的额外保护。如你所见，配置密钥认证一点也不困难。这是一个非常好的方法让你的 Linux 服务端安全可靠。
|
||||
|
||||
不久我就会带来另一篇有用的文章。到那时，继续关注 OSTechNix。
|
||||
不久我会带来另一篇有用的文章。请继续关注 OSTechNix。
|
||||
|
||||
干杯！
|
||||
|
||||
@ -227,9 +230,10 @@ via: https://www.ostechnix.com/configure-ssh-key-based-authentication-linux/
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[LuuMing](https://github.com/LuuMing)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
校对：[pityonline](https://github.com/pityonline)
|
||||
|
||||
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]:https://www.ostechnix.com/cdn-cgi/l/email-protection
|
||||
[a]: https://www.ostechnix.com/author/sk/
|
||||
[1]: https://www.ostechnix.com/sslh-share-port-https-ssh/
|
||||
[2]: https://www.ostechnix.com/scanssh-fast-ssh-server-open-proxy-scanner/
|
||||
@ -0,0 +1,987 @@
|
||||
75 个最常用的 Linux 应用程序（2018 年）
|
||||
======
|
||||
|
||||
|
||||
|
||||
对于许多应用程序来说，2018 年是非常好的一年，尤其是自由开源的应用程序。尽管各种 Linux 发行版都自带了很多默认的应用程序，但用户也可以自由地选择使用它们或者其它任何免费或付费替代方案。
|
||||
|
||||
下面汇总了[一系列的 Linux 应用程序][3]，这些应用程序都能够在 Linux 系统上安装，尽管还有很多其它选择。以下汇总中的任何应用程序都属于其类别中最常用的应用程序，如果你还没有用过，欢迎试用一下！
|
||||
|
||||
### 备份工具
|
||||
|
||||
#### Rsync
|
||||
|
||||
[Rsync][4] 是一个开源的、节约带宽的工具，它用于执行快速的增量文件传输，而且它也是一个免费工具。
|
||||
|
||||
```
|
||||
$ rsync [OPTION...] SRC... [DEST]
|
||||
```
|
||||
|
||||
想要了解更多示例和用法，可以参考《[10 个使用 Rsync 命令的实际例子][5]》。
|
||||
|
||||
#### Timeshift
|
||||
|
||||
[Timeshift][6] 能够通过增量快照来保护用户的系统数据，而且可以按照日期恢复指定的快照，类似于 Mac OS 中的 Time Machine 功能和 Windows 中的系统还原功能。
|
||||
|
||||
|
||||
|
||||
### BT（BitTorrent） 客户端
|
||||
|
||||
|
||||
|
||||
#### Deluge
|
||||
|
||||
[Deluge][7] 是一个漂亮的跨平台 BT 客户端，旨在优化 μTorrent 体验，并向用户免费提供服务。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Deluge。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:deluge-team/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install deluge
|
||||
```
|
||||
|
||||
#### qBittorent
|
||||
|
||||
[qBittorent][8] 是一个开源的 BT 客户端，旨在提供类似 μTorrent 的免费替代方案。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 qBittorent。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:qbittorrent-team/qbittorrent-stable
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install qbittorrent
|
||||
```
|
||||
|
||||
#### Transmission
|
||||
|
||||
[Transmission][9] 是一个强大的 BT 客户端，它主要关注速度和易用性，一般在很多 Linux 发行版上都有预装。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Transmission。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:transmissionbt/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install transmission-gtk transmission-cli transmission-common transmission-daemon
|
||||
```
|
||||
|
||||
### 云存储
|
||||
|
||||
|
||||
|
||||
#### Dropbox
|
||||
|
||||
[Dropbox][10] 团队在今年早些时候给他们的云服务换了一个名字，也为客户提供了更好的性能和集成了更多应用程序。Dropbox 会向用户免费提供 2 GB 存储空间。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Dropbox。
|
||||
|
||||
```
|
||||
$ cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86" | tar xzf - [On 32-Bit]
|
||||
$ cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf - [On 64-Bit]
|
||||
$ ~/.dropbox-dist/dropboxd
|
||||
```
|
||||
|
||||
#### Google Drive
|
||||
|
||||
[Google Drive][11] 是 Google 提供的云服务解决方案，这已经是一个广为人知的服务了。与 Dropbox 一样，可以通过它在所有联网的设备上同步文件。它免费提供了 15 GB 存储空间，包括Gmail、Google 图片、Google 地图等服务。
|
||||
|
||||
参考阅读：[5 个适用于 Linux 的 Google Drive 客户端][12]
|
||||
|
||||
#### Mega
|
||||
|
||||
[Mega][13] 也是一个出色的云存储解决方案，它的亮点除了高度的安全性之外，还有为用户免费提供高达 50 GB 的免费存储空间。它使用端到端加密，以确保用户的数据安全，所以如果忘记了恢复密钥，用户自己也无法访问到存储的数据。
|
||||
|
||||
参考阅读：[在 Ubuntu 下载 Mega 云存储客户端][14]
|
||||
|
||||
### 命令行编辑器
|
||||
|
||||
|
||||
|
||||
#### Vim
|
||||
|
||||
[Vim][15] 是 vi 文本编辑器的开源克隆版本，它的主要目的是可以高度定制化并能够处理任何类型的文本。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Vim。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jonathonf/vim
|
||||
$ sudo apt update
|
||||
$ sudo apt install vim
|
||||
```
|
||||
|
||||
#### Emacs
|
||||
|
||||
[Emacs][16] 是一个高度可配置的文本编辑器，最流行的一个分支 GNU Emacs 是用 Lisp 和 C 编写的，它的最大特点是可以自文档化、可扩展和可自定义。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Emacs。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kelleyk/emacs
|
||||
$ sudo apt update
|
||||
$ sudo apt install emacs25
|
||||
```
|
||||
|
||||
#### Nano
|
||||
|
||||
[Nano][17] 是一款功能丰富的命令行文本编辑器，比较适合高级用户。它可以通过多个终端进行不同功能的操作。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Nano。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:n-muench/programs-ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install nano
|
||||
```
|
||||
|
||||
### 下载器
|
||||
|
||||
|
||||
|
||||
#### Aria2
|
||||
|
||||
[Aria2][18] 是一个开源的、轻量级的、多软件源和多协议的命令行下载器，它支持 Metalink、torrent、HTTP/HTTPS、SFTP 等多种协议。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Aria2。
|
||||
|
||||
```
|
||||
$ sudo apt-get install aria2
|
||||
```
|
||||
|
||||
#### uGet
|
||||
|
||||
[uGet][19] 已经成为 Linux 各种发行版中排名第一的开源下载器，它可以处理任何下载任务，包括多连接、队列、类目等。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 uGet。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:plushuang-tw/uget-stable
|
||||
$ sudo apt update
|
||||
$ sudo apt install uget
|
||||
```
|
||||
|
||||
#### XDM
|
||||
|
||||
[XDM][20]（Xtreme Download Manager）是一个使用 Java 编写的开源下载软件。和其它下载器一样，它可以结合队列、种子、浏览器使用，而且还带有视频采集器和智能调度器。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 XDM。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:noobslab/apps
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install xdman
|
||||
```
|
||||
|
||||
### 电子邮件客户端
|
||||
|
||||
|
||||
|
||||
#### Thunderbird
|
||||
|
||||
[Thunderbird][21] 是最受欢迎的电子邮件客户端之一。它的优点包括免费、开源、可定制、功能丰富，而且最重要的是安装过程也很简便。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Thunderbird。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install thunderbird
|
||||
```
|
||||
|
||||
#### Geary
|
||||
|
||||
[Geary][22] 是一个基于 WebKitGTK+ 的开源电子邮件客户端。它是一个免费开源的功能丰富的软件，并被 GNOME 项目收录。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Geary。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:geary-team/releases
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install geary
|
||||
```
|
||||
|
||||
#### Evolution
|
||||
|
||||
[Evolution][23] 是一个免费开源的电子邮件客户端，可以用于电子邮件、会议日程、备忘录和联系人的管理。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Evolution。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:gnome3-team/gnome3-staging
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install evolution
|
||||
```
|
||||
|
||||
### 财务软件
|
||||
|
||||
|
||||
|
||||
#### GnuCash
|
||||
|
||||
[GnuCash][24] 是一款免费的跨平台开源软件，它适用于个人和中小型企业的财务任务。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 GnuCash。
|
||||
|
||||
```
|
||||
$ sudo sh -c 'echo "deb http://archive.getdeb.net/ubuntu $(lsb_release -sc)-getdeb apps" >> /etc/apt/sources.list.d/getdeb.list'
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gnucash
|
||||
```
|
||||
|
||||
#### KMyMoney
|
||||
|
||||
[KMyMoney][25] 是一个财务管理软件，它可以提供商用或个人理财所需的大部分主要功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 KmyMoney。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:claydoh/kmymoney2-kde4
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install kmymoney
|
||||
```
|
||||
|
||||
### IDE
|
||||
|
||||
|
||||
|
||||
#### Eclipse IDE
|
||||
|
||||
[Eclipse][26] 是最广为使用的 Java IDE，它包括一个基本工作空间和一个用于自定义编程环境的强大的的插件配置系统。
|
||||
|
||||
关于 Eclipse IDE 的安装，可以参考 [如何在 Debian 和 Ubuntu 上安装 Eclipse IDE][27] 这一篇文章。
|
||||
|
||||
#### Netbeans IDE
|
||||
|
||||
[Netbeans][28] 是一个相当受用户欢迎的 IDE，它支持使用 Java、PHP、HTML 5、JavaScript、C/C++ 或其他语言编写移动应用，桌面软件和 web 应用。
|
||||
|
||||
关于 Netbeans IDE 的安装，可以参考 [如何在 Debian 和 Ubuntu 上安装 Netbeans IDE][29] 这一篇文章。
|
||||
|
||||
#### Brackets
|
||||
|
||||
[Brackets][30] 是由 Adobe 开发的高级文本编辑器，它带有可视化工具，支持预处理程序，以及用于 web 开发的以设计为中心的用户流程。对于熟悉它的用户，它可以发挥 IDE 的作用。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Brackets。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:webupd8team/brackets
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install brackets
|
||||
```
|
||||
|
||||
#### Atom IDE
|
||||
|
||||
[Atom IDE][31] 是一个加强版的 Atom 编辑器，它添加了大量扩展和库以提高性能和增加功能。总之，它是各方面都变得更强大了的 Atom 。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Atom。
|
||||
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install atom --classic
|
||||
```
|
||||
|
||||
#### Light Table
|
||||
|
||||
[Light Table][32] 号称下一代的 IDE，它提供了数据流量统计和协作编程等的强大功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Light Table。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:dr-akulavich/lighttable
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install lighttable-installer
|
||||
```
|
||||
|
||||
#### Visual Studio Code
|
||||
|
||||
[Visual Studio Code][33] 是由微软开发的代码编辑器，它包含了文本编辑器所需要的最先进的功能，包括语法高亮、自动完成、代码调试、性能统计和图表显示等功能。
|
||||
|
||||
参考阅读：[在Ubuntu 下载 Visual Studio Code][34]
|
||||
|
||||
### 即时通信工具
|
||||
|
||||
|
||||
|
||||
#### Pidgin
|
||||
|
||||
[Pidgin][35] 是一个开源的即时通信工具，它几乎支持所有聊天平台，还支持额外扩展功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Pidgin。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jonathonf/backports
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install pidgin
|
||||
```
|
||||
|
||||
#### Skype
|
||||
|
||||
[Skype][36] 也是一个广为人知的软件了，任何感兴趣的用户都可以在 Linux 上使用。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Skype。
|
||||
|
||||
```
|
||||
$ sudo apt install snapd
|
||||
$ sudo snap install skype --classic
|
||||
```
|
||||
|
||||
#### Empathy
|
||||
|
||||
[Empathy][37] 是一个支持多协议语音、视频聊天、文本和文件传输的即时通信工具。它还允许用户添加多个服务的帐户，并用其与所有服务的帐户进行交互。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Empathy。
|
||||
|
||||
```
|
||||
$ sudo apt-get install empathy
|
||||
```
|
||||
|
||||
### Linux 防病毒工具
|
||||
|
||||
#### ClamAV/ClamTk
|
||||
|
||||
[ClamAV][38] 是一个开源的跨平台命令行防病毒工具，用于检测木马、病毒和其他恶意代码。而 [ClamTk][39] 则是它的前端 GUI。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 ClamAV 和 ClamTk。
|
||||
|
||||
```
|
||||
$ sudo apt-get install clamav
|
||||
$ sudo apt-get install clamtk
|
||||
```
|
||||
|
||||
### Linux 桌面环境
|
||||
|
||||
#### Cinnamon
|
||||
|
||||
[Cinnamon][40] 是 GNOME 3 的自由开源衍生产品，它遵循传统的 <ruby>桌面比拟<rt>desktop metaphor</rt></ruby> 约定。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Cinnamon。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:embrosyn/cinnamon
|
||||
$ sudo apt update
|
||||
$ sudo apt install cinnamon-desktop-environment lightdm
|
||||
```
|
||||
|
||||
#### Mate
|
||||
|
||||
[Mate][41] 桌面环境是 GNOME 2 的衍生和延续，目的是在 Linux 上通过使用传统的桌面比拟提供有一个吸引力的 UI。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Mate。
|
||||
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install ubuntu-mate-desktop
|
||||
```
|
||||
|
||||
#### GNOME
|
||||
|
||||
[GNOME][42] 是由一些免费和开源应用程序组成的桌面环境，它可以运行在任何 Linux 发行版和大多数 BSD 衍生版本上。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Gnome。
|
||||
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install ubuntu-desktop
|
||||
```
|
||||
|
||||
#### KDE
|
||||
|
||||
[KDE][43] 由 KDE 社区开发，它为用户提供图形解决方案以控制操作系统并执行不同的计算任务。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 KDE。
|
||||
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install kubuntu-desktop
|
||||
```
|
||||
|
||||
### Linux 维护工具
|
||||
|
||||
#### GNOME Tweak Tool
|
||||
|
||||
[GNOME Tweak Tool][44] 是用于自定义和调整 GNOME 3 和 GNOME Shell 设置的流行工具。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 GNOME Tweak Tool。
|
||||
|
||||
```
|
||||
$ sudo apt install gnome-tweak-tool
|
||||
```
|
||||
|
||||
#### Stacer
|
||||
|
||||
[Stacer][45] 是一款用于监控和优化 Linux 系统的免费开源应用程序。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Stacer。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:oguzhaninan/stacer
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install stacer
|
||||
```
|
||||
|
||||
#### BleachBit
|
||||
|
||||
[BleachBit][46] 是一个免费的磁盘空间清理器，它也可用作隐私管理器和系统优化器。
|
||||
|
||||
参考阅读：[在 Ubuntu 下载 BleachBit][47]
|
||||
|
||||
### Linux 终端工具
|
||||
|
||||
#### GNOME 终端
|
||||
|
||||
[GNOME 终端][48] 是 GNOME 的默认终端模拟器。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Gnome 终端。
|
||||
|
||||
```
|
||||
$ sudo apt-get install gnome-terminal
|
||||
```
|
||||
|
||||
#### Konsole
|
||||
|
||||
[Konsole][49] 是 KDE 的一个终端模拟器。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Konsole。
|
||||
|
||||
```
|
||||
$ sudo apt-get install konsole
|
||||
```
|
||||
|
||||
#### Terminator
|
||||
|
||||
[Terminator][50] 是一个功能丰富的终端程序，它基于 GNOME 终端，并且专注于整理终端功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Terminator。
|
||||
|
||||
```
|
||||
$ sudo apt-get install terminator
|
||||
```
|
||||
|
||||
#### Guake
|
||||
|
||||
[Guake][51] 是 GNOME 桌面环境下一个轻量级的可下拉式终端。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Guake。
|
||||
|
||||
```
|
||||
$ sudo apt-get install guake
|
||||
```
|
||||
|
||||
### 多媒体编辑工具
|
||||
|
||||
#### Ardour
|
||||
|
||||
[Ardour][52] 是一款漂亮的的<ruby>数字音频工作站<rt>Digital Audio Workstation</rt></ruby>，可以完成专业的录制、编辑和混音工作。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Ardour。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:dobey/audiotools
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install ardour
|
||||
```
|
||||
|
||||
#### Audacity
|
||||
|
||||
[Audacity][53] 是最著名的音频编辑软件之一，它是一款跨平台的开源多轨音频编辑器。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Audacity。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:ubuntuhandbook1/audacity
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install audacity
|
||||
```
|
||||
|
||||
#### GIMP
|
||||
|
||||
[GIMP][54] 是 Photoshop 的开源替代品中最受欢迎的。这是因为它有多种可自定义的选项、第三方插件以及活跃的用户社区。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Gimp。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:otto-kesselgulasch/gimp
|
||||
$ sudo apt update
|
||||
$ sudo apt install gimp
|
||||
```
|
||||
|
||||
#### Krita
|
||||
|
||||
[Krita][55] 是一款开源的绘画程序，它具有美观的 UI 和可靠的性能，也可以用作图像处理工具。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Krita。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kritalime/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install krita
|
||||
```
|
||||
|
||||
#### Lightworks
|
||||
|
||||
[Lightworks][56] 是一款功能强大、灵活美观的专业视频编辑工具。它拥有上百种配套的视觉效果功能，可以处理任何编辑任务，毕竟这个软件已经有长达 25 年的视频处理经验。
|
||||
|
||||
参考阅读：[在 Ubuntu 下载 Lightworks][57]
|
||||
|
||||
#### OpenShot
|
||||
|
||||
[OpenShot][58] 是一款屡获殊荣的免费开源视频编辑器，这主要得益于其出色的性能和强大的功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 `Openshot。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:openshot.developers/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install openshot-qt
|
||||
```
|
||||
|
||||
#### PiTiV
|
||||
|
||||
[Pitivi][59] 也是一个美观的视频编辑器，它有优美的代码库、优质的社区，还支持优秀的协作编辑功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 PiTiV。
|
||||
|
||||
```
|
||||
$ flatpak install --user https://flathub.org/repo/appstream/org.pitivi.Pitivi.flatpakref
|
||||
$ flatpak install --user http://flatpak.pitivi.org/pitivi.flatpakref
|
||||
$ flatpak run org.pitivi.Pitivi//stable
|
||||
```
|
||||
|
||||
### 音乐播放器
|
||||
|
||||
#### Rhythmbox
|
||||
|
||||
[Rhythmbox][60] 支持海量种类的音乐，目前被认为是最可靠的音乐播放器，并由 Ubuntu 自带。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Rhythmbox。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:fossfreedom/rhythmbox
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install rhythmbox
|
||||
```
|
||||
|
||||
#### Lollypop
|
||||
|
||||
[Lollypop][61] 是一款较为年轻的开源音乐播放器，它有很多高级选项，包括网络电台，滑动播放和派对模式。尽管功能繁多，它仍然尽量做到简单易管理。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Lollypop。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:gnumdk/lollypop
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install lollypop
|
||||
```
|
||||
|
||||
#### Amarok
|
||||
|
||||
[Amarok][62] 是一款功能强大的音乐播放器，它有一个直观的 UI 和大量的高级功能，而且允许用户根据自己的偏好去发现新音乐。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Amarok。
|
||||
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install amarok
|
||||
|
||||
```
|
||||
|
||||
#### Clementine
|
||||
|
||||
[Clementine][63] 是一款 Amarok 风格的音乐播放器，因此和 Amarok 相似，也有直观的用户界面、先进的控制模块，以及让用户搜索和发现新音乐的功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Clementine。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:me-davidsansome/clementine
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install clementine
|
||||
```
|
||||
|
||||
#### Cmus
|
||||
|
||||
[Cmus][64] 可以说是最高效的的命令行界面音乐播放器了，它具有快速可靠的特点，也支持使用扩展。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Cmus。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jmuc/cmus
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install cmus
|
||||
```
|
||||
|
||||
### 办公软件
|
||||
|
||||
#### Calligra 套件
|
||||
|
||||
[Calligra 套件][65]为用户提供了一套总共 8 个应用程序，涵盖办公、管理、图表等各个范畴。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Calligra 套件。
|
||||
|
||||
```
|
||||
$ sudo apt-get install calligra
|
||||
```
|
||||
|
||||
#### LibreOffice
|
||||
|
||||
[LibreOffice][66] 是开源社区中开发过程最活跃的办公套件，它以可靠性著称，也可以通过扩展来添加功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 LibreOffice。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:libreoffice/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install libreoffice
|
||||
```
|
||||
|
||||
#### WPS Office
|
||||
|
||||
[WPS Office][67] 是一款漂亮的办公套件，它有一个很具现代感的 UI。
|
||||
|
||||
参考阅读：[在 Ubuntu 安装 WPS Office][68]
|
||||
|
||||
### 屏幕截图工具
|
||||
|
||||
#### Shutter
|
||||
|
||||
[Shutter][69] 允许用户截取桌面的屏幕截图，然后使用一些效果进行编辑，还支持上传和在线共享。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Shutter。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository -y ppa:shutter/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install shutter
|
||||
```
|
||||
|
||||
#### Kazam
|
||||
|
||||
[Kazam][70] 可以用于捕获屏幕截图，它的输出对于任何支持 VP8/WebM 和 PulseAudio 视频播放器都可用。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Kazam。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kazam-team/unstable-series
|
||||
$ sudo apt update
|
||||
$ sudo apt install kazam python3-cairo python3-xlib
|
||||
```
|
||||
|
||||
#### Gnome Screenshot
|
||||
|
||||
[Gnome Screenshot][71] 过去曾经和 Gnome 一起捆绑，但现在已经独立出来。它以易于共享的格式进行截屏。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Gnome Screenshot。
|
||||
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gnome-screenshot
|
||||
```
|
||||
|
||||
### 录屏工具
|
||||
|
||||
#### SimpleScreenRecorder
|
||||
|
||||
[SimpleScreenRecorder][72] 面世时已经是录屏工具中的佼佼者，现在已成为 Linux 各个发行版中最有效、最易用的录屏工具之一。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 SimpleScreenRecorder。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install simplescreenrecorder
|
||||
```
|
||||
|
||||
#### recordMyDesktop
|
||||
|
||||
[recordMyDesktop][73] 是一个开源的会话记录器，它也能记录桌面会话的音频。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 recordMyDesktop。
|
||||
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gtk-recordmydesktop
|
||||
```
|
||||
|
||||
### 文本编辑器
|
||||
|
||||
#### Atom
|
||||
|
||||
[Atom][74] 是由 GitHub 开发和维护的可定制文本编辑器。它是开箱即用的，但也可以使用扩展和主题自定义 UI 来增强其功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Atom。
|
||||
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install atom --classic
|
||||
```
|
||||
|
||||
#### Sublime Text
|
||||
|
||||
[Sublime Text][75] 已经成为目前最棒的文本编辑器。它可定制、轻量灵活（即使打开了大量数据文件和加入了大量扩展），最重要的是可以永久免费使用。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Sublime Text。
|
||||
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install sublime-text
|
||||
```
|
||||
|
||||
#### Geany
|
||||
|
||||
[Geany][76] 是一个内存友好的文本编辑器，它具有基本的IDE功能，可以显示加载时间、扩展库函数等。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Geany。
|
||||
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install geany
|
||||
```
|
||||
|
||||
#### Gedit
|
||||
|
||||
[Gedit][77] 以其简单著称，在很多 Linux 发行版都有预装，它具有文本编辑器都具有的优秀的功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Gedit。
|
||||
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gedit
|
||||
```
|
||||
|
||||
### 备忘录软件
|
||||
|
||||
#### Evernote
|
||||
|
||||
[Evernote][78] 是一款云上的笔记程序，它带有待办列表和提醒功能，能够与不同类型的笔记完美配合。
|
||||
|
||||
Evernote 在 Linux 上没有官方提供的软件，但可以参考 [Linux 上的 6 个 Evernote 替代客户端][79] 这篇文章使用其它第三方工具。
|
||||
|
||||
#### Everdo
|
||||
|
||||
[Everdo][78] 是一款美观，安全，易兼容的备忘软件，可以用于处理待办事项和其它笔记。如果你认为 Evernote 有所不足，相信 Everdo 会是一个好的替代。
|
||||
|
||||
参考阅读：[在 Ubuntu 下载 Everdo][80]
|
||||
|
||||
#### Taskwarrior
|
||||
|
||||
[Taskwarrior][81] 是一个用于管理个人任务的开源跨平台命令行应用，它的速度和无干扰的环境是它的两大特点。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Taskwarrior。
|
||||
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install taskwarrior
|
||||
```
|
||||
|
||||
### 视频播放器
|
||||
|
||||
#### Banshee
|
||||
|
||||
[Banshee][82] 是一个开源的支持多格式的媒体播放器，于 2005 年开始开发并逐渐成长。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Banshee。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:banshee-team/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install banshee
|
||||
```
|
||||
|
||||
#### VLC
|
||||
|
||||
[VLC][83] 是我最喜欢的视频播放器，它几乎可以播放任何格式的音频和视频，它还可以播放网络电台、录制桌面会话以及在线播放电影。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 VLC。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:videolan/stable-daily
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install vlc
|
||||
```
|
||||
|
||||
#### Kodi
|
||||
|
||||
[Kodi][84] 是世界上最着名的媒体播放器之一，它有一个成熟的媒体中心，可以播放本地和远程的多媒体文件。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Kodi。
|
||||
|
||||
```
|
||||
$ sudo apt-get install software-properties-common
|
||||
$ sudo add-apt-repository ppa:team-xbmc/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install kodi
|
||||
```
|
||||
|
||||
#### SMPlayer
|
||||
|
||||
[SMPlayer][85] 是 MPlayer 的 GUI 版本，所有流行的媒体格式它都能够处理，并且它还有从 YouTube 和 Chromcast 和下载字幕的功能。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 SMPlayer。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:rvm/smplayer
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install smplayer
|
||||
```
|
||||
|
||||
### 虚拟化工具
|
||||
|
||||
#### VirtualBox
|
||||
|
||||
[VirtualBox][86] 是一个用于操作系统虚拟化的开源应用程序，在服务器、台式机和嵌入式系统上都可以运行。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 VirtualBox。
|
||||
|
||||
```
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install virtualbox-5.2
|
||||
$ virtualbox
|
||||
```
|
||||
|
||||
#### VMWare
|
||||
|
||||
[VMware][87] 是一个为客户提供平台虚拟化和云计算服务的数字工作区，是第一个成功将 x86 架构系统虚拟化的工作站。 VMware 工作站的其中一个产品就允许用户在虚拟内存中运行多个操作系统。
|
||||
|
||||
参阅 [在 Ubuntu 上安装 VMWare Workstation Pro][88] 可以了解 VMWare 的安装。
|
||||
|
||||
### 浏览器
|
||||
|
||||
#### Chrome
|
||||
|
||||
[Google Chrome][89] 无疑是最受欢迎的浏览器。Chrome 以其速度、简洁、安全、美观而受人喜爱，它遵循了 Google 的界面设计风格，是 web 开发人员不可缺少的浏览器，同时它也是免费开源的。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Google Chrome。
|
||||
|
||||
```
|
||||
$ wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
|
||||
$ sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install google-chrome-stable
|
||||
```
|
||||
|
||||
#### Firefox
|
||||
|
||||
[Firefox Quantum][90] 是一款漂亮、快速、完善并且可自定义的浏览器。它也是自由开源的，包含有开发人员所需要的工具，对于初学者也没有任何使用门槛。
|
||||
|
||||
使用以下命令在 Ubuntu 和 Debian 安装 Firefox Quantum。
|
||||
|
||||
```
|
||||
$ sudo add-apt-repository ppa:mozillateam/firefox-next
|
||||
$ sudo apt update && sudo apt upgrade
|
||||
$ sudo apt install firefox
|
||||
```
|
||||
|
||||
#### Vivaldi
|
||||
|
||||
[Vivaldi][91] 是一个基于 Chrome 的自由开源项目，旨在通过添加扩展来使 Chrome 的功能更加完善。色彩丰富的界面，性能良好、灵活性强是它的几大特点。
|
||||
|
||||
参考阅读：[在 Ubuntu 下载 Vivaldi][91]
|
||||
|
||||
以上就是我的推荐，你还有更好的软件向大家分享吗？欢迎评论。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.fossmint.com/most-used-linux-applications/
|
||||
|
||||
作者：[Martins D. Okoi][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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.fossmint.com/author/dillivine/
|
||||
[1]:https://plus.google.com/share?url=https://www.fossmint.com/most-used-linux-applications/ "Share on Google+"
|
||||
[2]:https://www.linkedin.com/shareArticle?mini=true&url=https://www.fossmint.com/most-used-linux-applications/ "Share on LinkedIn"
|
||||
[3]:https://www.fossmint.com/awesome-linux-software/
|
||||
[4]:https://rsync.samba.org/
|
||||
[5]:https://www.tecmint.com/rsync-local-remote-file-synchronization-commands/
|
||||
[6]:https://github.com/teejee2008/timeshift
|
||||
[7]:https://deluge-torrent.org/
|
||||
[8]:https://www.qbittorrent.org/
|
||||
[9]:https://transmissionbt.com/
|
||||
[10]:https://www.dropbox.com/
|
||||
[11]:https://www.google.com/drive/
|
||||
[12]:https://www.fossmint.com/best-google-drive-clients-for-linux/
|
||||
[13]:https://mega.nz/
|
||||
[14]:https://mega.nz/sync!linux
|
||||
[15]:https://www.vim.org/
|
||||
[16]:https://www.gnu.org/s/emacs/
|
||||
[17]:https://www.nano-editor.org/
|
||||
[18]:https://aria2.github.io/
|
||||
[19]:http://ugetdm.com/
|
||||
[20]:http://xdman.sourceforge.net/
|
||||
[21]:https://www.thunderbird.net/
|
||||
[22]:https://github.com/GNOME/geary
|
||||
[23]:https://github.com/GNOME/evolution
|
||||
[24]:https://www.gnucash.org/
|
||||
[25]:https://kmymoney.org/
|
||||
[26]:https://www.eclipse.org/ide/
|
||||
[27]:https://www.tecmint.com/install-eclipse-oxygen-ide-in-ubuntu-debian/
|
||||
[28]:https://netbeans.org/
|
||||
[29]:https://www.tecmint.com/install-netbeans-ide-in-ubuntu-debian-linux-mint/
|
||||
[30]:http://brackets.io/
|
||||
[31]:https://ide.atom.io/
|
||||
[32]:http://lighttable.com/
|
||||
[33]:https://code.visualstudio.com/
|
||||
[34]:https://code.visualstudio.com/download
|
||||
[35]:https://www.pidgin.im/
|
||||
[36]:https://www.skype.com/
|
||||
[37]:https://wiki.gnome.org/Apps/Empathy
|
||||
[38]:https://www.clamav.net/
|
||||
[39]:https://dave-theunsub.github.io/clamtk/
|
||||
[40]:https://github.com/linuxmint/cinnamon-desktop
|
||||
[41]:https://mate-desktop.org/
|
||||
[42]:https://www.gnome.org/
|
||||
[43]:https://www.kde.org/plasma-desktop
|
||||
[44]:https://github.com/nzjrs/gnome-tweak-tool
|
||||
[45]:https://github.com/oguzhaninan/Stacer
|
||||
[46]:https://www.bleachbit.org/
|
||||
[47]:https://www.bleachbit.org/download
|
||||
[48]:https://github.com/GNOME/gnome-terminal
|
||||
[49]:https://konsole.kde.org/
|
||||
[50]:https://gnometerminator.blogspot.com/p/introduction.html
|
||||
[51]:http://guake-project.org/
|
||||
[52]:https://ardour.org/
|
||||
[53]:https://www.audacityteam.org/
|
||||
[54]:https://www.gimp.org/
|
||||
[55]:https://krita.org/en/
|
||||
[56]:https://www.lwks.com/
|
||||
[57]:https://www.lwks.com/index.php?option=com_lwks&view=download&Itemid=206
|
||||
[58]:https://www.openshot.org/
|
||||
[59]:http://www.pitivi.org/
|
||||
[60]:https://wiki.gnome.org/Apps/Rhythmbox
|
||||
[61]:https://gnumdk.github.io/lollypop-web/
|
||||
[62]:https://amarok.kde.org/en
|
||||
[63]:https://www.clementine-player.org/
|
||||
[64]:https://cmus.github.io/
|
||||
[65]:https://www.calligra.org/tour/calligra-suite/
|
||||
[66]:https://www.libreoffice.org/
|
||||
[67]:https://www.wps.com/
|
||||
[68]:http://wps-community.org/downloads
|
||||
[69]:http://shutter-project.org/
|
||||
[70]:https://launchpad.net/kazam
|
||||
[71]:https://gitlab.gnome.org/GNOME/gnome-screenshot
|
||||
[72]:http://www.maartenbaert.be/simplescreenrecorder/
|
||||
[73]:http://recordmydesktop.sourceforge.net/about.php
|
||||
[74]:https://atom.io/
|
||||
[75]:https://www.sublimetext.com/
|
||||
[76]:https://www.geany.org/
|
||||
[77]:https://wiki.gnome.org/Apps/Gedit
|
||||
[78]:https://everdo.net/
|
||||
[79]:https://www.fossmint.com/evernote-alternatives-for-linux/
|
||||
[80]:https://everdo.net/linux/
|
||||
[81]:https://taskwarrior.org/
|
||||
[82]:http://banshee.fm/
|
||||
[83]:https://www.videolan.org/
|
||||
[84]:https://kodi.tv/
|
||||
[85]:https://www.smplayer.info/
|
||||
[86]:https://www.virtualbox.org/wiki/VirtualBox
|
||||
[87]:https://www.vmware.com/
|
||||
[88]:https://www.tecmint.com/install-vmware-workstation-in-linux/
|
||||
[89]:https://www.google.com/chrome/
|
||||
[90]:https://www.mozilla.org/en-US/firefox/
|
||||
[91]:https://vivaldi.com/
|
||||
|
||||
@ -0,0 +1,211 @@
|
||||
树莓派自建 NAS 云盘之——树莓派搭建网络存储盘
|
||||
======
|
||||
> 跟随这些逐步指导构建你自己的基于树莓派的 NAS 系统。
|
||||
|
||||
|
||||
|
||||
我将在接下来的这三篇文章中讲述如何搭建一个简便、实用的 NAS 云盘系统。我在这个中心化的存储系统中存储数据，并且让它每晚都会自动的备份增量数据。本系列文章将利用 NFS 文件系统将磁盘挂载到同一网络下的不同设备上，使用 [Nextcloud][1] 来离线访问数据、分享数据。
|
||||
|
||||
本文主要讲述将数据盘挂载到远程设备上的软硬件步骤。本系列第二篇文章将讨论数据备份策略、如何添加定时备份数据任务。最后一篇文章中我们将会安装 Nextcloud 软件，用户通过 Nextcloud 提供的 web 界面可以方便的离线或在线访问数据。本系列教程最终搭建的 NAS 云盘支持多用户操作、文件共享等功能，所以你可以通过它方便的分享数据，比如说你可以发送一个加密链接，跟朋友分享你的照片等等。
|
||||
|
||||
最终的系统架构如下图所示：
|
||||
|
||||
|
||||
|
||||
|
||||
### 硬件
|
||||
|
||||
首先需要准备硬件。本文所列方案只是其中一种示例，你也可以按不同的硬件方案进行采购。
|
||||
|
||||
最主要的就是[树莓派 3][2]，它带有四核 CPU、1G RAM，以及（比较）快速的网络接口。数据将存储在两个 USB 磁盘驱动器上（这里使用 1TB 磁盘）；其中一个磁盘用于每天数据存储，另一个用于数据备份。请务必使用有源 USB 磁盘驱动器或者带附加电源的 USB 集线器，因为树莓派无法为两个 USB 磁盘驱动器供电。
|
||||
|
||||
### 软件
|
||||
|
||||
在该社区中最活跃的操作系统当属 [Raspbian][3]，便于定制个性化项目。已经有很多 [操作指南][4] 讲述如何在树莓派中安装 Raspbian 系统，所以这里不再赘述。在撰写本文时，最新的官方支持版本是 [Raspbian Stretch][5]，它对我来说很好使用。
|
||||
|
||||
到此，我将假设你已经配置好了基本的 Raspbian 系统并且可以通过 `ssh` 访问到你的树莓派。
|
||||
|
||||
### 准备 USB 磁盘驱动器
|
||||
|
||||
为了更好地读写数据，我建议使用 ext4 文件系统去格式化磁盘。首先，你必须先找到连接到树莓派的磁盘。你可以在 `/dev/sd/<x>` 中找到磁盘设备。使用命令 `fdisk -l`，你可以找到刚刚连接的两块 USB 磁盘驱动器。请注意，操作下面的步骤将会清除 USB 磁盘驱动器上的所有数据，请做好备份。
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo fdisk -l
|
||||
|
||||
<...>
|
||||
|
||||
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 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: 0xe8900690
|
||||
|
||||
Device Boot Start End Sectors Size Id Type
|
||||
/dev/sda1 2048 1953525167 1953523120 931.5G 83 Linux
|
||||
|
||||
|
||||
Disk /dev/sdb: 931.5 GiB, 1000204886016 bytes, 1953525168 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: 0x6aa4f598
|
||||
|
||||
Device Boot Start End Sectors Size Id Type
|
||||
/dev/sdb1 * 2048 1953521663 1953519616 931.5G 83 Linux
|
||||
|
||||
```
|
||||
|
||||
由于这些设备是连接到树莓派的唯一的 1TB 的磁盘，所以我们可以很容易的辨别出 `/dev/sda` 和 `/dev/sdb` 就是那两个 USB 磁盘驱动器。每个磁盘末尾的分区表提示了在执行以下的步骤后如何查看，这些步骤将会格式化磁盘并创建分区表。为每个 USB 磁盘驱动器按以下步骤进行操作（假设你的磁盘也是 `/dev/sda` 和 `/dev/sdb`，第二次操作你只要替换命令中的 `sda` 为 `sdb` 即可）。
|
||||
|
||||
首先，删除磁盘分区表，创建一个新的并且只包含一个分区的新分区表。在 `fdisk` 中，你可以使用交互单字母命令来告诉程序你想要执行的操作。只需要在提示符 `Command(m for help):` 后输入相应的字母即可（可以使用 `m` 命令获得更多详细信息）：
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo fdisk /dev/sda
|
||||
|
||||
Welcome to fdisk (util-linux 2.29.2).
|
||||
Changes will remain in memory only, until you decide to write them.
|
||||
Be careful before using the write command.
|
||||
|
||||
|
||||
Command (m for help): o
|
||||
Created a new DOS disklabel with disk identifier 0x9c310964.
|
||||
|
||||
Command (m for help): n
|
||||
Partition type
|
||||
p primary (0 primary, 0 extended, 4 free)
|
||||
e extended (container for logical partitions)
|
||||
Select (default p): p
|
||||
Partition number (1-4, default 1):
|
||||
First sector (2048-1953525167, default 2048):
|
||||
Last sector, +sectors or +size{K,M,G,T,P} (2048-1953525167, default 1953525167):
|
||||
|
||||
Created a new partition 1 of type 'Linux' and of size 931.5 GiB.
|
||||
|
||||
Command (m for help): p
|
||||
|
||||
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 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: 0x9c310964
|
||||
|
||||
Device Boot Start End Sectors Size Id Type
|
||||
/dev/sda1 2048 1953525167 1953523120 931.5G 83 Linux
|
||||
|
||||
Command (m for help): w
|
||||
The partition table has been altered.
|
||||
Syncing disks.
|
||||
```
|
||||
|
||||
现在，我们将用 ext4 文件系统格式化新创建的分区 `/dev/sda1`：
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo mkfs.ext4 /dev/sda1
|
||||
mke2fs 1.43.4 (31-Jan-2017)
|
||||
Discarding device blocks: done
|
||||
|
||||
<...>
|
||||
|
||||
Allocating group tables: done
|
||||
Writing inode tables: done
|
||||
Creating journal (1024 blocks): done
|
||||
Writing superblocks and filesystem accounting information: done
|
||||
```
|
||||
|
||||
重复以上步骤后，让我们根据用途来对它们建立标签：
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo e2label /dev/sda1 data
|
||||
pi@raspberrypi:~ $ sudo e2label /dev/sdb1 backup
|
||||
```
|
||||
|
||||
现在，让我们安装这些磁盘并存储一些数据。以我运营该系统超过一年的经验来看，当树莓派启动时（例如在断电后），USB 磁盘驱动器并不是总被挂载，因此我建议使用 autofs 在需要的时候进行挂载。
|
||||
|
||||
首先，安装 autofs 并创建挂载点：
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo apt install autofs
|
||||
pi@raspberrypi:~ $ sudo mkdir /nas
|
||||
```
|
||||
|
||||
然后添加下面这行来挂载设备 `/etc/auto.master`：
|
||||
|
||||
```
|
||||
/nas /etc/auto.usb
|
||||
```
|
||||
|
||||
如果不存在以下内容，则创建 `/etc/auto.usb`，然后重新启动 autofs 服务：
|
||||
|
||||
```
|
||||
data -fstype=ext4,rw :/dev/disk/by-label/data
|
||||
backup -fstype=ext4,rw :/dev/disk/by-label/backup
|
||||
pi@raspberrypi3:~ $ sudo service autofs restart
|
||||
```
|
||||
|
||||
现在你应该可以分别访问 `/nas/data` 以及 `/nas/backup` 磁盘了。显然，到此还不会令人太兴奋，因为你只是擦除了磁盘中的数据。不过，你可以执行以下命令来确认设备是否已经挂载成功：
|
||||
|
||||
```
|
||||
pi@raspberrypi3:~ $ cd /nas/data
|
||||
pi@raspberrypi3:/nas/data $ cd /nas/backup
|
||||
pi@raspberrypi3:/nas/backup $ mount
|
||||
<...>
|
||||
/etc/auto.usb on /nas type autofs (rw,relatime,fd=6,pgrp=463,timeout=300,minproto=5,maxproto=5,indirect)
|
||||
<...>
|
||||
/dev/sda1 on /nas/data type ext4 (rw,relatime,data=ordered)
|
||||
/dev/sdb1 on /nas/backup type ext4 (rw,relatime,data=ordered)
|
||||
```
|
||||
|
||||
首先进入对应目录以确保 autofs 能够挂载设备。autofs 会跟踪文件系统的访问记录，并随时挂载所需要的设备。然后 `mount` 命令会显示这两个 USB 磁盘驱动器已经挂载到我们想要的位置了。
|
||||
|
||||
设置 autofs 的过程容易出错，如果第一次尝试失败，请不要沮丧。你可以上网搜索有关教程。
|
||||
|
||||
### 挂载网络存储
|
||||
|
||||
现在你已经设置了基本的网络存储，我们希望将它安装到远程 Linux 机器上。这里使用 NFS 文件系统，首先在树莓派上安装 NFS 服务器：
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo apt install nfs-kernel-server
|
||||
```
|
||||
|
||||
然后，需要告诉 NFS 服务器公开 `/nas/data` 目录，这是从树莓派外部可以访问的唯一设备（另一个用于备份）。编辑 `/etc/exports` 添加如下内容以允许所有可以访问 NAS 云盘的设备挂载存储：
|
||||
|
||||
```
|
||||
/nas/data *(rw,sync,no_subtree_check)
|
||||
```
|
||||
|
||||
更多有关限制挂载到单个设备的详细信息，请参阅 `man exports`。经过上面的配置，任何人都可以访问数据，只要他们可以访问 NFS 所需的端口：`111` 和 `2049`。我通过上面的配置，只允许通过路由器防火墙访问到我的家庭网络的 22 和 443 端口。这样，只有在家庭网络中的设备才能访问 NFS 服务器。
|
||||
|
||||
如果要在 Linux 计算机挂载存储，运行以下命令：
|
||||
|
||||
```
|
||||
you@desktop:~ $ sudo mkdir /nas/data
|
||||
you@desktop:~ $ sudo mount -t nfs <raspberry-pi-hostname-or-ip>:/nas/data /nas/data
|
||||
```
|
||||
|
||||
同样，我建议使用 autofs 来挂载该网络设备。如果需要其他帮助，请参看 [如何使用 Autofs 来挂载 NFS 共享][6]。
|
||||
|
||||
现在你可以在远程设备上通过 NFS 系统访问位于你树莓派 NAS 云盘上的数据了。在后面一篇文章中，我将介绍如何使用 `rsync` 自动将数据备份到第二个 USB 磁盘驱动器。你将会学到如何使用 `rsync` 创建增量备份，在进行日常备份的同时还能节省设备空间。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/7/network-attached-storage-Raspberry-Pi
|
||||
|
||||
作者：[Manuel Dewald][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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/ntlx
|
||||
[1]: https://nextcloud.com/
|
||||
[2]: https://www.raspberrypi.org/products/raspberry-pi-3-model-b/
|
||||
[3]: https://www.raspbian.org/
|
||||
[4]: https://www.raspberrypi.org/documentation/installation/installing-images/
|
||||
[5]: https://www.raspberrypi.org/blog/raspbian-stretch/
|
||||
[6]: https://opensource.com/article/18/6/using-autofs-mount-nfs-shares
|
||||
|
||||
|
||||
125
published/20180803 5 Essential Tools for Linux Development.md
Normal file
125
published/20180803 5 Essential Tools for Linux Development.md
Normal file
@ -0,0 +1,125 @@
|
||||
Linux 开发的五大必备工具
|
||||
======
|
||||
> Linux 上的开发工具如此之多，以至于会担心找不到恰好适合你的。
|
||||
|
||||
|
||||
|
||||
Linux 已经成为工作、娱乐和个人生活等多个领域的支柱，人们已经越来越离不开它。在 Linux 的帮助下，技术的变革速度超出了人们的想象，Linux 开发的速度也以指数规模增长。因此，越来越多的开发者也不断地加入开源和学习 Linux 开发地潮流当中。在这个过程之中，合适的工具是必不可少的，可喜的是，随着 Linux 的发展，大量适用于 Linux 的开发工具也不断成熟。甚至可以说，这样的工具已经多得有点惊人。
|
||||
|
||||
为了选择更合适自己的开发工具，缩小选择范围是很必要的。但是这篇文章并不会要求你必须使用某个工具，而只是缩小到五个工具类别，然后对每个类别提供一个例子。然而，对于大多数类别，都会有不止一种选择。下面我们来看一下。
|
||||
|
||||
### 容器
|
||||
|
||||
放眼于现实，现在已经是容器的时代了。容器既及其容易部署，又可以方便地构建开发环境。如果你针对的是特定的平台的开发，将开发流程所需要的各种工具都创建到容器映像中是一种很好的方法，只要使用这一个容器映像，就能够快速启动大量运行所需服务的实例。
|
||||
|
||||
一个使用容器的最佳范例是使用 [Docker][1]，使用容器（或 Docker）有这些好处：
|
||||
|
||||
* 开发环境保持一致
|
||||
* 部署后即可运行
|
||||
* 易于跨平台部署
|
||||
* Docker 映像适用于多种开发环境和语言
|
||||
* 部署单个容器或容器集群都并不繁琐
|
||||
|
||||
通过 [Docker Hub][2]，几乎可以找到适用于任何平台、任何开发环境、任何服务器、任何服务的映像，几乎可以满足任何一种需求。使用 Docker Hub 中的映像，就相当于免除了搭建开发环境的步骤，可以直接开始开发应用程序、服务器、API 或服务。
|
||||
|
||||
Docker 在所有 Linux 平台上都很容易安装，例如可以通过终端输入以下命令在 Ubuntu 上安装 Docker：
|
||||
|
||||
```
|
||||
sudo apt-get install docker.io
|
||||
```
|
||||
|
||||
Docker 安装完毕后，就可以从 Docker 仓库中拉取映像，然后开始开发和部署了（如下图）。
|
||||
|
||||
![Docker images][4]
|
||||
|
||||
*图 1： Docker 镜像准备部署*
|
||||
|
||||
### 版本控制工具
|
||||
|
||||
如果你正在开发一个大型项目，又或者参与团队开发，版本控制工具是必不可少的，它可以用于记录代码变更、提交代码以及合并代码。如果没有这样的工具，项目几乎无法妥善管理。在 Linux 系统上，[Git][6] 和 [GitHub][7] 的易用性和流行程度是其它版本控制工具无法比拟的。如果你对 Git 和 GitHub 还不太熟悉，可以简单理解为 Git 是在本地计算机上安装的版本控制系统，而 GitHub 则是用于上传和管理项目的远程存储库。 Git 可以安装在大多数的 Linux 发行版上。例如在基于 Debian 的系统上，只需要通过以下这一条简单的命令就可以安装：
|
||||
|
||||
```
|
||||
sudo apt-get install git
|
||||
```
|
||||
|
||||
安装完毕后，就可以使用 Git 来实施版本控制了（如下图）。
|
||||
|
||||
![Git installed][9]
|
||||
|
||||
*图 2：Git 已经安装，可以用于很多重要任务*
|
||||
|
||||
Github 会要求用户创建一个帐户。用户可以免费使用 GitHub 来管理非商用项目，当然也可以使用 GitHub 的付费模式（更多相关信息，可以参阅[价格矩阵][10]）。
|
||||
|
||||
### 文本编辑器
|
||||
|
||||
如果没有文本编辑器，在 Linux 上开发将会变得异常艰难。当然，文本编辑器之间孰优孰劣，具体还是要取决于开发者的需求。对于文本编辑器，有人可能会使用 vim、emacs 或 nano，也有人会使用带有 GUI 的编辑器。但由于重点在于开发，我们需要的是一种能够满足开发人员需求的工具。不过我首先要说，vim 对于开发人员来说确实是一个利器，但前提是要对 vim 非常熟悉，在这种前提下，vim 能够满足你的所有需求，甚至还能给你更好的体验。然而，对于一些开发者（尤其是刚开始接触 Linux 的新手）来说，这不仅难以帮助他们快速达成需求，甚至还会是一个需要逾越的障碍。考虑到这篇文章的目标是帮助 Linux 的新手（而不仅仅是为各种编辑器的死忠粉宣传他们拥护的编辑器），我更倾向于使用 GUI 编辑器。
|
||||
|
||||
就文本编辑器而论，选择 [Bluefish][11] 一般不会有错。 Bluefish 可以从大部分软件库中安装，它支持项目管理、远程文件多线程操作、搜索和替换、递归打开文件、侧边栏、集成 make/lint/weblint/xmllint、无限制撤销/重做、在线拼写检查、自动恢复、全屏编辑、语法高亮（如下图）、多种语言等等。
|
||||
|
||||
![Bluefish][13]
|
||||
|
||||
*图 3：运行在 Ubuntu 18.04 上的 Bluefish*
|
||||
|
||||
### IDE
|
||||
|
||||
<ruby>集成开发环境<rt>Integrated Development Environment</rt></ruby>（IDE）是包含一整套全面的工具、可以实现一站式功能的开发环境。 开发者除了可以使用 IDE 编写代码，还可以编写文档和构建软件。在 Linux 上也有很多适用的 IDE，其中 [Geany][14] 就包含在标准软件库中，它对用户非常友好，功能也相当强大。 Geany 具有语法高亮、代码折叠、自动完成，构建代码片段、自动关闭 XML 和 HTML 标签、调用提示、支持多种文件类型、符号列表、代码导航、构建编译，简单的项目管理和内置的插件系统等强大功能。
|
||||
|
||||
Geany 也能在系统上轻松安装，例如执行以下命令在基于 Debian 的 Linux 发行版上安装 Geany：
|
||||
|
||||
```
|
||||
sudo apt-get install geany
|
||||
```
|
||||
|
||||
安装完毕后，就可以快速上手这个易用且强大的 IDE 了（如下图）。
|
||||
|
||||
![Geany][16]
|
||||
|
||||
*图 4：Geany 可以作为你的 IDE*
|
||||
|
||||
### 文本比较工具
|
||||
|
||||
有时候会需要比较两个文件的内容来找到它们之间的不同之处，它们可能是同一文件的两个不同副本（有一个经过编译，而另一个没有）。这种情况下，你肯定不想要凭借肉眼来找出差异，而是想要使用像 [Meld][17] 这样的工具。 Meld 是针对开发者的文本比较和合并工具，可以使用 Meld 来发现两个文件之间的差异。虽然你可以使用命令行中的文本比较工具，但就效率而论，Meld 无疑更为优秀。
|
||||
|
||||
Meld 可以打开两个文件进行比较，并突出显示文件之间的差异之处。 Meld 还允许用户从两个文件的其中一方合并差异（下图显示了 Meld 同时打开两个文件）。
|
||||
|
||||
![Comparing two files][19]
|
||||
|
||||
*图 5： 以简单差异的模式比较两个文件*
|
||||
|
||||
Meld 也可以通过大多数标准的软件库安装，在基于 Debian 的系统上，执行以下命令就可以安装：
|
||||
|
||||
```
|
||||
sudo apt-get install meld
|
||||
```
|
||||
|
||||
### 高效地工作
|
||||
|
||||
以上提到的五个工具除了帮助你完成工作，而且有助于提高效率。尽管适用于 Linux 开发者的工具有很多，但对于以上几个类别，你最好分别使用一个对应的工具。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/learn/intro-to-linux/2018/8/5-essential-tools-linux-development
|
||||
|
||||
作者：[Jack Wallen][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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/jlwallen
|
||||
[1]:https://www.docker.com/
|
||||
[2]:https://hub.docker.com/
|
||||
[4]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_1.jpg?itok=V1Bsbkg9 "Docker images"
|
||||
[6]:https://git-scm.com/
|
||||
[7]:https://github.com/
|
||||
[9]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_2.jpg?itok=YJjhe4O6 "Git installed"
|
||||
[10]:https://github.com/pricing
|
||||
[11]:http://bluefish.openoffice.nl/index.html
|
||||
[13]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_3.jpg?itok=66A7Svme "Bluefish"
|
||||
[14]:https://www.geany.org/
|
||||
[16]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_4.jpg?itok=jRcA-0ue "Geany"
|
||||
[17]:http://meldmerge.org/
|
||||
[19]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_5.jpg?itok=eLkfM9oZ "Comparing two files"
|
||||
[20]:https://training.linuxfoundation.org/linux-courses/system-administration-training/introduction-to-linux
|
||||
|
||||
@ -1,4 +1,5 @@
|
||||
# 5 个给孩子的非常好的 Linux 教育软件和游戏
|
||||
5 个给孩子的非常好的 Linux 游戏和教育软件
|
||||
=================
|
||||
|
||||
|
||||
|
||||
@ -8,39 +9,39 @@ Linux 是一个非常强大的操作系统，因此因特网上的大多数服
|
||||
|
||||
**相关阅读**：[使用一个 Linux 发行版的新手指南][1]
|
||||
|
||||
### 1. GCompris
|
||||
### 1、GCompris
|
||||
|
||||
如果你正在为你的孩子寻找一款最佳的教育软件，[GCompris][2] 将是你的最好的开端。这款软件专门为 2 到 10 岁的孩子所设计。作为所有的 Linux 教育软件套装的巅峰之作，GCompris 为孩子们提供了大约 100 项活动。它囊括了你期望你的孩子学习的所有内容，从阅读材料到科学、地理、绘画、代数、测验、等等。
|
||||
如果你正在为你的孩子寻找一款最佳的教育软件，[GCompris][2] 将是你的最好的开端。这款软件专门为 2 到 10 岁的孩子所设计。作为所有的 Linux 教育软件套装的巅峰之作，GCompris 为孩子们提供了大约 100 项活动。它囊括了你期望你的孩子学习的所有内容，从阅读材料到科学、地理、绘画、代数、测验等等。
|
||||
|
||||
![Linux educational software and games][3]
|
||||
|
||||
GCompris 甚至有一项活动可以帮你的孩子学习计算机的相关知识。如果你的孩子还很小，你希望他去学习字母、颜色、和形状，GCompris 也有这方面的相关内容。更重要的是，它也为孩子们准备了一些益智类游戏，比如国际象棋、井字棋、好记性、以及猜词游戏。GCompris 并不是一个仅在 Linux 上可运行的游戏。它也可以运行在 Windows 和 Android 上。
|
||||
GCompris 甚至有一项活动可以帮你的孩子学习计算机的相关知识。如果你的孩子还很小，你希望他去学习字母、颜色和形状，GCompris 也有这方面的相关内容。更重要的是，它也为孩子们准备了一些益智类游戏，比如国际象棋、井字棋、好记性、以及猜词游戏。GCompris 并不是一个仅在 Linux 上可运行的游戏。它也可以运行在 Windows 和 Android 上。
|
||||
|
||||
### 2. TuxMath
|
||||
### 2、TuxMath
|
||||
|
||||
很多学生认为数学是们非常难的课程。你可以通过 Linux 教育软件如 [TuxMath][4] 来让你的孩子了解数学技能，从而来改变这种看法。TuxMath 是为孩子开发的顶级的数学教育辅助游戏。在这个游戏中，你的角色是在如雨点般下降的数学问题中帮助 Linux 企鹅 Tux 来保护它的星球。
|
||||
很多学生认为数学是门非常难的课程。你可以通过 Linux 教育软件如 [TuxMath][4] 来让你的孩子了解数学技能，从而来改变这种看法。TuxMath 是为孩子开发的顶级的数学教育辅助游戏。在这个游戏中，你的角色是在如雨点般下降的数学问题中帮助 Linux 企鹅 Tux 来保护它的星球。
|
||||
|
||||
![linux-educational-software-tuxmath-1][5]
|
||||
|
||||
在它们落下来毁坏 Tux 的星球之前，找到问题的答案，就可以使用你的激光去帮助 Tux 拯救它的星球。数字问题的难度每过一关就会提升一点。这个游戏非常适合孩子，因为它可以让孩子们去开动脑筋解决问题。而且还有助他们学好数学，以及帮助他们开发智力。
|
||||
|
||||
### 3. Sugar on a Stick
|
||||
### 3、Sugar on a Stick
|
||||
|
||||
[Sugar on a Stick][6] 是献给孩子们的学习程序 —— 一个广受好评的全新教学法。这个程序为你的孩子提供一个成熟的教学平台，在那里，他们可以收获创造、探索、发现和思考方面的技能。和 GCompris 一样，Sugar on a Stick 为孩子们带来了包括游戏和谜题在内的大量学习资源。
|
||||
[Sugar on a Stick][6] 是献给孩子们的学习程序 —— 一个广受好评的全新教学法。这个程序为你的孩子提供一个成熟的教学平台，在那里，他们可以收获创造、探索、发现和思考方面的技能。和 GCompris 一样，Sugar on a Stick 为孩子们带来了包括游戏和谜题在内的大量学习资源。
|
||||
|
||||
![linux-educational-software-sugar-on-a-stick][7]
|
||||
|
||||
关于 Sugar on a Stick 最大的一个好处是你可以将它配置在一个 U 盘上。你只要有一台 X86 的 PC，插入那个 U 盘，然后就可以从 U 盘引导这个发行版。Sugar on a Stick 是由 Sugar 实验室提供的一个项目 —— 这个实验室是一个由志愿者运作的非盈利组织。
|
||||
|
||||
### 4. KDE Edu Suite
|
||||
### 4、KDE Edu Suite
|
||||
|
||||
[KDE Edu Suite][8] 是一个用途与众不同的软件包。带来了大量不同领域的应用程序，KDE 社区已经证实，它不仅是一系列成年人授权的问题；它还关心年青一代如何适应他们周围的一切。它囊括了一系列孩子们使用的应用程序，从科学到数学、地理等等。
|
||||
[KDE Edu Suite][8] 是一个用途与众不同的软件包。带来了大量不同领域的应用程序，KDE 社区已经证实，它不仅可以给成年人授权；它还关心年青一代如何适应他们周围的一切。它囊括了一系列孩子们使用的应用程序，从科学到数学、地理等等。
|
||||
|
||||
![linux-educational-software-kde-1][9]
|
||||
|
||||
KDE Edu 套件根据长大后所必需的知识为基础，既能够用作学校的教学软件，也能够作为孩子们的学习 APP。它提供了大量的可免费下载的软件包。KDE Edu 套件在主流的 GNU/Linux 发行版都能安装。
|
||||
|
||||
### 5. Tux Paint
|
||||
### 5、Tux Paint
|
||||
|
||||
![linux-educational-software-tux-paint-2][10]
|
||||
|
||||
@ -61,20 +62,20 @@ via: https://www.maketecheasier.com/5-best-linux-software-packages-for-kids/
|
||||
作者：[Kenneth Kimari][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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
|
||||
|
||||
[a]: https://www.maketecheasier.com/author/kennkimari/
|
||||
[1]: https://www.maketecheasier.com/beginner-guide-to-using-linux-distro/ "The Beginner’s Guide to Using a Linux Distro"
|
||||
[1]: https://www.maketecheasier.com/beginner-guide-to-using-linux-distro/
|
||||
[2]: http://www.gcompris.net/downloads-en.html
|
||||
[3]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-gcompris.jpg "Linux educational software and games"
|
||||
[3]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-gcompris.jpg
|
||||
[4]: https://tuxmath.en.uptodown.com/ubuntu
|
||||
[5]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-tuxmath-1.jpg "linux-educational-software-tuxmath-1"
|
||||
[5]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-tuxmath-1.jpg
|
||||
[6]: http://wiki.sugarlabs.org/go/Sugar_on_a_Stick/Downloads
|
||||
[7]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-sugar-on-a-stick.png "linux-educational-software-sugar-on-a-stick"
|
||||
[7]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-sugar-on-a-stick.png
|
||||
[8]: https://edu.kde.org/
|
||||
[9]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-kde-1.jpg "linux-educational-software-kde-1"
|
||||
[10]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-tux-paint-2.jpg "linux-educational-software-tux-paint-2"
|
||||
[9]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-kde-1.jpg
|
||||
[10]: https://www.maketecheasier.com/assets/uploads/2018/07/Linux-educational-software-tux-paint-2.jpg
|
||||
[11]: http://www.tuxpaint.org/
|
||||
[12]: http://edubuntu.org/
|
||||
[12]: http://edubuntu.org/
|
||||
@ -1,19 +1,16 @@
|
||||
Part-II 树莓派自建 NAS 云盘之数据自动备份
|
||||
树莓派自建 NAS 云盘之——数据自动备份
|
||||
======
|
||||
> 把你的树莓派变成数据的安全之所。
|
||||
|
||||
|
||||
|
||||
在《树莓派自建 NAS 云盘》系列的 [第一篇][1] 文章中，我们讨论了建立 NAS 的一些基本步骤，添加了两块 1TB 的存储硬盘驱动（一个用于数据存储，一个用于数据备份），并且通过 网络文件系统（NFS）将数据存储盘挂载到远程终端上。本文是此系列的第二篇文章，我们将探讨数据自动备份。数据自动备份保证了数据的安全，为硬件损坏后的数据恢复提供便利以及减少了文件误操作带来的不必要的麻烦。
|
||||
|
||||
|
||||
在《树莓派自建 NAS 云盘》系列的 [第一篇][1] 文章中，我们讨论了建立 NAS 的一些基本步骤，添加了两块 1TB 的存储硬盘驱动（一个用于数据存储，一个用于数据备份），并且通过网络文件系统（NFS）将数据存储盘挂载到远程终端上。本文是此系列的第二篇文章，我们将探讨数据自动备份。数据自动备份保证了数据的安全，为硬件损坏后的数据恢复提供便利以及减少了文件误操作带来的不必要的麻烦。
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
### 备份策略
|
||||
|
||||
我们就从为小型 NAS 构想一个备份策略着手开始吧。我建议每天有时间节点有计划的去备份数据，以防止干扰到我们正常的访问 NAS，比如备份时间点避开正在访问 NAS 并写入文件的时间点。举个例子，你可以每天凌晨 2 点去进行数据备份。
|
||||
我们就从为小型 NAS 构想一个备份策略着手开始吧。我建议每天有时间节点、有计划的去备份数据，以防止干扰到我们正常的访问 NAS，比如备份时间点避开正在访问 NAS 并写入文件的时间点。举个例子，你可以每天凌晨 2 点去进行数据备份。
|
||||
|
||||
另外，你还得决定每天的备份需要被保留的时间长短，因为如果没有时间限制，存储空间很快就会被用完。一般每天的备份保留一周便可以，如果数据出了问题，你便可以很方便的从备份中恢复出来原数据。但是如果需要恢复数据到更久之前怎么办？可以将每周一的备份文件保留一个月、每个月的备份保留更长时间。让我们把每月的备份保留一年时间，每一年的备份保留更长时间、例如五年。
|
||||
|
||||
@ -24,27 +21,24 @@ Part-II 树莓派自建 NAS 云盘之数据自动备份
|
||||
* 每年 12 个月备份
|
||||
* 每五年 5 个年备份
|
||||
|
||||
|
||||
你应该还记得，我们搭建的备份盘和数据盘大小相同（每个 1 TB）。如何将不止 10 个 1TB 数据的备份从数据盘存放到只有 1TB 大小的备份盘呢？如果你创建的是完整备份，这显然不可能。因此，你需要创建增量备份，它是每一份备份都基于上一份备份数据而创建的。增量备份方式不会每隔一天就成倍的去占用存储空间，它每天只会增加一点占用空间。
|
||||
|
||||
以下是我的情况：我的 NAS 自 2016 年 8 月开始运行，备份盘上有 20 个备份。目前，我在数据盘上存储了 406GB 的文件。我的备份盘用了 726GB。当然，备份盘空间使用率在很大程度上取决于数据的更改频率，但正如你所看到的，增量备份不会占用 20 个完整备份所需的空间。然而，随着时间的推移，1TB 空间也可能不足以进行备份。一旦数据增长接近 1TB 限制（或任何备份盘容量），应该选择更大的备份盘空间并将数据移动转移过去。
|
||||
|
||||
### 利用 rsync 进行数据备份
|
||||
|
||||
利用 rsync 命令行工具可以生成完整备份。
|
||||
利用 `rsync` 命令行工具可以生成完整备份。
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ rsync -a /nas/data/ /nas/backup/2018-08-01
|
||||
|
||||
```
|
||||
|
||||
这段命令将挂载在 /nas/data/ 目录下的数据盘中的数据进行了完整的复制备份。备份文件保存在 /nas/backup/2018-08-01 目录下。`-a` 参数是以归档模式进行备份，这将会备份所有的元数据，例如文件的修改日期、权限、拥有者以及软连接文件。
|
||||
这段命令将挂载在 `/nas/data/` 目录下的数据盘中的数据进行了完整的复制备份。备份文件保存在 `/nas/backup/2018-08-01` 目录下。`-a` 参数是以归档模式进行备份，这将会备份所有的元数据，例如文件的修改日期、权限、拥有者以及软连接文件。
|
||||
|
||||
现在，你已经在 8 月 1 日创建了完整的初始备份，你将在 8 月 2 日创建第一个增量备份。
|
||||
|
||||
```
|
||||
pi@raspberrypi:~ $ rsync -a --link-dest /nas/backup/2018-08-01/ /nas/data/ /nas/backup/2018-08-02
|
||||
|
||||
```
|
||||
|
||||
上面这行代码又创建了一个关于 `/nas/data` 目录中数据的备份。备份路径是 `/nas/backup/2018-08-02`。这里的参数 `--link-dest` 指定了一个备份文件所在的路径。这样，这次备份会与 `/nas/backup/2018-08-01` 的备份进行比对，只备份已经修改过的文件，未做修改的文件将不会被复制，而是创建一个到上一个备份文件中它们的硬链接。
|
||||
@ -53,142 +47,81 @@ pi@raspberrypi:~ $ rsync -a --link-dest /nas/backup/2018-08-01/ /nas/data/ /nas/
|
||||
|
||||
|
||||
|
||||
左侧框是在进行了第二次备份后的原数据状态。中间的盒子是昨天的备份。昨天的备份中只有图片 `file1.jpg` 并没有 `file2.txt` 。右侧的框反映了今天的增量备份。增量备份命令创建昨天不存在的 `file2.txt`。由于 `file1.jpg` 自昨天以来没有被修改，所以今天创建了一个硬链接，它不会额外占用磁盘上的空间。
|
||||
左侧框是在进行了第二次备份后的原数据状态。中间的方块是昨天的备份。昨天的备份中只有图片 `file1.jpg` 并没有 `file2.txt` 。右侧的框反映了今天的增量备份。增量备份命令创建昨天不存在的 `file2.txt`。由于 `file1.jpg` 自昨天以来没有被修改，所以今天创建了一个硬链接，它不会额外占用磁盘上的空间。
|
||||
|
||||
### 自动化备份
|
||||
|
||||
你肯定也不想每天凌晨去输入命令进行数据备份吧。你可以创建一个任务定时去调用下面的脚本让它自动化备份
|
||||
你肯定也不想每天凌晨去输入命令进行数据备份吧。你可以创建一个任务定时去调用下面的脚本让它自动化备份。
|
||||
|
||||
```
|
||||
#!/bin/bash
|
||||
|
||||
|
||||
|
||||
TODAY=$(date +%Y-%m-%d)
|
||||
|
||||
DATADIR=/nas/data/
|
||||
|
||||
BACKUPDIR=/nas/backup/
|
||||
|
||||
SCRIPTDIR=/nas/data/backup_scripts
|
||||
|
||||
LASTDAYPATH=${BACKUPDIR}/$(ls ${BACKUPDIR} | tail -n 1)
|
||||
|
||||
TODAYPATH=${BACKUPDIR}/${TODAY}
|
||||
|
||||
if [[ ! -e ${TODAYPATH} ]]; then
|
||||
|
||||
mkdir -p ${TODAYPATH}
|
||||
|
||||
mkdir -p ${TODAYPATH}
|
||||
fi
|
||||
|
||||
|
||||
|
||||
rsync -a --link-dest ${LASTDAYPATH} ${DATADIR} ${TODAYPATH} $@
|
||||
|
||||
|
||||
|
||||
${SCRIPTDIR}/deleteOldBackups.sh
|
||||
|
||||
```
|
||||
|
||||
第一段代码指定了数据路径、备份路劲、脚本路径以及昨天和今天的备份路径。第二段代码调用 rsync 命令。最后一段代码执行 `deleteOldBackups.sh` 脚本，它会清除一些过期的没有必要的备份数据。如果不想频繁的调用 `deleteOldBackups.sh`，你也可以手动去执行它。
|
||||
第一段代码指定了数据路径、备份路径、脚本路径以及昨天和今天的备份路径。第二段代码调用 `rsync` 命令。最后一段代码执行 `deleteOldBackups.sh` 脚本，它会清除一些过期的没有必要的备份数据。如果不想频繁的调用 `deleteOldBackups.sh`，你也可以手动去执行它。
|
||||
|
||||
下面是今天讨论的备份策略的一个简单完整的示例脚本。
|
||||
|
||||
```
|
||||
#!/bin/bash
|
||||
|
||||
BACKUPDIR=/nas/backup/
|
||||
|
||||
|
||||
|
||||
function listYearlyBackups() {
|
||||
|
||||
for i in 0 1 2 3 4 5
|
||||
|
||||
do ls ${BACKUPDIR} | egrep "$(date +%Y -d "${i} year ago")-[0-9]{2}-[0-9]{2}" | sort -u | head -n 1
|
||||
|
||||
done
|
||||
|
||||
for i in 0 1 2 3 4 5
|
||||
do ls ${BACKUPDIR} | egrep "$(date +%Y -d "${i} year ago")-[0-9]{2}-[0-9]{2}" | sort -u | head -n 1
|
||||
done
|
||||
}
|
||||
|
||||
|
||||
|
||||
function listMonthlyBackups() {
|
||||
|
||||
for i in 0 1 2 3 4 5 6 7 8 9 10 11 12
|
||||
|
||||
do ls ${BACKUPDIR} | egrep "$(date +%Y-%m -d "${i} month ago")-[0-9]{2}" | sort -u | head -n 1
|
||||
|
||||
done
|
||||
|
||||
for i in 0 1 2 3 4 5 6 7 8 9 10 11 12
|
||||
do ls ${BACKUPDIR} | egrep "$(date +%Y-%m -d "${i} month ago")-[0-9]{2}" | sort -u | head -n 1
|
||||
done
|
||||
}
|
||||
|
||||
|
||||
|
||||
function listWeeklyBackups() {
|
||||
|
||||
for i in 0 1 2 3 4
|
||||
|
||||
do ls ${BACKUPDIR} | grep "$(date +%Y-%m-%d -d "last monday -${i} weeks")"
|
||||
|
||||
done
|
||||
|
||||
for i in 0 1 2 3 4
|
||||
do ls ${BACKUPDIR} | grep "$(date +%Y-%m-%d -d "last monday -${i} weeks")"
|
||||
done
|
||||
}
|
||||
|
||||
|
||||
|
||||
function listDailyBackups() {
|
||||
|
||||
for i in 0 1 2 3 4 5 6
|
||||
|
||||
do ls ${BACKUPDIR} | grep "$(date +%Y-%m-%d -d "-${i} day")"
|
||||
|
||||
done
|
||||
|
||||
for i in 0 1 2 3 4 5 6
|
||||
do ls ${BACKUPDIR} | grep "$(date +%Y-%m-%d -d "-${i} day")"
|
||||
done
|
||||
}
|
||||
|
||||
|
||||
|
||||
function getAllBackups() {
|
||||
|
||||
listYearlyBackups
|
||||
|
||||
listMonthlyBackups
|
||||
|
||||
listWeeklyBackups
|
||||
|
||||
listDailyBackups
|
||||
|
||||
listYearlyBackups
|
||||
listMonthlyBackups
|
||||
listWeeklyBackups
|
||||
listDailyBackups
|
||||
}
|
||||
|
||||
|
||||
|
||||
function listUniqueBackups() {
|
||||
|
||||
getAllBackups | sort -u
|
||||
|
||||
getAllBackups | sort -u
|
||||
}
|
||||
|
||||
|
||||
|
||||
function listBackupsToDelete() {
|
||||
|
||||
ls ${BACKUPDIR} | grep -v -e "$(echo -n $(listUniqueBackups) |sed "s/ /\\\|/g")"
|
||||
|
||||
ls ${BACKUPDIR} | grep -v -e "$(echo -n $(listUniqueBackups) |sed "s/ /\\\|/g")"
|
||||
}
|
||||
|
||||
|
||||
|
||||
cd ${BACKUPDIR}
|
||||
|
||||
listBackupsToDelete | while read file_to_delete; do
|
||||
|
||||
rm -rf ${file_to_delete}
|
||||
|
||||
rm -rf ${file_to_delete}
|
||||
done
|
||||
|
||||
```
|
||||
|
||||
这段脚本会首先根据你的备份策略列出所有需要保存的备份文件，然后它会删除那些再也不需要了的备份目录。
|
||||
@ -197,7 +130,6 @@ done
|
||||
|
||||
```
|
||||
0 2 * * * /nas/data/backup_scripts/daily.sh
|
||||
|
||||
```
|
||||
|
||||
有关创建定时任务请参考 [cron 创建定时任务][2]。
|
||||
@ -218,12 +150,12 @@ via: https://opensource.com/article/18/8/automate-backups-raspberry-pi
|
||||
作者：[Manuel Dewald][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[jrg](https://github.com/jrglinux)
|
||||
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
|
||||
|
||||
[a]: https://opensource.com/users/ntlx
|
||||
[1]: https://opensource.com/article/18/7/network-attached-storage-Raspberry-Pi
|
||||
[1]: https://linux.cn/article-10104-1.html
|
||||
[2]: https://opensource.com/article/17/11/how-use-cron-linux
|
||||
[3]: https://nextcloud.com/
|
||||
|
||||
@ -0,0 +1,84 @@
|
||||
Linux 下如何创建 M3U 播放列表
|
||||
======
|
||||
|
||||
> 简介：关于如何在Linux终端中根据乱序文件创建M3U播放列表实现循序播放的小建议。
|
||||
|
||||
![Create M3U playlists in Linux Terminal][1]
|
||||
|
||||
我是外国电视连续剧的粉丝，这些连续剧不太容易从 DVD 或像 [Netflix][2] 这样的流媒体上获得。好在，您可以在 YouTube 上找到一些内容并[从 YouTube 下载][3]。
|
||||
|
||||
现在出现了一个问题。你的文件可能不是按顺序存储的。在 GNU/Linux中，文件不是按数字顺序自然排序的，因此我必须创建 .m3u 播放列表，以便 [MPV 视频播放器][4]可以按顺序播放视频而不是乱顺进行播放。
|
||||
|
||||
同样的，有时候表示第几集的数字是在文件名中间或结尾的，像这样 “My Web Series S01E01.mkv”。这里的剧集信息位于文件名的中间，“S01E01”告诉我们人类这是第一集，后面还有其它剧集。
|
||||
|
||||
因此我要做的事情就是在视频墓中创建一个 .m3u 播放列表，并告诉 MPV 播放这个 .m3u 播放列表，MPV 自然会按顺序播放这些视频.
|
||||
|
||||
### 什么是 M3U 文件?
|
||||
|
||||
[M3U][5] 基本上就是个按特定顺序包含文件名的文本文件。当类似 MPV 或 VLC 这样的播放器打开 M3U 文件时，它会尝试按给定的顺序播放指定文件。
|
||||
|
||||
### 创建 M3U 来按顺序播放音频/视频文件
|
||||
|
||||
就我而言, 我使用了下面命令：
|
||||
|
||||
```
|
||||
$/home/shirish/Videos/web-series-video/$ ls -1v |grep .mkv > /tmp/1.m3u && mv /tmp/1.m3u .
|
||||
```
|
||||
|
||||
然我们拆分一下看看每个部分表示什么意思：
|
||||
|
||||
`ls -1v` = 这就是用普通的 `ls` 来列出目录中的内容. 其中 `-1` 表示每行显示一个文件。而 `-v` 表示根据文本中的数字（版本）进行自然排序。
|
||||
|
||||
`| grep .mkv` = 基本上就是告诉 `ls` 寻找那些以 `.mkv` 结尾的文件。它也可以是 `.mp4` 或其他任何你想要的媒体文件格式。
|
||||
|
||||
通过在控制台上运行命令来进行试运行通常是个好主意：
|
||||
|
||||
```
|
||||
ls -1v |grep .mkv
|
||||
My Web Series S01E01 [Episode 1 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E02 [Episode 2 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E03 [Episode 3 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E04 [Episode 4 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E05 [Episode 5 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E06 [Episode 6 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E07 [Episode 7 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E08 [Episode 8 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
```
|
||||
|
||||
结果显示我要做的是正确的。现在下一步就是让输出以 `.m3u` 播放列表的格式输出。
|
||||
|
||||
```
|
||||
ls -1v |grep .mkv > /tmp/web_playlist.m3u && mv /tmp/web_playlist.m3u .
|
||||
```
|
||||
|
||||
这就在当前目录中创建了 .m3u 文件。这个 .m3u 播放列表只不过是一个 .txt 文件，其内容与上面相同，扩展名为 .m3u 而已。 你也可以手动编辑它，并按照想要的顺序添加确切的文件名。
|
||||
|
||||
之后你只需要这样做：
|
||||
|
||||
```
|
||||
mpv web_playlist.m3u
|
||||
```
|
||||
|
||||
一般来说，MPV 和播放列表的好处在于你不需要一次性全部看完。 您可以一次看任意长时间，然后在下一次查看其余部分。
|
||||
|
||||
我希望写一些有关 MPV 的文章，以及如何制作在媒体文件中嵌入字幕的 mkv 文件，但这是将来的事情了。
|
||||
|
||||
注意: 这是开源软件，不鼓励盗版。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/create-m3u-playlist-linux/
|
||||
|
||||
作者：[Shirsh][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
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/shirish/
|
||||
[1]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/08/Create-M3U-Playlists.jpeg
|
||||
[2]:https://itsfoss.com/netflix-open-source-ai/
|
||||
[3]:https://itsfoss.com/download-youtube-linux/
|
||||
[4]:https://itsfoss.com/mpv-video-player/
|
||||
[5]:https://en.wikipedia.org/wiki/M3U
|
||||
@ -1,17 +1,18 @@
|
||||
使用 browser-mpris2（Chrome 扩展）将 YouTube 播放器控件添加到 Linux 桌面
|
||||
使用 Chrome 扩展将 YouTube 播放器控件添加到 Linux 桌面
|
||||
======
|
||||
一个我怀念的 Unity 功能（虽然只使用了一小段时间）是在 Web 浏览器中访问 YouTube 等网站时自动获取 Ubuntu 声音指示器中的播放器控件，因此你可以直接从顶部栏暂停或停止视频，以及浏览视频/歌曲信息和预览。
|
||||
|
||||
这个 Unity 功能已经消失很久了，但我正在为 Gnome Shell 寻找类似的东西，然后我遇到了 **[browser-mpris2][1]，这是一个为 Google Chrome/Chromium 实现 MPRIS v2 接口的扩展，目前只支持 YouTube**，我想可能会有一些 Linux Uprising 的读者会喜欢这个。
|
||||
一个我怀念的 Unity 功能（虽然只使用了一小段时间）是在 Web 浏览器中访问 YouTube 等网站时在 Ubuntu 声音指示器中自动出现播放器控件，因此你可以直接从顶部栏暂停或停止视频，以及浏览视频/歌曲信息和预览。
|
||||
|
||||
**该扩展还适用于 Opera 和 Vivaldi 等基于 Chromium 的 Web 浏览器。**
|
||||
**
|
||||
** **browser-mpris2 也支持 Firefox，但因为通过 about:debugging 加载扩展是临时的，而这是 browser-mpris2 所需要的，因此本文不包括 Firefox 的指导。开发人员[打算][2]将来将扩展提交到 Firefox 插件网站上。**
|
||||
这个 Unity 功能已经消失很久了，但我正在为 Gnome Shell 寻找类似的东西，然后我遇到了 [browser-mpris2][1]，这是一个为 Google Chrome/Chromium 实现 MPRIS v2 接口的扩展，目前只支持 YouTube，我想可能会有一些读者会喜欢这个。
|
||||
|
||||
**使用此 Chrome 扩展，你可以在支持 MPRIS2 的 applets 中获得 YouTube 媒体播放器控件（播放、暂停、停止和查找
|
||||
）**。例如，如果你使用 Gnome Shell，你可将 YouTube 媒体播放器控件作为永久通知，或者你可以使用 Media Player Indicator 之类的扩展来实现此目的。在 Cinnamon /Linux Mint with Cinnamon 中，它出现在声音 Applet 中。
|
||||
该扩展还适用于 Opera 和 Vivaldi 等基于 Chromium 的 Web 浏览器。
|
||||
|
||||
**我无法在 Unity 上用它**，我不知道为什么。我没有在不同桌面环境（KDE、Xfce、MATE 等）中使用其他支持 MPRIS2 的 applet 尝试此扩展。如果你尝试过，请告诉我们它是否适用于你的桌面环境/支持 MPRIS2 的 applet。
|
||||
browser-mpris2 也支持 Firefox，但因为通过 `about:debugging` 加载扩展是临时的，而这是 browser-mpris2 所需要的，因此本文不包括 Firefox 的指导。开发人员[打算][2]将来将扩展提交到 Firefox 插件网站上。
|
||||
|
||||
使用此 Chrome 扩展，你可以在支持 MPRIS2 的 applets 中获得 YouTube 媒体播放器控件（播放、暂停、停止和查找
|
||||
）。例如，如果你使用 Gnome Shell，你可将 YouTube 媒体播放器控件作为永久显示的控件，或者你可以使用 Media Player Indicator 之类的扩展来实现此目的。在 Cinnamon /Linux Mint with Cinnamon 中，它出现在声音 Applet 中。
|
||||
|
||||
我无法在 Unity 上用它，我不知道为什么。我没有在不同桌面环境（KDE、Xfce、MATE 等）中使用其他支持 MPRIS2 的 applet 尝试此扩展。如果你尝试过，请告诉我们它是否适用于你的桌面环境/支持 MPRIS2 的 applet。
|
||||
|
||||
以下是在使用 Gnome Shell 的 Ubuntu 18.04 并装有 Chromium 浏览器的[媒体播放器指示器][3]的截图，其中显示了有关当前正在播放的 YouTube 视频的信息及其控件（播放/暂停，停止和查找）：
|
||||
|
||||
@ -19,42 +20,41 @@
|
||||
|
||||
在 Linux Mint 19 Cinnamon 中使用其默认声音 applet 和 Chromium 浏览器的截图：
|
||||
|
||||
|
||||
|
||||
|
||||
### 如何为 Google Chrom/Chromium安装 browser-mpris2
|
||||
|
||||
**1\. 如果你还没有安装 Git 就安装它**
|
||||
1、 如果你还没有安装 Git 就安装它
|
||||
|
||||
在 Debian/Ubuntu/Linux Mint 中，使用此命令安装 git：
|
||||
|
||||
```
|
||||
sudo apt install git
|
||||
|
||||
```
|
||||
|
||||
**2\. 下载并安装 [browser-mpris2][1] 所需文件。**
|
||||
2、 下载并安装 [browser-mpris2][1] 所需文件。
|
||||
|
||||
下面的命令克隆了 browser-mpris2 的 Git 仓库并将 chrome-mpris2 安装到 `/usr/local/bin/`（在一个你可以保存 browser-mpris2 文件夹的地方运行 `git clone ...` 命令，由于它会被 Chrome/Chromium 使用，你不能删除它）：
|
||||
|
||||
下面的命令克隆了 browser-mpris2 的 Git 仓库并将 chrome-mpris2 安装到 `/usr/local/bin/`（在一个你可以保存 browser-mpris2 文件夹的地方运行 “git clone ...” 命令，由于它会被 Chrome/Chromium 使用，你不能删除它）：
|
||||
```
|
||||
git clone https://github.com/otommod/browser-mpris2
|
||||
sudo install browser-mpris2/native/chrome-mpris2 /usr/local/bin/
|
||||
|
||||
```
|
||||
|
||||
**3\. 在基于 Chrome/Chromium 的 Web 浏览器中加载此扩展。**
|
||||
3、 在基于 Chrome/Chromium 的 Web 浏览器中加载此扩展。
|
||||
|
||||
|
||||
|
||||
打开 Google Chrome、Chromium、Opera 或 Vivaldi 浏览器，进入 Extensions 页面（在 URL 栏中输入 `chrome://extensions`），在屏幕右上角切换到`开发者模式`。然后选择 `Load Unpacked` 并选择 chrome-mpris2 目录（确保没有选择子文件夹）。
|
||||
打开 Google Chrome、Chromium、Opera 或 Vivaldi 浏览器，进入 Extensions 页面（在 URL 栏中输入 `chrome://extensions`），在屏幕右上角切换到“开发者模式”。然后选择 “Load Unpacked” 并选择 chrome-mpris2 目录（确保没有选择子文件夹）。
|
||||
|
||||
复制扩展 ID 并保存它，因为你以后需要它（它类似于这样：`emngjajgcmeiligomkgpngljimglhhii`，但它会与你的不一样，因此确保使用你计算机中的 ID！）。
|
||||
|
||||
**4\. 运行 **`install-chrome.py`**（在 `browser-mpris2/native` 文件夹中），指定扩展 id 和 chrome-mpris2 路径。
|
||||
4、 运行 `install-chrome.py`（在 `browser-mpris2/native` 文件夹中），指定扩展 id 和 chrome-mpris2 路径。
|
||||
|
||||
在终端中使用此命令（将 `REPLACE-THIS-WITH-EXTENSION-ID` 替换为上一步中 `chrome://extensions` 下显示的 browser-mpris2 扩展 ID）安装此扩展：
|
||||
|
||||
```
|
||||
browser-mpris2/native/install-chrome.py REPLACE-THIS-WITH-EXTENSION-ID /usr/local/bin/chrome-mpris2
|
||||
|
||||
```
|
||||
|
||||
你只需要运行此命令一次，无需将其添加到启动或其他类似的地方。你在 Google Chrome 或 Chromium 浏览器中播放的任何 YouTube 视频都应显示在你正在使用的任何 MPRISv2 applet 中。你无需重启 Web 浏览器。
|
||||
@ -66,7 +66,7 @@ via: https://www.linuxuprising.com/2018/08/add-youtube-player-controls-to-your.h
|
||||
作者：[Logix][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
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
|
||||
|
||||
@ -0,0 +1,153 @@
|
||||
如何提交你的第一个 Linux 内核补丁
|
||||
======
|
||||
> 学习如何做出你的首个 Linux 内核贡献，以及在开始之前你应该知道什么。
|
||||
|
||||
|
||||
|
||||
Linux 内核是最大且变动最快的开源项目之一，它由大约 53,600 个文件和近 2,000 万行代码组成。在全世界范围内超过 15,600 位程序员为它贡献代码，Linux 内核项目的维护者使用了如下的协作模型。
|
||||
|
||||
|
||||
|
||||
本文中，为了便于在 Linux 内核中提交你的第一个贡献，我将为你提供一个必需的快速检查列表，以告诉你在提交补丁时，应该去查看和了解的内容。对于你贡献的第一个补丁的提交流程方面的更多内容，请阅读 [KernelNewbies 的第一个内核补丁教程][1]。
|
||||
|
||||
### 为内核作贡献
|
||||
|
||||
**第 1 步：准备你的系统。**
|
||||
|
||||
本文开始之前，假设你的系统已经具备了如下的工具：
|
||||
|
||||
+ 文本编辑器
|
||||
+ Email 客户端
|
||||
+ 版本控制系统（例如：git）
|
||||
|
||||
**第 2 步：下载 Linux 内核代码仓库。**
|
||||
|
||||
```
|
||||
git clone -b staging-testing
|
||||
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
|
||||
```
|
||||
|
||||
复制你的当前配置：
|
||||
|
||||
```
|
||||
cp /boot/config-`uname -r`* .config
|
||||
```
|
||||
|
||||
**第 3 步：构建/安装你的内核。**
|
||||
|
||||
```
|
||||
make -jX
|
||||
sudo make modules_install install
|
||||
```
|
||||
|
||||
**第 4 步：创建一个分支并切换到该分支。**
|
||||
|
||||
```
|
||||
git checkout -b first-patch
|
||||
```
|
||||
|
||||
**第 5 步：更新你的内核并指向到最新的代码。**
|
||||
|
||||
```
|
||||
git fetch origin
|
||||
git rebase origin/staging-testing
|
||||
```
|
||||
|
||||
**第 6 步：在最新的代码库上产生一个变更。**
|
||||
|
||||
使用 `make` 命令重新编译，确保你的变更没有错误。
|
||||
|
||||
**第 7 步：提交你的变更并创建一个补丁。**
|
||||
|
||||
```
|
||||
git add <file>
|
||||
git commit -s -v
|
||||
git format-patch -o /tmp/ HEAD^
|
||||
```
|
||||
|
||||
|
||||
|
||||
主题是由冒号分隔的文件名组成，跟着是使用祈使语态来描述补丁做了什么。空行之后是强制的 `signed off` 标记，最后是你的补丁的 `diff` 信息。
|
||||
|
||||
下面是另外一个简单补丁的示例：
|
||||
|
||||
|
||||
|
||||
接下来，[从命令行使用邮件][2]（在本例子中使用的是 Mutt）发送这个补丁：
|
||||
|
||||
```
|
||||
mutt -H /tmp/0001-<whatever your filename is>
|
||||
```
|
||||
|
||||
使用 [get_maintainer.pl 脚本][11]，去了解你的补丁应该发送给哪位维护者的列表。
|
||||
|
||||
### 提交你的第一个补丁之前，你应该知道的事情
|
||||
|
||||
* [Greg Kroah-Hartman](3) 的 [staging tree][4] 是提交你的 [第一个补丁][1] 的最好的地方，因为他更容易接受新贡献者的补丁。在你熟悉了补丁发送流程以后，你就可以去发送复杂度更高的子系统专用的补丁。
|
||||
* 你也可以从纠正代码中的编码风格开始。想学习更多关于这方面的内容，请阅读 [Linux 内核编码风格文档][5]。
|
||||
* [checkpatch.pl][6] 脚本可以帮你检测编码风格方面的错误。例如，运行如下的命令：`perl scripts/checkpatch.pl -f drivers/staging/android/* | less`
|
||||
* 你可以去补全开发者留下的 TODO 注释中未完成的内容：`find drivers/staging -name TODO`
|
||||
* [Coccinelle][7] 是一个模式匹配的有用工具。
|
||||
* 阅读 [归档的内核邮件][8]。
|
||||
* 为找到灵感，你可以去遍历 [linux.git 日志][9]去查看以前的作者的提交内容。
|
||||
* 注意：不要与你的补丁的审核者在邮件顶部交流！下面就是一个这样的例子：
|
||||
|
||||
**错误的方式：**
|
||||
|
||||
```
|
||||
Chris,
|
||||
Yes let’s schedule the meeting tomorrow, on the second floor.
|
||||
|
||||
> On Fri, Apr 26, 2013 at 9:25 AM, Chris wrote:
|
||||
> Hey John, I had some questions:
|
||||
> 1. Do you want to schedule the meeting tomorrow?
|
||||
> 2. On which floor in the office?
|
||||
> 3. What time is suitable to you?
|
||||
```
|
||||
（注意那最后一个问题，在回复中无意中落下了。）
|
||||
|
||||
**正确的方式：**
|
||||
|
||||
```
|
||||
Chris,
|
||||
See my answers below...
|
||||
|
||||
> On Fri, Apr 26, 2013 at 9:25 AM, Chris wrote:
|
||||
> Hey John, I had some questions:
|
||||
> 1. Do you want to schedule the meeting tomorrow?
|
||||
Yes tomorrow is fine.
|
||||
> 2. On which floor in the office?
|
||||
Let's keep it on the second floor.
|
||||
> 3. What time is suitable to you?
|
||||
09:00 am would be alright.
|
||||
```
|
||||
（所有问题全部回复，并且这种方式还保存了阅读的时间。）
|
||||
* [Eudyptula challenge][10] 是学习内核基础知识的非常好的方式。
|
||||
|
||||
想学习更多内容，阅读 [KernelNewbies 的第一个内核补丁教程][1]。之后如果你还有任何问题，可以在 [kernelnewbies 邮件列表][12] 或者 [#kernelnewbies IRC channel][13] 中提问。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/8/first-linux-kernel-patch
|
||||
|
||||
作者：[Sayli Karnik][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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://opensource.com/users/sayli
|
||||
[1]:https://kernelnewbies.org/FirstKernelPatch
|
||||
[2]:https://opensource.com/life/15/8/top-4-open-source-command-line-email-clients
|
||||
[3]:https://twitter.com/gregkh
|
||||
[4]:https://www.kernel.org/doc/html/v4.15/process/2.Process.html
|
||||
[5]:https://www.kernel.org/doc/html/v4.10/process/coding-style.html
|
||||
[6]:https://github.com/torvalds/linux/blob/master/scripts/checkpatch.pl
|
||||
[7]:http://coccinelle.lip6.fr/
|
||||
[8]:linux-kernel@vger.kernel.org
|
||||
[9]:https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/
|
||||
[10]:http://eudyptula-challenge.org/
|
||||
[11]:https://github.com/torvalds/linux/blob/master/scripts/get_maintainer.pl
|
||||
[12]:https://kernelnewbies.org/MailingList
|
||||
[13]:https://kernelnewbies.org/IRC
|
||||
@ -1,21 +1,20 @@
|
||||
在 Linux 中安全轻松地管理 Cron 定时任务
|
||||
在 Linux 中安全且轻松地管理 Cron 定时任务
|
||||
======
|
||||
|
||||
|
||||
|
||||
在 Linux 中遇到计划任务的时候，你首先会想到的大概就是 Cron 定时任务了。Cron 定时任务能帮助你在类 Unix 操作系统中计划性地执行命令或者任务。也可以参考一下我们之前的一篇[《关于 Cron 定时任务的新手指导》][1]。对于有一定 Linux 经验的人来说，设置 Cron 定时任务不是什么难事，但对于新手来说就不一定了，他们在编辑 Crontab 文件的时候不知不觉中犯的一些小错误，也有可能把整个 Cron 定时任务搞挂了。如果你在处理 Cron 定时任务的时候为了以防万一，可以尝试使用 **Crontab UI**，它是一个可以在类 Unix 操作系统上安全轻松管理 Cron 定时任务的页面工具。
|
||||
|
||||
Crontab UI 是使用 NodeJS 编写的免费开源软件。有了 Crontab UI，你在创建、删除和修改 Cron 定时任务的时候就不需要手工编辑 Crontab 文件了，只需要打开浏览器稍微操作一下，就能完成上面这些工作。你可以用 Crontab UI 轻松创建、编辑、暂停、删除、备份 Cron 定时任务，甚至还可以简单做到导入、导出、部署其它机器上的 Cron 定时任务，它还支持错误日志、邮件发送和钩子。
|
||||
在 Linux 中遇到计划任务的时候，你首先会想到的大概就是 Cron 定时任务了。Cron 定时任务能帮助你在类 Unix 操作系统中计划性地执行命令或者任务。也可以参考一下我们之前的一篇《[关于 Cron 定时任务的新手指导][1]》。对于有一定 Linux 经验的人来说，设置 Cron 定时任务不是什么难事，但对于新手来说就不一定了，他们在编辑 crontab 文件的时候不知不觉中犯的一些小错误，也有可能把整个 Cron 定时任务搞挂了。如果你在处理 Cron 定时任务的时候为了以防万一，可以尝试使用 **Crontab UI**，它是一个可以在类 Unix 操作系统上安全轻松管理 Cron 定时任务的 Web 页面工具。
|
||||
|
||||
Crontab UI 是使用 NodeJS 编写的自由开源软件。有了 Crontab UI，你在创建、删除和修改 Cron 定时任务的时候就不需要手工编辑 Crontab 文件了，只需要打开浏览器稍微操作一下，就能完成上面这些工作。你可以用 Crontab UI 轻松创建、编辑、暂停、删除、备份 Cron 定时任务，甚至还可以简单地做到导入、导出、部署其它机器上的 Cron 定时任务，它还支持错误日志、邮件发送和钩子。
|
||||
|
||||
### 安装 Crontab UI
|
||||
|
||||
只需要一条命令就可以安装好 Crontab UI，但前提是已经安装好 NPM。如果还没有安装 NPM，可以参考[《如何在 Linux 上安装 NodeJS》][2]这篇文章。
|
||||
只需要一条命令就可以安装好 Crontab UI，但前提是已经安装好 NPM。如果还没有安装 NPM，可以参考《[如何在 Linux 上安装 NodeJS][2]》这篇文章。
|
||||
|
||||
执行这一条命令来安装 Crontab UI。
|
||||
|
||||
```
|
||||
$ npm install -g crontab-ui
|
||||
|
||||
```
|
||||
|
||||
就是这么简单，下面继续来看看在 Crontab UI 上如何管理 Cron 定时任务。
|
||||
@ -23,29 +22,29 @@ $ npm install -g crontab-ui
|
||||
### 在 Linux 上安全轻松管理 Cron 定时任务
|
||||
|
||||
执行这一条命令启动 Crontab UI：
|
||||
|
||||
```
|
||||
$ crontab-ui
|
||||
|
||||
```
|
||||
|
||||
你会看到这样的输出：
|
||||
|
||||
```
|
||||
Node version: 10.8.0
|
||||
Crontab UI is running at http://127.0.0.1:8000
|
||||
|
||||
```
|
||||
|
||||
首先在你的防火墙和路由器上放开 8000 端口，然后打开浏览器访问 **<http://127.0.0.1:8000>**。
|
||||
首先在你的防火墙和路由器上放开 8000 端口，然后打开浏览器访问 `<http://127.0.0.1:8000>`。
|
||||
|
||||
注意，默认只有在本地才能访问到 Crontab UI 的控制台页面。但如果你想让 Crontab UI 使用系统的 IP 地址和自定义端口，也就是想让其它机器也访问到本地的 Crontab UI，你需要使用以下这个命令：
|
||||
|
||||
```
|
||||
$ HOST=0.0.0.0 PORT=9000 crontab-ui
|
||||
Node version: 10.8.0
|
||||
Crontab UI is running at http://0.0.0.0:9000
|
||||
|
||||
```
|
||||
|
||||
Crontab UI 就能够通过 <http://IP-Address>:9000 这样的 URL 被远程机器访问到了。
|
||||
Crontab UI 就能够通过 `<http://IP-Address>:9000` 这样的 URL 被远程机器访问到了。
|
||||
|
||||
Crontab UI 的控制台页面长这样：
|
||||
|
||||
@ -53,19 +52,17 @@ Crontab UI 的控制台页面长这样：
|
||||
|
||||
从上面的截图就可以看到，Crontab UI 的界面非常简洁，所有选项的含义都能不言自明。
|
||||
|
||||
输入 `Ctrl + C` 就可以关闭 Crontab UI。
|
||||
在终端输入 `Ctrl + C` 就可以关闭 Crontab UI。
|
||||
|
||||
**创建、编辑、运行、停止、删除 Cron 定时任务**
|
||||
|
||||
点击“New”，输入 Cron 定时任务的信息并点击“Save”保存，就可以创建一个新的 Cron 定时任务了。
|
||||
#### 创建、编辑、运行、停止、删除 Cron 定时任务
|
||||
|
||||
点击 “New”，输入 Cron 定时任务的信息并点击 “Save” 保存，就可以创建一个新的 Cron 定时任务了。
|
||||
|
||||
1. 为 Cron 定时任务命名，这是可选的；
|
||||
2. 你想要执行的完整命令；
|
||||
3. 设定计划执行的时间。你可以按照启动、每时、每日、每周、每月、每年这些指标快速指定计划任务，也可以明确指定任务执行的具体时间。指定好计划时间后，**Jobs** 区域就会显示 Cron 定时任务的句式。
|
||||
3. 设定计划执行的时间。你可以按照启动、每时、每日、每周、每月、每年这些指标快速指定计划任务，也可以明确指定任务执行的具体时间。指定好计划时间后，“Jobs” 区域就会显示 Cron 定时任务的句式。
|
||||
4. 选择是否为某个 Cron 定时任务记录错误日志。
|
||||
|
||||
|
||||
|
||||
这是我的一个 Cron 定时任务样例。
|
||||
|
||||
|
||||
@ -74,41 +71,40 @@ Crontab UI 的控制台页面长这样：
|
||||
|
||||
|
||||
|
||||
如果你需要更改 Cron 定时任务中的某些参数，只需要点击 **Edit** 按钮并按照你的需求更改对应的参数。点击 **Run** 按钮可以立即执行 Cron 定时任务，点击 **Stop** 则可以立即停止 Cron 定时任务。如果想要查看某个 Cron 定时任务的详细日志，可以点击 **Log** 按钮。对于不再需要的 Cron 定时任务，就可以按 **Delete** 按钮删除。
|
||||
如果你需要更改 Cron 定时任务中的某些参数，只需要点击 “Edit” 按钮并按照你的需求更改对应的参数。点击 “Run” 按钮可以立即执行 Cron 定时任务，点击 “Stop” 则可以立即停止 Cron 定时任务。如果想要查看某个 Cron 定时任务的详细日志，可以点击 “Log” 按钮。对于不再需要的 Cron 定时任务，就可以按 “Delete” 按钮删除。
|
||||
|
||||
**备份 Cron 定时任务**
|
||||
#### 备份 Cron 定时任务
|
||||
|
||||
点击控制台页面的 **Backup** 按钮并确认，就可以备份所有 Cron 定时任务。
|
||||
点击控制台页面的 “Backup” 按钮并确认，就可以备份所有 Cron 定时任务。
|
||||
|
||||
|
||||
|
||||
备份之后，一旦 Crontab 文件出现了错误，就可以使用备份来恢复了。
|
||||
|
||||
**导入/导出其它机器上的 Cron 定时任务**
|
||||
#### 导入/导出其它机器上的 Cron 定时任务
|
||||
|
||||
Crontab UI 还有一个令人注目的功能，就是导入、导出、部署其它机器上的 Cron 定时任务。如果同一个网络里的多台机器都需要执行同样的 Cron 定时任务，只需要点击 **Export** 按钮并选择文件的保存路径，所有的 Cron 定时任务都会导出到 `crontab.db` 文件中。
|
||||
Crontab UI 还有一个令人注目的功能，就是导入、导出、部署其它机器上的 Cron 定时任务。如果同一个网络里的多台机器都需要执行同样的 Cron 定时任务，只需要点击 “Export” 按钮并选择文件的保存路径，所有的 Cron 定时任务都会导出到 `crontab.db` 文件中。
|
||||
|
||||
以下是 `crontab.db` 文件的内容：
|
||||
|
||||
```
|
||||
$ cat Downloads/crontab.db
|
||||
{"name":"Remove Pacman Cache","command":"rm -rf /var/cache/pacman","schedule":"@monthly","stopped":false,"timestamp":"Thu Aug 23 2018 10:34:19 GMT+0000 (Coordinated Universal Time)","logging":"true","mailing":{},"created":1535020459093,"_id":"lcVc1nSdaceqS1ut"}
|
||||
|
||||
```
|
||||
|
||||
导出成文件以后，你就可以把这个 `crontab.db` 文件放置到其它机器上并导入成 Cron 定时任务，而不需要在每一台主机上手动设置 Cron 定时任务。总之，在一台机器上设置完，导出，再导入到其他机器，就完事了。
|
||||
|
||||
**在 Crontab 文件获取/保存 Cron 定时任务**
|
||||
#### 在 Crontab 文件获取/保存 Cron 定时任务
|
||||
|
||||
你可能在使用 Crontab UI 之前就已经使用 `crontab` 命令创建过 Cron 定时任务。如果是这样，你可以点击控制台页面上的 **Get from crontab** 按钮来获取已有的 Cron 定时任务。
|
||||
你可能在使用 Crontab UI 之前就已经使用 `crontab` 命令创建过 Cron 定时任务。如果是这样，你可以点击控制台页面上的 “Get from crontab” 按钮来获取已有的 Cron 定时任务。
|
||||
|
||||
|
||||
|
||||
同样地，你也可以使用 Crontab UI 来将新的 Cron 定时任务保存到 Crontab 文件中，只需要点击 **Save to crontab** 按钮就可以了。
|
||||
同样地，你也可以使用 Crontab UI 来将新的 Cron 定时任务保存到 Crontab 文件中，只需要点击 “Save to crontab” 按钮就可以了。
|
||||
|
||||
管理 Cron 定时任务并没有想象中那么难，即使是新手使用 Crontab UI 也能轻松管理 Cron 定时任务。赶快开始尝试并发表一下你的看法吧。
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/how-to-easily-and-safely-manage-cron-jobs-in-linux/
|
||||
@ -116,7 +112,7 @@ via: https://www.ostechnix.com/how-to-easily-and-safely-manage-cron-jobs-in-linu
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[HankChow](https://github.com/HankChow)
|
||||
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
|
||||
|
||||
@ -2,20 +2,21 @@
|
||||
======
|
||||
|
||||
|
||||
你喜欢音乐吗？那么 Fedora 中可能有你正在寻找的东西。本文介绍在 Fedora 上运行的不同音乐播放器。无论你有大量的音乐库，还是小型音乐库，或者根本没有音乐库，你都会被覆盖到。这里有四个图形程序和一个基于终端的音乐播放器，可以让你挑选。
|
||||
|
||||
你喜欢音乐吗？那么 Fedora 中可能有你正在寻找的东西。本文介绍在 Fedora 上运行的各种音乐播放器。无论你有庞大的音乐库，还是小一些的，抑或根本没有，你都可以用到音乐播放器。这里有四个图形程序和一个基于终端的音乐播放器，可以让你挑选。
|
||||
|
||||
### Quod Libet
|
||||
|
||||
Quod Libet 是你的大型音频库的管理员。如果你有一个大量的音频库，你不想只听，但也要管理，Quod Libet 可能是一个很好的选择。
|
||||
Quod Libet 是一个完备的大型音频库管理器。如果你有一个庞大的音频库，你不想只是听，也想要管理，Quod Libet 可能是一个很好的选择。
|
||||
|
||||
![][1]
|
||||
|
||||
Quod Libet 可以从磁盘上的多个位置导入音乐，并允许你编辑音频文件的标签 - 因此一切都在你的控制之下。额外地，它还有各种插件可用，从简单的均衡器到 [last.fm][2] 同步。你也可以直接从 [Soundcloud][3] 搜索和播放音乐。
|
||||
Quod Libet 可以从磁盘上的多个位置导入音乐，并允许你编辑音频文件的标签 —— 因此一切都在你的控制之下。此外，它还有各种插件可用，从简单的均衡器到 [last.fm][2] 同步。你也可以直接从 [Soundcloud][3] 搜索和播放音乐。
|
||||
|
||||
Quod Libet 在 HiDPI 屏幕上工作得很好，它有 Fedora 的 RPM 包，如果你运行 [Silverblue][5]，它在 [Flathub][4] 中也有。使用 Gnome Software 或命令行安装它：
|
||||
|
||||
Quod Libet 在 HiDPI 屏幕上工作得很好，它有 Fedora 的 RPM 包，如果你运行[Silverblue][5]，它在 [Flathub][4] 中也有。使用 Gnome Software 或命令行安装它：
|
||||
```
|
||||
$ sudo dnf install quodlibet
|
||||
|
||||
```
|
||||
|
||||
### Audacious
|
||||
@ -24,14 +25,14 @@ $ sudo dnf install quodlibet
|
||||
|
||||
![][6]
|
||||
|
||||
Audacious 可能不会立即管理你的所有音乐，但你如果想将音乐组织为文件，它能做得很好。你还可以导出和导入播放列表，而无需重新组织音乐文件本身。
|
||||
Audacious 可能不直接管理你的所有音乐，但你如果想将音乐按文件组织起来，它能做得很好。你还可以导出和导入播放列表，而无需重新组织音乐文件本身。
|
||||
|
||||
额外地，你可以让它看起来像 Winamp。要让它与上面的截图相同，请进入 “Settings/Appearance,”，选择顶部的 “Winamp Classic Interface”，然后选择右下方的 “Refugee” 皮肤。而鲍勃是你的叔叔！这就完成了。
|
||||
此外，你可以让它看起来像 Winamp。要让它与上面的截图相同，请进入 “Settings/Appearance”，选择顶部的 “Winamp Classic Interface”，然后选择右下方的 “Refugee” 皮肤。就这么简单。
|
||||
|
||||
Audacious 在 Fedora 中作为 RPM 提供，可以使用 Gnome Software 或在终端运行以下命令安装：
|
||||
|
||||
```
|
||||
$ sudo dnf install audacious
|
||||
|
||||
```
|
||||
|
||||
### Lollypop
|
||||
@ -40,25 +41,25 @@ Lollypop 是一个音乐播放器，它与 GNOME 集成良好。如果你喜欢
|
||||
|
||||
![][7]
|
||||
|
||||
除了与 GNOME Shell 的良好视觉集成之外，它还可以很好地用于 HiDPI 屏幕，并支持黑暗主题。
|
||||
除了与 GNOME Shell 的良好视觉集成之外，它还可以很好地用于 HiDPI 屏幕，并支持暗色主题。
|
||||
|
||||
额外地，Lollypop 有一个集成的封面下载器和一个所谓的派对模式（右上角的音符按钮），它可以自动选择和播放音乐。它还集成了 [last.fm][2] 或 [libre.fm][8] 等在线服务。
|
||||
|
||||
它有 Fedora 的 RPM 也有用于 [Silverblue][5] 工作站的 [Flathub][4]，使用 Gnome Software 或终端进行安装：
|
||||
|
||||
```
|
||||
$ sudo dnf install lollypop
|
||||
|
||||
```
|
||||
|
||||
### Gradio
|
||||
|
||||
如果你没有任何音乐但仍喜欢听怎么办？或者你只是喜欢收音机？Gradio 就是为你准备的。
|
||||
如果你没有任何音乐但仍想听怎么办？或者你只是喜欢收音机？Gradio 就是为你准备的。
|
||||
|
||||
![][9]
|
||||
|
||||
Gradio 是一个简单的收音机，它允许你搜索和播放网络电台。你可以按国家、语言或直接搜索找到它们。额外地，它可视化地集成到了 GNOME Shell 中，可以与 HiDPI 屏幕配合使用，并且可以选择黑暗主题。
|
||||
|
||||
可以在 [Flathub][4] 中找到 Gradio，它同时可以运行在 Fedora Workstation 和 [Silverblue][5] 中。使用 Gnome Software 安装它
|
||||
可以在 [Flathub][4] 中找到 Gradio，它同时可以运行在 Fedora Workstation 和 [Silverblue][5] 中。使用 Gnome Software 安装它。
|
||||
|
||||
### sox
|
||||
|
||||
@ -67,19 +68,19 @@ Gradio 是一个简单的收音机，它允许你搜索和播放网络电台。
|
||||
![][10]
|
||||
|
||||
sox 是一个非常简单的基于终端的音乐播放器。你需要做的就是运行如下命令：
|
||||
|
||||
```
|
||||
$ play file.mp3
|
||||
|
||||
```
|
||||
|
||||
接着 sox 就会为你播放。除了单独的音频文件外，sox 还支持 m3u 格式的播放列表。
|
||||
|
||||
额外地，因为 sox 是基于终端的程序，你可以在 ssh 中运行它。你有一个带扬声器的家用服务器吗？或者你想从另一台电脑上播放音乐吗？尝试将它与 [tmux][11] 一起使用，这样即使会话关闭也可以继续听。
|
||||
此外，因为 sox 是基于终端的程序，你可以通过 ssh 运行它。你有一个带扬声器的家用服务器吗？或者你想从另一台电脑上播放音乐吗？尝试将它与 [tmux][11] 一起使用，这样即使会话关闭也可以继续听。
|
||||
|
||||
sox 在 Fedora 中以 RPM 提供。运行下面的命令安装：
|
||||
|
||||
```
|
||||
$ sudo dnf install sox
|
||||
|
||||
```
|
||||
|
||||
|
||||
@ -90,19 +91,19 @@ via: https://fedoramagazine.org/5-cool-music-player-apps/
|
||||
作者：[Adam Šamalík][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
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
|
||||
|
||||
[a]:https://fedoramagazine.org/author/asamalik/
|
||||
[1]:https://fedoramagazine.org/wp-content/uploads/2018/08/qodlibet-300x217.png
|
||||
[1]:https://fedoramagazine.org/wp-content/uploads/2018/08/qodlibet-768x555.png
|
||||
[2]:https://last.fm
|
||||
[3]:https://soundcloud.com/
|
||||
[4]:https://flathub.org/home
|
||||
[5]:https://teamsilverblue.org/
|
||||
[6]:https://fedoramagazine.org/wp-content/uploads/2018/08/audacious-300x136.png
|
||||
[7]:https://fedoramagazine.org/wp-content/uploads/2018/08/lollypop-300x172.png
|
||||
[6]:https://fedoramagazine.org/wp-content/uploads/2018/08/audacious-768x348.png
|
||||
[7]:https://fedoramagazine.org/wp-content/uploads/2018/08/lollypop-768x439.png
|
||||
[8]:https://libre.fm
|
||||
[9]:https://fedoramagazine.org/wp-content/uploads/2018/08/gradio.png
|
||||
[10]:https://fedoramagazine.org/wp-content/uploads/2018/08/sox-300x179.png
|
||||
[9]:https://fedoramagazine.org/wp-content/uploads/2018/08/gradio-768x499.png
|
||||
[10]:https://fedoramagazine.org/wp-content/uploads/2018/08/sox-768x457.png
|
||||
[11]:https://fedoramagazine.org/use-tmux-more-powerful-terminal/
|
||||
133
published/20180824 What Stable Kernel Should I Use.md
Normal file
133
published/20180824 What Stable Kernel Should I Use.md
Normal file
@ -0,0 +1,133 @@
|
||||
我应该使用哪些稳定版内核？
|
||||
======
|
||||
> 本文作者 Greg Kroah-Hartman 是 Linux 稳定版内核的维护负责人。
|
||||
|
||||
很多人都问我这样的问题，在他们的产品/设备/笔记本/服务器等上面应该使用什么样的稳定版内核。一直以来，尤其是那些现在已经延长支持时间的内核，都是由我和其他人提供支持，因此，给出这个问题的答案并不是件容易的事情。在这篇文章我将尝试去给出我在这个问题上的看法。当然，你可以任意选用任何一个你想去使用的内核版本，这里只是我的建议。
|
||||
|
||||
和以前一样，在这里给出的这些看法只代表我个人的意见。
|
||||
|
||||
### 可选择的内核有哪些
|
||||
|
||||
下面列出了我建议你应该去使用的内核的列表，从最好的到最差的都有。我在下面将详细介绍，但是如果你只想得到一个结论，它就是你想要的：
|
||||
|
||||
建议你使用的内核的分级，从最佳的方案到最差的方案如下：
|
||||
|
||||
* 你最喜欢的 Linux 发行版支持的内核
|
||||
* 最新的稳定版
|
||||
* 最新的 LTS （长期支持）版本
|
||||
* 仍然处于维护状态的老的 LTS 版本
|
||||
|
||||
绝对不要去使用的内核：
|
||||
|
||||
* 不再维护的内核版本
|
||||
|
||||
给上面的列表给出具体的数字，今天是 2018 年 8 月 24 日，kernel.org 页面上可以看到是这样：
|
||||
|
||||
![][1]
|
||||
|
||||
因此，基于上面的列表，那它应该是：
|
||||
|
||||
* 4.18.5 是最新的稳定版
|
||||
* 4.14.67 是最新的 LTS 版本
|
||||
* 4.9.124、4.4.152、以及 3.16.57 是仍然处于维护状态的老的 LTS 版本
|
||||
* 4.17.19 和 3.18.119 是过去 60 天内有过发布的 “生命周期终止” 的内核版本，它们仍然保留在 kernel.org 站点上，是为了仍然想去使用它们的那些人。
|
||||
|
||||
非常容易，对吗？
|
||||
|
||||
Ok，现在我给出这样选择的一些理由：
|
||||
|
||||
### Linux 发行版内核
|
||||
|
||||
对于大多数 Linux 用户来说，最好的方案就是使用你喜欢的 Linux 发行版的内核。就我本人而言，我比较喜欢基于社区的、内核不断滚动升级的用最新内核的 Linux 发行版，并且它也是由开发者社区来支持的。这种类型的发行版有 Fedora、openSUSE、Arch、Gentoo、CoreOS，以及其它的。
|
||||
|
||||
所有这些发行版都使用了上游的最新的稳定版内核，并且确保定期打了需要的 bug 修复补丁。当它拥有了最新的修复之后（[记住所有的修复都是安全修复][2])，这就是你可以使用的最安全、最好的内核之一。
|
||||
|
||||
有些社区的 Linux 发行版需要很长的时间才发行一个新内核版本，但是最终发行的版本和所支持的内核都是非常好的。这些也都非常好用，Debian 和 Ubuntu 就是这样的例子。
|
||||
|
||||
如果我没有在这里列出你所喜欢的发行版，并不是意味着它们的内核不够好。查看这些发行版的网站，确保它们的内核包是不断应用最新的安全补丁进行升级过的，那么它就应该是很好的。
|
||||
|
||||
许多人好像喜欢旧式、“传统” 模式的发行版，使用 RHEL、SLES、CentOS 或者 “LTS” Ubuntu 发行版。这些发行版挑选一个特定的内核版本，然后使用好几年，甚至几十年。他们反向移植了最新的 bug 修复，有时也有一些内核的新特性，所有的只是追求堂吉诃德式的保持版本号不变而已，尽管他们已经在那个旧的内核版本上做了成千上万的变更。这项工作是一项真正吃力不讨好的工作，分配到这些任务的开发人员做了一些精彩的工作才能实现这些目标。所以如果你希望永远不看到你的内核版本号发生过变化，那么就使用这些发行版。他们通常会为使用而付出一些钱，当发生错误时能够从这些公司得到一些支持，那就是值得的。
|
||||
|
||||
所以，你能使用的最好的内核是你可以求助于别人，而别人可以为你提供支持的内核。使用那些支持，你通常都已经为它支付过费用了（对于企业发行版），而这些公司也知道他们职责是什么。
|
||||
|
||||
但是，如果你不希望去依赖别人，而是希望你自己管理你的内核，或者你有发行版不支持的硬件，那么你应该去使用最新的稳定版：
|
||||
|
||||
### 最新的稳定版
|
||||
|
||||
最新的稳定版内核是 Linux 内核开发者社区宣布为“稳定版”的最新的一个内核。大约每三个月，社区发行一个包含了对所有新硬件支持的、新的稳定版内核，最新版的内核不但改善内核性能，同时还包含内核各部分的 bug 修复。接下来的三个月之后，进入到下一个内核版本的 bug 修复将被反向移植进入这个稳定版内核中，因此，使用这个内核版本的用户将确保立即得到这些修复。
|
||||
|
||||
最新的稳定版内核通常也是主流社区发行版所使用的内核，因此你可以确保它是经过测试和拥有大量用户使用的内核。另外，内核社区（全部开发者超过 4000 人）也将帮助这个发行版提供对用户的支持，因为这是他们做的最新的一个内核。
|
||||
|
||||
三个月之后，将发行一个新的稳定版内核，你应该去更新到它以确保你的内核始终是最新的稳定版，因为当最新的稳定版内核发布之后，对你的当前稳定版内核的支持通常会落后几周时间。
|
||||
|
||||
如果你在上一个 LTS （长期支持）版本发布之后购买了最新的硬件，为了能够支持最新的硬件，你几乎是绝对需要去运行这个最新的稳定版内核。对于台式机或新的服务器，最新的稳定版内核通常是推荐运行的内核。
|
||||
|
||||
### 最新的 LTS 版本
|
||||
|
||||
如果你的硬件为了保证正常运行（像大多数的嵌入式设备），需要依赖供应商的源码<ruby>树外<rt>out-of-tree</rt></ruby>的补丁，那么对你来说，最好的内核版本是最新的 LTS 版本。这个版本拥有所有进入稳定版内核的最新 bug 修复，以及大量的用户测试和使用。
|
||||
|
||||
请注意，这个最新的 LTS 版本没有新特性，并且也几乎不会增加对新硬件的支持，因此，如果你需要使用一个新设备，那你的最佳选择就是最新的稳定版内核，而不是最新的 LTS 版内核。
|
||||
|
||||
另外，对于这个 LTS 版本的用户来说，他也不用担心每三个月一次的“重大”升级。因此，他们将一直坚持使用这个 LTS 版本，并每年升级一次，这是一个很好的实践。
|
||||
|
||||
使用这个 LTS 版本的不利方面是，你没法得到在最新版本内核上实现的内核性能提升，除非在未来的一年中，你升级到下一个 LTS 版内核。
|
||||
|
||||
另外，如果你使用的这个内核版本有问题，你所做的第一件事情就是向任意一位内核开发者报告发生的问题，并向他们询问，“最新的稳定版内核中是否也存在这个问题？”并且，你需要意识到，对它的支持不会像使用最新的稳定版内核那样容易得到。
|
||||
|
||||
现在，如果你坚持使用一个有大量的补丁集的内核，并且不希望升级到每年一次的新 LTS 版内核上，那么，或许你应该去使用老的 LTS 版内核：
|
||||
|
||||
### 老的 LTS 版本
|
||||
|
||||
传统上，这些版本都由社区提供 2 年时间的支持，有时候当一个重要的 Linux 发行版（像 Debian 或 SLES）依赖它时，这个支持时间会更长。然而在过去一年里，感谢 Google、Linaro、Linaro 成员公司、[kernelci.org][3]、以及其它公司在测试和基础设施上的大量投入，使得这些老的 LTS 版内核得到更长时间的支持。
|
||||
|
||||
最新的 LTS 版本以及它们将被支持多长时间，这是 2018 年 8 月 24 日显示在 [kernel.org/category/releases.html][4] 上的信息：
|
||||
|
||||
![][5]
|
||||
|
||||
Google 和其它公司希望这些内核使用的时间更长的原因是，由于现在几乎所有的 SoC 芯片的疯狂的（也有人说是打破常规）开发模型。这些设备在芯片发行前几年就启动了他们的开发周期，而那些代码从来不会合并到上游，最终结果是新打造的芯片是基于一个 2 年以前的老内核发布的。这些 SoC 的代码树通常增加了超过 200 万行的代码，这使得它们成为我们前面称之为“类 Linux 内核“的东西。
|
||||
|
||||
如果在 2 年后，这个 LTS 版本停止支持，那么来自社区的支持将立即停止，并且没有人对它再进行 bug 修复。这导致了在全球各地数以百万计的非常不安全的设备仍然在使用中，这对任何生态系统来说都不是什么好事情。
|
||||
|
||||
由于这种依赖，这些公司现在要求新设备不断更新到最新的 LTS 版本——这些为它们特定发布的版本（例如现在的每个 4.9.y 版本）。其中一个这样的例子就是新 Android 设备对内核版本的要求，这些新设备所带的 “Andrid O” 版本（和现在的 “Android P” 版本）指定了最低允许使用的内核版本，并且 Andoird 安全更新版本也开始越来越频繁在设备上要求使用这些 “.y” 版本。
|
||||
|
||||
我注意到一些生产商现在已经在做这些事情。Sony 是其中一个非常好的例子，在他们的大多数新手机上，通过他们每季度的安全更新版本，将设备更新到最新的 4.4.y 发行版上。另一个很好的例子是一家小型公司 Essential，据我所知，他们持续跟踪 4.4.y 版本的速度比其它公司都快。
|
||||
|
||||
当使用这种老的内核时有个重大警告。反向移植到这种内核中的安全修复不如最新版本的 LTS 内核多，因为这些使用老的 LTS 内核的设备的传统模式是一个更加简化的用户模式。这些内核不能用于任何“通用计算”模式中，在这里用的是<ruby>不可信用户<rt>untrusted user</rt></ruby>或虚拟机，极大地削弱了对老的内核做像最近的 Spectre 这样的修复的能力，如果在一些分支中存在这样的 bug 的话。
|
||||
|
||||
因此，仅在你能够完全控制的设备，或者限定在一个非常强大的安全模型（像 Android 一样强制使用 SELinux 和应用程序隔离）时使用老的 LTS 版本。绝对不要在有不可信用户/程序，或虚拟机的服务器上使用这些老的 LTS 版内核。
|
||||
|
||||
此外，如果社区对它有支持的话，社区对这些老的 LTS 版内核相比正常的 LTS 版内核的支持要少的多。如果你使用这些内核，那么你只能是一个人在战斗，你需要有能力去独自支持这些内核，或者依赖你的 SoC 供应商为你提供支持（需要注意的是，几乎没有供应商会为你提供支持，因此，你要特别注意 ……）。
|
||||
|
||||
### 不再维护的内核发行版
|
||||
|
||||
更让人感到惊讶的事情是，许多公司只是随便选一个内核发行版，然后将它封装到它们的产品里，并将它毫不犹豫地承载到数十万的部件中。其中一个这样的糟糕例子是 Lego Mindstorm 系统，不知道是什么原因在它们的设备上随意选取了一个 -rc 的内核发行版。-rc 的发行版是开发中的版本，根本没有 Linux 内核开发者认为它适合任何人使用，更不用说是数百万的用户了。
|
||||
|
||||
当然，如果你愿意，你可以随意地使用它，但是需要注意的是，可能真的就只有你一个人在使用它。社区不会为你提供支持，因为他们不可能关注所有内核版本的特定问题，因此如果出现错误，你只能独自去解决它。对于一些公司和系统来说，这么做可能还行，但是如果没有为此有所规划，那么要当心因此而产生的“隐性”成本。
|
||||
|
||||
### 总结
|
||||
|
||||
基于以上原因，下面是一个针对不同类型设备的简短列表，这些设备我推荐适用的内核如下：
|
||||
|
||||
* 笔记本 / 台式机：最新的稳定版内核
|
||||
* 服务器：最新的稳定版内核或最新的 LTS 版内核
|
||||
* 嵌入式设备：最新的 LTS 版内核或老的 LTS 版内核（如果使用的安全模型非常强大和严格）
|
||||
|
||||
至于我，在我的机器上运行什么样的内核？我的笔记本运行的是最新的开发版内核（即 Linus 的开发树）再加上我正在做修改的内核，我的服务器上运行的是最新的稳定版内核。因此，尽管我负责 LTS 发行版的支持工作，但我自己并不使用 LTS 版内核，除了在测试系统上。我依赖于开发版和最新的稳定版内核，以确保我的机器运行的是目前我们所知道的最快的也是最安全的内核版本。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://kroah.com/log/blog/2018/08/24/what-stable-kernel-should-i-use/
|
||||
|
||||
作者：[Greg Kroah-Hartman][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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://kroah.com
|
||||
[1]:https://s3.amazonaws.com/kroah.com/images/kernel.org_2018_08_24.png
|
||||
[2]:http://kroah.com/log/blog/2018/02/05/linux-kernel-release-model/
|
||||
[3]:https://kernelci.org/
|
||||
[4]:https://www.kernel.org/category/releases.html
|
||||
[5]:https://s3.amazonaws.com/kroah.com/images/kernel.org_releases_2018_08_24.png
|
||||
88
published/20180827 4 tips for better tmux sessions.md
Normal file
88
published/20180827 4 tips for better tmux sessions.md
Normal file
@ -0,0 +1,88 @@
|
||||
更好利用 tmux 会话的 4 个技巧
|
||||
======
|
||||
|
||||
|
||||
|
||||
tmux 是一个终端多路复用工具，它可以让你系统上的终端支持多面板。你可以排列面板位置，在每个面板运行不同进程，这通常可以更好的地利用你的屏幕。我们在 [这篇早期的文章][1] 中向读者介绍过这一强力工具。如果你已经开始使用 tmux 了，那么这里有一些技巧可以帮你更好地使用它。
|
||||
|
||||
本文假设你当前的前缀键是 `Ctrl+b`。如果你已重新映射该前缀，只需在相应位置替换为你定义的前缀即可。
|
||||
|
||||
### 设置终端为自动使用 tmux
|
||||
|
||||
使用 tmux 的一个最大好处就是可以随意的从会话中断开和重连。这使得远程登录会话功能更加强大。你有没有遇到过丢失了与远程系统的连接，然后好希望能够恢复在远程系统上做过的那些工作的情况？tmux 能够解决这一问题。
|
||||
|
||||
然而，有时在远程系统上工作时，你可能会忘记开启会话。避免出现这一情况的一个方法就是每次通过交互式 shell 登录系统时都让 tmux 启动或附加上一个会话。
|
||||
|
||||
在你远程系统上的 `~/.bash_profile` 文件中加入下面内容：
|
||||
|
||||
```
|
||||
if [ -z "$TMUX" ]; then
|
||||
tmux attach -t default || tmux new -s default
|
||||
fi
|
||||
```
|
||||
|
||||
然后注销远程系统，并使用 SSH 重新登录。你会发现你处在一个名为 `default` 的 tmux 会话中了。如果退出该会话，则下次登录时还会重新生成此会话。但更重要的是，若您正常地从会话中分离，那么下次登录时你会发现之前工作并没有丢失 - 这在连接中断时非常有用。
|
||||
|
||||
你当然也可以将这段配置加入本地系统中。需要注意的是，大多数 GUI 界面的终端并不会自动使用这个 `default` 会话，因此它们并不是登录 shell。虽然你可以修改这一行为，但它可能会导致终端嵌套执行附加到 tmux 会话这一动作，从而导致会话不太可用，因此当进行此操作时请一定小心。
|
||||
|
||||
### 使用缩放功能使注意力专注于单个进程
|
||||
|
||||
虽然 tmux 的目的就是在单个会话中提供多窗口、多面板和多进程的能力，但有时候你需要专注。如果你正在与一个进程进行交互并且需要更多空间，或需要专注于某个任务，则可以使用缩放命令。该命令会将当前面板扩展，占据整个当前窗口的空间。
|
||||
|
||||
缩放在其他情况下也很有用。比如，想象你在图形桌面上运行一个终端窗口。面板会使得从 tmux 会话中拷贝和粘帖多行内容变得相对困难。但若你缩放了面板，就可以很容易地对多行数据进行拷贝/粘帖。
|
||||
|
||||
要对当前面板进行缩放，按下 `Ctrl+b, z`。需要恢复的话，按下相同按键组合来恢复面板。
|
||||
|
||||
### 绑定一些有用的命令
|
||||
|
||||
tmux 默认有大量的命令可用。但将一些更常用的操作绑定到容易记忆的快捷键会很有用。下面一些例子可以让会话变得更好用，你可以添加到 `~/.tmux.conf` 文件中：
|
||||
|
||||
```
|
||||
bind r source-file ~/.tmux.conf \; display "Reloaded config"
|
||||
```
|
||||
|
||||
该命令重新读取你配置文件中的命令和键绑定。添加该条绑定后，退出任意一个 tmux 会话然后重启一个会话。现在你做了任何更改后，只需要简单的按下 `Ctrl+b, r` 就能将修改的内容应用到现有的会话中了。
|
||||
|
||||
```
|
||||
bind V split-window -h
|
||||
bind H split-window
|
||||
```
|
||||
|
||||
这些命令可以很方便地对窗口进行横向切分（按下 `Shift+V`）和纵向切分（`Shift+H`）。
|
||||
|
||||
若你想查看所有绑定的快捷键，按下 `Ctrl+B, ?` 可以看到一个列表。你首先看到的应该是复制模式下的快捷键绑定，表示的是当你在 tmux 中进行复制粘帖时对应的快捷键。你添加的那两个键绑定会在<ruby>前缀模式<rt>prefix mode</rt></ruby>中看到。请随意把玩吧！
|
||||
|
||||
### 使用 powerline 更清晰
|
||||
|
||||
[如前文所示][2]，powerline 工具是对 shell 的绝佳补充。而且它也兼容在 tmux 中使用。由于 tmux 接管了整个终端空间，powerline 窗口能提供的可不仅仅是更好的 shell 提示那么简单。
|
||||
|
||||
[][3]
|
||||
|
||||
如果你还没有这么做，按照 [这篇文章][4] 中的指示来安装该工具。然后[使用 sudo][5] 来安装附件：
|
||||
|
||||
```
|
||||
sudo dnf install tmux-powerline
|
||||
```
|
||||
|
||||
接着重启会话，就会在底部看到一个漂亮的新状态栏。根据终端的宽度，默认的状态栏会显示你当前会话 ID、打开的窗口、系统信息、日期和时间，以及主机名。若你进入了使用 git 进行版本控制的项目目录中还能看到分支名和用色彩标注的版本库状态。
|
||||
|
||||
当然，这个状态栏具有很好的可配置性。享受你新增强的 tmux 会话吧，玩的开心点。
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/4-tips-better-tmux-sessions/
|
||||
|
||||
作者：[Paul W. Frields][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
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/pfrields/
|
||||
[1]:https://fedoramagazine.org/use-tmux-more-powerful-terminal/
|
||||
[2]:https://fedoramagazine.org/add-power-terminal-powerline/
|
||||
[3]:https://fedoramagazine.org/wp-content/uploads/2018/08/Screenshot-from-2018-08-25-19-36-53.png
|
||||
[4]:https://fedoramagazine.org/add-power-terminal-powerline/
|
||||
[5]:https://fedoramagazine.org/howto-use-sudo/
|
||||
@ -0,0 +1,52 @@
|
||||
解决 Arch Linux 中出现的 “error：failed to commit transaction (conflicting files)”
|
||||
======
|
||||
|
||||
|
||||
|
||||
自我更新 Arch Linux 桌面以来已经有一个月了。今天我试着更新我的 Arch Linux 系统，然后遇到一个错误 “error：failed to commit transaction (conflicting files) stfl：/usr/lib/libstfl.so.0 exists in filesystem”。看起来是 pacman 无法更新一个已经存在于文件系统上的库 (/usr/lib/libstfl.so.0)。如果你也遇到了同样的问题，下面是一个快速解决方案。
|
||||
|
||||
### 解决 Arch Linux 中出现的 “error：failed to commit transaction (conflicting files)”
|
||||
|
||||
有三种方法。
|
||||
|
||||
1。简单在升级时忽略导致问题的 stfl 库并尝试再次更新系统。请参阅此指南以了解 [如何在更新时忽略软件包][1]。
|
||||
|
||||
2。使用命令覆盖这个包：
|
||||
|
||||
```
|
||||
$ sudo pacman -Syu --overwrite /usr/lib/libstfl.so.0
|
||||
```
|
||||
|
||||
3。手工删掉 stfl 库然后再次升级系统。请确保目标包不被其他任何重要的包所依赖。可以通过去 archlinux.org 查看是否有这种冲突。
|
||||
|
||||
```
|
||||
$ sudo rm /usr/lib/libstfl.so.0
|
||||
```
|
||||
|
||||
现在，尝试更新系统：
|
||||
|
||||
```
|
||||
$ sudo pacman -Syu
|
||||
```
|
||||
|
||||
我选择第三种方法，直接删除该文件然后升级 Arch Linux 系统。很有效！
|
||||
|
||||
希望本文对你有所帮助。还有更多好东西。敬请期待！
|
||||
|
||||
干杯！
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/how-to-solve-error-failed-to-commit-transaction-conflicting-files-in-arch-linux/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
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]:https://www.ostechnix.com/safely-ignore-package-upgraded-arch-linux/
|
||||
@ -11,101 +11,84 @@
|
||||
|
||||
### 在 Linux 中使用 Wondershaper 限制网络带宽
|
||||
|
||||
`wondershaper` 是用于显示系统网卡网络带宽的简单脚本。它使用了 `iproute` 和 `tc` 命令，但大大简化了操作过程。
|
||||
`wondershaper` 是用于显示系统网卡网络带宽的简单脚本。它使用了 iproute 的 `tc` 命令，但大大简化了操作过程。
|
||||
|
||||
**安装 Wondershaper**
|
||||
#### 安装 Wondershaper
|
||||
|
||||
使用 `git clone` 克隆 Wondershaper 的版本库就可以安装最新版本：
|
||||
|
||||
```
|
||||
$ git clone https://github.com/magnific0/wondershaper.git
|
||||
|
||||
```
|
||||
|
||||
按照以下命令进入 `wondershaper` 目录并安装：
|
||||
|
||||
```
|
||||
$ cd wondershaper
|
||||
|
||||
$ sudo make install
|
||||
|
||||
```
|
||||
|
||||
然后执行以下命令，可以让 `wondershaper` 在每次系统启动时都自动开始服务：
|
||||
|
||||
```
|
||||
$ sudo systemctl enable wondershaper.service
|
||||
|
||||
$ sudo systemctl start wondershaper.service
|
||||
|
||||
```
|
||||
|
||||
如果你不强求安装最新版本，也可以使用软件包管理器（官方和非官方均可）来进行安装。
|
||||
|
||||
`wondershaper` 在 [Arch 用户软件仓库][1]（Arch User Repository, AUR）中可用，所以可以使用类似 [`yay`][2] 这些 AUR 辅助软件在基于 Arch 的系统中安装 `wondershaper` 。
|
||||
`wondershaper` 在 [Arch 用户软件仓库][1]（Arch User Repository，AUR）中可用，所以可以使用类似 [yay][2] 这些 AUR 辅助软件在基于 Arch 的系统中安装 `wondershaper` 。
|
||||
|
||||
```
|
||||
$ yay -S wondershaper-git
|
||||
|
||||
```
|
||||
|
||||
对于Debian、Ubuntu 和 Linux Mint 可以使用以下命令安装：
|
||||
对于 Debian、Ubuntu 和 Linux Mint 可以使用以下命令安装：
|
||||
|
||||
```
|
||||
$ sudo apt-get install wondershaper
|
||||
|
||||
```
|
||||
|
||||
对于 Fedora 可以使用以下命令安装：
|
||||
|
||||
```
|
||||
$ sudo dnf install wondershaper
|
||||
|
||||
```
|
||||
|
||||
对于 RHEL、CentOS，只需要启用 EPEL 仓库，就可以使用以下命令安装：
|
||||
|
||||
```
|
||||
$ sudo yum install epel-release
|
||||
|
||||
$ sudo yum install wondershaper
|
||||
|
||||
```
|
||||
|
||||
在每次系统启动时都自动启动 `wondershaper` 服务。
|
||||
|
||||
```
|
||||
$ sudo systemctl enable wondershaper.service
|
||||
|
||||
$ sudo systemctl start wondershaper.service
|
||||
|
||||
```
|
||||
|
||||
**用法**
|
||||
#### 用法
|
||||
|
||||
首先需要找到网络接口的名称，通过以下几个命令都可以查询到网卡的详细信息：
|
||||
|
||||
```
|
||||
$ ip addr
|
||||
|
||||
$ route
|
||||
|
||||
$ ifconfig
|
||||
|
||||
```
|
||||
|
||||
在确定网卡名称以后，就可以按照以下的命令限制网络带宽：
|
||||
|
||||
```
|
||||
$ sudo wondershaper -a <adapter> -d <rate> -u <rate>
|
||||
|
||||
```
|
||||
|
||||
例如，如果网卡名称是 `enp0s8`，并且需要把上行、下行速率分别限制为 1024 Kbps 和 512 Kbps，就可以执行以下命令：
|
||||
|
||||
```
|
||||
$ sudo wondershaper -a enp0s8 -d 1024 -u 512
|
||||
|
||||
```
|
||||
|
||||
其中参数的含义是：
|
||||
@ -114,20 +97,16 @@ $ sudo wondershaper -a enp0s8 -d 1024 -u 512
|
||||
* `-d`：下行带宽
|
||||
* `-u`：上行带宽
|
||||
|
||||
|
||||
|
||||
如果要对网卡解除网络带宽的限制，只需要执行：
|
||||
|
||||
```
|
||||
$ sudo wondershaper -c -a enp0s8
|
||||
|
||||
```
|
||||
|
||||
或者：
|
||||
|
||||
```
|
||||
$ sudo wondershaper -c enp0s8
|
||||
|
||||
```
|
||||
|
||||
如果系统中有多个网卡，为确保稳妥，需要按照上面的方法手动设置每个网卡的上行、下行速率。
|
||||
@ -149,13 +128,14 @@ DSPEED="2048"
|
||||
# Upload rate in Kbps
|
||||
#
|
||||
USPEED="512"
|
||||
|
||||
```
|
||||
|
||||
Wondershaper 使用前：
|
||||
|
||||
|
||||
|
||||
Wondershaper 使用后：
|
||||
|
||||
|
||||
|
||||
可以看到，使用 Wondershaper 限制网络带宽之后，下行速率与限制之前相比已经大幅下降。
|
||||
@ -164,21 +144,16 @@ Wondershaper 使用后：
|
||||
|
||||
```
|
||||
$ wondershaper -h
|
||||
|
||||
```
|
||||
|
||||
也可以查看 Wondershaper 的用户手册：
|
||||
|
||||
```
|
||||
$ man wondershaper
|
||||
|
||||
```
|
||||
|
||||
As far as tested, Wondershaper worked just fine as described above. Give it a try and let us know what do you think about this utility.
|
||||
根据测试，Wondershaper 按照上面的方式可以有很好的效果。你可以试用一下，然后发表你的看法。
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/how-to-limit-network-bandwidth-in-linux-using-wondershaper/
|
||||
@ -186,7 +161,7 @@ via: https://www.ostechnix.com/how-to-limit-network-bandwidth-in-linux-using-won
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[HankChow](https://github.com/HankChow)
|
||||
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
|
||||
|
||||
@ -1,21 +1,17 @@
|
||||
如何在 Linux 上使用网络配置工具 Netplan
|
||||
======
|
||||
> netplan 是一个命令行工具，用于在某些 Linux 发行版上配置网络。
|
||||
|
||||
|
||||
|
||||
多年以来 Linux 管理员和用户们使用相同的方式配置他们的网络接口。例如，如果你是 Ubuntu 用户，你能够用桌面 GUI 配置网络连接，也可以在 /etc/network/interfaces 文件里配置。配置相当简单且从未失败。在文件中配置看起来就像这样：
|
||||
多年以来 Linux 管理员和用户们以相同的方式配置他们的网络接口。例如，如果你是 Ubuntu 用户，你能够用桌面 GUI 配置网络连接，也可以在 `/etc/network/interfaces` 文件里配置。配置相当简单且可以奏效。在文件中配置看起来就像这样：
|
||||
|
||||
```
|
||||
auto enp10s0
|
||||
|
||||
iface enp10s0 inet static
|
||||
|
||||
address 192.168.1.162
|
||||
|
||||
netmask 255.255.255.0
|
||||
|
||||
gateway 192.168.1.100
|
||||
|
||||
dns-nameservers 1.0.0.1,1.1.1.1
|
||||
```
|
||||
|
||||
@ -25,7 +21,7 @@ dns-nameservers 1.0.0.1,1.1.1.1
|
||||
sudo systemctl restart networking
|
||||
```
|
||||
|
||||
或者，如果你使用不带systemd 的发行版，你可以通过老办法来重启网络：
|
||||
或者，如果你使用不带 systemd 的发行版，你可以通过老办法来重启网络：
|
||||
|
||||
```
|
||||
sudo /etc/init.d/networking restart
|
||||
@ -33,13 +29,13 @@ sudo /etc/init.d/networking restart
|
||||
|
||||
你的网络将会重新启动，新的配置将会生效。
|
||||
|
||||
这就是多年以来的做法。但是现在，在某些发行版上（例如 Ubuntu Linux 18.04），网络的配置与控制发生了很大的变化。不需要那个 interfaces 文件和 /etc/init.d/networking 脚本，我们现在转向使用 [Netplan][1]。Netplan 是一个在某些 Linux 发行版上配置网络连接的命令行工具。Netplan 使用 YAML 描述文件来配置网络接口，然后，通过这些描述为任何给定的呈现工具生成必要的配置选项。
|
||||
这就是多年以来的做法。但是现在，在某些发行版上（例如 Ubuntu Linux 18.04），网络的配置与控制发生了很大的变化。不需要那个 `interfaces` 文件和 `/etc/init.d/networking` 脚本，我们现在转向使用 [Netplan][1]。Netplan 是一个在某些 Linux 发行版上配置网络连接的命令行工具。Netplan 使用 YAML 描述文件来配置网络接口，然后，通过这些描述为任何给定的呈现工具生成必要的配置选项。
|
||||
|
||||
我将向你展示如何在 Linux 上使用 Netplan 配置静态 IP 地址和 DHCP 地址。我会在 Ubuntu Server 18.04 上演示。有句忠告，你创建的 .yaml 文件中的间距必须保持一致，否则将会失败。你不用为每行使用特定的间距，只需保持一致就行了。
|
||||
我将向你展示如何在 Linux 上使用 Netplan 配置静态 IP 地址和 DHCP 地址。我会在 Ubuntu Server 18.04 上演示。有句忠告，你创建的 .yaml 文件中的缩进必须保持一致，否则将会失败。你不用为每行使用特定的缩进间距，只需保持一致就行了。
|
||||
|
||||
### 新的配置文件
|
||||
|
||||
打开终端窗口（或者通过 SSH 登录进 Ubuntu 服务器）。你会在 /etc/netplan 文件夹下发现 Netplan 的新配置文件。使用 cd/etc/netplan 命令进入到那个文件夹下。一旦进到了那个文件夹，也许你就能够看到一个文件：
|
||||
打开终端窗口（或者通过 SSH 登录进 Ubuntu 服务器）。你会在 `/etc/netplan` 文件夹下发现 Netplan 的新配置文件。使用 `cd /etc/netplan` 命令进入到那个文件夹下。一旦进到了那个文件夹，也许你就能够看到一个文件：
|
||||
|
||||
```
|
||||
01-netcfg.yaml
|
||||
@ -55,13 +51,11 @@ sudo cp /etc/netplan/01-netcfg.yaml /etc/netplan/01-netcfg.yaml.bak
|
||||
|
||||
### 网络设备名称
|
||||
|
||||
在你开始配置静态 IP 之前，你需要知道设备名称。要做到这一点，你可以使用命令 ip a，然后找出哪一个设备将会被用到（图 1）。
|
||||
在你开始配置静态 IP 之前，你需要知道设备名称。要做到这一点，你可以使用命令 `ip a`，然后找出哪一个设备将会被用到（图 1）。
|
||||
|
||||
![netplan][3]
|
||||
|
||||
图 1：使用 ip a 命令找出设备名称
|
||||
|
||||
[Used with permission][4] （译注：这是什么鬼？）
|
||||
*图 1：使用 ip a 命令找出设备名称*
|
||||
|
||||
我将为 ens5 配置一个静态的 IP。
|
||||
|
||||
@ -75,67 +69,46 @@ sudo nano /etc/netplan/01-netcfg.yaml
|
||||
|
||||
文件的布局看起来就像这样：
|
||||
|
||||
```
|
||||
network:
|
||||
|
||||
Version: 2
|
||||
|
||||
Renderer: networkd
|
||||
|
||||
ethernets:
|
||||
|
||||
DEVICE_NAME:
|
||||
|
||||
Dhcp4: yes/no
|
||||
|
||||
Addresses: [IP/NETMASK]
|
||||
|
||||
Gateway: GATEWAY
|
||||
|
||||
Nameservers:
|
||||
|
||||
Addresses: [NAMESERVER, NAMESERVER]
|
||||
Version: 2
|
||||
Renderer: networkd
|
||||
ethernets:
|
||||
DEVICE_NAME:
|
||||
Dhcp4: yes/no
|
||||
Addresses: [IP/NETMASK]
|
||||
Gateway: GATEWAY
|
||||
Nameservers:
|
||||
Addresses: [NAMESERVER, NAMESERVER]
|
||||
```
|
||||
|
||||
其中：
|
||||
|
||||
* DEVICE_NAME 是需要配置设备的实际名称。
|
||||
|
||||
* yes/no 代表是否启用 dhcp4。
|
||||
|
||||
* IP 是设备的 IP 地址。
|
||||
|
||||
* NETMASK 是 IP 地址的掩码。
|
||||
|
||||
* GATEWAY 是网关的地址。
|
||||
|
||||
* NAMESERVER 是由逗号分开的 DNS 服务器列表。
|
||||
* `DEVICE_NAME` 是需要配置设备的实际名称。
|
||||
* `yes`/`no` 代表是否启用 dhcp4。
|
||||
* `IP` 是设备的 IP 地址。
|
||||
* `NETMASK` 是 IP 地址的掩码。
|
||||
* `GATEWAY` 是网关的地址。
|
||||
* `NAMESERVER` 是由逗号分开的 DNS 服务器列表。
|
||||
|
||||
这是一份 .yaml 文件的样例：
|
||||
|
||||
```
|
||||
network:
|
||||
|
||||
version: 2
|
||||
|
||||
renderer: networkd
|
||||
|
||||
ethernets:
|
||||
|
||||
ens5:
|
||||
|
||||
dhcp4: no
|
||||
|
||||
addresses: [192.168.1.230/24]
|
||||
|
||||
gateway4: 192.168.1.254
|
||||
|
||||
nameservers:
|
||||
|
||||
addresses: [8.8.4.4,8.8.8.8]
|
||||
version: 2
|
||||
renderer: networkd
|
||||
ethernets:
|
||||
ens5:
|
||||
dhcp4: no
|
||||
addresses: [192.168.1.230/24]
|
||||
gateway4: 192.168.1.254
|
||||
nameservers:
|
||||
addresses: [8.8.4.4,8.8.8.8]
|
||||
```
|
||||
|
||||
编辑上面的文件以达到你想要的效果。保存并关闭文件。
|
||||
|
||||
注意，掩码已经不用再配置为 255.255.255.0 这种形式。取而代之的是，掩码已被添加进了 IP 地址中。
|
||||
注意，掩码已经不用再配置为 `255.255.255.0` 这种形式。取而代之的是，掩码已被添加进了 IP 地址中。
|
||||
|
||||
### 测试配置
|
||||
|
||||
@ -165,20 +138,13 @@ sudo netplan apply
|
||||
|
||||
```
|
||||
network:
|
||||
|
||||
version: 2
|
||||
|
||||
renderer: networkd
|
||||
|
||||
ethernets:
|
||||
|
||||
ens5:
|
||||
|
||||
Addresses: []
|
||||
|
||||
dhcp4: true
|
||||
|
||||
optional: true
|
||||
version: 2
|
||||
renderer: networkd
|
||||
ethernets:
|
||||
ens5:
|
||||
Addresses: []
|
||||
dhcp4: true
|
||||
optional: true
|
||||
```
|
||||
|
||||
保存并退出。用下面命令来测试文件：
|
||||
@ -187,15 +153,15 @@ network:
|
||||
sudo netplan try
|
||||
```
|
||||
|
||||
Netplan 应该会成功配置 DHCP 服务。这时你可以使用 ip a 命令得到动态分配的地址，然后重新配置静态地址。或者，你可以直接使用 DHCP 分配的地址（但看看这是一个服务器，你可能不想这样做）。
|
||||
Netplan 应该会成功配置 DHCP 服务。这时你可以使用 `ip a` 命令得到动态分配的地址，然后重新配置静态地址。或者，你可以直接使用 DHCP 分配的地址（但看看这是一个服务器，你可能不想这样做）。
|
||||
|
||||
也许你有不只一个的网络接口，你可以命名第二个 .yaml 文件为 02-netcfg.yaml 。Netplan 会按照数字顺序应用配置文件，因此 01 会在 02 之前使用。根据你的需要创建多个配置文件。
|
||||
也许你有不只一个的网络接口，你可以命名第二个 .yaml 文件为 `02-netcfg.yaml` 。Netplan 会按照数字顺序应用配置文件，因此 01 会在 02 之前使用。根据你的需要创建多个配置文件。
|
||||
|
||||
### 就是这些了
|
||||
|
||||
不管你信不信，那些就是所有关于使用 Netplan 的东西了。虽然它对于我们习惯性的配置网络地址来说是一个相当大的改变，但并不是所有人都用的惯。但这种配置方式值得一提...因此你会适应的。
|
||||
不管怎样，那些就是所有关于使用 Netplan 的东西了。虽然它对于我们习惯性的配置网络地址来说是一个相当大的改变，但并不是所有人都用的惯。但这种配置方式值得一提……因此你会适应的。
|
||||
|
||||
在 Linux Foundation 和 edX 上通过 ["Introduction to Linux"] 课程学习更多关于 Linux 的内容。
|
||||
在 Linux Foundation 和 edX 上通过 [“Introduction to Linux”][5] 课程学习更多关于 Linux 的内容。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -204,7 +170,7 @@ via: https://www.linux.com/learn/intro-to-linux/2018/9/how-use-netplan-network-c
|
||||
作者：[Jack Wallen][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[LuuMing](https://github.com/LuuMing)
|
||||
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
|
||||
|
||||
@ -1,10 +1,11 @@
|
||||
如何在 Linux 中列出可用的软件包组
|
||||
======
|
||||
|
||||
我们知道，如果想要在 Linux 中安装软件包，可以使用软件包管理器来进行安装。由于系统管理员需要频繁用到软件包管理器，所以它是 Linux 当中的一个重要工具。
|
||||
|
||||
但是如果想一次性安装一个软件包组，在 Linux 中有可能吗？又如何通过命令去实现呢？
|
||||
|
||||
在 Linux 中确实可以用软件包管理器来达到这样的目的。很多软件包管理器都有这样的选项来实现这个功能，但就我所知，`apt` 或 `apt-get` 软件包管理器却并没有这个选项。因此对基于 Debian 的系统，需要使用的命令是 `tasksel`，而不是 `apt`或 `apt-get` 这样的官方软件包管理器。
|
||||
在 Linux 中确实可以用软件包管理器来达到这样的目的。很多软件包管理器都有这样的选项来实现这个功能，但就我所知，`apt` 或 `apt-get` 软件包管理器却并没有这个选项。因此对基于 Debian 的系统，需要使用的命令是 `tasksel`，而不是 `apt` 或 `apt-get` 这样的官方软件包管理器。
|
||||
|
||||
在 Linux 中安装软件包组有很多好处。对于 LAMP 来说，安装过程会包含多个软件包，但如果安装软件包组命令来安装，只安装一个包就可以了。
|
||||
|
||||
@ -13,19 +14,20 @@
|
||||
软件包组是一组用于公共功能的软件包，包括系统工具、声音和视频。 安装软件包组的过程中，会获取到一系列的依赖包，从而大大节省了时间。
|
||||
|
||||
**推荐阅读：**
|
||||
**(#)** [如何在 Linux 上按照大小列出已安装的软件包][1]
|
||||
**(#)** [如何在 Linux 上查看/列出可用的软件包更新][2]
|
||||
**(#)** [如何在 Linux 上查看软件包的安装/更新/升级/移除/卸载时间][3]
|
||||
**(#)** [如何在 Linux 上查看一个软件包的详细信息][4]
|
||||
**(#)** [如何查看一个软件包是否在你的 Linux 发行版上可用][5]
|
||||
**(#)** [萌新指导：一个可视化的 Linux 包管理工具][6]
|
||||
**(#)** [老手必会：命令行软件包管理器的用法][7]
|
||||
|
||||
- [如何在 Linux 上按照大小列出已安装的软件包][1]
|
||||
- [如何在 Linux 上查看/列出可用的软件包更新][2]
|
||||
- [如何在 Linux 上查看软件包的安装/更新/升级/移除/卸载时间][3]
|
||||
- [如何在 Linux 上查看一个软件包的详细信息][4]
|
||||
- [如何查看一个软件包是否在你的 Linux 发行版上可用][5]
|
||||
- [萌新指导：一个可视化的 Linux 包管理工具][6]
|
||||
- [老手必会：命令行软件包管理器的用法][7]
|
||||
|
||||
### 如何在 CentOS/RHEL 系统上列出可用的软件包组
|
||||
|
||||
RHEL 和 CentOS 系统使用的是 RPM 软件包，因此可以使用 `yum` 软件包管理器来获取相关的软件包信息。
|
||||
|
||||
`yum` 是 Yellowdog Updater, Modified 的缩写，它是一个用于基于 RPM 系统（例如 RHEL 和 CentOS）的，开源的命令行软件包管理工具。它是从分发库或其它第三方库中获取、安装、删除、查询和管理 RPM 包的主要工具。
|
||||
`yum` 是 “Yellowdog Updater, Modified” 的缩写，它是一个用于基于 RPM 系统（例如 RHEL 和 CentOS）的，开源的命令行软件包管理工具。它是从发行版仓库或其它第三方库中获取、安装、删除、查询和管理 RPM 包的主要工具。
|
||||
|
||||
**推荐阅读：** [使用 yum 命令在 RHEL/CentOS 系统上管理软件包][8]
|
||||
|
||||
@ -69,10 +71,9 @@ Available Language Groups:
|
||||
.
|
||||
.
|
||||
Done
|
||||
|
||||
```
|
||||
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 Performance Tools 组相关联的软件包。
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 “Performance Tools” 组相关联的软件包。
|
||||
|
||||
```
|
||||
# yum groupinfo "Performance Tools"
|
||||
@ -103,18 +104,17 @@ Group: Performance Tools
|
||||
tiobench
|
||||
tuned
|
||||
tuned-utils
|
||||
|
||||
```
|
||||
|
||||
### 如何在 Fedora 系统上列出可用的软件包组
|
||||
|
||||
Fedora 系统使用的是 DNF 软件包管理器，因此可以通过 DNF 软件包管理器来获取相关的信息。
|
||||
|
||||
DNF 的含义是 Dandified yum。、DNF 软件包管理器是 YUM 软件包管理器的一个分支，它使用 hawkey/libsolv 库作为后端。从 Fedora 18 开始，Aleš Kozumplík 开始着手 DNF 的开发，直到在Fedora 22 开始加入到系统中。
|
||||
DNF 的含义是 “Dandified yum”。DNF 软件包管理器是 YUM 软件包管理器的一个分支，它使用 hawkey/libsolv 库作为后端。从 Fedora 18 开始，Aleš Kozumplík 开始着手 DNF 的开发，直到在 Fedora 22 开始加入到系统中。
|
||||
|
||||
`dnf` 命令可以在 Fedora 22 及更高版本上安装、更新、搜索和删除软件包， 它可以自动解决软件包的依赖关系并其顺利安装，不会产生问题。
|
||||
|
||||
由于一些长期未被解决的问题的存在，YUM 被 DNF 逐渐取代了。而 Aleš Kozumplík 的 DNF 却并未对 yum 的这些问题作出修补，他认为这是技术上的难题，YUM 团队也从不接受这些更改。而且 YUM 的代码量有 5.6 万行，而 DNF 只有 2.9 万行。因此已经不需要沿着 YUM 的方向继续开发了，重新开一个分支才是更好的选择。
|
||||
YUM 被 DNF 取代是由于 YUM 中存在一些长期未被解决的问题。为什么 Aleš Kozumplík 没有对 yum 的这些问题作出修补呢，他认为补丁解决存在技术上的难题，而 YUM 团队也不会马上接受这些更改，还有一些重要的问题。而且 YUM 的代码量有 5.6 万行，而 DNF 只有 2.9 万行。因此已经不需要沿着 YUM 的方向继续开发了，重新开一个分支才是更好的选择。
|
||||
|
||||
**推荐阅读：** [在 Fedora 系统上使用 DNF 命令管理软件包][9]
|
||||
|
||||
@ -167,13 +167,11 @@ Available Groups:
|
||||
Hardware Support
|
||||
Sound and Video
|
||||
System Tools
|
||||
|
||||
```
|
||||
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 Editor 组相关联的软件包。
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 “Editor” 组相关联的软件包。
|
||||
|
||||
```
|
||||
|
||||
# dnf groupinfo Editors
|
||||
Last metadata expiration check: 0:04:57 ago on Sun 09 Sep 2018 07:10:36 PM IST.
|
||||
|
||||
@ -267,7 +265,7 @@ i | yast2_basis | 20150918-25.1 | @System |
|
||||
| yast2_install_wf | 20150918-25.1 | Main Repository (OSS) |
|
||||
```
|
||||
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 file_server 组相关联的软件包。另外 `zypper` 还允许用户使用不同的选项执行相同的操作。
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 “file_server” 组相关联的软件包。另外 `zypper` 还允许用户使用不同的选项执行相同的操作。
|
||||
|
||||
```
|
||||
# zypper info file_server
|
||||
@ -346,7 +344,7 @@ Contents :
|
||||
| yast2-tftp-server | package | Recommended
|
||||
```
|
||||
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。
|
||||
如果需要列出相关联的软件包，也可以执行以下这个命令。
|
||||
|
||||
```
|
||||
# zypper info pattern file_server
|
||||
@ -385,7 +383,7 @@ Contents :
|
||||
| yast2-tftp-server | package | Recommended
|
||||
```
|
||||
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。
|
||||
如果需要列出相关联的软件包，也可以执行以下这个命令。
|
||||
|
||||
```
|
||||
# zypper info -t pattern file_server
|
||||
@ -431,7 +429,7 @@ Contents :
|
||||
|
||||
[tasksel][11] 是 Debian/Ubuntu 系统上一个很方便的工具，只需要很少的操作就可以用它来安装好一组软件包。可以在 `/usr/share/tasksel` 目录下的 `.desc` 文件中安排软件包的安装任务。
|
||||
|
||||
默认情况下，`tasksel` 工具是作为 Debian 系统的一部分安装的，但桌面版 Ubuntu 则没有自带 `tasksel`，类似软件包管理器中的元包（meta-packages）。
|
||||
默认情况下，`tasksel` 工具是作为 Debian 系统的一部分安装的，但桌面版 Ubuntu 则没有自带 `tasksel`，这个功能类似软件包管理器中的元包（meta-packages）。
|
||||
|
||||
`tasksel` 工具带有一个基于 zenity 的简单用户界面，例如命令行中的弹出图形对话框。
|
||||
|
||||
@ -483,7 +481,7 @@ u openssh-server OpenSSH server
|
||||
u server Basic Ubuntu server
|
||||
```
|
||||
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 lamp-server 组相关联的软件包。
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 “lamp-server” 组相关联的软件包。
|
||||
|
||||
```
|
||||
# tasksel --task-desc "lamp-server"
|
||||
@ -494,7 +492,7 @@ Selects a ready-made Linux/Apache/MySQL/PHP server.
|
||||
|
||||
基于 Arch Linux 的系统使用的是 pacman 软件包管理器，因此可以通过 pacman 软件包管理器来获取相关的信息。
|
||||
|
||||
pacman 是 package manager 的缩写。`pacman` 可以用于安装、构建、删除和管理 Arch Linux 软件包。`pacman` 使用 libalpm（Arch Linux Package Management 库，ALPM）作为后端来执行所有操作。
|
||||
pacman 是 “package manager” 的缩写。`pacman` 可以用于安装、构建、删除和管理 Arch Linux 软件包。`pacman` 使用 libalpm（Arch Linux Package Management 库，ALPM）作为后端来执行所有操作。
|
||||
|
||||
**推荐阅读：** [使用 pacman 在基于 Arch Linux 的系统上管理软件包][13]
|
||||
|
||||
@ -536,10 +534,9 @@ realtime
|
||||
sugar-fructose
|
||||
tesseract-data
|
||||
vim-plugins
|
||||
|
||||
```
|
||||
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 gnome 组相关联的软件包。
|
||||
如果需要列出相关联的软件包，可以执行以下这个命令。下面的例子是列出和 “gnome” 组相关联的软件包。
|
||||
|
||||
```
|
||||
# pacman -Sg gnome
|
||||
@ -603,7 +600,6 @@ Interrupt signal received
|
||||
```
|
||||
# pacman -Sg gnome | wc -l
|
||||
64
|
||||
|
||||
```
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
@ -613,7 +609,7 @@ via: https://www.2daygeek.com/how-to-list-an-available-package-groups-in-linux/
|
||||
作者：[Prakash Subramanian][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[HankChow](https://github.com/HankChow)
|
||||
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
|
||||
|
||||
@ -1,43 +1,46 @@
|
||||
ScreenCloud：一个截屏程序
|
||||
ScreenCloud：一个增强的截屏程序
|
||||
======
|
||||
[ScreenCloud][1]是一个很棒的小程序，你甚至不知道你需要它。桌面 Linux 的默认屏幕截图流程很好（Prt Scr 按钮），我们甚至有一些[强大的截图工具][2]，如 [Shutter][3]。但是，ScreenCloud 有一个非常简单但非常方便的功能，让我爱上了它。在我们深入它之前，让我们先看一个背景故事。
|
||||
|
||||
我截取了很多截图。远远超过平均水平。收据、注册详细信息、开发工作、文章中程序的截图等等。我接下来要做的就是打开浏览器，浏览我最喜欢的云存储并将重要的内容转储到那里，以便我可以在手机上以及 PC 上的多个操作系统上访问它们。这也让我可以轻松与我的团队分享我正在使用的程序的截图。
|
||||
[ScreenCloud][1]是一个很棒的小程序，你甚至不知道你需要它。桌面 Linux 的默认屏幕截图流程很好（`PrtScr` 按钮），我们甚至有一些[强大的截图工具][2]，如 [Shutter][3]。但是，ScreenCloud 有一个非常简单但非常方便的功能，让我爱上了它。在我们深入它之前，让我们先看一个背景故事。
|
||||
|
||||
我截取了很多截图，远超常人。收据、注册详细信息、开发工作、文章中程序的截图等等。我接下来要做的就是打开浏览器，浏览我最喜欢的云存储并将重要的内容转储到那里，以便我可以在手机上以及 PC 上的多个操作系统上访问它们。这也让我可以轻松与我的团队分享我正在使用的程序的截图。
|
||||
|
||||
我对这个标准的截图流程没有抱怨，打开浏览器并登录我的云，然后手动上传屏幕截图，直到我遇到 ScreenCloud。
|
||||
|
||||
### ScreenCloud
|
||||
|
||||
ScreenCloud 是跨平台的程序，它提供简单的屏幕截图和灵活的[云备份选项][4]管理。这包括使用你自己的[ FTP 服务器][5]。
|
||||
ScreenCloud 是跨平台的程序，它提供轻松的屏幕截图功能和灵活的[云备份选项][4]管理。这包括使用你自己的 [FTP 服务器][5]。
|
||||
|
||||
![][6]
|
||||
|
||||
ScreenCloud 很精简，投入了大量的注意力给小的东西。它为你提供了非常容易记住的热键来捕获全屏、活动窗口或捕获用鼠标选择的区域。
|
||||
ScreenCloud 很顺滑，在细节上投入了大量的精力。它为你提供了非常容易记住的热键来捕获全屏、活动窗口或鼠标选择区域。
|
||||
|
||||
![][7]ScreenCloud 的默认键盘快捷键
|
||||
![][7]
|
||||
|
||||
*ScreenCloud 的默认键盘快捷键*
|
||||
|
||||
截取屏幕截图后，你可以设置 ScreenCloud 如何处理图像或直接将其上传到你选择的云服务。它甚至支持 SFTP。截图上传后（通常在几秒钟内），图像链接就会被自动复制到剪贴板，这让你可以轻松共享。
|
||||
|
||||
![][8]
|
||||
|
||||
你还可以使用 ScreenCloud 进行一些基本编辑。为此，你需要将 “Save to” 设置为 “Ask me”。此设置在下拉框中有并且通常是默认设置。当使用它时，当你截取屏幕截图时，你会看到编辑文件的选项。在这里，你可以在屏幕截图中添加箭头、文本和数字。
|
||||
你还可以使用 ScreenCloud 进行一些基本编辑。为此，你需要将 “Save to” 设置为 “Ask me”。此设置在应用图标菜单中有并且通常是默认设置。当使用它时，当你截取屏幕截图时，你会看到编辑文件的选项。在这里，你可以在屏幕截图中添加箭头、文本和数字。
|
||||
|
||||
![Editing screenshots with ScreenCloud][9]Editing screenshots with ScreenCloud
|
||||
![Editing screenshots with ScreenCloud][9]
|
||||
|
||||
*用 ScreenCloud 编辑截屏*
|
||||
|
||||
### 在 Linux 上安装 ScreenCloud
|
||||
|
||||
ScreenCloud 可在[ Snap 商店][10]中找到。因此，你可以通过访问[ Snap 商店][12]或运行以下命令，轻松地将其安装在 Ubuntu 和其他[启用 Snap ][11]的发行版上。
|
||||
ScreenCloud 可在 [Snap 商店][10]中找到。因此，你可以通过访问 [Snap 商店][12]或运行以下命令，轻松地将其安装在 Ubuntu 和其他[启用 Snap][11] 的发行版上。
|
||||
|
||||
```
|
||||
sudo snap install screencloud
|
||||
|
||||
```
|
||||
|
||||
对于无法通过 Snap 安装程序的 Linux 发行版，你可以[在这里][1]下载 AppImage。进入下载文件夹，右键单击并在那里打开终端。然后运行以下命令。
|
||||
|
||||
```
|
||||
sudo chmod +x ScreenCloud-v1.4.0-x86_64.AppImage
|
||||
|
||||
```
|
||||
|
||||
然后，你可以通过双击下载的文件来启动程序。
|
||||
@ -57,7 +60,7 @@ via: https://itsfoss.com/screencloud-app/
|
||||
作者：[Aquil Roshan][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
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
|
||||
|
||||
73
published/20180917 4 scanning tools for the Linux desktop.md
Normal file
73
published/20180917 4 scanning tools for the Linux desktop.md
Normal file
@ -0,0 +1,73 @@
|
||||
用于 Linux 桌面的 4 个扫描工具
|
||||
======
|
||||
|
||||
> 使用这些开源软件之一驱动你的扫描仪来实现无纸化办公。
|
||||
|
||||
|
||||
|
||||
尽管无纸化世界还没有到来，但越来越多的人通过扫描文件和照片来摆脱纸张的束缚。不过，仅仅拥有一台扫描仪还不足够。你还需要软件来驱动扫描仪。
|
||||
|
||||
然而问题是许多扫描仪制造商没有与他们的设备适配在一起的软件的 Linux 版本。不过在大多数情况下，即使没有也没多大关系。因为在 Linux 桌面上已经有很好的扫描软件了。它们能够与许多扫描仪配合很好的完成工作。
|
||||
|
||||
现在就让我们看看四个简单又灵活的开源 Linux 扫描工具。我已经使用过了下面这些工具（甚至[早在 2014 年][1]写过关于其中三个工具的文章）并且觉得它们非常有用。希望你也会这样认为。
|
||||
|
||||
### Simple Scan
|
||||
|
||||
这是我最喜欢的一个软件之一，[Simple Scan][2] 小巧、快捷、高效且易用。如果你以前见过它，那是因为 Simple Scan 是 GNOME 桌面上的默认扫描应用程序，也是许多 Linux 发行版的默认扫描程序。
|
||||
|
||||
你只需单击一下就能扫描文档或照片。扫描过某些内容后，你可以旋转或裁剪它并将其另存为图像（仅限 JPEG 或 PNG 格式）或 PDF 格式。也就是说 Simple Scan 可能会很慢，即使你用较低分辨率来扫描文档。最重要的是，Simple Scan 在扫描时会使用一组全局的默认值，例如 150dpi 用于文本，300dpi 用于照片。你需要进入 Simple Scan 的首选项才能更改这些设置。
|
||||
|
||||
如果你扫描的内容超过了几页，还可以在保存之前重新排序页面。如果有必要的话 —— 假如你正在提交已签名的表格 —— 你可以使用 Simple Scan 来发送电子邮件。
|
||||
|
||||
### Skanlite
|
||||
|
||||
从很多方面来看，[Skanlite][3] 是 Simple Scan 在 KDE 世界中的表兄弟。虽然 Skanlite 功能很少，但它可以出色的完成工作。
|
||||
|
||||
你可以自己配置这个软件的选项，包括自动保存扫描文件、设置扫描质量以及确定扫描保存位置。 Skanlite 可以保存为以下图像格式：JPEG、PNG、BMP、PPM、XBM 和 XPM。
|
||||
|
||||
其中一个很棒的功能是 Skanlite 能够将你扫描的部分内容保存到单独的文件中。当你想要从照片中删除某人或某物时，这就派上用场了。
|
||||
|
||||
### Gscan2pdf
|
||||
|
||||
这是我另一个最爱的老软件，[gscan2pdf][4] 可能会显得很老旧了，但它仍然包含一些比这里提到的其他软件更好的功能。即便如此，gscan2pdf 仍然显得很轻便。
|
||||
|
||||
除了以各种图像格式（JPEG、PNG 和 TIFF）保存扫描外，gscan2pdf 还可以将它们保存为 PDF 或 [DjVu][5] 文件。你可以在单击“扫描”按钮之前设置扫描的分辨率，无论是黑白、彩色还是纸张大小，每当你想要更改任何这些设置时，都可以进入 gscan2pdf 的首选项。你还可以旋转、裁剪和删除页面。
|
||||
|
||||
虽然这些都不是真正的杀手级功能，但它们会给你带来更多的灵活性。
|
||||
|
||||
### GIMP
|
||||
|
||||
你大概会知道 [GIMP][6] 是一个图像编辑工具。但是你恐怕不知道可以用它来驱动你的扫描仪吧。
|
||||
|
||||
你需要安装 [XSane][7] 扫描软件和 GIMP XSane 插件。这两个应该都可以从你的 Linux 发行版的包管理器中获得。在软件里，选择“文件>创建>扫描仪/相机”。单击“扫描仪”，然后单击“扫描”按钮即可进行扫描。
|
||||
|
||||
如果这不是你想要的，或者它不起作用，你可以将 GIMP 和一个叫作 [QuiteInsane][8] 的插件结合起来。使用任一插件，都能使 GIMP 成为一个功能强大的扫描软件，它可以让你设置许多选项，如是否扫描彩色或黑白、扫描的分辨率，以及是否压缩结果等。你还可以使用 GIMP 的工具来修改或应用扫描后的效果。这使得它非常适合扫描照片和艺术品。
|
||||
|
||||
### 它们真的能够工作吗？
|
||||
|
||||
所有的这些软件在大多数时候都能够在各种硬件上运行良好。我将它们与我过去几年来拥有的多台多功能打印机一起使用 —— 无论是使用 USB 线连接还是通过无线连接。
|
||||
|
||||
你可能已经注意到我在前一段中写过“大多数时候运行良好”。这是因为我确实遇到过一个例外：一个便宜的 canon 多功能打印机。我使用的软件都没有检测到它。最后我不得不下载并安装 canon 的 Linux 扫描仪软件才使它工作。
|
||||
|
||||
你最喜欢的 Linux 开源扫描工具是什么？发表评论，分享你的选择。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/9/linux-scanner-tools
|
||||
|
||||
作者：[Scott Nesbitt][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[way-ww](https://github.com/way-ww)
|
||||
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/scottnesbitt
|
||||
[1]: https://opensource.com/life/14/8/3-tools-scanners-linux-desktop
|
||||
[2]: https://gitlab.gnome.org/GNOME/simple-scan
|
||||
[3]: https://www.kde.org/applications/graphics/skanlite/
|
||||
[4]: http://gscan2pdf.sourceforge.net/
|
||||
[5]: http://en.wikipedia.org/wiki/DjVu
|
||||
[6]: http://www.gimp.org/
|
||||
[7]: https://en.wikipedia.org/wiki/Scanner_Access_Now_Easy#XSane
|
||||
[8]: http://sourceforge.net/projects/quiteinsane/
|
||||
@ -0,0 +1,170 @@
|
||||
Linux 防火墙：关于 iptables 和 firewalld 的那些事
|
||||
======
|
||||
|
||||
> 以下是如何使用 iptables 和 firewalld 工具来管理 Linux 防火墙规则。
|
||||
|
||||
|
||||
|
||||
这篇文章摘自我的书《[Linux in Action][1]》，尚未发布的第二个曼宁出版项目。
|
||||
|
||||
### 防火墙
|
||||
|
||||
防火墙是一组规则。当数据包进出受保护的网络区域时，进出内容（特别是关于其来源、目标和使用的协议等信息）会根据防火墙规则进行检测，以确定是否允许其通过。下面是一个简单的例子:
|
||||
|
||||
![防火墙过滤请求] [3]
|
||||
|
||||
*防火墙可以根据协议或基于目标的规则过滤请求。*
|
||||
|
||||
一方面， [iptables][4] 是 Linux 机器上管理防火墙规则的工具。
|
||||
|
||||
另一方面，[firewalld][5] 也是 Linux 机器上管理防火墙规则的工具。
|
||||
|
||||
你有什么问题吗？如果我告诉你还有另外一种工具，叫做 [nftables][6]，这会不会糟蹋你的美好一天呢？
|
||||
|
||||
好吧，我承认整件事确实有点好笑，所以让我来解释一下。这一切都从 Netfilter 开始，它在 Linux 内核模块级别控制访问网络栈。几十年来，管理 Netfilter 钩子的主要命令行工具是 iptables 规则集。
|
||||
|
||||
因为调用这些规则所需的语法看起来有点晦涩难懂，所以各种用户友好的实现方式，如 [ufw][7] 和 firewalld 被引入，作为更高级别的 Netfilter 解释器。然而，ufw 和 firewalld 主要是为解决单独的计算机所面临的各种问题而设计的。构建全方面的网络解决方案通常需要 iptables，或者从 2014 年起，它的替代品 nftables (nft 命令行工具)。
|
||||
|
||||
iptables 没有消失，仍然被广泛使用着。事实上，在未来的许多年里，作为一名管理员，你应该会使用 iptables 来保护的网络。但是 nftables 通过操作经典的 Netfilter 工具集带来了一些重要的崭新的功能。
|
||||
|
||||
从现在开始，我将通过示例展示 firewalld 和 iptables 如何解决简单的连接问题。
|
||||
|
||||
### 使用 firewalld 配置 HTTP 访问
|
||||
|
||||
正如你能从它的名字中猜到的，firewalld 是 [systemd][8] 家族的一部分。firewalld 可以安装在 Debian/Ubuntu 机器上，不过，它默认安装在 RedHat 和 CentOS 上。如果您的计算机上运行着像 Apache 这样的 web 服务器，您可以通过浏览服务器的 web 根目录来确认防火墙是否正在工作。如果网站不可访问，那么 firewalld 正在工作。
|
||||
|
||||
你可以使用 `firewall-cmd` 工具从命令行管理 firewalld 设置。添加 `–state` 参数将返回当前防火墙的状态:
|
||||
|
||||
```
|
||||
# firewall-cmd --state
|
||||
running
|
||||
```
|
||||
|
||||
默认情况下，firewalld 处于运行状态，并拒绝所有传入流量，但有几个例外，如 SSH。这意味着你的网站不会有太多的访问者，这无疑会为你节省大量的数据传输成本。然而，这不是你对 web 服务器的要求，你希望打开 HTTP 和 HTTPS 端口，按照惯例，这两个端口分别被指定为 80 和 443。firewalld 提供了两种方法来实现这个功能。一个是通过 `–add-port` 参数，该参数直接引用端口号及其将使用的网络协议（在本例中为TCP）。 另外一个是通过 `–permanent` 参数，它告诉 firewalld 在每次服务器启动时加载此规则：
|
||||
|
||||
```
|
||||
# firewall-cmd --permanent --add-port=80/tcp
|
||||
# firewall-cmd --permanent --add-port=443/tcp
|
||||
```
|
||||
|
||||
`–reload` 参数将这些规则应用于当前会话：
|
||||
|
||||
```
|
||||
# firewall-cmd --reload
|
||||
```
|
||||
|
||||
查看当前防火墙上的设置，运行 `–list-services`：
|
||||
|
||||
```
|
||||
# firewall-cmd --list-services
|
||||
dhcpv6-client http https ssh
|
||||
```
|
||||
|
||||
假设您已经如前所述添加了浏览器访问，那么 HTTP、HTTPS 和 SSH 端口现在都应该是和 `dhcpv6-client` 一样开放的 —— 它允许 Linux 从本地 DHCP 服务器请求 IPv6 IP 地址。
|
||||
|
||||
### 使用 iptables 配置锁定的客户信息亭
|
||||
|
||||
我相信你已经看到了信息亭——它们是放在机场、图书馆和商务场所的盒子里的平板电脑、触摸屏和 ATM 类电脑，邀请顾客和路人浏览内容。大多数信息亭的问题是，你通常不希望用户像在自己家一样，把他们当成自己的设备。它们通常不是用来浏览、观看 YouTube 视频或对五角大楼发起拒绝服务攻击的。因此，为了确保它们没有被滥用，你需要锁定它们。
|
||||
|
||||
一种方法是应用某种信息亭模式，无论是通过巧妙使用 Linux 显示管理器还是控制在浏览器级别。但是为了确保你已经堵塞了所有的漏洞，你可能还想通过防火墙添加一些硬性的网络控制。在下一节中，我将讲解如何使用iptables 来完成。
|
||||
|
||||
关于使用 iptables，有两件重要的事情需要记住：你给出的规则的顺序非常关键；iptables 规则本身在重新启动后将无法保持。我会一次一个地在解释这些。
|
||||
|
||||
### 信息亭项目
|
||||
|
||||
为了说明这一切，让我们想象一下，我们为一家名为 BigMart 的大型连锁商店工作。它们已经存在了几十年；事实上，我们想象中的祖父母可能是在那里购物并长大的。但是如今，BigMart 公司总部的人可能只是在数着亚马逊将他们永远赶下去的时间。
|
||||
|
||||
尽管如此，BigMart 的 IT 部门正在尽他们最大努力提供解决方案，他们向你发放了一些具有 WiFi 功能信息亭设备，你在整个商店的战略位置使用这些设备。其想法是，登录到 BigMart.com 产品页面，允许查找商品特征、过道位置和库存水平。信息亭还允许进入 bigmart-data.com，那里储存着许多图像和视频媒体信息。
|
||||
|
||||
除此之外，您还需要允许下载软件包更新。最后，您还希望只允许从本地工作站访问 SSH，并阻止其他人登录。下图说明了它将如何工作：
|
||||
|
||||
![信息亭流量IP表] [10]
|
||||
|
||||
*信息亭业务流由 iptables 控制。 *
|
||||
|
||||
### 脚本
|
||||
|
||||
以下是 Bash 脚本内容：
|
||||
|
||||
```
|
||||
#!/bin/bash
|
||||
iptables -A OUTPUT -p tcp -d bigmart.com -j ACCEPT
|
||||
iptables -A OUTPUT -p tcp -d bigmart-data.com -j ACCEPT
|
||||
iptables -A OUTPUT -p tcp -d ubuntu.com -j ACCEPT
|
||||
iptables -A OUTPUT -p tcp -d ca.archive.ubuntu.com -j ACCEPT
|
||||
iptables -A OUTPUT -p tcp --dport 80 -j DROP
|
||||
iptables -A OUTPUT -p tcp --dport 443 -j DROP
|
||||
iptables -A INPUT -p tcp -s 10.0.3.1 --dport 22 -j ACCEPT
|
||||
iptables -A INPUT -p tcp -s 0.0.0.0/0 --dport 22 -j DROP
|
||||
```
|
||||
|
||||
我们从基本规则 `-A` 开始分析，它告诉 iptables 我们要添加规则。`OUTPUT` 意味着这条规则应该成为输出链的一部分。`-p` 表示该规则仅使用 TCP 协议的数据包，正如 `-d` 告诉我们的，目的地址是 [bigmart.com][11]。`-j` 参数的作用是当数据包符合规则时要采取的操作是 `ACCEPT`。第一条规则表示允许（或接受）请求。但，往下的规则你能看到丢弃（或拒绝）的请求。
|
||||
|
||||
规则顺序是很重要的。因为 iptables 会对一个请求遍历每个规则，直到遇到匹配的规则。一个向外发出的浏览器请求，比如访问 bigmart.com 是会通过的，因为这个请求匹配第一条规则，但是当它到达 `dport 80` 或 `dport 443` 规则时——取决于是 HTTP 还是 HTTPS 请求——它将被丢弃。当遇到匹配时，iptables 不再继续往下检查了。（LCTT 译注：此处原文有误，径改。）
|
||||
|
||||
另一方面，向 ubuntu.com 发出软件升级的系统请求，只要符合其适当的规则，就会通过。显然，我们在这里做的是，只允许向我们的 BigMart 或 Ubuntu 发送 HTTP 或 HTTPS 请求，而不允许向其他目的地发送。
|
||||
|
||||
最后两条规则将处理 SSH 请求。因为它不使用端口 80 或 443 端口，而是使用 22 端口，所以之前的两个丢弃规则不会拒绝它。在这种情况下，来自我的工作站的登录请求将被接受，但是对其他任何地方的请求将被拒绝。这一点很重要：确保用于端口 22 规则的 IP 地址与您用来登录的机器的地址相匹配——如果不这样做，将立即被锁定。当然，这没什么大不了的，因为按照目前的配置方式，只需重启服务器，iptables 规则就会全部丢失。如果使用 LXC 容器作为服务器并从 LXC 主机登录，则使用主机 IP 地址连接容器，而不是其公共地址。
|
||||
|
||||
如果机器的 IP 发生变化，请记住更新这个规则；否则，你会被拒绝访问。
|
||||
|
||||
在家玩（是在某种一次性虚拟机上）？太好了。创建自己的脚本。现在我可以保存脚本，使用 `chmod` 使其可执行，并以 `sudo` 的形式运行它。不要担心“igmart-data.com 没找到”之类的错误 —— 当然没找到；它不存在。
|
||||
|
||||
```
|
||||
chmod +X scriptname.sh
|
||||
sudo ./scriptname.sh
|
||||
```
|
||||
|
||||
你可以使用 `cURL` 命令行测试防火墙。请求 ubuntu.com 奏效，但请求 [manning.com][13] 是失败的 。
|
||||
|
||||
|
||||
```
|
||||
curl ubuntu.com
|
||||
curl manning.com
|
||||
```
|
||||
|
||||
### 配置 iptables 以在系统启动时加载
|
||||
|
||||
现在，我如何让这些规则在每次信息亭启动时自动加载？第一步是将当前规则保存。使用 `iptables-save` 工具保存规则文件。这将在根目录中创建一个包含规则列表的文件。管道后面跟着 `tee` 命令，是将我的`sudo` 权限应用于字符串的第二部分：将文件实际保存到否则受限的根目录。
|
||||
|
||||
然后我可以告诉系统每次启动时运行一个相关的工具，叫做 `iptables-restore` 。我们在上一章节（LCTT 译注：指作者的书）中看到的常规 cron 任务并不适用，因为它们在设定的时间运行，但是我们不知道什么时候我们的计算机可能会决定崩溃和重启。
|
||||
|
||||
有许多方法来处理这个问题。这里有一个：
|
||||
|
||||
在我的 Linux 机器上，我将安装一个名为 [anacron][14] 的程序，该程序将在 `/etc/` 目录中为我们提供一个名为 `anacrontab` 的文件。我将编辑该文件并添加这个 `iptables-restore` 命令，告诉它加载那个 .rule 文件的当前内容。当引导后，规则每天（必要时）01:01 时加载到 iptables 中（LCTT 译注：anacron 会补充执行由于机器没有运行而错过的 cron 任务，因此，即便 01:01 时机器没有启动，也会在机器启动会尽快执行该任务）。我会给该任务一个标识符（`iptables-restore`），然后添加命令本身。如果你在家和我一起这样，你应该通过重启系统来测试一下。
|
||||
|
||||
```
|
||||
sudo iptables-save | sudo tee /root/my.active.firewall.rules
|
||||
sudo apt install anacron
|
||||
sudo nano /etc/anacrontab
|
||||
1 1 iptables-restore iptables-restore < /root/my.active.firewall.rules
|
||||
```
|
||||
|
||||
我希望这些实际例子已经说明了如何使用 iptables 和 firewalld 来管理基于 Linux 的防火墙上的连接问题。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/9/linux-iptables-firewalld
|
||||
|
||||
作者：[David Clinton][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[heguangzhi](https://github.com/heguangzhi)
|
||||
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/remyd
|
||||
[1]: https://www.manning.com/books/linux-in-action?a_aid=bootstrap-it&a_bid=4ca15fc9&chan=opensource
|
||||
[2]: /file/409116
|
||||
[3]: https://opensource.com/sites/default/files/uploads/iptables1.jpg (firewall filtering request)
|
||||
[4]: https://en.wikipedia.org/wiki/Iptables
|
||||
[5]: https://firewalld.org/
|
||||
[6]: https://wiki.nftables.org/wiki-nftables/index.php/Main_Page
|
||||
[7]: https://en.wikipedia.org/wiki/Uncomplicated_Firewall
|
||||
[8]: https://en.wikipedia.org/wiki/Systemd
|
||||
[9]: /file/409121
|
||||
[10]: https://opensource.com/sites/default/files/uploads/iptables2.jpg (kiosk traffic flow ip tables)
|
||||
[11]: http://bigmart.com/
|
||||
[12]: http://youtube.com/
|
||||
[13]: http://manning.com/
|
||||
[14]: https://sourceforge.net/projects/anacron/
|
||||
@ -1,7 +1,7 @@
|
||||
3 个用于数据科学的顶级 Python 库
|
||||
======
|
||||
|
||||
>使用这些库把 Python 变成一个科学数据分析和建模工具。
|
||||
> 使用这些库把 Python 变成一个科学数据分析和建模工具。
|
||||
|
||||
![][7]
|
||||
|
||||
@ -49,7 +49,6 @@ matrix_two = np.arange(1,10).reshape(3,3)
|
||||
matrix_two
|
||||
```
|
||||
|
||||
Here is the output:
|
||||
输出如下：
|
||||
|
||||
```
|
||||
@ -62,9 +61,7 @@ array([[1, 2, 3],
|
||||
|
||||
```
|
||||
matrix_multiply = np.dot(matrix_one, matrix_two)
|
||||
|
||||
matrix_multiply
|
||||
|
||||
```
|
||||
|
||||
相乘后的输出如下：
|
||||
@ -96,17 +93,15 @@ matrix_multiply
|
||||
|
||||
### Pandas
|
||||
|
||||
[Pandas][3] 是另一个可以提高你的 Python 数据科学技能的优秀库。就和 NumPy 一样，它属于 SciPy 开源软件家族，可以在 BSD 免费许可证许可下使用。
|
||||
[Pandas][3] 是另一个可以提高你的 Python 数据科学技能的优秀库。就和 NumPy 一样，它属于 SciPy 开源软件家族，可以在 BSD 自由许可证许可下使用。
|
||||
|
||||
Pandas 提供了多功能并且很强大的工具用于管理数据结构和执行大量数据分析。该库能够很好的处理不完整、非结构化和无序的真实世界数据，并且提供了用于整形、聚合、分析和可视化数据集的工具
|
||||
Pandas 提供了多能而强大的工具，用于管理数据结构和执行大量数据分析。该库能够很好的处理不完整、非结构化和无序的真实世界数据，并且提供了用于整形、聚合、分析和可视化数据集的工具
|
||||
|
||||
Pandas 中有三种类型的数据结构：
|
||||
|
||||
* Series: 一维、相同数据类型的数组
|
||||
* DataFrame: 二维异型矩阵
|
||||
* Panel: 三维大小可变数组
|
||||
|
||||
|
||||
* Series：一维、相同数据类型的数组
|
||||
* DataFrame：二维异型矩阵
|
||||
* Panel：三维大小可变数组
|
||||
|
||||
例如，我们来看一下如何使用 Panda 库（缩写成 `pd`）来执行一些描述性统计计算。
|
||||
|
||||
@ -232,7 +227,7 @@ via: https://opensource.com/article/18/9/top-3-python-libraries-data-science
|
||||
作者：[Dr.Michael J.Garbade][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[ucasFL](https://github.com/ucasFL)
|
||||
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
|
||||
|
||||
@ -1,7 +1,7 @@
|
||||
简化 Django 开发的八个 Python 包
|
||||
======
|
||||
|
||||
这个月的 Python 专栏将介绍一些 Django 包，它们有益于你的工作，以及你的个人或业余项目。
|
||||
> 这个月的 Python 专栏将介绍一些 Django 包，它们有益于你的工作，以及你的个人或业余项目。
|
||||
|
||||
|
||||
|
||||
@ -11,32 +11,31 @@ Django 开发者们，在这个月的 Python 专栏中，我们会介绍一些
|
||||
|
||||
### 有用又省时的工具集合：django-extensions
|
||||
|
||||
[Django-extensions][4] 这个 Django 包非常受欢迎，全是有用的工具，比如下面这些管理命令：
|
||||
[django-extensions][4] 这个 Django 包非常受欢迎，全是有用的工具，比如下面这些管理命令：
|
||||
|
||||
* **shell_plus** 打开 Django 的管理 shell，这个 shell 已经自动导入了所有的数据库模型。在测试复杂的数据关系时，就不需要再从几个不同的应用里做 import 的操作了。
|
||||
* **clean_pyc** 删除项目目录下所有位置的 .pyc 文件
|
||||
* **create_template_tags** 在指定的应用下，创建模板标签的目录结构。
|
||||
* **describe_form** 输出模型的表单定义，可以粘贴到 forms.py 文件中。（需要注意的是，这种方法创建的是普通 Django 表单，而不是模型表单。）
|
||||
* **notes** 输出你项目里所有带 TODO，FIXME 等标记的注释。
|
||||
* `shell_plus` 打开 Django 的管理 shell，这个 shell 已经自动导入了所有的数据库模型。在测试复杂的数据关系时，就不需要再从几个不同的应用里做导入操作了。
|
||||
* `clean_pyc` 删除项目目录下所有位置的 .pyc 文件
|
||||
* `create_template_tags` 在指定的应用下，创建模板标签的目录结构。
|
||||
* `describe_form` 输出模型的表单定义，可以粘贴到 `forms.py` 文件中。（需要注意的是，这种方法创建的是普通 Django 表单，而不是模型表单。）
|
||||
* `notes` 输出你项目里所有带 TODO、FIXME 等标记的注释。
|
||||
|
||||
Django-extensions 还包括几个有用的抽象基类，在定义模型时，它们能满足常见的模式。当你需要以下模型时，可以继承这些基类：
|
||||
|
||||
* `TimeStampedModel`：这个模型的基类包含了 `created` 字段和 `modified` 字段，还有一个 `save()` 方法，在适当的场景下，该方法自动更新 `created` 和 `modified` 字段的值。
|
||||
* `ActivatorModel`：如果你的模型需要像 `status`、`activate_date` 和 `deactivate_date` 这样的字段，可以使用这个基类。它还自带了一个启用 `.active()` 和 `.inactive()` 查询集的 manager。
|
||||
* `TitleDescriptionModel` 和 `TitleSlugDescriptionModel`：这两个模型包括了 `title` 和 `description` 字段，其中 `description` 字段还包括 `slug`，它根据 `title` 字段自动产生。
|
||||
|
||||
* **TimeStampedModel** : 这个模型的基类包含了 **created** 字段和 **modified** 字段，还有一个 **save()** 方法，在适当的场景下，该方法自动更新 created 和 modified 字段的值。
|
||||
* **ActivatorModel** : 如果你的模型需要像 **status**，**activate_date** 和 **deactivate_date** 这样的字段，可以使用这个基类。它还自带了一个启用 **.active()** 和 **.inactive()** 查询集的 manager。
|
||||
* **TitleDescriptionModel** 和 **TitleSlugDescriptionModel** : 这两个模型包括了 **title** 和 **description** 字段，其中 description 字段还包括 **slug**，它根据 **title** 字段自动产生。
|
||||
|
||||
Django-extensions 还有其他更多的功能，也许对你的项目有帮助，所以，去浏览一下它的[文档][5]吧！
|
||||
django-extensions 还有其他更多的功能，也许对你的项目有帮助，所以，去浏览一下它的[文档][5]吧！
|
||||
|
||||
### 12 因子应用的配置：django-environ
|
||||
|
||||
在 Django 项目的配置方面，[Django-environ][6] 提供了符合 [12 因子应用][7] 方法论的管理方法。它是其他一些库的集合，包括 [envparse][8] 和 [honcho][9] 等。安装了 django-environ 之后，在项目的根目录创建一个 .env 文件，用这个文件去定义那些随环境不同而不同的变量，或者需要保密的变量。（比如 API keys，是否启用 debug，数据库的 URLs 等）
|
||||
在 Django 项目的配置方面，[django-environ][6] 提供了符合 [12 因子应用][7] 方法论的管理方法。它是另外一些库的集合，包括 [envparse][8] 和 [honcho][9] 等。安装了 django-environ 之后，在项目的根目录创建一个 `.env` 文件，用这个文件去定义那些随环境不同而不同的变量，或者需要保密的变量。（比如 API 密钥，是否启用调试，数据库的 URL 等）
|
||||
|
||||
然后，在项目的 settings.py 中引入 **environ**，并参考[官方文档的例子][10]设置好 **environ.PATH()** 和 **environ.Env()**。就可以通过 **env('VARIABLE_NAME')** 来获取 .env 文件中定义的变量值了。
|
||||
然后，在项目的 `settings.py` 中引入 `environ`，并参考[官方文档的例子][10]设置好 `environ.PATH()` 和 `environ.Env()`。就可以通过 `env('VARIABLE_NAME')` 来获取 `.env` 文件中定义的变量值了。
|
||||
|
||||
### 创建出色的管理命令：django-click
|
||||
|
||||
[Django-click][11] 是基于 [Click][12] 的， ( 我们[之前推荐过][13]… [两次][14] Click)，它对编写 Django 管理命令很有帮助。这个库没有很多文档，但是代码仓库中有个存放[测试命令][15]的目录，非常有参考价值。 Django-click 基本的 Hello World 命令是这样写的：
|
||||
[django-click][11] 是基于 [Click][12] 的，（我们[之前推荐过][13]… [两次][14] Click)，它对编写 Django 管理命令很有帮助。这个库没有很多文档，但是代码仓库中有个存放[测试命令][15]的目录，非常有参考价值。 django-click 基本的 Hello World 命令是这样写的：
|
||||
|
||||
```
|
||||
# app_name.management.commands.hello.py
|
||||
@ -57,31 +56,31 @@ Hello, Lacey
|
||||
|
||||
### 处理有限状态机：django-fsm
|
||||
|
||||
[Django-fsm][16] 给 Django 的模型添加了有限状态机的支持。如果你管理一个新闻网站，想用类似于“写作中”，“编辑中”，“已发布”来流转文章的状态，django-fsm 能帮你定义这些状态，还能管理状态变化的规则与限制。
|
||||
[django-fsm][16] 给 Django 的模型添加了有限状态机的支持。如果你管理一个新闻网站，想用类似于“写作中”、“编辑中”、“已发布”来流转文章的状态，django-fsm 能帮你定义这些状态，还能管理状态变化的规则与限制。
|
||||
|
||||
Django-fsm 为模型提供了 FSMField 字段，用来定义模型实例的状态。用 django-fsm 的 **@transition** 修饰符，可以定义状态变化的方法，并处理状态变化的任何副作用。
|
||||
Django-fsm 为模型提供了 FSMField 字段，用来定义模型实例的状态。用 django-fsm 的 `@transition` 修饰符，可以定义状态变化的方法，并处理状态变化的任何副作用。
|
||||
|
||||
虽然 django-fsm 文档很轻量，不过 [Django 中的工作流（状态）][17] 这篇 GitHubGist 对有限状态机和 django-fsm 做了非常好的介绍。
|
||||
虽然 django-fsm 文档很轻量，不过 [Django 中的工作流（状态）][17] 这篇 GitHub Gist 对有限状态机和 django-fsm 做了非常好的介绍。
|
||||
|
||||
### 联系人表单：#django-contact-form
|
||||
|
||||
联系人表单可以说是网站的标配。但是不要自己去写全部的样板代码，用 [django-contact-form][18] 在几分钟内就可以搞定。它带有一个可选的能过滤垃圾邮件的表单类（也有不过滤的普通表单类）和一个 **ContactFormView** 基类，基类的方法可以覆盖或自定义修改。而且它还能引导你完成模板的创建，好让表单正常工作。
|
||||
联系人表单可以说是网站的标配。但是不要自己去写全部的样板代码，用 [django-contact-form][18] 在几分钟内就可以搞定。它带有一个可选的能过滤垃圾邮件的表单类（也有不过滤的普通表单类）和一个 `ContactFormView` 基类，基类的方法可以覆盖或自定义修改。而且它还能引导你完成模板的创建，好让表单正常工作。
|
||||
|
||||
### 用户注册和认证：django-allauth
|
||||
|
||||
[Django-allauth][19] 是一个 Django 应用，它为用户注册，登录注销，密码重置，还有第三方用户认证（比如 GitHub 或 Twitter）提供了视图，表单和 URLs，支持邮件地址作为用户名的认证方式，而且有大量的文档记录。第一次用的时候，它的配置可能会让人有点晕头转向；请仔细阅读[安装说明][20]，在[自定义你的配置][21]时要专注，确保启用某个功能的所有配置都用对了。
|
||||
[django-allauth][19] 是一个 Django 应用，它为用户注册、登录/注销、密码重置，还有第三方用户认证（比如 GitHub 或 Twitter）提供了视图、表单和 URL，支持邮件地址作为用户名的认证方式，而且有大量的文档记录。第一次用的时候，它的配置可能会让人有点晕头转向；请仔细阅读[安装说明][20]，在[自定义你的配置][21]时要专注，确保启用某个功能的所有配置都用对了。
|
||||
|
||||
### 处理 Django REST 框架的用户认证：django-rest-auth
|
||||
|
||||
如果 Django 开发中涉及到对外提供 API，你很可能用到了 [Django REST Framework][22] (DRF)。如果你在用 DRF，那么你应该试试 django-rest-auth，它提供了用户注册，登录/注销，密码重置和社交媒体认证的 endpoints （是通过添加 django-allauth 的支持来实现的，这两个包协作得很好）。
|
||||
如果 Django 开发中涉及到对外提供 API，你很可能用到了 [Django REST Framework][22]（DRF）。如果你在用 DRF，那么你应该试试 django-rest-auth，它提供了用户注册、登录/注销，密码重置和社交媒体认证的端点（是通过添加 django-allauth 的支持来实现的，这两个包协作得很好）。
|
||||
|
||||
### Django REST 框架的 API 可视化：django-rest-swagger
|
||||
|
||||
[Django REST Swagger][24] 提供了一个功能丰富的用户界面，用来和 Django REST 框架的 API 交互。你只需要安装 Django REST Swagger，把它添加到 Django 项目的 installed apps 中，然后在 urls.py 中添加 Swagger 的视图和 URL 模式就可以了，剩下的事情交给 API 的 docstring 处理。
|
||||
[Django REST Swagger][24] 提供了一个功能丰富的用户界面，用来和 Django REST 框架的 API 交互。你只需要安装 Django REST Swagger，把它添加到 Django 项目的已安装应用中，然后在 `urls.py` 中添加 Swagger 的视图和 URL 模式就可以了，剩下的事情交给 API 的 docstring 处理。
|
||||
|
||||
|
||||
|
||||
API 的用户界面按照 app 的维度展示了所有 endpoints 和可用方法，并列出了这些 endpoints 的可用操作，而且它提供了和 API 交互的功能（比如添加/删除/获取记录）。django-rest-swagger 从 API 视图中的 docstrings 生成每个 endpoint 的文档，通过这种方法，为你的项目创建了一份 API 文档，这对你，对前端开发人员和用户都很有用。
|
||||
API 的用户界面按照 app 的维度展示了所有端点和可用方法，并列出了这些端点的可用操作，而且它提供了和 API 交互的功能（比如添加/删除/获取记录）。django-rest-swagger 从 API 视图中的 docstrings 生成每个端点的文档，通过这种方法，为你的项目创建了一份 API 文档，这对你，对前端开发人员和用户都很有用。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@ -90,7 +89,7 @@ via: https://opensource.com/article/18/9/django-packages
|
||||
作者：[Jeff Triplett][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[belitex](https://github.com/belitex)
|
||||
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
|
||||
|
||||
@ -118,4 +117,4 @@ via: https://opensource.com/article/18/9/django-packages
|
||||
[21]: https://django-allauth.readthedocs.io/en/latest/configuration.html
|
||||
[22]: http://www.django-rest-framework.org/
|
||||
[23]: https://django-rest-auth.readthedocs.io/
|
||||
[24]: https://django-rest-swagger.readthedocs.io/en/latest/
|
||||
[24]: https://django-rest-swagger.readthedocs.io/en/latest/
|
||||
@ -0,0 +1,115 @@
|
||||
WinWorld：大型的废弃操作系统、软件、游戏的博物馆
|
||||
=====
|
||||
|
||||
|
||||
|
||||
有一天，我正在测试 Dosbox -- 这是一个[在 Linux 平台上运行 MS-DOS 游戏与程序的软件][1]。当我在搜索一些常用的软件，例如 Turbo C++ 时，我意外留意到了一个叫做 [WinWorld][2] 的网站。我查看了这个网站上的某些内容，并且着实被惊艳到了。WinWorld 收集了非常多经典的，但已经被它们的开发者所抛弃许久的操作系统、软件、应用、开发工具、游戏以及各式各样的工具。它是一个以保存和分享古老的、已经被废弃的或者预发布版本程序为目的的线上博物馆，由社区成员和志愿者运营。
|
||||
|
||||
WinWorld 于 2013 年开始运营。它的创始者声称是被 Yahoo birefcases 激发了灵感并以此构建了这个网站。这个网站原目标是保存并且分享老旧软件。多年来，许多志愿者以不同方式提供了帮助，WinWorld 收集的老旧软件增长迅速。整个 WinWorld 仓库都是自由开源的，所有人都可以使用。
|
||||
|
||||
### WinWorld 保存了大量的废弃操作系统、软件、系统应用以及游戏
|
||||
|
||||
就像我刚才说的那样， WinWorld 存储了大量的被抛弃并且不再被开发的软件。
|
||||
|
||||
**Linux 与 Unix：**
|
||||
|
||||
这里我给出了完整的 UNIX 和 LINUX 操作系统的列表，以及它们各自的简要介绍、首次发行的年代。
|
||||
|
||||
* **A/UX** - 于 1988 年推出，移植到苹果的 68k Macintosh 平台的 Unix 系统。
|
||||
* **AIX** - 于 1986 年推出，IBM 移植的 Unix 系统。
|
||||
* **AT &T System V Unix** - 于 1983 年推出，最早的商业版 Unix 之一。
|
||||
* **Banyan VINES** - 于 1984 年推出，专为 Unix 设计的网络操作系统。
|
||||
* **Corel Linux** - 于 1999 年推出，商业 Linux 发行版。
|
||||
* **DEC OSF-1** - 于 1991 年推出，由 DEC 公司开发的 Unix 版本。
|
||||
* **Digital UNIX** - 由 DEC 于 1995 年推出，**OSF-1** 的重命名版本。
|
||||
* **FreeBSD 1.0** - 于 1993 年推出，FreeBSD 的首个发行版。这个系统是基于 4.3BSD 开发的。
|
||||
* **Gentus Linux** - 由 ABIT 于 2000 年推出，未遵守 GPL 协议的 Linux 发行版。
|
||||
* **HP-UX** - 于 1992 年推出，UNIX 的变种系统。
|
||||
* **IRIX** - 由硅谷图形公司（SGI）于 1988 年推出的操作系统。
|
||||
* **Lindows** - 于 2002 年推出，与 Corel Linux 类似的商业操作系统。
|
||||
* **Linux Kernel** - 0.01 版本于 90 年代早期推出，Linux 源代码的副本。
|
||||
* **Mandrake Linux** - 于 1999 年推出。基于 Red Hat Linux 的 Linux 发行版，稍后被重新命名为 Mandriva。
|
||||
* **NEWS-OS** - 由 Sony 于 1989 年推出，BSD 的变种。
|
||||
* **NeXTStep** - 由史蒂夫·乔布斯创立的 NeXT 公司于 1987 年推出，基于 Unix 的操作系统。
|
||||
* **PC/IX** - 于 1984 年推出，为 IBM 个人电脑服务的基于 Unix 的操作系统。
|
||||
* **Red Hat Linux 5.0** - 由 Red Hat 推出，商业 Linux 发行版。
|
||||
* **Sun Solaris** - 由 Sun Microsystem 于 1992 年推出，基于 Unix 的操作系统。
|
||||
* **SunOS** - 由 Sun Microsystem 于 1982 年推出，衍生自 BSD 基于 Unix 的操作系统。
|
||||
* **Tru64 UNIX** - 由 DEC 开发，旧称 OSF/1。
|
||||
* **Ubuntu 4.10** - 基于 Debian 的知名操作系统。这是早期的 beta 预发布版本，比第一个 Ubuntu 正式发行版更早推出。
|
||||
* **Ultrix** - 由 DEC 开发， UNIX 克隆。
|
||||
* **UnixWare** - 由 Novell 推出， UNIX 变种。
|
||||
* **Xandros Linux** - 首个版本于 2003 年推出。基于 Corel Linux 的专有 Linux 发行版。
|
||||
* **Xenix** - 最初由微软于 1984 推出，UNIX 变种操作系统。
|
||||
|
||||
不仅仅是 Linux/Unix，你还能找到例如 DOS、Windows、Apple/Mac、OS 2、Novell netware 等其他的操作系统与 shell。
|
||||
|
||||
**DOS & CP/M：**
|
||||
|
||||
* 86-DOS
|
||||
* Concurrent CPM-86 & Concurrent DOS
|
||||
* CP/M 86 & CP/M-80
|
||||
* DOS Plus
|
||||
* DR-DOS
|
||||
* GEM
|
||||
* MP/M
|
||||
* MS-DOS
|
||||
* 多任务的 MS-DOS 4.00
|
||||
* 多用户 DOS
|
||||
* PC-DOS
|
||||
* PC-MOS
|
||||
* PTS-DOS
|
||||
* Real/32
|
||||
* Tandy Deskmate
|
||||
* Wendin DOS
|
||||
|
||||
**Windows：**
|
||||
|
||||
* BackOffice Server
|
||||
* Windows 1.0/2.x/3.0/3.1/95/98/2000/ME/NT 3.X/NT 4.0
|
||||
* Windows Whistler
|
||||
* WinFrame
|
||||
|
||||
**Apple/Mac：**
|
||||
|
||||
* Mac OS 7/8/9
|
||||
* Mac OS X
|
||||
* System Software (0-6)
|
||||
|
||||
**OS/2：**
|
||||
|
||||
* Citrix Multiuser
|
||||
* OS/2 1.x
|
||||
* OS/2 2.0
|
||||
* OS/2 3.x
|
||||
* OS/2 Warp 4
|
||||
|
||||
于此同时，WinWorld 也收集了大量的旧软件、系统应用、开发工具和游戏。你也可以一起看看它们。
|
||||
|
||||
说实话，这个网站列出的绝大部分东西，我甚至都不知道它们存在过。其中列出的某些工具发布于我出生之前。
|
||||
|
||||
如果您需要或者打算去测试一个经典的程序（例如游戏、软件、操作系统），并且在其他地方找不到它们，那么来 WinWorld 资源库看看，下载它们然后开始你的探险吧。祝您好运！
|
||||
|
||||
|
||||
|
||||
**免责声明：**
|
||||
|
||||
OSTechNix 并非隶属于 WinWorld。我们 OSTechNix 并不确保 WinWorld 站点存储数据的真实性与可靠性。而且在你所在的地区，或许从第三方站点下载软件是违法行为。本篇文章作者和 OSTechNix 都不会承担任何责任，使用此服务意味着您将自行承担风险。（LCTT 译注：本站和译者亦同样申明。）
|
||||
|
||||
本篇文章到此为止。希望这对您有用，更多的好文章即将发布，敬请期待！
|
||||
|
||||
谢谢各位的阅读！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
via: https://www.ostechnix.com/winworld-a-large-collection-of-defunct-oss-software-and-games/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[thecyanbird](https://github.com/thecyanbird)
|
||||
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]: https://www.ostechnix.com/how-to-run-ms-dos-games-and-programs-in-linux/
|
||||
[2]: https://winworldpc.com/library/
|
||||
@ -0,0 +1,129 @@
|
||||
Clinews：从命令行阅读新闻和最新头条
|
||||
======
|
||||
|
||||
|
||||
|
||||
不久前，我们写了一个名为 [InstantNews][1] 的命令行新闻客户端，它可以帮助你立即在命令行阅读新闻和最新头条新闻。今天，我偶然发现了一个名为 **Clinews** 的类似，它的其功能与此相同 —— 在终端阅读来自热门网站的新闻和最新头条，还有博客。你无需安装 GUI 应用或移动应用。你可以直接从终端阅读世界上正在发生的事情。它是使用 **NodeJS** 编写的自由开源程序。
|
||||
|
||||
### 安装 Clinews
|
||||
|
||||
由于 Clinews 是使用 NodeJS 编写的，因此你可以使用 NPM 包管理器安装。如果尚未安装 NodeJS，请按照以下链接中的说明进行安装。
|
||||
|
||||
安装 node 后，运行以下命令安装 Clinews：
|
||||
|
||||
```
|
||||
$ npm i -g clinews
|
||||
```
|
||||
|
||||
你也可以使用 **Yarn** 安装 Clinews：
|
||||
|
||||
```
|
||||
$ yarn global add clinews
|
||||
```
|
||||
|
||||
Yarn 本身可以使用 npm 安装
|
||||
|
||||
```
|
||||
$ npm -i yarn
|
||||
```
|
||||
|
||||
### 配置 News API
|
||||
|
||||
Clinews 从 [News API][2] 中检索所有新闻标题。News API 是一个简单易用的 API，它返回当前在一系列新闻源和博客上发布的头条的 JSON 元数据。它目前提供来自 70 个热门源的实时头条，包括 Ars Technica、BBC、Blooberg、CNN、每日邮报、Engadget、ESPN、金融时报、谷歌新闻、hacker News，IGN、Mashable、国家地理、Reddit r/all、路透社、 Speigel Online、Techcrunch、The Guardian、The Hindu、赫芬顿邮报、纽约时报、The Next Web、华尔街日报，今日美国和[等等][3]。
|
||||
|
||||
首先，你需要 News API 的 API 密钥。进入 [https://newsapi.org/register][4] 并注册一个免费帐户来获取 API 密钥。
|
||||
|
||||
从 News API 获得 API 密钥后，编辑 `.bashrc`：
|
||||
|
||||
```
|
||||
$ vi ~/.bashrc
|
||||
```
|
||||
|
||||
在最后添加 newsapi API 密钥，如下所示：
|
||||
|
||||
```
|
||||
export IN_API_KEY="Paste-API-key-here"
|
||||
```
|
||||
|
||||
请注意，你需要将密钥粘贴在双引号内。保存并关闭文件。
|
||||
|
||||
运行以下命令以更新更改。
|
||||
|
||||
```
|
||||
$ source ~/.bashrc
|
||||
```
|
||||
|
||||
完成。现在继续并从新闻源获取最新的头条新闻。
|
||||
|
||||
### 在命令行阅读新闻和最新头条
|
||||
|
||||
要阅读特定新闻源的新闻和最新头条，例如 **The Hindu**，请运行：
|
||||
|
||||
```
|
||||
$ news fetch the-hindu
|
||||
```
|
||||
|
||||
这里，`the-hindu` 是新闻源的源id（获取 id）。
|
||||
|
||||
上述命令将从 The Hindu 新闻站获取最新的 10 个头条，并将其显示在终端中。此外，它还显示新闻的简要描述、发布的日期和时间以及到源的实际链接。
|
||||
|
||||
**示例输出：**
|
||||
|
||||
|
||||
|
||||
要在浏览器中阅读新闻，请按住 Ctrl 键并单击 URL。它将在你的默认 Web 浏览器中打开。
|
||||
|
||||
要查看所有的新闻源，请运行：
|
||||
|
||||
```
|
||||
$ news sources
|
||||
```
|
||||
|
||||
**示例输出：**
|
||||
|
||||
|
||||
|
||||
正如你在上面的截图中看到的，Clinews 列出了所有新闻源，包括新闻源的名称、获取 ID、网站描述、网站 URL 以及它所在的国家/地区。在撰写本指南时，Clinews 目前支持 70 多个新闻源。
|
||||
|
||||
Clinews 还可以搜索符合搜索条件/术语的所有源的新闻报道。例如，要列出包含单词 “Tamilnadu” 的所有新闻报道，请使用以下命令：
|
||||
|
||||
```
|
||||
$ news search "Tamilnadu"
|
||||
```
|
||||
|
||||
此命令将会筛选所有新闻源中含有 “Tamilnadu” 的报道。
|
||||
|
||||
Clinews 有一些其它选项可以帮助你
|
||||
|
||||
* 限制你想看的新闻报道的数量，
|
||||
* 排序新闻报道（热门、最新），
|
||||
* 智能显示新闻报道分类（例如商业、娱乐、游戏、大众、音乐、政治、科学和自然、体育、技术）
|
||||
|
||||
更多详细信息，请参阅帮助部分：
|
||||
|
||||
```
|
||||
$ clinews -h
|
||||
```
|
||||
|
||||
就是这些了。希望这篇对你有用。还有更多好东西。敬请关注！
|
||||
|
||||
干杯！
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/clinews-read-news-and-latest-headlines-from-commandline/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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.ostechnix.com/author/sk/
|
||||
[1]: https://www.ostechnix.com/get-news-instantly-commandline-linux/
|
||||
[2]: https://newsapi.org/
|
||||
[3]: https://newsapi.org/sources
|
||||
[4]: https://newsapi.org/register
|
||||
@ -0,0 +1,76 @@
|
||||
Hegemon：使用 Rust 编写的模块化系统监视程序
|
||||
======
|
||||
|
||||
|
||||
|
||||
在类 Unix 系统中监视运行进程时，最常用的程序是 `top` 和它的增强版 `htop`。我个人最喜欢的是 `htop`。但是，开发人员不时会发布这些程序的替代品。`top` 和 `htop` 工具的一个替代品是 `Hegemon`。它是使用 Rust 语言编写的模块化系统监视程序。
|
||||
|
||||
关于 Hegemon 的功能，我们可以列出以下这些：
|
||||
|
||||
* Hegemon 会监控 CPU、内存和交换页的使用情况。
|
||||
* 它监控系统的温度和风扇速度。
|
||||
* 更新间隔时间可以调整。默认值为 3 秒。
|
||||
* 我们可以通过扩展数据流来展示更详细的图表和其他信息。
|
||||
* 单元测试。
|
||||
* 干净的界面。
|
||||
* 自由开源。
|
||||
|
||||
### 安装 Hegemon
|
||||
|
||||
确保已安装 Rust 1.26 或更高版本。要在 Linux 发行版中安装 Rust，请参阅以下指南：
|
||||
|
||||
- [在 Linux 中安装 Rust 编程语言][2]
|
||||
|
||||
另外要安装 [libsensors][1] 库。它在大多数 Linux 发行版的默认仓库中都有。例如，你可以使用以下命令将其安装在基于 RPM 的系统（如 Fedora）中：
|
||||
|
||||
```
|
||||
$ sudo dnf install lm_sensors-devel
|
||||
```
|
||||
|
||||
在像 Ubuntu、Linux Mint 这样的基于 Debian 的系统上，可以使用这个命令安装它：
|
||||
|
||||
```
|
||||
$ sudo apt-get install libsensors4-dev
|
||||
```
|
||||
|
||||
在安装 Rust 和 libsensors 后，使用命令安装 Hegemon：
|
||||
|
||||
```
|
||||
$ cargo install hegemon
|
||||
```
|
||||
|
||||
安装 hegemon 后，使用以下命令开始监视 Linux 系统中正在运行的进程：
|
||||
|
||||
```
|
||||
$ hegemon
|
||||
```
|
||||
|
||||
以下是 Arch Linux 桌面的示例输出。
|
||||
|
||||
|
||||
|
||||
要退出，请按 `Q`。
|
||||
|
||||
|
||||
请注意，hegemon 仍处于早期开发阶段，并不能完全取代 `top` 命令。它可能存在 bug 和功能缺失。如果你遇到任何 bug，请在项目的 GitHub 页面中报告它们。开发人员计划在即将推出的版本中引入更多功能。所以，请关注这个项目。
|
||||
|
||||
就是这些了。希望这篇文章有用。还有更多的好东西。敬请关注！
|
||||
|
||||
干杯!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/hegemon-a-modular-system-monitor-application-written-in-rust/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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.ostechnix.com/author/sk/
|
||||
[1]: https://github.com/lm-sensors/lm-sensors
|
||||
[2]: https://www.ostechnix.com/install-rust-programming-language-in-linux/
|
||||
@ -0,0 +1,281 @@
|
||||
Linux 系统上交换空间的介绍
|
||||
======
|
||||
|
||||
> 学习如何修改你的系统上的交换空间的容量，以及你到底需要多大的交换空间。
|
||||
|
||||
|
||||
|
||||
当今无论什么操作系统<ruby>交换<rt>Swap</rt></ruby>空间是非常常见的。Linux 使用交换空间来增加主机可用的虚拟内存。它可以在常规文件或逻辑卷上使用一个或多个专用交换分区或交换文件。
|
||||
|
||||
典型计算机中有两种基本类型的内存。第一种类型，随机存取存储器 (RAM)，用于存储计算机使用的数据和程序。只有程序和数据存储在 RAM 中，计算机才能使用它们。随机存储器是易失性存储器；也就是说，如果计算机关闭了，存储在 RAM 中的数据就会丢失。
|
||||
|
||||
硬盘是用于长期存储数据和程序的磁性介质。该磁介质可以很好的保存数据；即使计算机断电，存储在磁盘上的数据也会保留下来。CPU（中央处理器）不能直接访问硬盘上的程序和数据；它们必须首先复制到 RAM 中，RAM 是 CPU 访问代码指令和操作数据的地方。在引导过程中，计算机将特定的操作系统程序（如内核、init 或 systemd）以及硬盘上的数据复制到 RAM 中，在 RAM 中，计算机的处理器 CPU 可以直接访问这些数据。
|
||||
|
||||
### 交换空间
|
||||
|
||||
交换空间是现代 Linux 系统中的第二种内存类型。交换空间的主要功能是当全部的 RAM 被占用并且需要更多内存时，用磁盘空间代替 RAM 内存。
|
||||
|
||||
例如，假设你有一个 8GB RAM 的计算机。如果你启动的程序没有填满 RAM，一切都好，不需要交换。假设你在处理电子表格，当添加更多的行时，你电子表格会增长，加上所有正在运行的程序，将会占用全部的 RAM 。如果这时没有可用的交换空间，你将不得不停止处理电子表格，直到关闭一些其他程序来释放一些 RAM 。
|
||||
|
||||
内核使用一个内存管理程序来检测最近没有使用的内存块（内存页）。内存管理程序将这些相对不经常使用的内存页交换到硬盘上专门指定用于“分页”或交换的特殊分区。这会释放 RAM，为输入电子表格更多数据腾出了空间。那些换出到硬盘的内存页面被内核的内存管理代码跟踪，如果需要，可以被分页回 RAM。
|
||||
|
||||
Linux 计算机中的内存总量是 RAM + 交换分区，交换分区被称为虚拟内存.
|
||||
|
||||
### Linux 交换分区类型
|
||||
|
||||
Linux 提供了两种类型的交换空间。默认情况下，大多数 Linux 在安装时都会创建一个交换分区，但是也可以使用一个特殊配置的文件作为交换文件。交换分区顾名思义就是一个标准磁盘分区，由 `mkswap` 命令指定交换空间。
|
||||
|
||||
如果没有可用磁盘空间来创建新的交换分区，或者卷组中没有空间为交换空间创建逻辑卷，则可以使用交换文件。这只是一个创建好并预分配指定大小的常规文件。然后运行 `mkswap` 命令将其配置为交换空间。除非绝对必要，否则我不建议使用文件来做交换空间。（LCTT 译注：Ubuntu 近来的版本采用了交换文件而非交换空间，所以我对于这种说法保留看法）
|
||||
|
||||
### 频繁交换
|
||||
|
||||
当总虚拟内存（RAM 和交换空间）变得快满时，可能会发生频繁交换。系统花了太多时间在交换空间和 RAM 之间做内存块的页面切换，以至于几乎没有时间用于实际工作。这种情况的典型症状是：系统变得缓慢或完全无反应，硬盘指示灯几乎持续亮起。
|
||||
|
||||
使用 `free` 的命令来显示 CPU 负载和内存使用情况，你会发现 CPU 负载非常高，可能达到系统中 CPU 内核数量的 30 到 40 倍。另一个情况是 RAM 和交换空间几乎完全被分配了。
|
||||
|
||||
事实上，查看 SAR（系统活动报告）数据也可以显示这些内容。在我的每个系统上都安装 SAR ，并将这些用于数据分析。
|
||||
|
||||
### 交换空间的正确大小是多少？
|
||||
|
||||
许多年前，硬盘上分配给交换空间大小是计算机上的 RAM 的两倍（当然，这是大多数计算机的 RAM 以 KB 或 MB 为单位的时候）。因此，如果一台计算机有 64KB 的 RAM，应该分配 128KB 的交换分区。该规则考虑到了这样的事实情况，即 RAM 大小在当时非常小，分配超过 2 倍的 RAM 用于交换空间并不能提高性能。使用超过两倍的 RAM 进行交换，比实际执行有用的工作的时候，大多数系统将花费更多的时间。
|
||||
|
||||
RAM 现在已经很便宜了，如今大多数计算机的 RAM 都达到了几十亿字节。我的大多数新电脑至少有 8GB 内存，一台有 32GB 内存，我的主工作站有 64GB 内存。我的旧电脑有 4 到 8GB 的内存。
|
||||
|
||||
当操作具有大量 RAM 的计算机时，交换空间的限制性能系数远低于 2 倍。[Fedora 28 在线安装指南][1] 定义了当前关于交换空间分配的方法。下面内容是我提出的建议。
|
||||
|
||||
下表根据系统中的 RAM 大小以及是否有足够的内存让系统休眠，提供了交换分区的推荐大小。建议的交换分区大小是在安装过程中自动建立的。但是，为了满足系统休眠，您需要在自定义分区阶段编辑交换空间。
|
||||
|
||||
_表 1: Fedora 28 文档中推荐的系统交换空间_
|
||||
|
||||
| **系统内存大小** | **推荐的交换空间** | **推荐的交换空间大小（支持休眠模式）** |
|
||||
|--------------------------|-----------------------------|---------------------------------------|
|
||||
| 小于 2 GB | 2 倍 RAM | 3 倍 RAM |
|
||||
| 2 GB - 8 GB | 等于 RAM 大小 | 2 倍 RAM |
|
||||
| 8 GB - 64 GB | 0.5 倍 RAM | 1.5 倍 RAM |
|
||||
| 大于 64 GB | 工作量相关 | 不建议休眠模式 |
|
||||
|
||||
在上面列出的每个范围之间的边界(例如，具有 2GB、8GB 或 64GB 的系统 RAM)，请根据所选交换空间和支持休眠功能请谨慎使用。如果你的系统资源允许，增加交换空间可能会带来更好的性能。
|
||||
|
||||
当然，大多数 Linux 管理员对多大的交换空间量有自己的想法。下面的表2 包含了基于我在多种环境中的个人经历所做出的建议。这些可能不适合你，但是和表 1 一样，它们可能对你有所帮助。
|
||||
|
||||
|
||||
_表 2: 作者推荐的系统交换空间_
|
||||
|
||||
| RAM 大小 | 推荐的交换空间 |
|
||||
|---------------|------------------------|
|
||||
| ≤ 2GB | 2X RAM |
|
||||
| 2GB – 8GB | = RAM |
|
||||
| >8GB | 8GB |
|
||||
|
||||
|
||||
这两个表中共同点，随着 RAM 数量的增加，超过某一点增加更多交换空间只会导致在交换空间几乎被全部使用之前就发生频繁交换。根据以上建议，则应尽可能添加更多 RAM，而不是增加更多交换空间。如类似影响系统性能的情况一样，请使用最适合你的建议。根据 Linux 环境中的条件进行测试和更改是需要时间和精力的。
|
||||
|
||||
### 向非 LVM 磁盘环境添加更多交换空间
|
||||
|
||||
面对已安装 Linux 的主机并对交换空间的需求不断变化，有时有必要修改系统定义的交换空间的大小。此过程可用于需要增加交换空间大小的任何情况。它假设有足够的可用磁盘空间。此过程还假设磁盘分区为 “原始的” EXT4 和交换分区，而不是使用逻辑卷管理（LVM）。
|
||||
|
||||
基本步骤很简单:
|
||||
|
||||
1. 关闭现有的交换空间。
|
||||
2. 创建所需大小的新交换分区。
|
||||
3. 重读分区表。
|
||||
4. 将分区配置为交换空间。
|
||||
5. 添加新分区到 `/etc/fstab`。
|
||||
6. 打开交换空间。
|
||||
|
||||
应该不需要重新启动机器。
|
||||
|
||||
为了安全起见，在关闭交换空间前，至少你应该确保没有应用程序在运行，也没有交换空间在使用。`free` 或 `top` 命令可以告诉你交换空间是否在使用中。为了更安全，您可以恢复到运行级别 1 或单用户模式。
|
||||
|
||||
使用关闭所有交换空间的命令关闭交换分区：
|
||||
|
||||
```
|
||||
swapoff -a
|
||||
```
|
||||
|
||||
现在查看硬盘上的现有分区。
|
||||
|
||||
```
|
||||
fdisk -l
|
||||
```
|
||||
|
||||
这将显示每个驱动器上的分区表。按编号标识当前的交换分区。
|
||||
|
||||
使用以下命令在交互模式下启动 `fdisk`：
|
||||
|
||||
```
|
||||
fdisk /dev/<device name>
|
||||
```
|
||||
|
||||
例如：
|
||||
|
||||
```
|
||||
fdisk /dev/sda
|
||||
```
|
||||
|
||||
此时，`fdisk` 是交互方式的，只在指定的磁盘驱动器上进行操作。
|
||||
|
||||
使用 `fdisk` 的 `p` 子命令验证磁盘上是否有足够的可用空间来创建新的交换分区。硬盘上的空间以 512 字节的块以及起始和结束柱面编号的形式显示，因此您可能需要做一些计算来确定分配分区之间和末尾的可用空间。
|
||||
|
||||
使用 `n` 子命令创建新的交换分区。`fdisk` 会问你开始柱面。默认情况下，它选择编号最低的可用柱面。如果你想改变这一点，输入开始柱面的编号。
|
||||
|
||||
`fdisk` 命令允许你以多种格式输入分区的大小，包括最后一个柱面号或字节、KB 或 MB 的大小。例如，键入 4000M ，这将在新分区上提供大约 4GB 的空间，然后按回车键。
|
||||
|
||||
使用 `p` 子命令来验证分区是否按照指定的方式创建的。请注意，除非使用结束柱面编号，否则分区可能与你指定的不完全相同。`fdisk` 命令只能在整个柱面上增量的分配磁盘空间，因此你的分区可能比你指定的稍小或稍大。如果分区不是您想要的，你可以删除它并重新创建它。
|
||||
|
||||
现在指定新分区是交换分区了 。子命令 `t` 允许你指定定分区的类型。所以输入 `t`，指定分区号，当它要求十六进制分区类型时，输入 `82`，这是 Linux 交换分区类型，然后按回车键。
|
||||
|
||||
当你对创建的分区感到满意时，使用 `w` 子命令将新的分区表写入磁盘。`fdisk` 程序将退出，并在完成修改后的分区表的编写后返回命令提示符。当 `fdisk` 完成写入新分区表时，会收到以下消息:
|
||||
|
||||
```
|
||||
The partition table has been altered!
|
||||
Calling ioctl() to re-read partition table.
|
||||
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
|
||||
The kernel still uses the old table.
|
||||
The new table will be used at the next reboot.
|
||||
Syncing disks.
|
||||
```
|
||||
|
||||
此时，你使用 `partprobe` 命令强制内核重新读取分区表，这样就不需要执行重新启动机器。
|
||||
|
||||
```
|
||||
partprobe
|
||||
```
|
||||
|
||||
使用命令 `fdisk -l` 列出分区，新交换分区应该在列出的分区中。确保新的分区类型是 “Linux swap”。
|
||||
|
||||
修改 `/etc/fstab` 文件以指向新的交换分区。如下所示：
|
||||
|
||||
```
|
||||
LABEL=SWAP-sdaX swap swap defaults 0 0
|
||||
```
|
||||
|
||||
其中 `X` 是分区号。根据新交换分区的位置，添加以下内容：
|
||||
|
||||
```
|
||||
/dev/sdaY swap swap defaults 0 0
|
||||
```
|
||||
|
||||
请确保使用正确的分区号。现在，可以执行创建交换分区的最后一步。使用 `mkswap` 命令将分区定义为交换分区。
|
||||
|
||||
```
|
||||
mkswap /dev/sdaY
|
||||
```
|
||||
|
||||
最后一步是使用以下命令启用交换空间：
|
||||
|
||||
```
|
||||
swapon -a
|
||||
```
|
||||
|
||||
你的新交换分区现在与以前存在的交换分区一起在线。您可以使用 `free` 或`top` 命令来验证这一点。
|
||||
|
||||
#### 在 LVM 磁盘环境中添加交换空间
|
||||
|
||||
如果你的磁盘使用 LVM ，更改交换空间将相当容易。同样，假设当前交换卷所在的卷组中有可用空间。默认情况下，LVM 环境中的 Fedora Linux 在安装过程将交换分区创建为逻辑卷。您可以非常简单地增加交换卷的大小。
|
||||
|
||||
以下是在 LVM 环境中增加交换空间大小的步骤:
|
||||
|
||||
1. 关闭所有交换空间。
|
||||
2. 增加指定用于交换空间的逻辑卷的大小。
|
||||
3. 为交换空间调整大小的卷配置。
|
||||
4. 启用交换空间。
|
||||
|
||||
首先，让我们使用 `lvs` 命令（列出逻辑卷）来验证交换空间是否存在以及交换空间是否是逻辑卷。
|
||||
|
||||
```
|
||||
[root@studentvm1 ~]# lvs
|
||||
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
|
||||
home fedora_studentvm1 -wi-ao---- 2.00g
|
||||
pool00 fedora_studentvm1 twi-aotz-- 2.00g 8.17 2.93
|
||||
root fedora_studentvm1 Vwi-aotz-- 2.00g pool00 8.17
|
||||
swap fedora_studentvm1 -wi-ao---- 8.00g
|
||||
tmp fedora_studentvm1 -wi-ao---- 5.00g
|
||||
usr fedora_studentvm1 -wi-ao---- 15.00g
|
||||
var fedora_studentvm1 -wi-ao---- 10.00g
|
||||
[root@studentvm1 ~]#
|
||||
```
|
||||
|
||||
你可以看到当前的交换空间大小为 8GB。在这种情况下，我们希望将 2GB 添加到此交换卷中。首先，停止现有的交换空间。如果交换空间正在使用，终止正在运行的程序。
|
||||
|
||||
```
|
||||
swapoff -a
|
||||
```
|
||||
|
||||
现在增加逻辑卷的大小。
|
||||
|
||||
```
|
||||
[root@studentvm1 ~]# lvextend -L +2G /dev/mapper/fedora_studentvm1-swap
|
||||
Size of logical volume fedora_studentvm1/swap changed from 8.00 GiB (2048 extents) to 10.00 GiB (2560 extents).
|
||||
Logical volume fedora_studentvm1/swap successfully resized.
|
||||
[root@studentvm1 ~]#
|
||||
```
|
||||
|
||||
运行 `mkswap` 命令将整个 10GB 分区变成交换空间。
|
||||
|
||||
```
|
||||
[root@studentvm1 ~]# mkswap /dev/mapper/fedora_studentvm1-swap
|
||||
mkswap: /dev/mapper/fedora_studentvm1-swap: warning: wiping old swap signature.
|
||||
Setting up swapspace version 1, size = 10 GiB (10737414144 bytes)
|
||||
no label, UUID=3cc2bee0-e746-4b66-aa2d-1ea15ef1574a
|
||||
[root@studentvm1 ~]#
|
||||
```
|
||||
|
||||
重新启用交换空间。
|
||||
|
||||
```
|
||||
[root@studentvm1 ~]# swapon -a
|
||||
[root@studentvm1 ~]#
|
||||
```
|
||||
|
||||
现在，使用 `lsblk ` 命令验证新交换空间是否存在。同样，不需要重新启动机器。
|
||||
|
||||
```
|
||||
[root@studentvm1 ~]# lsblk
|
||||
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
|
||||
sda 8:0 0 60G 0 disk
|
||||
|-sda1 8:1 0 1G 0 part /boot
|
||||
`-sda2 8:2 0 59G 0 part
|
||||
|-fedora_studentvm1-pool00_tmeta 253:0 0 4M 0 lvm
|
||||
| `-fedora_studentvm1-pool00-tpool 253:2 0 2G 0 lvm
|
||||
| |-fedora_studentvm1-root 253:3 0 2G 0 lvm /
|
||||
| `-fedora_studentvm1-pool00 253:6 0 2G 0 lvm
|
||||
|-fedora_studentvm1-pool00_tdata 253:1 0 2G 0 lvm
|
||||
| `-fedora_studentvm1-pool00-tpool 253:2 0 2G 0 lvm
|
||||
| |-fedora_studentvm1-root 253:3 0 2G 0 lvm /
|
||||
| `-fedora_studentvm1-pool00 253:6 0 2G 0 lvm
|
||||
|-fedora_studentvm1-swap 253:4 0 10G 0 lvm [SWAP]
|
||||
|-fedora_studentvm1-usr 253:5 0 15G 0 lvm /usr
|
||||
|-fedora_studentvm1-home 253:7 0 2G 0 lvm /home
|
||||
|-fedora_studentvm1-var 253:8 0 10G 0 lvm /var
|
||||
`-fedora_studentvm1-tmp 253:9 0 5G 0 lvm /tmp
|
||||
sr0 11:0 1 1024M 0 rom
|
||||
[root@studentvm1 ~]#
|
||||
```
|
||||
|
||||
您也可以使用 `swapon -s` 命令或 `top`、`free` 或其他几个命令来验证这一点。
|
||||
|
||||
```
|
||||
[root@studentvm1 ~]# free
|
||||
total used free shared buff/cache available
|
||||
Mem: 4038808 382404 2754072 4152 902332 3404184
|
||||
Swap: 10485756 0 10485756
|
||||
[root@studentvm1 ~]#
|
||||
```
|
||||
|
||||
请注意，不同的命令以不同的形式显示或要求输入设备文件。在 `/dev` 目录中访问特定设备有多种方式。在我的文章 [在 Linux 中管理设备][2] 中有更多关于 `/dev` 目录及其内容说明。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/9/swap-space-linux-systems
|
||||
|
||||
作者：[David Both][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[heguangzhi](https://github.com/heguangzhi)
|
||||
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/dboth
|
||||
[1]: https://docs.fedoraproject.org/en-US/fedora/f28/install-guide/
|
||||
[2]: https://linux.cn/article-8099-1.html
|
||||
@ -0,0 +1,239 @@
|
||||
如何将 Scikit-learn Python 库用于数据科学项目
|
||||
======
|
||||
|
||||
> 灵活多样的 Python 库为数据分析和数据挖掘提供了强力的机器学习工具。
|
||||
|
||||
|
||||
|
||||
Scikit-learn Python 库最初于 2007 年发布，通常用于解决各种方面的机器学习和数据科学问题。这个多种功能的库提供了整洁、一致、高效的 API 和全面的在线文档。
|
||||
|
||||
### 什么是 Scikit-learn？
|
||||
|
||||
[Scikit-learn][1] 是一个开源 Python 库，拥有强大的数据分析和数据挖掘工具。 在 BSD 许可下可用，并建立在以下机器学习库上：
|
||||
|
||||
- `NumPy`，一个用于操作多维数组和矩阵的库。它还具有广泛的数学函数汇集，可用于执行各种计算。
|
||||
- `SciPy`，一个由各种库组成的生态系统，用于完成技术计算任务。
|
||||
- `Matplotlib`，一个用于绘制各种图表和图形的库。
|
||||
|
||||
Scikit-learn 提供了广泛的内置算法，可以充分用于数据科学项目。
|
||||
|
||||
以下是使用 Scikit-learn 库的主要方法。
|
||||
|
||||
#### 1、分类
|
||||
|
||||
[分类][2]工具识别与提供的数据相关联的类别。例如，它们可用于将电子邮件分类为垃圾邮件或非垃圾邮件。
|
||||
|
||||
Scikit-learn 中的分类算法包括：
|
||||
|
||||
- <ruby>支持向量机<rt>Support vector machines</rt></ruby>（SVM）
|
||||
- <ruby>最邻近<rt>Nearest neighbors</rt></ruby>
|
||||
- <ruby>随机森林<rt>Random forest</rt></ruby>
|
||||
|
||||
#### 2、回归
|
||||
|
||||
回归涉及到创建一个模型去试图理解输入和输出数据之间的关系。例如，回归工具可用于理解股票价格的行为。
|
||||
|
||||
回归算法包括：
|
||||
|
||||
- <ruby>支持向量机<rt>Support vector machines</rt></ruby>（SVM）
|
||||
- <ruby>岭回归<rt>Ridge regression</rt></ruby>
|
||||
- Lasso（LCTT 译注：Lasso 即 least absolute shrinkage and selection operator，又译为最小绝对值收敛和选择算子、套索算法）
|
||||
|
||||
#### 3、聚类
|
||||
|
||||
Scikit-learn 聚类工具用于自动将具有相同特征的数据分组。 例如，可以根据客户数据的地点对客户数据进行细分。
|
||||
|
||||
聚类算法包括：
|
||||
|
||||
- K-means
|
||||
- <ruby>谱聚类<rt>Spectral clustering</rt></ruby>
|
||||
- Mean-shift
|
||||
|
||||
#### 4、降维
|
||||
|
||||
降维降低了用于分析的随机变量的数量。例如，为了提高可视化效率，可能不会考虑外围数据。
|
||||
|
||||
降维算法包括：
|
||||
|
||||
- <ruby>主成分分析<rt>Principal component analysis</rt></ruby>（PCA）
|
||||
- <ruby>功能选择<rt>Feature selection</rt></ruby>
|
||||
- <ruby>非负矩阵分解<rt>Non-negative matrix factorization</rt></ruby>
|
||||
|
||||
#### 5、模型选择
|
||||
|
||||
模型选择算法提供了用于比较、验证和选择要在数据科学项目中使用的最佳参数和模型的工具。
|
||||
|
||||
通过参数调整能够增强精度的模型选择模块包括：
|
||||
|
||||
- <ruby>网格搜索<rt>Grid search</rt></ruby>
|
||||
- <ruby>交叉验证<rt>Cross-validation</rt></ruby>
|
||||
- <ruby>指标<rt>Metrics</rt></ruby>
|
||||
|
||||
#### 6、预处理
|
||||
|
||||
Scikit-learn 预处理工具在数据分析期间的特征提取和规范化中非常重要。 例如，您可以使用这些工具转换输入数据（如文本）并在分析中应用其特征。
|
||||
|
||||
预处理模块包括：
|
||||
|
||||
- 预处理
|
||||
- 特征提取
|
||||
|
||||
### Scikit-learn 库示例
|
||||
|
||||
让我们用一个简单的例子来说明如何在数据科学项目中使用 Scikit-learn 库。
|
||||
|
||||
我们将使用[鸢尾花花卉数据集][3]，该数据集包含在 Scikit-learn 库中。 鸢尾花数据集包含有关三种花种的 150 个细节，三种花种分别为：
|
||||
|
||||
- Setosa：标记为 0
|
||||
- Versicolor：标记为 1
|
||||
- Virginica：标记为 2
|
||||
|
||||
数据集包括每种花种的以下特征（以厘米为单位）：
|
||||
|
||||
- 萼片长度
|
||||
- 萼片宽度
|
||||
- 花瓣长度
|
||||
- 花瓣宽度
|
||||
|
||||
#### 第 1 步：导入库
|
||||
|
||||
由于鸢尾花花卉数据集包含在 Scikit-learn 数据科学库中，我们可以将其加载到我们的工作区中，如下所示：
|
||||
|
||||
```
|
||||
from sklearn import datasets
|
||||
iris = datasets.load_iris()
|
||||
```
|
||||
|
||||
这些命令从 `sklearn` 导入数据集 `datasets` 模块，然后使用 `datasets` 中的 `load_iris()` 方法将数据包含在工作空间中。
|
||||
|
||||
#### 第 2 步：获取数据集特征
|
||||
|
||||
数据集 `datasets` 模块包含几种方法，使您更容易熟悉处理数据。
|
||||
|
||||
在 Scikit-learn 中，数据集指的是类似字典的对象，其中包含有关数据的所有详细信息。 使用 `.data` 键存储数据，该数据列是一个数组列表。
|
||||
|
||||
例如，我们可以利用 `iris.data` 输出有关鸢尾花花卉数据集的信息。
|
||||
|
||||
```
|
||||
print(iris.data)
|
||||
```
|
||||
|
||||
这是输出（结果已被截断）：
|
||||
|
||||
```
|
||||
[[5.1 3.5 1.4 0.2]
|
||||
[4.9 3. 1.4 0.2]
|
||||
[4.7 3.2 1.3 0.2]
|
||||
[4.6 3.1 1.5 0.2]
|
||||
[5. 3.6 1.4 0.2]
|
||||
[5.4 3.9 1.7 0.4]
|
||||
[4.6 3.4 1.4 0.3]
|
||||
[5. 3.4 1.5 0.2]
|
||||
[4.4 2.9 1.4 0.2]
|
||||
[4.9 3.1 1.5 0.1]
|
||||
[5.4 3.7 1.5 0.2]
|
||||
[4.8 3.4 1.6 0.2]
|
||||
[4.8 3. 1.4 0.1]
|
||||
[4.3 3. 1.1 0.1]
|
||||
[5.8 4. 1.2 0.2]
|
||||
[5.7 4.4 1.5 0.4]
|
||||
[5.4 3.9 1.3 0.4]
|
||||
[5.1 3.5 1.4 0.3]
|
||||
```
|
||||
|
||||
我们还使用 `iris.target` 向我们提供有关花朵不同标签的信息。
|
||||
|
||||
```
|
||||
print(iris.target)
|
||||
```
|
||||
|
||||
这是输出：
|
||||
|
||||
```
|
||||
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
|
||||
0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
|
||||
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2
|
||||
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
|
||||
2 2]
|
||||
```
|
||||
|
||||
如果我们使用 `iris.target_names`，我们将输出数据集中找到的标签名称的数组。
|
||||
|
||||
```
|
||||
print(iris.target_names)
|
||||
```
|
||||
|
||||
以下是运行 Python 代码后的结果：
|
||||
|
||||
```
|
||||
['setosa' 'versicolor' 'virginica']
|
||||
```
|
||||
|
||||
#### 第 3 步：可视化数据集
|
||||
|
||||
我们可以使用[箱形图][4]来生成鸢尾花数据集的视觉描绘。 箱形图说明了数据如何通过四分位数在平面上分布的。
|
||||
|
||||
以下是如何实现这一目标：
|
||||
|
||||
```
|
||||
import seaborn as sns
|
||||
box_data = iris.data # 表示数据数组的变量
|
||||
box_target = iris.target # 表示标签数组的变量
|
||||
sns.boxplot(data = box_data,width=0.5,fliersize=5)
|
||||
sns.set(rc={'figure.figsize':(2,15)})
|
||||
```
|
||||
|
||||
让我们看看结果：
|
||||
|
||||
|
||||
|
||||
在横轴上：
|
||||
|
||||
* 0 是萼片长度
|
||||
* 1 是萼片宽度
|
||||
* 2 是花瓣长度
|
||||
* 3 是花瓣宽度
|
||||
|
||||
垂直轴的尺寸以厘米为单位。
|
||||
|
||||
### 总结
|
||||
|
||||
以下是这个简单的 Scikit-learn 数据科学教程的完整代码。
|
||||
|
||||
```
|
||||
from sklearn import datasets
|
||||
iris = datasets.load_iris()
|
||||
print(iris.data)
|
||||
print(iris.target)
|
||||
print(iris.target_names)
|
||||
import seaborn as sns
|
||||
box_data = iris.data # 表示数据数组的变量
|
||||
box_target = iris.target # 表示标签数组的变量
|
||||
sns.boxplot(data = box_data,width=0.5,fliersize=5)
|
||||
sns.set(rc={'figure.figsize':(2,15)})
|
||||
```
|
||||
|
||||
Scikit-learn 是一个多功能的 Python 库，可用于高效完成数据科学项目。
|
||||
|
||||
如果您想了解更多信息，请查看 [LiveEdu][5] 上的教程，例如 Andrey Bulezyuk 关于使用 Scikit-learn 库创建[机器学习应用程序][6]的视频。
|
||||
|
||||
有什么评价或者疑问吗？ 欢迎在下面分享。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/9/how-use-scikit-learn-data-science-projects
|
||||
|
||||
作者：[Dr.Michael J.Garbade][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[Flowsnow](https://github.com/Flowsnow)
|
||||
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/drmjg
|
||||
[1]: http://scikit-learn.org/stable/index.html
|
||||
[2]: https://blog.liveedu.tv/regression-versus-classification-machine-learning-whats-the-difference/
|
||||
[3]: https://en.wikipedia.org/wiki/Iris_flower_data_set
|
||||
[4]: https://en.wikipedia.org/wiki/Box_plot
|
||||
[5]: https://www.liveedu.tv/guides/data-science/
|
||||
[6]: https://www.liveedu.tv/andreybu/REaxr-machine-learning-model-python-sklearn-kera/oPGdP-machine-learning-model-python-sklearn-kera/
|
||||
@ -1,40 +1,39 @@
|
||||
如何在 Ubuntu Linux 中使用 RAR 文件
|
||||
======
|
||||
|
||||
[RAR][1] 是一种非常好的归档文件格式。但相比之下 7-zip 能提供了更好的压缩率，并且默认情况下还可以在多个平台上轻松支持 Zip 文件。不过 RAR 仍然是最流行的归档格式之一。然而 [Ubuntu][2] 自带的归档管理器却不支持提取 RAR 文件，也不允许创建 RAR 文件。
|
||||
|
||||
方法总比问题多。只要安装 `unrar` 这款由 [RARLAB][3] 提供的免费软件，就能在 Ubuntu 上支持提取RAR文件了。你也可以试安装 `rar` 来创建和管理 RAR 文件。
|
||||
办法总比问题多。只要安装 `unrar` 这款由 [RARLAB][3] 提供的免费软件，就能在 Ubuntu 上支持提取 RAR 文件了。你也可以安装 `rar` 试用版来创建和管理 RAR 文件。
|
||||
|
||||
![RAR files in Ubuntu Linux][4]
|
||||
|
||||
### 提取 RAR 文件
|
||||
|
||||
在未安装 unrar 的情况下，提取 RAR 文件会报出“未能提取”错误，就像下面这样（以 [Ubuntu 18.04][5] 为例）：
|
||||
在未安装 `unrar` 的情况下，提取 RAR 文件会报出“未能提取”错误，就像下面这样（以 [Ubuntu 18.04][5] 为例）：
|
||||
|
||||
![Error in RAR extraction in Ubuntu][6]
|
||||
|
||||
如果要解决这个错误并提取 RAR 文件，请按照以下步骤安装 unrar：
|
||||
如果要解决这个错误并提取 RAR 文件，请按照以下步骤安装 `unrar`：
|
||||
|
||||
打开终端并输入：
|
||||
|
||||
```
|
||||
sudo apt-get install unrar
|
||||
|
||||
sudo apt-get install unrar
|
||||
```
|
||||
|
||||
安装 unrar 后，直接输入 `unrar` 就可以看到它的用法以及如何使用这个工具处理 RAR 文件。
|
||||
安装 `unrar` 后，直接输入 `unrar` 就可以看到它的用法以及如何使用这个工具处理 RAR 文件。
|
||||
|
||||
最常用到的功能是提取 RAR 文件。因此，可以**通过右键单击 RAR 文件并执行提取**，也可以借助此以下命令通过终端执行操作：
|
||||
|
||||
```
|
||||
unrar x FileName.rar
|
||||
|
||||
```
|
||||
|
||||
结果类似以下这样：
|
||||
|
||||
![Using unrar in Ubuntu][7]
|
||||
|
||||
如果家目录中不存在对应的文件，就必须使用 `cd` 命令移动到目标目录下。例如 RAR 文件如果在 `Music` 目录下，只需要使用 `cd Music` 就可以移动到相应的目录，然后提取 RAR 文件。
|
||||
如果压缩文件没放在家目录中，就必须使用 `cd` 命令移动到目标目录下。例如 RAR 文件如果在 `Music` 目录下，只需要使用 `cd Music` 就可以移动到相应的目录，然后提取 RAR 文件。
|
||||
|
||||
### 创建和管理 RAR 文件
|
||||
|
||||
@ -42,18 +41,16 @@ unrar x FileName.rar
|
||||
|
||||
`unrar` 不允许创建 RAR 文件。因此还需要安装 `rar` 命令行工具才能创建 RAR 文件。
|
||||
|
||||
要创建 RAR 文件，首先需要通过以下命令安装 rar：
|
||||
要创建 RAR 文件，首先需要通过以下命令安装 `rar`：
|
||||
|
||||
```
|
||||
sudo apt-get install rar
|
||||
|
||||
```
|
||||
|
||||
按照下面的命令语法创建 RAR 文件：
|
||||
|
||||
```
|
||||
rar a ArchiveName File_1 File_2 Dir_1 Dir_2
|
||||
|
||||
```
|
||||
|
||||
按照这个格式输入命令时，它会将目录中的每个文件添加到 RAR 文件中。如果需要某一个特定的文件，就要指定文件确切的名称或路径。
|
||||
@ -64,7 +61,6 @@ rar a ArchiveName File_1 File_2 Dir_1 Dir_2
|
||||
|
||||
```
|
||||
rar u ArchiveName Filename
|
||||
|
||||
```
|
||||
|
||||
在终端输入 `rar` 就可以列出 RAR 工具的相关命令。
|
||||
@ -82,7 +78,7 @@ via: https://itsfoss.com/use-rar-ubuntu-linux/
|
||||
作者：[Ankush Das][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[HankChow](https://github.com/HankChow)
|
||||
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
|
||||
|
||||
85
published/20180928 10 handy Bash aliases for Linux.md
Normal file
85
published/20180928 10 handy Bash aliases for Linux.md
Normal file
@ -0,0 +1,85 @@
|
||||
10 个 Linux 中方便的 Bash 别名
|
||||
======
|
||||
> 对 Bash 长命令使用压缩的版本来更有效率。
|
||||
|
||||
|
||||
|
||||
你有多少次在命令行上输入一个长命令，并希望有一种方法可以保存它以供日后使用？这就是 Bash 别名派上用场的地方。它们允许你将长而神秘的命令压缩为易于记忆和使用的东西。需要一些例子来帮助你入门吗？没问题！
|
||||
|
||||
要使用你创建的 Bash 别名，你需要将其添加到 `.bash_profile` 中，该文件位于你的家目录中。请注意，此文件是隐藏的，并只能从命令行访问。编辑此文件的最简单方法是使用 Vi 或 Nano 之类的东西。
|
||||
|
||||
### 10 个方便的 Bash 别名
|
||||
|
||||
1、 你有几次遇到需要解压 .tar 文件但无法记住所需的确切参数？别名可以帮助你！只需将以下内容添加到 `.bash_profile` 中，然后使用 `untar FileName` 解压缩任何 .tar 文件。
|
||||
|
||||
```
|
||||
alias untar='tar -zxvf '
|
||||
```
|
||||
2、 想要下载的东西，但如果出现问题可以恢复吗？
|
||||
|
||||
```
|
||||
alias wget='wget -c '
|
||||
```
|
||||
|
||||
3、 是否需要为新的网络帐户生成随机的 20 个字符的密码？没问题。
|
||||
|
||||
```
|
||||
alias getpass="openssl rand -base64 20"
|
||||
```
|
||||
|
||||
4、 下载文件并需要测试校验和？我们也可做到。
|
||||
|
||||
```
|
||||
alias sha='shasum -a 256 '
|
||||
```
|
||||
|
||||
5、 普通的 `ping` 将永远持续下去。我们不希望这样。相反，让我们将其限制在五个 `ping`。
|
||||
|
||||
```
|
||||
alias ping='ping -c 5'
|
||||
```
|
||||
|
||||
6、 在任何你想要的文件夹中启动 Web 服务器。
|
||||
|
||||
```
|
||||
alias www='python -m SimpleHTTPServer 8000'
|
||||
```
|
||||
|
||||
7、 想知道你的网络有多快？只需下载 Speedtest-cli 并使用此别名即可。你可以使用 `speedtest-cli --list` 命令选择离你所在位置更近的服务器。
|
||||
|
||||
```
|
||||
alias speed='speedtest-cli --server 2406 --simple'
|
||||
```
|
||||
|
||||
8、 你有多少次需要知道你的外部 IP 地址，但是不知道如何获取？我也是。
|
||||
|
||||
```
|
||||
alias ipe='curl ipinfo.io/ip'
|
||||
```
|
||||
|
||||
9、 需要知道你的本地 IP 地址？
|
||||
|
||||
```
|
||||
alias ipi='ipconfig getifaddr en0'
|
||||
```
|
||||
|
||||
10、 最后，让我们清空屏幕。
|
||||
|
||||
```
|
||||
alias c='clear'
|
||||
```
|
||||
|
||||
如你所见，Bash 别名是一种在命令行上简化生活的超级简便方法。想了解更多信息？我建议你 Google 搜索“Bash 别名”或在 Github 中看下。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/9/handy-bash-aliases
|
||||
|
||||
作者：[Patrick H.Mullins][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
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/pmullins
|
||||
@ -0,0 +1,86 @@
|
||||
一款免费且安全的在线 PDF 转换软件
|
||||
======
|
||||
|
||||
|
||||
|
||||
我们总在寻找一个更好用且更高效的解决方案，来我们的生活理加方便。 比方说，在处理 PDF 文档时，你肯定会想拥有一款工具，它能够在任何情形下都显得快速可靠。在这，我们想向你推荐 **EasyPDF** —— 一款可以胜任所有场合的在线 PDF 软件。通过大量的测试，我们可以保证：这款工具能够让你的 PDF 文档管理更加容易。
|
||||
|
||||
不过，关于 EasyPDF 有一些十分重要的事情，你必须知道。
|
||||
|
||||
* EasyPDF 是免费的、匿名的在线 PDF 转换软件。
|
||||
* 能够将 PDF 文档转换成 Word、Excel、PowerPoint、AutoCAD、JPG、GIF 和文本等格式格式的文档。
|
||||
* 能够从 Word、Excel、PowerPoint 等其他格式的文件创建 PDF 文件。
|
||||
* 能够进行 PDF 文档的合并、分割和压缩。
|
||||
* 能够识别扫描的 PDF 和图片中的内容。
|
||||
* 可以从你的设备或者云存储（Google Drive 和 DropBox）中上传文档。
|
||||
* 可以在 Windows、Linux、Mac 和智能手机上通过浏览器来操作。
|
||||
* 支持多种语言。
|
||||
|
||||
### EasyPDF的用户界面
|
||||
|
||||
|
||||
|
||||
EasyPDF 最吸引你眼球的就是平滑的用户界面，营造一种整洁的环境，这会让使用者感觉更加舒服。由于网站完全没有一点广告，EasyPDF 的整体使用体验相比以前会好很多。
|
||||
|
||||
每种不同类型的转换都有它们专门的菜单，只需要简单地向其中添加文件，你并不需要知道太多知识来进行操作。
|
||||
|
||||
许多类似网站没有做好相关的优化，使得在手机上的使用体验并不太友好。然而，EasyPDF 突破了这一个瓶颈。在智能手机上，EasyPDF 几乎可以秒开，并且可以顺畅的操作。你也通过 Chrome 的“三点菜单”把 EasyPDF 添加到手机的主屏幕上。
|
||||
|
||||
|
||||
|
||||
### 特性
|
||||
|
||||
除了好看的界面，EasyPDF 还非常易于使用。为了使用它，你 **不需要注册一个账号** 或者**留下一个邮箱**，它是完全匿名的。另外， EasyPDF 也不会对要转换的文件进行数量或者大小的限制，完全不需要安装！酷极了，不是吗？
|
||||
|
||||
首先，你需要选择一种想要进行的格式转换，比如，将 PDF 转换成 Word。然后，选择你想要转换的 PDF 文件。你可以通过两种方式来上传文件：直接拖拉或者从设备上的文件夹进行选择。还可以选择从[Google Drive][1] 或 [Dropbox][2]来上传文件。
|
||||
|
||||
选择要进行格式转换的文件后，点击 Convert 按钮开始转换过程。转换过程会在一分钟内完成，你并不需要等待太长时间。如果你还有对其他文件进行格式转换，在接着转换前，不要忘了将前面已经转换完成的文件下载保存。不然的话，你将会丢失前面的文件。
|
||||
|
||||
|
||||
|
||||
要进行其他类型的格式转换，直接返回到主页。
|
||||
|
||||
目前支持的几种格式转换类型如下：
|
||||
|
||||
* **PDF to Word** – 将 PDF 文档 转换成 Word 文档
|
||||
* **PDF 转换成 PowerPoint** – 将 PDF 文档 转换成 PowerPoint 演示讲稿
|
||||
* **PDF 转换成 Excel** – 将 PDF 文档 转换成 Excel 文档
|
||||
* **PDF 创建** – 从一些其他类型的文件（如，文本、doc、odt）来创建PDF文档
|
||||
* **Word 转换成 PDF** – 将 Word 文档 转换成 PDF 文档
|
||||
* **JPG 转换成 PDF** – 将 JPG images 转换成 PDF 文档
|
||||
* **PDF 转换成 AutoCAD** – 将 PDF 文档 转换成 .dwg 格式（DWG 是 CAD 文件的原生的格式）
|
||||
* **PDF 转换成 Text** – 将 PDF 文档 转换成 Text 文档
|
||||
* **PDF 分割** – 把 PDF 文件分割成多个部分
|
||||
* **PDF 合并** – 把多个 PDF 文件合并成一个文件
|
||||
* **PDF 压缩** – 将 PDF 文档进行压缩
|
||||
* **PDF 转换成 JPG** – 将 PDF 文档 转换成 JPG 图片
|
||||
* **PDF 转换成 PNG** – 将 PDF 文档 转换成 PNG 图片
|
||||
* **PDF 转换成 GIF** – 将 PDF 文档 转换成 GIF 文件
|
||||
* **在线文字内容识别** – 将扫描的纸质文档转换成能够进行编辑的文件（如，Word、Excel、文本）
|
||||
|
||||
想试一试吗？好极了！点击下面的链接，然后开始格式转换吧！
|
||||
|
||||
[][https://easypdf.com/]
|
||||
|
||||
### 总结
|
||||
|
||||
EasyPDF 名符其实，能够让 PDF 管理更加容易。就我测试过的 EasyPDF 服务而言，它提供了**完全免费**的简单易用的转换功能。它十分快速、安全和可靠。你会对它的服务质量感到非常满意，因为它不用支付任何费用，也不用留下像邮箱这样的个人信息。值得一试，也许你会找到你自己更喜欢的 PDF 工具。
|
||||
|
||||
好吧，我就说这些。更多的好东西还在后后面，请继续关注!
|
||||
|
||||
加油！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/easypdf-a-free-and-secure-online-pdf-conversion-suite/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[zhousiyu325](https://github.com/zhousiyu325)
|
||||
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]: https://www.ostechnix.com/how-to-mount-google-drive-locally-as-virtual-file-system-in-linux/
|
||||
[2]: https://www.ostechnix.com/install-dropbox-in-ubuntu-18-04-lts-desktop/
|
||||
@ -1,22 +1,23 @@
|
||||
# 如何在 Ubuntu 以及其他 Linux 发行版上安装 Popcorn Time
|
||||
如何在 Ubuntu 18.04 上安装 Popcorn Time
|
||||
======
|
||||
|
||||
**简要：这篇教程展示给你如何在 Ubuntu 和其他 Linux 发行版上安装 Popcorn Time，也会讨论一些 Popcorn Time 的便捷操作**
|
||||
> 简要：这篇教程展示给你如何在 Ubuntu 和其他 Linux 发行版上安装 Popcorn Time，也会讨论一些 Popcorn Time 的便捷操作。
|
||||
|
||||
[Popcorn Time][1] 是一个受开源 [Netflix][2] 启发的 [torrent][3] 流媒体应用，可以在 Linux，Mac上Windows 上运行。
|
||||
[Popcorn Time][1] 是一个受 [Netflix][2] 启发的开源的 [torrent][3] 流媒体应用，可以在 Linux、Mac、Windows 上运行。
|
||||
|
||||
传统的 torrents，在你看影片之前必须等待它下载完成。
|
||||
传统的 torrent，在你看影片之前必须等待它下载完成。
|
||||
|
||||
[Popcorn Time][4] 有所不同。它的使用基于 torrent，但是允许你（几乎）立即开始观看影片。他跟你在 Youtube 或者 Netflix 等流媒体网页上看影片一样，无需等待它下载完成。
|
||||
[Popcorn Time][4] 有所不同。它的使用基于 torrent，但是允许你（几乎）立即开始观看影片。它跟你在 Youtube 或者 Netflix 等流媒体网页上看影片一样，无需等待它下载完成。
|
||||
|
||||
![Popcorn Time in Ubuntu Linux][5]
|
||||
Popcorn Time
|
||||
|
||||
如果你不想在看在线电影时被突如其来的广告吓倒的话，Popcorn Time 是一个不错的选择。不过要记得，它的播放质量依赖于当前网络中可用的种子（seeds）数。
|
||||
*Popcorn Time*
|
||||
|
||||
Popcorn Time 还提供了一个不错的用户界面，让你能够浏览可用的电影，电视剧和其他视频内容。如果你曾经[在 Linux 上使用过 Netflix][6]，你会发现两者有一些相似之处。
|
||||
如果你不想在看在线电影时被突如其来的广告吓倒的话，Popcorn Time 是一个不错的选择。不过要记得，它的播放质量依赖于当前网络中可用的<ruby>种子<rt>seed</rt></ruby>数。
|
||||
|
||||
有些国家严格打击盗版，所以使用 torrent 下载电影是违法行为。在类似美国，英国和西欧等一些国家，你或许曾经收到过法律声明。也就是说，是否使用取决于你。已经警告过你了。
|
||||
(如果你仍想要冒险使用 Popcorn Time，你应该使用像 [Ivacy][7] 这样的 VPN 服务，它为使用 Torrents 和保护隐私有特别的设计。即便这样，也不能完全避免被查到。)
|
||||
Popcorn Time 还提供了一个不错的用户界面，让你能够浏览可用的电影、电视剧和其他视频内容。如果你曾经[在 Linux 上使用过 Netflix][6]，你会发现两者有一些相似之处。
|
||||
|
||||
有些国家严格打击盗版，所以使用 torrent 下载电影是违法行为。在类似美国、英国和西欧等一些国家，你或许曾经收到过法律声明。也就是说，是否使用取决于你。已经警告过你了。
|
||||
|
||||
Popcorn Time 一些主要的特点：
|
||||
|
||||
@ -24,39 +25,42 @@ Popcorn Time 一些主要的特点：
|
||||
* 有一个时尚的用户界面让你浏览可用的电影和电视剧资源
|
||||
* 调整流媒体的质量
|
||||
* 标记为稍后观看
|
||||
* 下载为离线观看
|
||||
* 下载为离线观看
|
||||
* 可以默认开启字幕，改变字母尺寸等
|
||||
* 使用键盘快捷键浏览
|
||||
|
||||
|
||||
### 如何在 Ubuntu 和其它 Linux 发行版上安装 Popcorn Time
|
||||
|
||||
这篇教程以 Ubuntu 18.04 为例，但是你可以使用类似的结构，在例如 Linux Mint，Debian，Manjaro，Deepin等 Linux 发行版上安装。
|
||||
这篇教程以 Ubuntu 18.04 为例，但是你可以使用类似的说明，在例如 Linux Mint、Debian、Manjaro、Deepin 等 Linux 发行版上安装。
|
||||
|
||||
Popcorn Time 在 Deepin Linux 的软件中心中也可用。Manjaro 和 Arch 用户也可以轻松地使用 AUR 来安装 Popcorn Time。
|
||||
|
||||
接下来我们看该如何在 Linux 上安装 Popcorn Time。事实上，这个过程非常简单。只需要按照说明操作复制粘贴我提到的这些命令即可。
|
||||
|
||||
#### 第一步：下载 Popcorn Time
|
||||
|
||||
你可以从它的官网上安装 Popcorn Time。它主页上的下载链接是。
|
||||
[Get Popcorn Time](https://popcorntime.sh/)
|
||||
你可以从它的官网上安装 Popcorn Time。下载链接在它的主页上。
|
||||
|
||||
- [下载 Popcorn Time](https://popcorntime.sh/)
|
||||
|
||||
#### 第二步：安装 Popcorn Time
|
||||
|
||||
下载完成之后，就该使用它了。下载下来的是一个 tar 文件，在这些文件里面包含有一个可执行文件。你可以把 tar 文件提取在任何位置，[Linux 常把附加软件安装在][8] /[opt 目录。][8]
|
||||
下载完成之后，就该使用它了。下载下来的是一个 tar 文件，在这些文件里面包含有一个可执行文件。你可以把 tar 文件提取在任何位置，[Linux 常把附加软件安装在][8] [/opt 目录][8]。
|
||||
|
||||
在 /opt 下创建一个新的目录：
|
||||
在 `/opt` 下创建一个新的目录：
|
||||
|
||||
```
|
||||
sudo mkdir /opt/popcorntime
|
||||
```
|
||||
|
||||
现在进入你下载文件的文件夹中，比如我把 Popcorn Time 下载到了主目录的 Downloads目录下。
|
||||
现在进入你下载文件的文件夹中，比如我把 Popcorn Time 下载到了主目录的 Downloads 目录下。
|
||||
|
||||
```
|
||||
cd ~/Downloads
|
||||
```
|
||||
|
||||
提取下载好的 Popcorn Time 文件到新创建的 /opt/popcorntime 目录下
|
||||
提取下载好的 Popcorn Time 文件到新创建的 `/opt/popcorntime` 目录下：
|
||||
|
||||
```
|
||||
sudo tar Jxf Popcorn-Time-* -C /opt/popcorntime
|
||||
@ -64,7 +68,7 @@ sudo tar Jxf Popcorn-Time-* -C /opt/popcorntime
|
||||
|
||||
#### 第三步：让所有用户可以使用 Popcorn Time
|
||||
|
||||
如果你想要系统中所有的用户无需经过 sudo 就可以运行 Popcorn Time。你需要在 /usr/bin 目录下创建一个[符号链接（软链接）][9]指向这个可执行文件。
|
||||
如果你想要系统中所有的用户无需经过 `sudo` 就可以运行 Popcorn Time。你需要在 `/usr/bin` 目录下创建一个[符号链接（软链接）][9]指向这个可执行文件。
|
||||
|
||||
```
|
||||
ln -sf /opt/popcorntime/Popcorn-Time /usr/bin/Popcorn-Time
|
||||
@ -76,13 +80,13 @@ ln -sf /opt/popcorntime/Popcorn-Time /usr/bin/Popcorn-Time
|
||||
|
||||
为此，你需要创建一个桌面入口。
|
||||
|
||||
打开一个终端窗口，在 /usr/share/applications 目录下创建一个名为 popcorntime.desktop 的文件。
|
||||
打开一个终端窗口，在 `/usr/share/applications` 目录下创建一个名为 `popcorntime.desktop` 的文件。
|
||||
|
||||
你可以使用任何[基于命令行的文本编辑器][10]。Ubuntu 默认安装了 [Nano][11]，所以你可以直接使用这个。
|
||||
|
||||
```
|
||||
sudo nano /usr/share/applications/popcorntime.desktop
|
||||
```
|
||||
```
|
||||
|
||||
在里面插入以下内容：
|
||||
|
||||
@ -95,11 +99,11 @@ Name = Popcorn-Time
|
||||
Exec = /usr/bin/Popcorn-Time
|
||||
Icon = /opt/popcorntime/popcorn.png
|
||||
Categories = Application;
|
||||
```
|
||||
```
|
||||
|
||||
如果你使用的是 Nano 编辑器，使用 Ctrl+X 保存输入的内容，当询问是否保存时，输入 Y，然后按回车保存并退出。
|
||||
如果你使用的是 Nano 编辑器，使用 `Ctrl+X` 保存输入的内容，当询问是否保存时，输入 `Y`，然后按回车保存并退出。
|
||||
|
||||
就快要完成了。最后一件事就是为 Popcorn Time 设置一个正确的图标。你可以下载一个 Popcorn Time 图标到 /opt/popcorntime 目录下，并命名为 popcorn.png。
|
||||
就快要完成了。最后一件事就是为 Popcorn Time 设置一个正确的图标。你可以下载一个 Popcorn Time 图标到 `/opt/popcorntime` 目录下，并命名为 `popcorn.png`。
|
||||
|
||||
你可以使用以下命令：
|
||||
|
||||
@ -109,13 +113,15 @@ sudo wget -O /opt/popcorntime/popcorn.png https://upload.wikimedia.org/wikipedia
|
||||
|
||||
这样就 OK 了。现在你可以搜索 Popcorn Time 然后点击启动它了。
|
||||
|
||||
![Popcorn Time installed on Ubuntu][12]
|
||||
在菜单里搜索 Popcorn Time
|
||||
![Popcorn Time installed on Ubuntu][12]
|
||||
|
||||
*在菜单里搜索 Popcorn Time*
|
||||
|
||||
第一次启动时，你必须接受这些条款和条件。
|
||||
|
||||
![Popcorn Time in Ubuntu][13]
|
||||
接受这些服务条款
|
||||
|
||||
*接受这些服务条款*
|
||||
|
||||
一旦你完成这些，你就可以享受你的电影和电视节目了。
|
||||
|
||||
@ -123,22 +129,17 @@ sudo wget -O /opt/popcorntime/popcorn.png https://upload.wikimedia.org/wikipedia
|
||||
|
||||
好了，这就是所有你在 Ubuntu 或者其他 Linux 发行版上安装 Popcorn Time 所需要的了。你可以直接开始看你最喜欢的影视节目了。
|
||||
|
||||
当然，如果你有兴趣的话，我建议你阅读以下关于 Popcorn Time 的小贴士，可以学到更多。
|
||||
|
||||
[![][15]][16]
|
||||
![][17]
|
||||
|
||||
### 高效使用 Popcorn Time 的七个小贴士
|
||||
|
||||
现在你已经安装好了 Popcorn Time 了，我接下来将要告诉你一些有用的 Popcorn Time 技巧。我保证它会增强你使用 Popcorn Time 的体验。
|
||||
|
||||
#### 1\. 使用高级设置
|
||||
#### 1、 使用高级设置
|
||||
|
||||
始终启用高级设置。它给了你更多的选项去调整 Popcorn Time 点击右上角的齿轮标记。查看其中的高级设置。
|
||||
|
||||
|
||||
|
||||
#### 2\. 在 VLC 或者其他播放器里观看影片
|
||||
#### 2、 在 VLC 或者其他播放器里观看影片
|
||||
|
||||
你知道你可以选择自己喜欢的播放器而不是 Popcorn Time 默认的播放器观看一个视频吗？当然，这个播放器必须已经安装在你的系统上了。
|
||||
|
||||
@ -148,29 +149,29 @@ sudo wget -O /opt/popcorntime/popcorn.png https://upload.wikimedia.org/wikipedia
|
||||
|
||||
|
||||
|
||||
#### 3\. 将影片标记为稍后观看
|
||||
#### 3、 将影片标记为稍后观看
|
||||
|
||||
只是浏览电影和电视节目，但是却没有时间和精力去看？这不是问题。你可以添加这些影片到书签里面，稍后可以在 Faveriate 标签里面访问这些影片。这可以让你创建一个你想要稍后观看的列表。
|
||||
|
||||
|
||||
|
||||
#### 4\. 检查 torrent 的信息和种子信息
|
||||
#### 4、 检查 torrent 的信息和种子信息
|
||||
|
||||
像我之前提到的，你在 Popcorn Time 的观看体验依赖于 torrent 的速度。好消息是 Popcorn Time 显示了 torrent 的信息，因此你可以知道流媒体的速度。
|
||||
|
||||
你可以在文件上看到一个绿色 / 黄色 / 红色的点。绿色意味着有足够的种子，文件很容易播放。黄色意味着有中等数量的种子，应该可以播放。红色意味着只有非常少可用的种子，播放的速度会很慢甚至无法观看。
|
||||
你可以在文件上看到一个绿色/黄色/红色的点。绿色意味着有足够的种子，文件很容易播放。黄色意味着有中等数量的种子，应该可以播放。红色意味着只有非常少可用的种子，播放的速度会很慢甚至无法观看。
|
||||
|
||||
|
||||
|
||||
#### 5\. 添加自定义字幕
|
||||
#### 5、 添加自定义字幕
|
||||
|
||||
如果你需要字幕而且它没有你想要的语言，你可以从外部网站下载自定义字幕。得到 .src 文件，然后就可以在 Popcorn Time 中使用它：
|
||||
|
||||
|
||||
|
||||
这是[用 VLC 自动下载字幕][19]
|
||||
你可以[用 VLC 自动下载字幕][19]。
|
||||
|
||||
#### 6\. 保存文件离线观看
|
||||
#### 6、 保存文件离线观看
|
||||
|
||||
用 Popcorn Time 播放内容时，它会下载并暂时存储这些内容。当你关闭 APP 时，缓存会被清理干净。你可以更改这个操作，使得下载的文件可以保存下来供你未来使用。
|
||||
|
||||
@ -178,7 +179,7 @@ sudo wget -O /opt/popcorntime/popcorn.png https://upload.wikimedia.org/wikipedia
|
||||
|
||||
|
||||
|
||||
#### 7\. 拖放外部 torrent 文件立即播放
|
||||
#### 7、 拖放外部 torrent 文件立即播放
|
||||
|
||||
我猜你不知道这个操作。如果你没有在 Popcorn Time 发现某些影片，从你最喜欢的 torrent 网站下载 torrent 文件，打开 Popcorn Time，然后拖放这个 torrent 文件到 Popcorn Time 里面。它将会立即播放文件，当然这个取决于种子。这次你不需要在观看前下载整个文件了。
|
||||
|
||||
@ -188,10 +189,7 @@ sudo wget -O /opt/popcorntime/popcorn.png https://upload.wikimedia.org/wikipedia
|
||||
|
||||
在 Popcorn Time 里面有很多的功能，但是我决定就此打住，剩下的就由你自己来探索吧。我希望你能发现更多 Popcorn Time 有用的功能和技巧。
|
||||
|
||||
我再提醒一遍，使用 Torrents 在很多国家是违法的。如果你还是这样做了，请做好防护措施，并使用 VPN 服务。如果你想要我的建议，你可以去看一下（让 [ProtonMail][21] 成名的）[瑞士的隐私公司 ProtonVPN][20]。新加坡的 [Ivacy][7] 也是一个不错的选择。如果你觉得这些都太贵了，你可以看一下[在 FOSS SHOP 上廉价的 VPN][22]
|
||||
|
||||
注意：这篇文章里包含了会员链接，请阅读我们的[会员隐私][23]。
|
||||
|
||||
我再提醒一遍，使用 Torrents 在很多国家是违法的。
|
||||
|
||||
-----------------------------------
|
||||
|
||||
@ -200,7 +198,7 @@ via: https://itsfoss.com/popcorn-time-ubuntu-linux/
|
||||
作者：[Abhishek Prakash][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[dianbanjiu](https://github.com/dianbanjiu)
|
||||
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
|
||||
|
||||
168
published/20181001 How to Install Pip on Ubuntu.md
Normal file
168
published/20181001 How to Install Pip on Ubuntu.md
Normal file
@ -0,0 +1,168 @@
|
||||
如何在 Ubuntu 上安装 pip
|
||||
======
|
||||
|
||||
**`pip` 是一个命令行工具，允许你安装 Python 编写的软件包。 学习如何在 Ubuntu 上安装 `pip` 以及如何使用它来安装 Python 应用程序。**
|
||||
|
||||
有许多方法可以[在 Ubuntu 上安装软件][1]。 你可以从软件中心安装应用程序，也可以从下载的 DEB 文件、PPA（LCTT 译注：PPA 即 Personal Package Archives，个人软件包集）、[Snap 软件包][2]，也可以使用 [Flatpak][3]、使用 [AppImage][4]，甚至用旧的源代码安装方式。
|
||||
|
||||
还有一种方法可以在 [Ubuntu][5] 中安装软件包。 它被称为 `pip`，你可以使用它来安装基于 Python 的应用程序。
|
||||
|
||||
### 什么是 pip
|
||||
|
||||
[pip][6] 代表 “pip Installs Packages”。 [pip][7] 是一个基于命令行的包管理系统。 用于安装和管理 [Python 语言][8]编写的软件。
|
||||
|
||||
你可以使用 `pip` 来安装 Python 包索引（[PyPI][9]）中列出的包。
|
||||
|
||||
作为软件开发人员，你可以使用 `pip` 为你自己的 Python 项目安装各种 Python 模块和包。
|
||||
|
||||
作为最终用户，你可能需要使用 `pip` 来安装一些 Python 开发的并且可以使用 `pip` 轻松安装的应用程序。 一个这样的例子是 [Stress Terminal][10] 应用程序，你可以使用 `pip` 轻松安装。
|
||||
|
||||
让我们看看如何在 Ubuntu 和其他基于 Ubuntu 的发行版上安装 `pip`。
|
||||
|
||||
### 如何在 Ubuntu 上安装 pip
|
||||
|
||||
![Install pip on Ubuntu Linux][11]
|
||||
|
||||
默认情况下，`pip` 未安装在 Ubuntu 上。 你必须首先安装它才能使用。 在 Ubuntu 上安装 `pip` 非常简单。 我马上展示给你。
|
||||
|
||||
Ubuntu 18.04 默认安装了 Python 2 和 Python 3。 因此，你应该为两个 Python 版本安装 `pip`。
|
||||
|
||||
`pip`，默认情况下是指 Python 2。`pip3` 代表 Python 3 中的 pip。
|
||||
|
||||
注意：我在本教程中使用的是 Ubuntu 18.04。 但是这里的教程应该适用于其他版本，如Ubuntu 16.04、18.10 等。你也可以在基于 Ubuntu 的其他 Linux 发行版上使用相同的命令，如 Linux Mint、Linux Lite、Xubuntu、Kubuntu 等。
|
||||
|
||||
#### 为 Python 2 安装 pip
|
||||
|
||||
首先，确保已经安装了 Python 2。 在 Ubuntu 上，可以使用以下命令进行验证。
|
||||
|
||||
```
|
||||
python2 --version
|
||||
```
|
||||
|
||||
如果没有错误并且显示了 Python 版本的有效输出，则说明安装了 Python 2。 所以现在你可以使用这个命令为 Python 2 安装 `pip`：
|
||||
|
||||
```
|
||||
sudo apt install python-pip
|
||||
```
|
||||
|
||||
这将安装 `pip` 和它的许多其他依赖项。 安装完成后，请确认你已正确安装了 `pip`。
|
||||
|
||||
```
|
||||
pip --version
|
||||
```
|
||||
|
||||
它应该显示一个版本号，如下所示：
|
||||
|
||||
```
|
||||
pip 9.0.1 from /usr/lib/python2.7/dist-packages (python 2.7)
|
||||
```
|
||||
|
||||
这意味着你已经成功在 Ubuntu 上安装了 `pip`。
|
||||
|
||||
#### 为 Python 3 安装 pip
|
||||
|
||||
你必须确保在 Ubuntu 上安装了 Python 3。 可以使用以下命令检查一下：
|
||||
|
||||
```
|
||||
python3 --version
|
||||
```
|
||||
|
||||
如果显示了像 Python 3.6.6 这样的数字，则说明 Python 3 在你的 Linux 系统上安装好了。
|
||||
|
||||
现在，你可以使用以下命令安装 `pip3`：
|
||||
|
||||
```
|
||||
sudo apt install python3-pip
|
||||
```
|
||||
|
||||
你应该使用以下命令验证 `pip3` 是否已正确安装：
|
||||
|
||||
```
|
||||
pip3 --version
|
||||
```
|
||||
|
||||
它应该显示一个这样的数字：
|
||||
|
||||
```
|
||||
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)
|
||||
```
|
||||
|
||||
这意味着 `pip3` 已成功安装在你的系统上。
|
||||
|
||||
### 如何使用 pip 命令
|
||||
|
||||
现在你已经安装了 `pip`，让我们快速看一些基本的 `pip` 命令。 这些命令将帮助你使用 `pip` 命令来搜索、安装和删除 Python 包。
|
||||
|
||||
要从 Python 包索引 PyPI 中搜索包，可以使用以下 `pip` 命令：
|
||||
|
||||
```
|
||||
pip search <search_string>
|
||||
```
|
||||
|
||||
例如，如果你搜索“stress”这个词，将会显示名称或描述中包含字符串“stress”的所有包。
|
||||
|
||||
```
|
||||
pip search stress
|
||||
stress (1.0.0) - A trivial utility for consuming system resources.
|
||||
s-tui (0.8.2) - Stress Terminal UI stress test and monitoring tool
|
||||
stressypy (0.0.12) - A simple program for calling stress and/or stress-ng from python
|
||||
fuzzing (0.3.2) - Tools for stress testing applications.
|
||||
stressant (0.4.1) - Simple stress-test tool
|
||||
stressberry (0.1.7) - Stress tests for the Raspberry Pi
|
||||
mobbage (0.2) - A HTTP stress test and benchmark tool
|
||||
stresser (0.2.1) - A large-scale stress testing framework.
|
||||
cyanide (1.3.0) - Celery stress testing and integration test support.
|
||||
pysle (1.5.7) - An interface to ISLEX, a pronunciation dictionary with stress markings.
|
||||
ggf (0.3.2) - global geometric factors and corresponding stresses of the optical stretcher
|
||||
pathod (0.17) - A pathological HTTP/S daemon for testing and stressing clients.
|
||||
MatPy (1.0) - A toolbox for intelligent material design, and automatic yield stress determination
|
||||
netblow (0.1.2) - Vendor agnostic network testing framework to stress network failures
|
||||
russtress (0.1.3) - Package that helps you to put lexical stress in russian text
|
||||
switchy (0.1.0a1) - A fast FreeSWITCH control library purpose-built on traffic theory and stress testing.
|
||||
nx4_selenium_test (0.1) - Provides a Python class and apps which monitor and/or stress-test the NoMachine NX4 web interface
|
||||
physical_dualism (1.0.0) - Python library that approximates the natural frequency from stress via physical dualism, and vice versa.
|
||||
fsm_effective_stress (1.0.0) - Python library that uses the rheological-dynamical analogy (RDA) to compute damage and effective buckling stress in prismatic shell structures.
|
||||
processpathway (0.3.11) - A nifty little toolkit to create stress-free, frustrationless image processing pathways from your webcam for computer vision experiments. Or observing your cat.
|
||||
```
|
||||
|
||||
如果要使用 `pip` 安装应用程序，可以按以下方式使用它：
|
||||
|
||||
```
|
||||
pip install <package_name>
|
||||
```
|
||||
|
||||
`pip` 不支持使用 tab 键补全包名，因此包名称需要准确指定。 它将下载所有必需的文件并安装该软件包。
|
||||
|
||||
如果要删除通过 `pip` 安装的 Python 包，可以使用 `pip` 中的 `uninstall` 选项。
|
||||
|
||||
```
|
||||
pip uninstall <installed_package_name>
|
||||
```
|
||||
|
||||
你可以在上面的命令中使用 `pip3` 代替 `pip`。
|
||||
|
||||
我希望这个快速提示可以帮助你在 Ubuntu 上安装 `pip`。 如果你有任何问题或建议，请在下面的评论部分告诉我。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/install-pip-ubuntu/
|
||||
|
||||
作者：[Abhishek Prakash][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[Flowsnow](https://github.com/Flowsnow)
|
||||
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/abhishek/
|
||||
[1]: https://itsfoss.com/how-to-add-remove-programs-in-ubuntu/
|
||||
[2]: https://itsfoss.com/use-snap-packages-ubuntu-16-04/
|
||||
[3]: https://itsfoss.com/flatpak-guide/
|
||||
[4]: https://itsfoss.com/use-appimage-linux/
|
||||
[5]: https://www.ubuntu.com/
|
||||
[6]: https://en.wikipedia.org/wiki/pip_(package_manager)
|
||||
[7]: https://pypi.org/project/pip/
|
||||
[8]: https://www.python.org/
|
||||
[9]: https://pypi.org/
|
||||
[10]: https://itsfoss.com/stress-terminal-ui/
|
||||
[11]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/10/install-pip-ubuntu.png
|
||||
@ -0,0 +1,177 @@
|
||||
cloc：计算不同编程语言源代码的行数
|
||||
======
|
||||
|
||||
|
||||
|
||||
作为一个开发人员，你可能需要不时地向你的领导或者同事分享你目前的工作与代码开发进展，抑或你的领导想对代码进行全方位的分析。这时，你就需要用到一些代码统计的工具，我知道其中一个是 [**Ohcount**][1]。今天，我遇到了另一个程序，**cloc**。你可以用 cloc 很容易地统计多种语言的源代码行数。它还可以计算空行数、代码行数、实际代码的行数，并通过整齐的表格进行结果输出。cloc 是自由开源的跨平台程序，使用 **Perl** 进行开发。
|
||||
|
||||
### 特点
|
||||
|
||||
cloc 有很多优势：
|
||||
|
||||
* 安装方便而且易用，不需要额外的依赖项
|
||||
* 可移植
|
||||
* 支持多种的结果格式导出，包括：纯文本、SQL、JSON、XML、YAML、CSV
|
||||
* 可以计算 git 的提交数
|
||||
* 可递归计算文件夹内的代码行数
|
||||
* 可计算压缩后的文件，如：tar、zip、Java 的 .ear 等类型
|
||||
* 开源，跨平台
|
||||
|
||||
### 安装
|
||||
|
||||
cloc 的安装包在大多数的类 Unix 操作系统的默认软件库内，所以你只需要使用默认的包管理器安装即可。
|
||||
|
||||
Arch Linux:
|
||||
|
||||
```
|
||||
$ sudo pacman -S cloc
|
||||
```
|
||||
|
||||
Debian/Ubuntu:
|
||||
|
||||
```
|
||||
$ sudo apt-get install cloc
|
||||
```
|
||||
|
||||
CentOS/Red Hat/Scientific Linux:
|
||||
|
||||
```
|
||||
$ sudo yum install cloc
|
||||
```
|
||||
|
||||
Fedora:
|
||||
|
||||
```
|
||||
$ sudo dnf install cloc
|
||||
```
|
||||
|
||||
FreeBSD:
|
||||
|
||||
```
|
||||
$ sudo pkg install cloc
|
||||
```
|
||||
|
||||
当然你也可以使用第三方的包管理器，比如 [**NPM**][2]。
|
||||
|
||||
```
|
||||
$ npm install -g cloc
|
||||
```
|
||||
|
||||
### 统计多种语言代码数据的使用举例
|
||||
|
||||
首先来几个简单的例子，比如下面在我目前工作目录中的的 C 代码。
|
||||
|
||||
```
|
||||
$ cat hello.c
|
||||
#include <stdio.h>
|
||||
int main()
|
||||
{
|
||||
// printf() displays the string inside quotation
|
||||
printf("Hello, World!");
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
|
||||
想要计算行数，只需要简单运行：
|
||||
|
||||
```
|
||||
$ cloc hello.c
|
||||
```
|
||||
|
||||
输出：
|
||||
|
||||
|
||||
|
||||
第一列是被分析文件的编程语言，上面我们可以看到这个文件是用 C 语言编写的。
|
||||
|
||||
第二列显示的是该种语言有多少文件，图中说明只有一个。
|
||||
|
||||
第三列显示空行的数量，图中显示是 0 行。
|
||||
|
||||
第四列显示注释的行数。
|
||||
|
||||
第五列显示该文件中实际的代码总行数。
|
||||
|
||||
这是一个有只有 6 行代码的源文件，我们看到统计的还算准确，那么如果用来统计一个行数较多的源文件呢？
|
||||
|
||||
```
|
||||
$ cloc file.tar.gz
|
||||
```
|
||||
|
||||
输出：
|
||||
|
||||
|
||||
|
||||
上述输出结果如果手动统计准确的代码行数非常困难，但是 cloc 只需要几秒，而且以易读的表格格式显示结果。你还可以在最后查看每个部分的总计，这在分析程序的源代码时非常方便。
|
||||
|
||||
除了源代码文件，cloc 还能递归计算各个目录及其子目录下的文件、压缩包、甚至 git commit 数目等。
|
||||
|
||||
文件夹中使用的例子：
|
||||
|
||||
```
|
||||
$ cloc dir/
|
||||
```
|
||||
|
||||
![][3]
|
||||
|
||||
子文件夹中使用的例子*：
|
||||
|
||||
```
|
||||
$ cloc dir/cloc/tests
|
||||
```
|
||||
|
||||
![][4]
|
||||
|
||||
计算一个压缩包中源代码的行数：
|
||||
|
||||
```
|
||||
$ cloc archive.zip
|
||||
```
|
||||
|
||||
![][5]
|
||||
|
||||
你还可以计算一个 git 项目，也可以像下面这样针对某次提交时的状态统计：
|
||||
|
||||
```
|
||||
$ git clone https://github.com/AlDanial/cloc.git
|
||||
|
||||
$ cd cloc
|
||||
|
||||
$ cloc 157d706
|
||||
```
|
||||
|
||||
![][6]
|
||||
|
||||
cloc 可以自动识别一些语言，使用下面的命令查看 cloc 支持的语言：
|
||||
|
||||
```
|
||||
$ cloc --show-lang
|
||||
```
|
||||
|
||||
更新信息请查阅 cloc 的使用帮助。
|
||||
|
||||
```
|
||||
$ cloc --help
|
||||
```
|
||||
|
||||
开始使用吧！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/cloc-count-the-lines-of-source-code-in-many-programming-languages/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[littleji](https://github.com/littleji)
|
||||
校对：[pityonline](https://github.com/pityonline)
|
||||
|
||||
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/ohcount-the-source-code-line-counter-and-analyzer/
|
||||
[2]: https://www.ostechnix.com/install-node-js-linux/
|
||||
[3]: http://www.ostechnix.com/wp-content/uploads/2018/10/cloc-2-1.png
|
||||
[4]: http://www.ostechnix.com/wp-content/uploads/2018/10/cloc-4.png
|
||||
[5]: http://www.ostechnix.com/wp-content/uploads/2018/10/cloc-3.png
|
||||
[6]: http://www.ostechnix.com/wp-content/uploads/2018/10/cloc-5.png
|
||||
167
published/20181011 A Front-end For Popular Package Managers.md
Normal file
167
published/20181011 A Front-end For Popular Package Managers.md
Normal file
@ -0,0 +1,167 @@
|
||||
Sysget：给主流的包管理器加个前端
|
||||
======
|
||||
|
||||
|
||||
|
||||
你是一个喜欢每隔几天尝试 Linux 操作系统的新发行版的发行版收割机吗？如果是这样，我有一些东西对你有用。 尝试 Sysget，这是一个类 Unix 操作系统中的流行软件包管理器的前端。 你不需要学习每个包管理器来执行基本的操作，例如安装、更新、升级和删除包。 你只需要对每个运行在类 Unix 操作系统上的包管理器记住一种语法即可。 Sysget 是包管理器的包装脚本，它是用 C++ 编写的。 源代码可在 GitHub 上免费获得。
|
||||
|
||||
使用 Sysget，你可以执行各种基本的包管理操作，包括：
|
||||
|
||||
- 安装包，
|
||||
- 更新包，
|
||||
- 升级包，
|
||||
- 搜索包，
|
||||
- 删除包，
|
||||
- 删除弃用包，
|
||||
- 更新数据库，
|
||||
- 升级系统，
|
||||
- 清除包管理器缓存。
|
||||
|
||||
**给 Linux 学习者的一个重要提示：**
|
||||
|
||||
Sysget 不会取代软件包管理器，绝对不适合所有人。如果你是经常切换到新 Linux 操作系统的新手，Sysget 可能会有所帮助。当在不同的 Linux 发行版中使用不同的软件包管理器时，就必须学习安装、更新、升级、搜索和删除软件包的新命令，这时 Sysget 就是帮助<ruby>发行版收割机<rt>distro hopper</rt></ruby>（或新 Linux 用户）的包装脚本。
|
||||
|
||||
如果你是 Linux 管理员或想要学习 Linux 深层的爱好者，你应该坚持使用你的发行版的软件包管理器并学习如何使用它。
|
||||
|
||||
### 安装 Sysget
|
||||
|
||||
安装 Sysget 很简单。 转到[发布页面][1]并下载最新的 Sysget 二进制文件并按如下所示进行安装。 在编写本指南时，Sysget 最新版本为1.2。
|
||||
|
||||
```
|
||||
$ sudo wget -O /usr/local/bin/sysget https://github.com/emilengler/sysget/releases/download/v1.2/sysget
|
||||
$ sudo mkdir -p /usr/local/share/sysget
|
||||
$ sudo chmod a+x /usr/local/bin/sysget
|
||||
```
|
||||
|
||||
### 用法
|
||||
|
||||
Sysget 命令与 APT 包管理器大致相同，因此它应该适合新手使用。
|
||||
|
||||
当你第一次运行 Sysget 时，系统会要求你选择要使用的包管理器。 由于我在 Ubuntu，我选择了 apt-get。
|
||||
|
||||
|
||||
|
||||
你必须根据正在运行的发行版选择正确的包管理器。 例如，如果你使用的是 Arch Linux，请选择 pacman。 对于 CentOS，请选择 yum。 对于 FreeBSD，请选择 pkg。 当前支持的包管理器列表是：
|
||||
|
||||
1. apt-get (Debian)
|
||||
2. xbps (Void)
|
||||
3. dnf (Fedora)
|
||||
4. yum (Enterprise Linux/Legacy Fedora)
|
||||
5. zypper (OpenSUSE)
|
||||
6. eopkg (Solus)
|
||||
7. pacman (Arch)
|
||||
8. emerge (Gentoo)
|
||||
9. pkg (FreeBSD)
|
||||
10. chromebrew (ChromeOS)
|
||||
11. homebrew (Mac OS)
|
||||
12. nix (Nix OS)
|
||||
13. snap (Independent)
|
||||
14. npm (Javascript, Global)
|
||||
|
||||
如果你分配了错误的包管理器，则可以使用以下命令设置新的包管理器：
|
||||
|
||||
```
|
||||
$ sudo sysget set yum
|
||||
Package manager changed to yum
|
||||
```
|
||||
|
||||
只需确保你选择了本地包管理器。
|
||||
|
||||
现在，你可以像使用本机包管理器一样执行包管理操作。
|
||||
|
||||
要安装软件包，例如 Emacs，只需运行：
|
||||
|
||||
```
|
||||
$ sudo sysget install emacs
|
||||
```
|
||||
|
||||
上面的命令将调用本机包管理器（在我的例子中是 “apt-get”）并安装给定的包。
|
||||
|
||||
|
||||
|
||||
同样，要删除包，只需运行：
|
||||
|
||||
```
|
||||
$ sudo sysget remove emacs
|
||||
```
|
||||
|
||||
|
||||
|
||||
更新软件仓库（数据库）：
|
||||
|
||||
```
|
||||
$ sudo sysget update
|
||||
```
|
||||
|
||||
搜索特定包：
|
||||
|
||||
```
|
||||
$ sudo sysget search emacs
|
||||
```
|
||||
|
||||
升级单个包：
|
||||
|
||||
```
|
||||
$ sudo sysget upgrade emacs
|
||||
```
|
||||
|
||||
升级所有包：
|
||||
|
||||
```
|
||||
$ sudo sysget upgrade
|
||||
```
|
||||
|
||||
移除废弃的包：
|
||||
|
||||
```
|
||||
$ sudo sysget autoremove
|
||||
```
|
||||
|
||||
清理包管理器的缓存：
|
||||
|
||||
```
|
||||
$ sudo sysget clean
|
||||
```
|
||||
|
||||
有关更多详细信息，请参阅帮助部分：
|
||||
|
||||
```
|
||||
$ sysget help
|
||||
Help of sysget
|
||||
sysget [OPTION] [ARGUMENT]
|
||||
|
||||
search [query] search for a package in the resporitories
|
||||
install [package] install a package from the repos
|
||||
remove [package] removes a package
|
||||
autoremove removes not needed packages (orphans)
|
||||
update update the database
|
||||
upgrade do a system upgrade
|
||||
upgrade [package] upgrade a specific package
|
||||
clean clean the download cache
|
||||
set [NEW MANAGER] set a new package manager
|
||||
```
|
||||
|
||||
请记住，不同 Linux 发行版中的所有包管理器的 Sysget 语法都是相同的。 你不需要记住每个包管理器的命令。
|
||||
|
||||
同样，我必须告诉你 Sysget 不是包管理器的替代品。 它只是类 Unix 系统中流行的包管理器的包装器，它只执行基本的包管理操作。
|
||||
|
||||
Sysget 对于不想去学习不同包管理器的新命令的新手和发行版收割机用户可能有些用处。 如果你有兴趣，试一试，看看它是否有帮助。
|
||||
|
||||
而且，这就是本次所有的内容了。 更多干货即将到来。 敬请关注！
|
||||
|
||||
祝快乐！
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/sysget-a-front-end-for-popular-package-managers/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[Flowsnow](https://github.com/Flowsnow)
|
||||
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://github.com/emilengler/sysget/releases
|
||||
@ -1,3 +1,4 @@
|
||||
Translating by ranchong
|
||||
How technology changes the rules for doing agile
|
||||
======
|
||||
|
||||
|
||||
@ -1,50 +0,0 @@
|
||||
Moving to Linux from dated Windows machines
|
||||
======
|
||||
|
||||
|
||||
|
||||
Every day, while working in the marketing department at ONLYOFFICE, I see Linux users discussing our office productivity software on the internet. Our products are popular among Linux users, which made me curious about using Linux as an everyday work tool. My old Windows XP-powered computer was an obstacle to performance, so I started reading about Linux systems (particularly Ubuntu) and decided to try it out as an experiment. Two of my colleagues joined me.
|
||||
|
||||
### Why Linux?
|
||||
|
||||
We needed to make a change, first, because our old systems were not enough in terms of performance: we experienced regular crashes, an overload every time more than two apps were active, a 50% chance of freezing when a machine was shut down, and so forth. This was rather distracting to our work, which meant we were considerably less efficient than we could be.
|
||||
|
||||
Upgrading to newer versions of Windows was an option, too, but that is an additional expense, plus our software competes against Microsoft's office suite. So that was an ideological question, too.
|
||||
|
||||
Second, as I mentioned earlier, ONLYOFFICE products are rather popular within the Linux community. By reading about Linux users' experience with our software, we became interested in joining them.
|
||||
|
||||
A week after we asked to change to Linux, we got our shiny new computer cases with [Kubuntu][1] inside. We chose version 16.04, which features KDE Plasma 5.5 and many KDE apps including Dolphin, as well as LibreOffice 5.1 and Firefox 45.
|
||||
|
||||
### What we like about Linux
|
||||
|
||||
Linux's biggest advantage, I believe, is its speed; for instance, it takes just seconds from pushing the machine's On button to starting your work. Everything seemed amazingly rapid from the very beginning: the overall responsiveness, the graphics, and even system updates.
|
||||
|
||||
One other thing that surprised me compared to Windows is that Linux allows you to configure nearly everything, including the entire look of your desktop. In Settings, I found how to change the color and shape of bars, buttons, and fonts; relocate any desktop element; and build a composition of widgets, even including comics and Color Picker. I believe I've barely scratched the surface of the available options and have yet to explore most of the customization opportunities that this system is well known for.
|
||||
|
||||
Linux distributions are generally a very safe environment. People rarely use antivirus apps in Linux, simply because there are so few viruses written for it. You save system speed, time, and, sure enough, money.
|
||||
|
||||
In general, Linux has refreshed our everyday work lives, surprising us with a number of new options and opportunities. Even in the short time we've been using it, we'd characterize it as:
|
||||
|
||||
* Fast and smooth to operate
|
||||
* Highly customizable
|
||||
* Relatively newcomer-friendly
|
||||
* Challenging with basic components, however very rewarding in return
|
||||
* Safe and secure
|
||||
* An exciting experience for everyone who seeks to refresh their workplace
|
||||
|
||||
|
||||
|
||||
Have you switched from Windows or MacOS to Kubuntu or another Linux variant? Or are you considering making the change? Please share your reasons for wanting to adopt Linux, as well as your impressions of going open source, in the comments.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/1/move-to-linux-old-windows
|
||||
|
||||
作者：[Michael Korotaev][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/michaelk
|
||||
[1]:https://kubuntu.org/
|
||||
@ -1,66 +0,0 @@
|
||||
9 ways to improve collaboration between developers and designers
|
||||
======
|
||||
|
||||
|
||||
|
||||
This article was co-written with [Jason Porter][1].
|
||||
|
||||
Design is a crucial element in any software project. Sooner or later, the developers' reasons for writing all this code will be communicated to the designers, human beings who aren't as familiar with its inner workings as the development team.
|
||||
|
||||
Stereotypes exist on both side of the divide; engineers often expect designers to be flaky and irrational, while designers often expect engineers to be inflexible and demanding. The truth is considerably more nuanced and, at the end of the day, the fates of designers and developers are forever intertwined.
|
||||
|
||||
Here are nine things that can improve collaboration between the two.
|
||||
|
||||
### 1\. First, knock down the wall. Seriously.
|
||||
|
||||
There are loads of memes about the "wall of confusion" in just about every industry. No matter what else you do, the first step toward tearing down this wall is getting both sides to agree it needs to be gone. Once everyone agrees the existing processes aren't functioning optimally, you can pick and choose from the rest of these ideas to begin fixing the problems.
|
||||
|
||||
### 2\. Learn to empathize.
|
||||
|
||||
Before rolling up any sleeves to build better communication, take a break. This is a great junction point for team building. A time to recognize that we're all people, we all have strengths and weaknesses, and most importantly, we're all on the same team. Discussions around workflows and productivity can become feisty, so it's crucial to build a foundation of trust and cooperation before diving on in.
|
||||
|
||||
### 3\. Recognize differences.
|
||||
|
||||
Designers and developers attack the same problem from different angles. Given a similar problem, designers will seek the solution with the biggest impact while developers will seek the solution with the least amount of waste. These two viewpoints do not have to be mutually exclusive. There is plenty of room for negotiation and compromise, and somewhere in the middle is where the end user receives the best experience possible.
|
||||
|
||||
### 4\. Embrace similarities.
|
||||
|
||||
This is all about workflow. CI/CD, scrum, agile, etc., are all basically saying the same thing: Ideate, iterate, investigate, and repeat. Iteration and reiteration are common denominators for both kinds of work. So instead of running a design cycle followed by a development cycle, it makes much more sense to run them concurrently and in tandem. Syncing cycles allows teams to communicate, collaborate, and influence each other every step of the way.
|
||||
|
||||
### 5\. Manage expectations.
|
||||
|
||||
All conflict can be distilled down to one simple idea: incompatible expectations. Therefore, an easy way to prevent systemic breakdowns is to manage expectations by ensuring that teams are thinking before talking and talking before doing. Setting expectations often evolves organically through everyday conversation. Forcing them to happen by having meetings can be counterproductive.
|
||||
|
||||
### 6\. Meet early and meet often.
|
||||
|
||||
Meeting once at the beginning of work and once at the end simply isn't enough. This doesn't mean you need daily or even weekly meetings. Setting a cadence for meetings can also be counterproductive. Let them happen whenever they're necessary. Great things can happen with impromptu meetings—even at the watercooler! If your team is distributed or has even one remote employee, video conferencing, text chat, or phone calls are all excellent ways to meet. It's important that everyone on the team has multiple ways to communicate with each other.
|
||||
|
||||
### 7\. Build your own lexicon.
|
||||
|
||||
Designers and developers sometimes have different terms for similar ideas. One person's card is another person's tile is a third person's box. Ultimately, the fit and accuracy of a term aren't as important as everyone's agreement to use the same term consistently.
|
||||
|
||||
### 8\. Make everyone a communication steward.
|
||||
|
||||
Everyone in the group is responsible for maintaining effective communication, regardless of how or when it happens. Each person should strive to say what they mean and mean what they say.
|
||||
|
||||
### 9\. Give a darn.
|
||||
|
||||
It only takes one member of a team to sabotage progress. Go all in. If every individual doesn't care about the product or the goal, there will be problems with motivation to make changes or continue the process.
|
||||
|
||||
This article is based on [Designers and developers: Finding common ground for effective collaboration][2], a talk the authors will be giving at [Red Hat Summit 2018][3], which will be held May 8-10 in San Francisco. [Register by May 7][3] to save US$ 500 off of registration. Use discount code **OPEN18** on the payment page to apply the discount.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/5/9-ways-improve-collaboration-developers-designers
|
||||
|
||||
作者：[Jason Brock][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/jkbrock
|
||||
[1]:https://opensource.com/users/lightguardjp
|
||||
[2]:https://agenda.summit.redhat.com/SessionDetail.aspx?id=154267
|
||||
[3]:https://www.redhat.com/en/summit/2018
|
||||
@ -1,133 +0,0 @@
|
||||
Translating by Ryze-Borgia
|
||||
|
||||
Linux vs Mac: 7 Reasons Why Linux is a Better Choice than Mac
|
||||
======
|
||||
Recently, we highlighted a few points about [why Linux is better than Windows][1]. Unquestionably, Linux is a superior platform. But, like other operating systems it has its drawbacks as well. For a very particular set of tasks (such as Gaming), Windows OS might prove to be better. And, likewise, for another set of tasks (such as video editing), a Mac-powered system might come in handy. It all trickles down to your preference and what you would like to do with your system. So, in this article, we will highlight a number of reasons why Linux is better than Mac.
|
||||
|
||||
If you’re already using a Mac or planning to get one, we recommend you to thoroughly analyze the reasons and decide whether you want to switch/keep using Linux or continue using Mac.
|
||||
|
||||
### 7 Reasons Why Linux is Better Than Mac
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][2]
|
||||
|
||||
Both Linux and macOS are Unix-like OS and give access to Unix commands, BASH and other shells. Both of them have fewer applications and games than Windows. But the similarity ends here.
|
||||
|
||||
Graphic designers and video editors swear by macOS whereas Linux is a favorite of developers, sysadmins and devops.
|
||||
|
||||
So the question is should you use Linux over Mac? If yes, why? Let me give you some practical and some ideological reasons why Linux is better than Mac.
|
||||
|
||||
#### 1\. Price
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][3]
|
||||
|
||||
Let’s suppose, you use the system only to browse stuff, watch movies, download photos, write a document, create a spreadsheet, and other similar stuff. And, in addition to those activities, you want to have a secure operating system.
|
||||
|
||||
In that case, you could choose to spend a couple of hundred bucks for a system to get things done. Or do you think spending more for a MacBook is a good idea? Well, you are the judge.
|
||||
|
||||
So, it really depends on what you prefer. Whether you want to spend on a Mac-powered system or get a budget laptop/PC and install any Linux distro for free. Personally, I’ll be happy with a Linux system except for editing videos and music production. In that case, Final Cut Pro (for video editing) and Logic Pro X (for music production) will be my preference.
|
||||
|
||||
#### 2\. Hardware Choices
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][4]
|
||||
|
||||
Linux is free. You can install it on computers with any configuration. No matter how powerful/old your system is, Linux will work. [Even if you have an 8-year old PC laying around, you can have Linux installed and expect it to run smoothly by selecting the right distro][5].
|
||||
|
||||
But, Mac is as an Apple-exclusive. If you want to assemble a PC or get a budget laptop (with DOS) and expect to install Mac OS, it’s almost impossible. Mac comes baked in with the system Apple manufactures.
|
||||
|
||||
There are [ways to install macOS on non Apple devices][6]. However, the kind of expertise and troubles it requires, it makes you question whether it’s worth the effort.
|
||||
|
||||
You will have a wide range of hardware choices when you go with Linux but a minimal set of configurations when it comes to Mac OS.
|
||||
|
||||
#### 3\. Security
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][7]
|
||||
|
||||
A lot of people are all praises for iOS and Mac for being a secure platform. Well, yes, it is secure in a way (maybe more secure than Windows OS), but probably not as secure as Linux.
|
||||
|
||||
I am not bluffing. There are malware and adware targeting macOS and the [number is growing every day][8]. I have seen not-so-techie users struggling with their slow mac. A quick investigation revealed that a [browser hijacking malware][9] was the culprit.
|
||||
|
||||
There are no 100% secure operating systems and Linux is not an exception. There are vulnerabilities in the Linux world as well but they are duly patched by the timely updates provided by Linux distributions.
|
||||
|
||||
Thankfully, we don’t have auto-running viruses or browser hijacking malwares in Linux world so far. And that’s one more reason why you should use Linux instead of a Mac.
|
||||
|
||||
#### 4\. Customization & Flexibility
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][10]
|
||||
|
||||
You don’t like something? Customize it or remove it. End of the story.
|
||||
|
||||
For example, if you do not like the [Gnome desktop environment][11] on Ubuntu 18.04.1, you might as well change it to [KDE Plasma][11]. You can also try some of the [Gnome extensions][12] to enhance your desktop experience. You won’t find this level of freedom and customization on Mac OS.
|
||||
|
||||
Besides, you can even modify the source code of your OS to add/remove something (which requires necessary technical knowledge) and create your own custom OS. Can you do that on Mac OS?
|
||||
|
||||
Moreover, you get an array of Linux distributions to choose from as per your needs. For instance, if you need to mimic the workflow on Mac OS, [Elementary OS][13] would help. Do you want to have a lightweight Linux distribution installed on your old PC? We’ve got you covered in our list of [lightweight Linux distros][5]. Mac OS lacks this kind of flexibility.
|
||||
|
||||
#### 5\. Using Linux helps your professional career [For IT/Tech students]
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][14]
|
||||
|
||||
This is kind of controversial and applicable to students and job seekers in the IT field. Using Linux doesn’t make you a super-intelligent being and could possibly get you any IT related job.
|
||||
|
||||
However, as you start using Linux and exploring it, you gain experience. As a techie, sooner or later you dive into the terminal, learning your way to move around the file system, installing applications via command line. You won’t even realize that you have learned the skills that newcomers in IT companies get trained on.
|
||||
|
||||
In addition to that, Linux has enormous scope in the job market. There are so many Linux related technologies (Cloud, Kubernetes, Sysadmin etc.) you can learn, earn certifications and get a nice paying job. And to learn these, you have to use Linux.
|
||||
|
||||
#### 6\. Reliability
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][15]
|
||||
|
||||
Ever wondered why Linux is the best OS to run on any server? Because it is more reliable!
|
||||
|
||||
But, why is that? Why is Linux more reliable than Mac OS?
|
||||
|
||||
The answer is simple – more control to the user while providing better security. Mac OS does not provide you with the full control of its platform. It does that to make things easier for you simultaneously enhancing your user experience. With Linux, you can do whatever you want – which may result in poor user experience (for some) – but it does make it more reliable.
|
||||
|
||||
#### 7\. Open Source
|
||||
|
||||
![Linux vs Mac: Why Linux is a Better Choice][16]
|
||||
|
||||
Open Source is something not everyone cares about. But to me, the most important aspect of Linux being a superior choice is its Open Source nature. And, most of the points discussed below are the direct advantages of an Open Source software.
|
||||
|
||||
To briefly explain, you get to see/modify the source code yourself if it is an open source software. But, for Mac, Apple gets an exclusive control. Even if you have the required technical knowledge, you will not be able to independently take a look at the source code of Mac OS.
|
||||
|
||||
In other words, a Mac-powered system enables you to get a car for yourself but the downside is you cannot open up the hood to see what’s inside. That’s bad!
|
||||
|
||||
If you want to dive in deeper to know about the benefits of an open source software, you should go through [Ben Balter’s article][17] on OpenSource.com.
|
||||
|
||||
### Wrapping Up
|
||||
|
||||
Now that you’ve known why Linux is better than Mac OS. What do you think about it? Are these reasons enough for you to choose Linux over Mac OS? If not, then what do you prefer and why?
|
||||
|
||||
Let us know your thoughts in the comments below.
|
||||
|
||||
Note: The artwork here is based on Club Penguins.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/linux-vs-mac/
|
||||
|
||||
作者：[Ankush Das][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://itsfoss.com/author/ankush/
|
||||
[1]: https://itsfoss.com/linux-better-than-windows/
|
||||
[2]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/Linux-vs-mac-featured.png
|
||||
[3]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/linux-vs-mac-1.jpeg
|
||||
[4]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/linux-vs-mac-4.jpeg
|
||||
[5]: https://itsfoss.com/lightweight-linux-beginners/
|
||||
[6]: https://hackintosh.com/
|
||||
[7]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/linux-vs-mac-2.jpeg
|
||||
[8]: https://www.computerworld.com/article/3262225/apple-mac/warning-as-mac-malware-exploits-climb-270.html
|
||||
[9]: https://www.imore.com/how-to-remove-browser-hijack
|
||||
[10]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/linux-vs-mac-3.jpeg
|
||||
[11]: https://www.gnome.org/
|
||||
[12]: https://itsfoss.com/best-gnome-extensions/
|
||||
[13]: https://elementary.io/
|
||||
[14]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/linux-vs-mac-5.jpeg
|
||||
[15]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/linux-vs-mac-6.jpeg
|
||||
[16]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/linux-vs-mac-7.jpeg
|
||||
[17]: https://opensource.com/life/15/12/why-open-source
|
||||
@ -1,46 +0,0 @@
|
||||
How Writing Can Expand Your Skills and Grow Your Career
|
||||
======
|
||||
|
||||
|
||||
|
||||
At the recent [Open Source Summit in Vancouver][1], I participated in a panel discussion called [How Writing can Change Your Career for the Better (Even if You don't Identify as a Writer][2]. The panel was moderated by Rikki Endsley, Community Manager and Editor for Opensource.com, and it included VM (Vicky) Brasseur, Open Source Strategy Consultant; Alex Williams, Founder, Editor in Chief, The New Stack; and Dawn Foster, Consultant, The Scale Factory.
|
||||
|
||||
The talk was [inspired by this article][3], in which Rikki examined some ways that writing can "spark joy" and improve your career in unexpected ways. Full disclosure: I have known Rikki for a long time. We worked at the same company for many years, raised our children together, and remain close friends.
|
||||
|
||||
### Write and learn
|
||||
|
||||
As Rikki noted in the talk description, “even if you don't consider yourself to be ‘a writer,’ you should consider writing about your open source contributions, project, or community.” Writing can be a great way to share knowledge and engage others in your work, but it has personal benefits as well. It can help you meet new people, learn new skills, and improve your communication style.
|
||||
|
||||
I find that writing often clarifies for me what I don’t know about a particular topic. The process highlights gaps in my understanding and motivates me to fill in those gaps through further research, reading, and asking questions.
|
||||
|
||||
“Writing about what you don't know can be much harder and more time consuming, but also much more fulfilling and help your career. I've found that writing about what I don't know helps me learn, because I have to research it and understand it well enough to explain it,” Rikki said.
|
||||
|
||||
Writing about what you’ve just learned can be valuable to other learners as well. In her blog, [Julia Evans][4] often writes about learning new technical skills. She has a friendly, approachable style along with the ability to break down topics into bite-sized pieces. In her posts, Evans takes readers through her learning process, identifying what was and was not helpful to her along the way, essentially removing obstacles for her readers and clearing a path for those new to the topic.
|
||||
|
||||
### Communicate more clearly
|
||||
|
||||
Writing can help you practice thinking and speaking more precisely, especially if you’re writing (or speaking) for an international audience. [In this article,][5] for example, Isabel Drost-Fromm provides tips for removing ambiguity for non-native English speakers. Writing can also help you organize your thoughts before a presentation, whether you’re speaking at a conference or to your team.
|
||||
|
||||
“The process of writing the articles helps me organize my talks and slides, and it was a great way to provide ‘notes’ for conference attendees, while sharing the topic with a larger international audience that wasn't at the event in person,” Rikki stated.
|
||||
|
||||
If you’re interested in writing, I encourage you to do it. I highly recommend the articles mentioned here as a way to get started thinking about the story you have to tell. Unfortunately, our discussion at Open Source Summit was not recorded, but I hope we can do another talk in the future and share more ideas.
|
||||
|
||||
Check out the schedule of talks for Open Source Summit Europe and sign up to receive updates:
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/blog/2018/9/how-writing-can-help-you-learn-new-skills-and-grow-your-career
|
||||
|
||||
作者：[Amber Ankerholz][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.linux.com/users/aankerholz
|
||||
[1]: https://events.linuxfoundation.org/events/open-source-summit-north-america-2018/
|
||||
[2]: https://ossna18.sched.com/event/FAOF/panel-discussion-how-writing-can-change-your-career-for-the-better-even-if-you-dont-identify-as-a-writer-moderated-by-rikki-endsley-opensourcecom-red-hat?iframe=no#
|
||||
[3]: https://opensource.com/article/18/2/career-changing-magic-writing
|
||||
[4]: https://jvns.ca/
|
||||
[5]: https://www.linux.com/blog/event/open-source-summit-eu/2017/12/technical-writing-international-audience
|
||||
@ -1,3 +1,5 @@
|
||||
thecyanbird translating
|
||||
|
||||
Linux Has a Code of Conduct and Not Everyone is Happy With it
|
||||
======
|
||||
**Linux kernel has a new code of conduct (CoC). Linus Torvalds took a break from Linux kernel development just 30 minutes after signing this code of conduct. And since **the writer of this code of conduct has had a controversial past,** it has now become a point of heated discussion. With all the politics involved, not many people are happy with this new CoC.**
|
||||
|
||||
@ -1,126 +0,0 @@
|
||||
WinWorld – A Large Collection Of Defunct OSs, Software And Games
|
||||
======
|
||||
|
||||
|
||||
|
||||
The other day, I was testing **Dosbox** which is used to [**run MS-DOS games and programs in Linux**][1]. While searching for some classic programs like Turbo C++, I stumbled upon a website named **WinWorld**. I went through a few links in this site and quite surprised. WinWorld has a plenty of good-old and classic OSs, software, applications, development tools, games and a lot of other miscellaneous utilities which are abandoned by the developers a long time ago. It is an online museum run by community members, volunteers and is dedicated to the preservation and sharing of vintage, abandoned, and pre-release software.
|
||||
|
||||
WinWorld was started back in 2003 and its founder claims that the idea to start this site inspired by Yahoo briefcases. The primary purpose of this site is to preserve and share old software. Over the years, many people volunteered to improve this site in numerous ways and the collection of old software in WinWorld has grown exponentially. The entire WinWorld library is free, open and available to everyone.
|
||||
|
||||
### WinWorld Hosts A Huge Collection Of Defunct OSs, Software, System Applications And Games
|
||||
|
||||
Like I already said, WinWorld hosts a huge collection of abandonware which are no-longer in development.
|
||||
|
||||
**Linux and Unix:**
|
||||
|
||||
Here, I have given the complete list of UNIX and LINUX OSs with brief summary of the each OS and the release year of first version.
|
||||
|
||||
* **A/UX** – An early port of Unix to Apple’s 68k based Macintosh platform, released in 1988.
|
||||
* **AIX** – A Unix port originally developed by IBM, released in 1986.
|
||||
* **AT &T System V Unix** – One of the first commercial versions of the Unix OS, released in 1983.
|
||||
* **Banyan VINES** – A network operating system originally designed for Unix, released in 1984.
|
||||
* **Corel Linux** – A commercial Linux distro, released in 1999.
|
||||
* **DEC OSF-1** – A version of UNIX developed by Digital Equipment Corporation (DEC), released in 1991.
|
||||
* **Digital UNIX** – A renamed version of **OSF-1** , released by DEC in 1995.**
|
||||
**
|
||||
* **FreeBSD** **1.0** – The first release of FreeBSD, released in 1993. It is based on 4.3BSD.
|
||||
* **Gentus Linux** – A distribution that failed to comply with GPL. Developed by ABIT and released in 2000.
|
||||
* **HP-UX** – A UNIX variant, released in 1992.
|
||||
* **IRIX** – An a operating system developed by Silicon Graphics Inc (SGI ) and it is released in 1988.
|
||||
* **Lindows** – Similar to Corel Linux. It is developed for commercial purpose and released in 2002.
|
||||
* **Linux Kernel** – A copy of the Linux Sourcecode, version 0.01. Released in the early 90’s.
|
||||
* **Mandrake Linux** – A Linux distribution based on Red Hat Linux. It was later renamed to Mandriva. Released in 1999.
|
||||
* **NEWS-OS** – A variant of BSD, developed by Sony and released in 1989.
|
||||
* **NeXTStep** – A Unix based OS from NeXT computers headed by **Steve Jobs**. It is released in 1987.
|
||||
* **PC/IX** – A UNIX variant created for IBM PCs. Released in 1984.
|
||||
* **Red Hat Linux 5.0** – A commercial Linux distribution by Red Hat.
|
||||
* **Sun Solaris** – A Unix based OS by Sun Microsystems. Released in 1992.
|
||||
* **SunOS** – A Unix-based OS derived from BSD by Sun Microsystems, released in 1982.
|
||||
* **Tru64 UNIX** – A formerly known OSF/1 by DEC.
|
||||
* **Ubuntu 4.10** – The well-known OS based on Debian.This was a beta pre-release, prior to the very first official Ubuntu release.
|
||||
* **Ultrix** – A UNIX clone developed by DEC.
|
||||
* **UnixWare** – A UNIX variant from Novell.
|
||||
* **Xandros Linux** – A proprietary variant of Linux. It is based on Corel Linux. The first version is released in 2003.
|
||||
* **Xenix** – A UNIX variant originally published by Microsoft released in 1984.
|
||||
|
||||
|
||||
|
||||
Not just Linux/Unix, you can find other operating systems including DOS, Windows, Apple/Mac, OS 2, Novell netware and other OSs and shells.
|
||||
|
||||
**DOS & CP/M:**
|
||||
|
||||
* 86-DOS
|
||||
* Concurrent CPM-86 & Concurrent DOS
|
||||
* CP/M 86 & CP/M-80
|
||||
* DOS Plus
|
||||
* DR-DOS
|
||||
* GEM
|
||||
* MP/M
|
||||
* MS-DOS
|
||||
* Multitasking MS-DOS 4.00
|
||||
* Multiuser DOS
|
||||
* PC-DOS
|
||||
* PC-MOS
|
||||
* PTS-DOS
|
||||
* Real/32
|
||||
* Tandy Deskmate
|
||||
* Wendin DOS
|
||||
|
||||
|
||||
|
||||
**Windows:**
|
||||
|
||||
* BackOffice Server
|
||||
* Windows 1.0/2.x/3.0/3.1/95/98/2000/ME/NT 3.X/NT 4.0
|
||||
* Windows Whistler
|
||||
* WinFrame
|
||||
|
||||
|
||||
|
||||
**Apple/Mac:**
|
||||
|
||||
* Mac OS 7/8/9
|
||||
* Mac OS X
|
||||
* System Software (0-6)
|
||||
|
||||
|
||||
|
||||
**OS/2:**
|
||||
|
||||
* Citrix Multiuser
|
||||
* OS/2 1.x
|
||||
* OS/2 2.0
|
||||
* OS/2 3.x
|
||||
* OS/2 Warp 4
|
||||
|
||||
|
||||
|
||||
Also, WinWorld hosts a huge collection of old software, system applications, development tools and games. Go and check them out as well.
|
||||
|
||||
To be honest, I don’t even know the existence of most of the stuffs listed in this site. Some of the tools listed here were released years before I was born.
|
||||
|
||||
Just in case, If you ever in need of or wanted to test a classic stuff (be it a game, software, OS), look nowhere, just head over to WinWorld library and download them that you want to explore. Good luck!
|
||||
|
||||
**Disclaimer:**
|
||||
|
||||
OSTechNix is not affiliated with WinWorld site in any way. We, at OSTechNix, don’t know the authenticity and integrity of the stuffs hosted in this site. Also, downloading software from third-party sites is not safe or may be illegal in your region. Neither the author nor OSTechNix is responsible for any kind of damage. Use this service at your own risk.
|
||||
|
||||
And, that’s all for now. Hope this was useful. More good stuffs to come. Stay tuned!
|
||||
|
||||
Cheers!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/winworld-a-large-collection-of-defunct-oss-software-and-games/
|
||||
|
||||
作者：[SK][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.ostechnix.com/author/sk/
|
||||
[1]: https://www.ostechnix.com/how-to-run-ms-dos-games-and-programs-in-linux/
|
||||
@ -0,0 +1,66 @@
|
||||
IssueHunt: A New Bounty Hunting Platform for Open Source Software
|
||||
======
|
||||
One of the issues that many open-source developers and companies struggle with is funding. There is an assumption, an expectation even, among the community that Free and Open Source Software must be provided free of cost. But even FOSS needs funding for continued development. How can we keep expecting better quality software if we don’t create systems that enable continued development?
|
||||
|
||||
We already wrote an article about [open source funding platforms][1] out there that try to tackle this shortcoming, as of this July there is a new contender in the market that aims to help fill this gap: [IssueHunt][2].
|
||||
|
||||
### IssueHunt: A Bounty Hunting platform for Open Source Software
|
||||
|
||||
![IssueHunt website][3]
|
||||
|
||||
IssueHunt offers a service that pays freelance developers for contributing to open-source code. It does so through what are called bounties: financial rewards granted to whoever solves a given problem. The funding for these bounties comes from anyone who is willing to donate to have any given bug fixed or feature added.
|
||||
|
||||
If there is a problem with a piece of open-source software that you want fixed, you can offer up a reward amount of your choosing to whoever fixes it.
|
||||
|
||||
Do you want your own product snapped? Offer a bounty on IssueHunt to whoever snaps it. It’s as simple as that.
|
||||
|
||||
And if you are a programmer, you can browse through open issues. Fix the issue (if you could), submit a pull request on the GitHub repository and if your pull request is merged, you get the money.
|
||||
|
||||
#### IssueHunt was originally an internal project for Boostnote
|
||||
|
||||
![IssueHunt][4]
|
||||
|
||||
The product came to be when the developers behind the note-taking app [Boostnote][5] reached out to the community for contributions to their own product.
|
||||
|
||||
In the first two years of utilizing IssueHunt, Boostnote received over 8,400 Github stars through hundreds contributors and overwhelming donations.
|
||||
|
||||
The product was so successful that the team decided to open it up to the rest of the community.
|
||||
|
||||
Today, [a list of projects utilize this service][6], offering thousands of dollars in bounties among them.
|
||||
|
||||
Boostnote boasts [$2,800 in total bounties][7], while Settings Sync, previously known as Visual Studio Code Settings Sync, offers [more than $1,600 in bounties.][8]
|
||||
|
||||
There are other services that provide something similar to what IssueHunt is offering here. Perhaps the most notable is [Bountysource][9], which offers a similar bounty service to IssueHunt, while also offering subscription payment processing similar to [Librepay][10].
|
||||
|
||||
#### What do you think of IssueHunt?
|
||||
|
||||
At the time of writing this article, IssueHunt is in its infancy, but I am incredibly excited to see where this project ends up in the comings years.
|
||||
|
||||
I don’t know about you, but I am more than happy paying for FOSS. If the product is high quality and adds value to my life, then I will happily pay the developer the product. Especially since FOSS developers are creating products that respect my freedom in the process.
|
||||
|
||||
That being said, I will definitely keep my eye on IssueHunt moving forward for ways I can support the community either with my own money or by spreading the word where contribution is needed.
|
||||
|
||||
But what do you think? Do you agree with me, or do you think software should be Gratis free, and that contributions should be made on a volunteer basis? Let us know what you think in the comments below.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/issuehunt/
|
||||
|
||||
作者：[Phillip Prado][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://itsfoss.com/author/phillip/
|
||||
[1]: https://itsfoss.com/open-source-funding-platforms/
|
||||
[2]: https://issuehunt.io
|
||||
[3]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/issuehunt-website.png
|
||||
[4]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/issuehunt.jpg
|
||||
[5]: https://itsfoss.com/boostnote-linux-review/
|
||||
[6]: https://issuehunt.io/repos
|
||||
[7]: https://issuehunt.io/repos/53266139
|
||||
[8]: https://issuehunt.io/repos/47984369
|
||||
[9]: https://www.bountysource.com/
|
||||
[10]: https://liberapay.com/
|
||||
@ -0,0 +1,75 @@
|
||||
Troubleshooting Node.js Issues with llnode
|
||||
======
|
||||
|
||||
|
||||
|
||||
The llnode plugin lets you inspect Node.js processes and core dumps; it adds the ability to inspect JavaScript stack frames, objects, source code and more. At [Node+JS Interactive][1], Matheus Marchini, Node.js Collaborator and Lead Software Engineer at Sthima, will host a [workshop][2] on how to use llnode to find and fix issues quickly and reliably, without bloating your application with logs or compromising performance. He explains more in this interview.
|
||||
|
||||
**Linux.com: What are some common issues that happen with a Node.js application in production?**
|
||||
|
||||
**Matheus Marchini:** One of the most common issues Node.js developers might experience -- either in production or during development -- are unhandled exceptions. They happen when your code throws an error, and this error is not properly handled. There's a variation of this issue with Promises, although in this case, the problem is worse: if a Promise is rejected but there's no handler for that rejection, the application might enter into an undefined state and it can start to misbehave.
|
||||
|
||||
The application might also crash when it's using too much memory. This usually happens when there's a memory leak in the application, although we usually don't have classic memory leaks in Node.js. Instead of unreferenced objects, we might have objects that are not used anymore but are still retained by another object, leading the Garbage Collector to ignore them. If this happens with several objects, we can quickly exhaust our available memory.
|
||||
|
||||
Memory is not the only resource that might get exhausted. Given the asynchronous nature of Node.js and how it scales for a large number of requests, the application might start to run out on other resources such as opened file descriptions and a number of concurrent connections to a database.
|
||||
|
||||
Infinite loops are not that common because we usually catch those during development, but every once in a while one manages to slip through our tests and get into our production servers. These are pretty catastrophic because they will block the main thread, rendering the entire application unresponsive.
|
||||
|
||||
The last issues I'd like to point out are performance issues. Those can happen for a variety of reasons, ranging from unoptimized function to I/O latency.
|
||||
|
||||
**Linux.com: Are there any quick tests you can do to determine what might be happening with your Node.js application?**
|
||||
|
||||
**Marchini:** Node.js and V8 have several tools and features built-in which developers can use to find issues faster. For example, if you're facing performance issues, you might want to use the built-in [V8 CpuProfiler][3]. Memory issues can be tracked down with [V8 Sampling Heap Profiler][4]. All of these options are interesting because you can open their results in Chrome DevTools and get some nice graphical visualizations by default.
|
||||
|
||||
If you are using native modules on your project, V8 built-in tools might not give you enough insights, since they focus only on JavaScript metrics. As an alternative to V8 CpuProfiler, you can use system profiler tools, such as [perf for Linux][5] and Dtrace for FreeBSD / OS X. You can grab the result from these tools and turn them into flamegraphs, making it easier to find which functions are taking more time to process.
|
||||
|
||||
You can use third-party tools as well: [node-report][6] is an amazing first failure data capture which doesn't introduce a significant overhead. When your application crashes, it will generate a report with detailed information about the state of the system, including environment variables, flags used, operating system details, etc. You can also generate this report on demand, and it is extremely useful when asking for help in forums, for example. The best part is that, after installing it through npm, you can enable it with a flag -- no need to make changes in your code!
|
||||
|
||||
But one of the tools I'm most amazed by is [llnode][7].
|
||||
|
||||
**Linux.com: When would you want to use something like llnode; and what exactly is it?**
|
||||
|
||||
**Marchini:** **** llnode is useful when debugging infinite loops, uncaught exceptions or out of memory issues since it allows you to inspect the state of your application when it crashed. How does llnode do this? You can tell Node.js and your operating system to take a core dump of your application when it crashes and load it into llnode. llnode will analyze this core dump and give you useful information such as how many objects were allocated in the heap, the complete stack trace for the process (including native calls and V8 internals), pending requests and handlers in the event loop queue, etc.
|
||||
|
||||
The most impressive feature llnode has is its ability to inspect objects and functions: you can see which variables are available for a given function, look at the function's code and inspect which properties your objects have with their respective values. For example, you can look up which variables are available for your HTTP handler function and which parameters it received. You can also look at headers and the payload of a given request.
|
||||
|
||||
llnode is a plugin for [lldb][8], and it uses lldb features alongside hints provided by V8 and Node.js to recreate the process heap. It uses a few heuristics, too, so results might not be entirely correct sometimes. But most of the times the results are good enough -- and way better than not using any tool.
|
||||
|
||||
This technique -- which is called post-mortem debugging -- is not something new, though, and it has been part of the Node.js project since 2012. This is a common technique used by C and C++ developers, but not many dynamic runtimes support it. I'm happy we can say Node.js is one of those runtimes.
|
||||
|
||||
**Linux.com: What are some key items folks should know before adding llnode to their environment?**
|
||||
|
||||
**Marchini:** To install and use llnode you'll need to have lldb installed on your system. If you're on OS X, lldb is installed as part of Xcode. On Linux, you can install it from your distribution's repository. We recommend using LLDB 3.9 or later.
|
||||
|
||||
You'll also have to set up your environment to generate core dumps. First, remember to set the flag --abort-on-uncaught-exception when running a Node.js application, otherwise, Node.js won't generate a core dump when an uncaught exception happens. You'll also need to tell your operating system to generate core dumps when an application crashes. The most common way to do that is by running `ulimit -c unlimited`, but this will only apply to your current shell session. If you're using a process manager such as systemd I suggest looking at the process manager docs. You can also generate on-demand core dumps of a running process with tools such as gcore.
|
||||
|
||||
**Linux.com: What can we expect from llnode in the future?**
|
||||
|
||||
**Marchini:** llnode collaborators are working on several features and improvements to make the project more accessible for developers less familiar with native debugging tools. To accomplish that, we're improving the overall user experience as well as the project's documentation and installation process. Future versions will include colorized output, more reliable output for some commands and a simplified mode focused on JavaScript information. We are also working on a JavaScript API which can be used to automate some analysis, create graphical user interfaces, etc.
|
||||
|
||||
If this project sounds interesting to you, and you would like to get involved, feel free join the conversation in [our issues tracker][9] or contact me on social [@mmarkini][10]. I would love to help you get started!
|
||||
|
||||
Learn more at [Node+JS Interactive][1], coming up October 10-12, 2018 in Vancouver, Canada.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/blog/2018/9/troubleshooting-nodejs-issues-llnode
|
||||
|
||||
作者：[The Linux Foundation][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.linux.com/users/ericstephenbrown
|
||||
[1]: https://events.linuxfoundation.org/events/node-js-interactive-2018/?utm_source=Linux.com&utm_medium=article&utm_campaign=jsint18
|
||||
[2]: http://sched.co/G285
|
||||
[3]: https://nodejs.org/api/inspector.html#inspector_cpu_profiler
|
||||
[4]: https://github.com/v8/sampling-heap-profiler
|
||||
[5]: http://www.brendangregg.com/blog/2014-09-17/node-flame-graphs-on-linux.html
|
||||
[6]: https://github.com/nodejs/node-report
|
||||
[7]: https://github.com/nodejs/llnode
|
||||
[8]: https://lldb.llvm.org/
|
||||
[9]: https://github.com/nodejs/llnode/issues
|
||||
[10]: https://twitter.com/mmarkini
|
||||
@ -0,0 +1,44 @@
|
||||
Creator of the World Wide Web is Creating a New Decentralized Web
|
||||
======
|
||||
**Creator of the world wide web, Tim Berners-Lee has unveiled his plans to create a new decentralized web where the data will be controlled by the users.**
|
||||
|
||||
[Tim Berners-Lee][1] is known for creating the world wide web, i.e., the internet you know today. More than two decades later, Tim is working to free the internet from the clutches of corporate giants and give the power back to the people via a decentralized web.
|
||||
|
||||
Berners-Lee was unhappy with the way ‘powerful forces’ of the internet handle data of the users for their own agenda. So he [started working on his own open source project][2] Solid “to restore the power and agency of individuals on the web.”
|
||||
|
||||
> Solid changes the current model where users have to hand over personal data to digital giants in exchange for perceived value. As we’ve all discovered, this hasn’t been in our best interests. Solid is how we evolve the web in order to restore balance — by giving every one of us complete control over data, personal or not, in a revolutionary way.
|
||||
|
||||
![Tim Berners-Lee is creating a decentralized web with open source project Solid][3]
|
||||
|
||||
Basically, [Solid][4] is a platform built using the existing web where you create own ‘pods’ (personal data store). You decide where this pod will be hosted, who will access which data element and how the data will be shared through this pod.
|
||||
|
||||
Berners-Lee believes that Solid “will empower individuals, developers and businesses with entirely new ways to conceive, build and find innovative, trusted and beneficial applications and services.”
|
||||
|
||||
Developers need to integrate Solid into their apps and sites. Solid is still in the early stages so there are no apps for now but the project website claims that “the first wave of Solid apps are being created now.”
|
||||
|
||||
Berners-Lee has created a startup called [Inrupt][5] and has taken a sabbatical from MIT to work full-time on Solid and to take it “from the vision of a few to the reality of many.”
|
||||
|
||||
If you are interested in Solid, [learn how to create apps][6] or [contribute to the project][7] in your own way. Of course, it will take a lot of effort to build and drive the broad adoption of Solid so every bit of contribution will count to the success of a decentralized web.
|
||||
|
||||
Do you think a [decentralized web][8] will be a reality? What do you think of decentralized web in general and project Solid in particular?
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/solid-decentralized-web/
|
||||
|
||||
作者：[Abhishek Prakash][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://itsfoss.com/author/abhishek/
|
||||
[1]: https://en.wikipedia.org/wiki/Tim_Berners-Lee
|
||||
[2]: https://medium.com/@timberners_lee/one-small-step-for-the-web-87f92217d085
|
||||
[3]: https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/09/tim-berners-lee-solid-project.jpeg
|
||||
[4]: https://solid.inrupt.com/
|
||||
[5]: https://www.inrupt.com/
|
||||
[6]: https://solid.inrupt.com/docs/getting-started
|
||||
[7]: https://solid.inrupt.com/community
|
||||
[8]: https://tech.co/decentralized-internet-guide-2018-02
|
||||
84
sources/talk/20181003 13 tools to measure DevOps success.md
Normal file
84
sources/talk/20181003 13 tools to measure DevOps success.md
Normal file
@ -0,0 +1,84 @@
|
||||
13 tools to measure DevOps success
|
||||
======
|
||||
How's your DevOps initiative really going? Find out with open source tools
|
||||
|
||||
|
||||
In today's enterprise, business disruption is all about agility with quality. Traditional processes and methods of developing software are challenged to keep up with the complexities that come with these new environments. Modern DevOps initiatives aim to help organizations use collaborations among different IT teams to increase agility and accelerate software application deployment.
|
||||
|
||||
How is the DevOps initiative going in your organization? Whether or not it's going as well as you expected, you need to do assessments to verify your impressions. Measuring DevOps success is very important because these initiatives target the very processes that determine how IT works. DevOps also values measuring behavior, although measurements are more about your business processes and less about your development and IT systems.
|
||||
|
||||
A metrics-oriented mindset is critical to ensuring DevOps initiatives deliver the intended results. Data-driven decisions and focused improvement activities lead to increased quality and efficiency. Also, the use of feedback to accelerate delivery is one reason DevOps creates a successful IT culture.
|
||||
|
||||
With DevOps, as with any IT initiative, knowing what to measure is always the first step. Let's examine how to use continuous delivery improvement and open source tools to assess your DevOps program on three key metrics: team efficiency, business agility, and security. These will also help you identify what challenges your organization has and what problems you are trying to solve with DevOps.
|
||||
|
||||
### 3 tools for measuring team efficiency
|
||||
|
||||
Measuring team efficiency—in terms of how the DevOps initiative fits into your organization and how well it works for cultural innovation—is the hardest area to measure. The key metrics that enable the DevOps team to work more effectively on culture and organization are all about agile software development, such as knowledge sharing, prioritizing tasks, resource utilization, issue tracking, cross-functional teams, and collaboration. The following open source tools can help you improve and measure team efficiency:
|
||||
|
||||
* [FunRetro][1] is a simple, intuitive tool that helps you collaborate across teams and improve what you do.
|
||||
* [Kanboard][2] is a [kanban][3] board that helps you visualize your work in progress to focus on your goal.
|
||||
* [Bugzilla][4] is a popular development tool with issue-tracking capabilities.
|
||||
|
||||
|
||||
|
||||
### 6 tools for measuring business agility
|
||||
|
||||
Speed is all that matters for accelerating business agility. Because DevOps gives organizations capabilities to deliver software faster with fewer failures, it's fast gaining acceptance. The key metrics are deployment time, change lead time, release frequency, and failover time. Puppet's [2017 State of DevOps Report][5] shows that high-performing DevOps practitioners deploy code updates 46x more frequently and high performers experience change lead times of under an hour, or 440x faster than average. Following are some open source tools to help you measure business agility:
|
||||
|
||||
* [Kubernetes][6] is a container-orchestration system for automating deployment, scaling, and management of containerized applications. (Read more about [Kubernetes][7] on Opensource.com.)
|
||||
* [CRI-O][8] is a Kubernetes orchestrator used to manage and launch containerized workloads without relying on a traditional container engine.
|
||||
* [Ansible][9] is a popular automation engine used to automate apps and IT infrastructure and run tasks including installing and configuring applications.
|
||||
* [Jenkins][10] is an automation tool used to automate the software development process with continuous integration. It facilitates the technical aspects of continuous delivery.
|
||||
* [Spinnaker][11] is a multi-cloud continuous delivery platform for releasing software changes with high velocity and confidence. It combines a powerful and flexible pipeline management system with integrations to the major cloud providers.
|
||||
* [Istio][12] is a service mesh that helps reduce the complexity of deployments and eases the strain on your development teams.
|
||||
|
||||
|
||||
|
||||
### 4 tools for measuring security
|
||||
|
||||
Security is always the last phase of measuring your DevOps initiative's success. Enterprises that have combined development and operations teams under a DevOps model are generally successful in releasing code at a much faster rate. But this has increased the need for integrating security in the DevOps process (this is known as DevSecOps), because the faster you release code, the faster you release any vulnerabilities in it.
|
||||
|
||||
Measuring security vulnerabilities early ensures that builds are stable before they pass to the next stage in the release pipeline. In addition, measuring security can help overcome resistance to DevOps adoption. You need tools that can help your dev and ops teams identify and prioritize vulnerabilities as they are using software, and teams must ensure they don't introduce vulnerabilities when making changes. These open source tools can help you measure security:
|
||||
|
||||
* [Gauntlt][13] is a ruggedization framework that enables security testing by devs, ops, and security.
|
||||
* [Vault][14] securely manages secrets and encrypts data in transit, including storing credentials and API keys and encrypting passwords for user signups.
|
||||
* [Clair][15] is a project for static analysis of vulnerabilities in appc and Docker containers.
|
||||
* [SonarQube][16] is a platform for continuous inspection of code quality. It performs automatic reviews with static analysis of code to detect bugs, code smells, and security vulnerabilities.
|
||||
|
||||
|
||||
|
||||
**[See our related security article,[7 open source tools for rugged DevOps][17].]**
|
||||
|
||||
Many DevOps initiatives start small. DevOps requires a commitment to a new culture and process rather than new technologies. That's why organizations looking to implement DevOps will likely need to adopt open source tools for collecting data and using it to optimize business success. In that case, highly visible, useful measurements will become an essential part of every DevOps initiative's success
|
||||
|
||||
### What to read next
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/10/devops-measurement-tools
|
||||
|
||||
作者：[Daniel Oh][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/daniel-oh
|
||||
[1]: https://funretro.io/
|
||||
[2]: http://kanboard.net/
|
||||
[3]: https://en.wikipedia.org/wiki/Kanban
|
||||
[4]: https://www.bugzilla.org/
|
||||
[5]: https://puppet.com/resources/whitepaper/state-of-devops-report
|
||||
[6]: https://kubernetes.io/
|
||||
[7]: https://opensource.com/resources/what-is-kubernetes
|
||||
[8]: https://github.com/kubernetes-incubator/cri-o
|
||||
[9]: https://github.com/ansible
|
||||
[10]: https://jenkins.io/
|
||||
[11]: https://www.spinnaker.io/
|
||||
[12]: https://istio.io/
|
||||
[13]: http://gauntlt.org/
|
||||
[14]: https://www.hashicorp.com/blog/vault.html
|
||||
[15]: https://github.com/coreos/clair
|
||||
[16]: https://www.sonarqube.org/
|
||||
[17]: https://opensource.com/article/18/9/open-source-tools-rugged-devops
|
||||
@ -0,0 +1,97 @@
|
||||
Interview With Peter Ganten, CEO of Univention GmbH
|
||||
======
|
||||
I have been asking the Univention team to share the behind-the-scenes story of [**Univention**][1] for a couple of months. Finally, today we got the interview of **Mr. Peter H. Ganten** , CEO of Univention GmbH. Despite his busy schedule, in this interview, he shares what he thinks of the Univention project and its impact on open source ecosystem, what open source developers and companies will need to do to keep thriving and what are the biggest challenges for open source projects.
|
||||
|
||||
**OSTechNix: What’s your background and why have you founded Univention?**
|
||||
|
||||
**Peter Ganten:** I studied physics and psychology. In psychology I was a research assistant and coded evaluation software. I realized how important it is that results have to be disclosed in order to verify or falsify them. The same goes for the code that leads to the results. This brought me into contact with Open Source Software (OSS) and Linux.
|
||||
|
||||
|
||||
|
||||
I was a kind of technical lab manager and I had the opportunity to try out a lot, which led to my book about Debian. That was still in the New Economy era where the first business models emerged on how to make money with Open Source. When the bubble burst, I had the plan to make OSS a solid business model without venture capital but with Hanseatic business style – seriously, steadily, no bling bling.
|
||||
|
||||
**What were the biggest challenges at the beginning?**
|
||||
|
||||
When I came from the university, the biggest challenge clearly was to gain entrepreneurial and business management knowledge. I quickly learned that it’s not about Open Source software as an end to itself but always about customer value, and the benefits OSS offers its customers. We all had to learn a lot.
|
||||
|
||||
In the beginning, we expected that Linux on the desktop would become established in a similar way as Linux on the server. However, this has not yet been proven true. The replacement has happened with Android and the iPhone. Our conclusion then was to change our offerings towards ID management and enterprise servers.
|
||||
|
||||
**Why does UCS matter? And for whom makes it sense to use it?**
|
||||
|
||||
There is cool OSS in all areas, but many organizations are not capable to combine it all together and make it manageable. For the basic infrastructure (Windows desktops, users, user rights, roles, ID management, apps) we need a central instance to which groupware, CRM etc. is connected. Without Univention this would have to be laboriously assembled and maintained manually. This is possible for very large companies, but far too complex for many other organizations.
|
||||
|
||||
[**UCS**][2] can be used out of the box and is scalable. That’s why it’s becoming more and more popular – more than 10,000 organizations are using UCS already today.
|
||||
|
||||
**Who are your users and most important clients? What do they love most about UCS?**
|
||||
|
||||
The Core Edition is free of charge and used by organizations from all sectors and industries such as associations, micro-enterprises, universities or large organizations with thousands of users. In the enterprise environment, where Long Term Servicing (LTS) and professional support are particularly important, we have organizations ranging in size from 30-50 users to several thousand users. One of the target groups is the education system in Germany. In many large cities and within their school administrations UCS is used, for example, in Cologne, Hannover, Bremen, Kassel and in several federal states. They are looking for manageable IT and apps for schools. That’s what we offer, because we can guarantee these authorities full control over their users’ identities.
|
||||
|
||||
Also, more and more cloud service providers and MSPs want to take UCS to deliver a selection of cloud-based app solutions.
|
||||
|
||||
**Is UCS 100% Open Source? If so, how can you run a profitable business selling it?**
|
||||
|
||||
Yes, UCS is 100% Open Source, every line, the whole code is OSS. You can download and use UCS Core Edition for **FREE!**
|
||||
|
||||
We know that in large, complex organizations, vendor support and liability is needed for LTS, SLAs, and we offer that with our Enterprise subscriptions and consulting services. We don’t offer these in the Core Edition.
|
||||
|
||||
**And what are you giving back to the OS community?**
|
||||
|
||||
A lot. We are involved in the Debian team and co-finance the LTS maintenance for Debian. For important OS components in UCS like [**OpenLDAP**][3], Samba or KVM we co-finance the development or have co-developed them ourselves. We make it all freely available.
|
||||
|
||||
We are also involved on the political level in ensuring that OSS is used. We are engaged, for example, in the [**Free Software Foundation Europe (FSFE)**][4] and the [**German Open Source Business Alliance**][5], of which I am the chairman. We are working hard to make OSS more successful.
|
||||
|
||||
**How can I get started with UCS?**
|
||||
|
||||
It’s easy to get started with the Core Edition, which, like the Enterprise Edition, has an App Center and can be easily installed on your own hardware or as an appliance in a virtual machine. Just [**download Univention ISO**][6] and install it as described in the below link.
|
||||
|
||||
Alternatively, you can try the [**UCS Online Demo**][7] to get a first impression of Univention Corporate Server without actually installing it on your system.
|
||||
|
||||
**What do you think are the biggest challenges for Open Source?**
|
||||
|
||||
There is a certain attitude you can see over and over again even in bigger projects: OSS alone is viewed as an almost mandatory prerequisite for a good, sustainable, secure and trustworthy IT solution – but just having decided to use OSS is no guarantee for success. You have to carry out projects professionally and cooperate with the manufacturers. A danger is that in complex projects people think: “Oh, OSS is free, I just put it all together by myself”. But normally you do not have the know-how to successfully implement complex software solutions. You would never proceed like this with Closed Source. There people think: “Oh, the software costs 3 $ millions, so it’s okay if I have to spend another 300,000 Dollars on consultants.”
|
||||
|
||||
At OSS this is different. If such projects fail and leave burnt ground behind, we have to explain again and again that the failure of such projects is not due to the nature of OSS but to its poor implementation and organization in a specific project: You have to conclude reasonable contracts and involve partners as in the proprietary world, but you’ll gain a better solution.
|
||||
|
||||
Another challenge: We must stay innovative, move forward, attract new people who are enthusiastic about working on projects. That’s sometimes a challenge. For example, there are a number of proprietary cloud services that are good but lead to extremely high dependency. There are approaches to alternatives in OSS, but no suitable business models yet. So it’s hard to find and fund developers. For example, I can think of Evernote and OneNote for which there is no reasonable OSS alternative.
|
||||
|
||||
**And what will the future bring for Univention?**
|
||||
|
||||
I don’t have a crystal ball, but we are extremely optimistic. We see a very high growth potential in the education market. More OSS is being made in the public sector, because we have repeatedly experienced the dead ends that can be reached if we solely rely on Closed Source.
|
||||
|
||||
Overall, we will continue our organic growth at double-digit rates year after year.
|
||||
|
||||
UCS and its core functionalities of identity management, infrastructure management and app center will increasingly be offered and used from the cloud as a managed service. We will support our technology in this direction, e.g., through containers, so that a hypervisor or bare metal is not always necessary for operation.
|
||||
|
||||
**You have been the CEO of Univention for a long time. What keeps you motivated?**
|
||||
|
||||
I have been the CEO of Univention for more than 16 years now. My biggest motivation is to realize that something is moving. That we offer the better way for IT. That the people who go this way with us are excited to work with us. I go home satisfied in the evening (of course not every evening). It’s totally cool to work with the team I have. It motivates and pushes you every time I need it myself.
|
||||
|
||||
I’m a techie and nerd at heart, I enjoy dealing with technology. So I’m totally happy at this place and I’m grateful to the world that I can do whatever I want every day. Not everyone can say that.
|
||||
|
||||
**Who gives you inspiration?**
|
||||
|
||||
My employees, the customers and the Open Source projects. The exchange with other people.
|
||||
|
||||
The motivation behind everything is that we want to make sure that mankind will be able to influence and change the IT that surrounds us today and in the future just the way we want it and we thinks it’s good. We want to make a contribution to this. That is why Univention is there. That is important to us every day.
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/interview-with-peter-ganten-ceo-of-univention-gmbh/
|
||||
|
||||
作者：[SK][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.ostechnix.com/author/sk/
|
||||
[1]: https://www.ostechnix.com/introduction-univention-corporate-server/
|
||||
[2]: https://www.univention.com/products/ucs/
|
||||
[3]: https://www.ostechnix.com/redhat-and-suse-announced-to-withdraw-support-for-openldap/
|
||||
[4]: https://fsfe.org/
|
||||
[5]: https://osb-alliance.de/
|
||||
[6]: https://www.univention.com/downloads/download-ucs/
|
||||
[7]: https://www.univention.com/downloads/ucs-online-demo/
|
||||
108
sources/talk/20181008 3 areas to drive DevOps change.md
Normal file
108
sources/talk/20181008 3 areas to drive DevOps change.md
Normal file
@ -0,0 +1,108 @@
|
||||
3 areas to drive DevOps change
|
||||
======
|
||||
Driving large-scale organizational change is painful, but when it comes to DevOps, the payoff is worth the pain.
|
||||
|
||||
|
||||
Pain avoidance is a powerful motivator. Some studies hint that even [plants experience a type of pain][1] and take steps to defend themselves. Yet we have plenty of examples of humans enduring pain on purpose—exercise often hurts, but we still do it. When we believe the payoff is worth the pain, we'll endure almost anything.
|
||||
|
||||
The truth is that driving large-scale organizational change is painful. It hurts for those having to change their values and behaviors, it hurts for leadership, and it hurts for the people just trying to do their jobs. In the case of DevOps, though, I can tell you the pain is worth it.
|
||||
|
||||
I've seen firsthand how teams learn they must spend time improving their technical processes, take ownership of their automation pipelines, and become masters of their fate. They gain the tools they need to be successful.
|
||||
|
||||
![Improvements after DevOps transformation][3]
|
||||
|
||||
Image by Lee Eason. CC BY-SA 4.0
|
||||
|
||||
This chart shows the value of that change. In a company where I directed a DevOps transformation, its 60+ teams submitted more than 900 requests per month to release management. If you add up the time those tickets stayed open, it came to more than 350 days per month. What could your company do with an extra 350 person-days per month? In addition to the improvements seen above, they went from 100 to 9,000 deployments per month, a 24% decrease in high-severity bugs, happier engineers, and improved net promoter scores (NPS). The biggest NPS improvements link to the teams furthest along on their DevOps journey, as the [Puppet State of DevOps][4] report predicted. The bottom line is that investments into technical process improvement translate into better business outcomes.
|
||||
|
||||
DevOps leaders must focus on three main areas to drive this change: executives, culture, and team health.
|
||||
|
||||
### Executives
|
||||
|
||||
The bottom line is that investments into technical process improvement translate into better business outcomes.
|
||||
|
||||
The larger your organization, the greater the distance (and opportunities for misunderstanding) between business leadership and the individuals delivering services to your customers. To make things worse, the landscape of tools and practices in technology is changing at an accelerating rate. This makes it practically impossible for business leaders to understand on their own how transformations like DevOps or agile work.
|
||||
|
||||
The larger your organization, the greater the distance (and opportunities for misunderstanding) between business leadership and the individuals delivering services to your customers. To make things worse, the landscape of tools and practices in technology is changing at an accelerating rate. This makes it practically impossible for business leaders to understand on their own how transformations like DevOps or agile work.
|
||||
|
||||
DevOps leaders must help executives come along for the ride. Educating leaders gives them options when they're making decisions and makes it more likely they'll choose paths that help your company.
|
||||
|
||||
For example, let's say your executives believe DevOps is going to improve how you deploy your products into production, but they don't understand how. You've been working with a software team to help automate their deployment. When an executive hears about a deploy failure (and there will be failures), they will want to understand how it occurred. When they learn the software team did the deployment rather than the release management team, they may try to protect the business by decreeing all production releases must go through traditional change controls. You will lose credibility, and teams will be far less likely to trust you and accept further changes.
|
||||
|
||||
It takes longer to rebuild trust with executives and get their support after an incident than it would have taken to educate them in the first place. Put the time in upfront to build alignment, and it will pay off as you implement tactical changes.
|
||||
|
||||
Two pieces of advice when building that alignment:
|
||||
|
||||
* First, **don't ignore any constraints** they raise. If they have worries about contracts or security, make the heads of legal and security your new best friends. By partnering with them, you'll build their trust and avoid making costly mistakes.
|
||||
* Second, **use metrics to build a bridge** between what your delivery teams are doing and your executives' concerns. If the business has a goal to reduce customer churn, and you know from research that many customers leave because of unplanned downtime, reinforce that your teams are committed to tracking and improving Mean Time To Detection and Resolution (MTTD and MTTR). You can use those key metrics to show meaningful progress that teams and executives understand and get behind.
|
||||
|
||||
|
||||
|
||||
### Culture
|
||||
|
||||
DevOps is a culture of continuous improvement focused on code, build, deploy, and operational processes. Culture describes the organization's values and behaviors. Essentially, we're talking about changing how people behave, which is never easy.
|
||||
|
||||
I recommend reading [The Wolf in CIO's Clothing][5]. Spend time thinking about psychology and motivation. Read [Drive][6] or at least watch Daniel Pink's excellent [TED Talk][7]. Read [The Hero with a Thousand Faces][8] and learn to identify the different journeys everyone is on. If none of these things sound interesting, you are not the right person to drive change in your company. Otherwise, read on!
|
||||
|
||||
Essentially, we're talking about changing how people behave, which is never easy.
|
||||
|
||||
Most rational people behave according to their values. Most organizations don't have explicit values everyone understands and lives by. Therefore, you'll need to identify the organization's values that have led to the behaviors that have led to the current state. You also need to make sure you can tell the story about how those values came to be and how they led to where you are. When you tell that story, be careful not to demonize those values—they aren't immoral or evil. People did the best they could at the time, given what they knew and what resources they had.
|
||||
|
||||
Most rational people behave according to their values. Most organizations don't have explicit values everyone understands and lives by. Therefore, you'll need to identify the organization's values that have led to the behaviors that have led to the current state. You also need to make sure you can tell the story about how those values came to be and how they led to where you are. When you tell that story, be careful not to demonize those values—they aren't immoral or evil. People did the best they could at the time, given what they knew and what resources they had.
|
||||
|
||||
Explain that the company and its organizational goals are changing, and the team must alter its values. It's helpful to express this in terms of contrast. For example, your company may have historically valued cost savings above all else. That value is there for a reason—the company was cash-strapped. To get new products out, the infrastructure group had to tightly couple services by sharing database clusters or servers. Over time, those practices created a real mess that became hard to maintain. Simple changes started breaking things in unexpected ways. This led to tight change-control processes that were painful for delivery teams, so they stopped changing things.
|
||||
|
||||
Play that movie for five years, and you end up with little to no innovation, legacy technology, attraction and retention problems, and poor-quality products. You've grown the company, but you've hit a ceiling, and you can't continue to grow with those same values and behaviors. Now you must put engineering efficiency above cost saving. If one option will help teams maintain their service easier, but the other option is cheaper in the short term, you go with the first option.
|
||||
|
||||
You must tell this story again and again. Then you must celebrate any time a team expresses the new value through their behavior—even if they make a mistake. When a team has a deploy failure, congratulate them for taking the risk and encourage them to keep learning. Explain how their behavior is leading to the right outcome and support them. Over time, teams will see the message is real, and they'll feel safe altering their behavior.
|
||||
|
||||
### Team health
|
||||
|
||||
Have you ever been in a planning meeting and heard something like this: "We can't really estimate that story until John gets back from vacation. He's the only one who knows that area of the code well enough." Or: "We can't get this task done because it's got a cross-team dependency on network engineering, and the guy that set up the firewall is out sick." Or: "John knows that system best; if he estimated the story at a 3, then let's just go with that." When the team works on that story, who will most likely do the work? That's right, John will, and the cycle will continue.
|
||||
|
||||
For a long time, we've accepted that this is just the nature of software development. If we don't solve for it, we perpetuate the cycle.
|
||||
|
||||
Entropy will always drive teams naturally towards disorder and bad health. Our job as team members and leaders is to intentionally manage against that entropy and keep our teams healthy. Transformations like DevOps, agile, moving to the cloud, or refactoring a legacy application all amplify and accelerate that entropy. That's because transformations add new skills and expertise needed for the team to take on that new type of work.
|
||||
|
||||
Let's look at an example of a product team refactoring its legacy monolith. As usual, they build those new services in AWS. The legacy monolith was deployed to the data center, monitored, and backed up by IT. IT made sure the application's infosec requirements were met at the infrastructure layer. They conducted disaster recovery tests, patched the servers, and installed and configured required intrusion detection and antivirus agents. And they kept change control records, required for the annual audit process, of everything was done to the application's infrastructure.
|
||||
|
||||
I often see product teams make the fatal mistake of thinking IT is all cost and bottleneck. They're hungry to shed the skin of IT and use the public cloud, but they never stop to appreciate the critical services IT provides. Moving to the cloud means you implement these things differently; they don't go away. AWS is still a data center, and any team utilizing it accepts the related responsibilities.
|
||||
|
||||
In practice, this means product teams must learn how to do those IT services when they move to the cloud. So, when our fictional product team starts refactoring its legacy application and putting new services in in the cloud, it will need a vastly expanded skillset to be successful. Those skills don't magically appear—they're learned or hired—and team leaders and managers must actively manage the process.
|
||||
|
||||
I built [Tekata.io][9] because I couldn't find any tools to support me as I helped my teams evolve. Tekata is free and easy to use, but the tool is not as important as the people and process. Make sure you build continuous learning into your cadence and keep track of your team's weak spots. Those weak spots affect your ability to deliver, and filling them usually involves learning new things, so there's a wonderful synergy here. In fact, 76% of millennials think professional development opportunities are [one of the most important elements][10] of company culture.
|
||||
|
||||
### Proof is in the payoff
|
||||
|
||||
DevOps transformations involve altering the behavior, and therefore the culture, of your teams. That must be done with executive support and understanding. At the same time, those behavior changes mean learning new skills, and that process must also be managed carefully. But the payoff for pulling this off is more productive teams, happier and more engaged team members, higher quality products, and happier customers.
|
||||
|
||||
Lee Eason will present [Tales From A DevOps Transformation][11] at [All Things Open][12], October 21-23 in Raleigh, N.C.
|
||||
|
||||
Disclaimer: All opinions are statements in this article are exclusively those of Lee Eason and are not representative of Ipreo or IHS Markit.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/10/tales-devops-transformation
|
||||
|
||||
作者：[Lee Eason][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/leeeason
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://link.springer.com/article/10.1007%2Fs00442-014-2995-6
|
||||
[2]: /file/411061
|
||||
[3]: https://opensource.com/sites/default/files/uploads/devops-delays.png (Improvements after DevOps transformation)
|
||||
[4]: https://puppet.com/resources/whitepaper/state-of-devops-report
|
||||
[5]: https://www.gartner.com/en/publications/wolf-cio
|
||||
[6]: https://en.wikipedia.org/wiki/Drive:_The_Surprising_Truth_About_What_Motivates_Us
|
||||
[7]: https://www.ted.com/talks/dan_pink_on_motivation?language=en#t-2094
|
||||
[8]: https://en.wikipedia.org/wiki/The_Hero_with_a_Thousand_Faces
|
||||
[9]: https://tekata.io/
|
||||
[10]: https://www.execu-search.com/~/media/Resources/pdf/2017_Hiring_Outlook_eBook
|
||||
[11]: https://allthingsopen.org/talk/tales-from-a-devops-transformation/
|
||||
[12]: https://allthingsopen.org/
|
||||
@ -0,0 +1,47 @@
|
||||
4 best practices for giving open source code feedback
|
||||
======
|
||||
A few simple guidelines can help you provide better feedback.
|
||||
|
||||
|
||||
|
||||
In the previous article I gave you tips for [how to receive feedback][1], especially in the context of your first free and open source project contribution. Now it's time to talk about the other side of that same coin: providing feedback.
|
||||
|
||||
If I tell you that something you did in your contribution is "stupid" or "naive," how would you feel? You'd probably be angry, hurt, or both, and rightfully so. These are mean-spirited words that when directed at people, can cut like knives. Words matter, and they matter a great deal. Therefore, put as much thought into the words you use when leaving feedback for a contribution as you do into any other form of contribution you give to the project. As you compose your feedback, think to yourself, "How would I feel if someone said this to me? Is there some way someone might take this another way, a less helpful way?" If the answer to that last question has even the chance of being a yes, backtrack and rewrite your feedback. It's better to spend a little time rewriting now than to spend a lot of time apologizing later.
|
||||
|
||||
When someone does make a mistake that seems like it should have been obvious, remember that we all have different experiences and knowledge. What's obvious to you may not be to someone else. And, if you recall, there once was a time when that thing was not obvious to you. We all make mistakes. We all typo. We all forget commas, semicolons, and closing brackets. Save yourself a lot of time and effort: Point out the mistake, but leave out the judgement. Stick to the facts. After all, if the mistake is that obvious, then no critique will be necessary, right?
|
||||
|
||||
1. **Avoid ad hominem comments.** Remember to review only the contribution and not the person who contributed it. That is to say, point out, "the contribution could be more efficient here in this way…" rather than, "you did this inefficiently." The latter is ad hominem feedback. Ad hominem is a Latin phrase meaning "to the person," which is where your feedback is being directed: to the person who contributed it rather than to the contribution itself. By providing feedback on the person you make that feedback personal, and the contributor is justified in taking it personally. Be careful when crafting your feedback to make sure you're addressing only the contents of the contribution and not accidentally criticizing the person who submitted it for review.
|
||||
|
||||
2. **Include positive comments.** Not all of your feedback has to (or should) be critical. As you review the contribution and you see something that you like, provide feedback on that as well. Several academic studies—including an important one by [Baumeister, Braslavsky, Finkenauer, and Vohs][2]—show that humans focus more on negative feedback than positive. When your feedback is solely negative, it can be very disheartening for contributors. Including positive reinforcement and feedback is motivating to people and helps them feel good about their contribution and the time they spent on it, which all adds up to them feeling more inclined to provide another contribution in the future. It doesn't have to be some gushing paragraph of flowery praise, but a quick, "Huh, that's a really smart way to handle that. It makes everything flow really well," can go a long way toward encouraging someone to keep contributing.
|
||||
|
||||
3. **Questions are feedback, too.** Praise is one less common but valuable type of review feedback. Questions are another. If you're looking at a contribution and can't tell why the submitter
|
||||
|
||||
When your feedback is solely negative, it can be very disheartening for contributors.
|
||||
|
||||
did things the way they did, or if the contribution just doesn't make a lot of sense to you, asking for more information acts as feedback. It tells the submitter that something they contributed isn't as clear as they thought and that it may need some work to make the approach more obvious, or if it's a code contribution, a comment to explain what's going on and why. A simple, "I don't understand this part here. Could you please tell me what it's doing and why you chose that way?" can start a dialogue that leads to a contribution that's much easier for future contributors to understand and maintain.
|
||||
|
||||
4. **Expect a negotiation.** Using questions as a form of feedback implies that there will be answers to those questions, or perhaps other questions in response. Whether your feedback is in question or statement format, you should expect to generate some sort of dialogue throughout the process. An alternative is to see your feedback as incontrovertible, your word as law. Although this is definitely one approach you can take, it's rarely a good one. When providing feedback on a contribution, it's best to collaborate rather than dictate. As these dialogues arise, embracing them as opportunities for conversation and learning on both sides is important. Be willing to discuss their approach and your feedback, and to take the time to understand their perspective.
|
||||
|
||||
|
||||
|
||||
|
||||
The bottom line is: Don't be a jerk. If you're not sure whether the feedback you're planning to leave makes you sound like a jerk, pause to have someone else review it before you click Send. Have empathy for the person at the receiving end of that feedback. While the maxim is thousands of years old, it still rings true today that you should try to do unto others as you would have them do unto you. Put yourself in their shoes and aim to be helpful and supportive rather than simply being right.
|
||||
|
||||
_Adapted from[Forge Your Future with Open Source][3] by VM (Vicky) Brasseur, Copyright © 2018 The Pragmatic Programmers LLC. Reproduced with the permission of the publisher._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/10/best-practices-giving-open-source-code-feedback
|
||||
|
||||
作者：[VM(Vicky) Brasseur][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/vmbrasseur
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/article/18/10/6-tips-receiving-feedback
|
||||
[2]: https://www.msudenver.edu/media/content/sri-taskforce/documents/Baumeister-2001.pdf
|
||||
[3]: http://www.pragprog.com/titles/vbopens
|
||||
@ -0,0 +1,82 @@
|
||||
GCC: Optimizing Linux, the Internet, and Everything
|
||||
======
|
||||
|
||||
|
||||
|
||||
Software is useless if computers can't run it. Even the most talented developer is at the mercy of the compiler when it comes to run-time performance - if you don’t have a reliable compiler toolchain you can’t build anything serious. The GNU Compiler Collection (GCC) provides a robust, mature and high performance partner to help you get the most out of your software. With decades of development by thousands of people GCC is one of the most respected compilers in the world. If you are building applications and not using GCC, you are missing out on the best possible solution.
|
||||
|
||||
GCC is the “de facto-standard open source compiler today” [1] according to LLVM.org and the foundation used to build complete systems - from the kernel upwards. GCC supports over 60 hardware platforms, including ARM, Intel, AMD, IBM POWER, SPARC, HP PA-RISC, and IBM Z, as well as a variety of operating environments, including GNU, Linux, Windows, macOS, FreeBSD, NetBSD, OpenBSD, DragonFly BSD, Solaris, AIX, HP-UX, and RTEMS. It offers highly compliant C/C++ compilers and support for popular C libraries, such as GNU C Library (glibc), Newlib, musl, and the C libraries included with various BSD operating systems, as well as front-ends for Fortran, Ada, and GO languages. GCC also functions as a cross compiler, creating executable code for a platform other than the one on which the compiler is running. GCC is the core component of the tightly integrated GNU toolchain, produced by the GNU Project, that includes glibc, Binutils, and the GNU Debugger (GDB).
|
||||
|
||||
"My all-time favorite GNU tool is GCC, the GNU Compiler Collection. At a time when developer tools were expensive, GCC was the second GNU tool and the one that enabled a community to write and build all the others. This tool single-handedly changed the industry and led to the creation of the free software movement, since a good, free compiler is a prerequisite to a community creating software." —Dave Neary, Open Source and Standards team at Red Hat. [2]
|
||||
|
||||
### Optimizing Linux
|
||||
|
||||
As the default compiler for the Linux kernel source, GCC delivers trusted, stable performance along with the additional extensions needed to correctly build the kernel. GCC is a standard component of popular Linux distributions, such as Arch Linux, CentOS, Debian, Fedora, openSUSE, and Ubuntu, where it routinely compiles supporting system components. This includes the default libraries used by Linux (such as libc, libm, libintl, libssh, libssl, libcrypto, libexpat, libpthread, and ncurses) which depend on GCC to provide correctness and performance and are used by applications and system utilities to access Linux kernel features. Many of the application packages included with a distribution are also built with GCC, such as Python, Perl, Ruby, nginx, Apache HTTP Server, OpenStack, Docker, and OpenShift. This combination of kernel, libraries, and application software translates into a large volume of code built with GCC for each Linux distribution. For the openSUSE distribution nearly 100% of native code is built by GCC, including 6,135 source packages producing 5,705 shared libraries and 38,927 executables. This amounts to about 24,540 source packages compiled weekly. [3]
|
||||
|
||||
The base version of GCC included in Linux distributions is used to create the kernel and libraries that define the system Application Binary Interface (ABI). User space developers have the option of downloading the latest stable version of GCC to gain access to advanced features, performance optimizations, and improvements in usability. Linux distributions offer installation instructions or prebuilt toolchains for deploying the latest version of GCC along with other GNU tools that help to enhance developer productivity and improve deployment time.
|
||||
|
||||
### Optimizing the Internet
|
||||
|
||||
GCC is one of the most widely adopted core compilers for embedded systems, enabling the development of software for the growing world of IoT devices. GCC offers a number of extensions that make it well suited for embedded systems software development, including fine-grained control using compiler built-ins, #pragmas, inline assembly, and application-focussed command-line options. GCC supports a broad base of embedded architectures, including ARM, AMCC, AVR, Blackfin, MIPS, RISC-V, Renesas Electronics V850, and NXP and Freescale Power-based processors, producing efficient, high quality code. The cross-compilation capability offered by GCC is critical to this community, and prebuilt cross-compilation toolchains [4] are a major requirement. For example, the GNU ARM Embedded toolchains are integrated and validated packages featuring the Arm Embedded GCC compiler, libraries, and other tools necessary for bare-metal software development. These toolchains are available for cross-compilation on Windows, Linux and macOS host operating systems and target the popular ARM Cortex-R and Cortex-M processors, which have shipped in tens of billions of internet capable devices. [5]
|
||||
|
||||
GCC empowers Cloud Computing, providing a reliable development platform for software that needs to directly manages computing resources, like database and web serving engines and backup and security software. GCC is fully compliant with C++11 and C++14 and offers experimental support for C++17 and C++2a [6], creating performant object code with a solid debugging information. Some examples of applications that utilize GCC include: MySQL Database Management System, which requires GCC for Linux [7]; the Apache HTTP Server, which recommends using GCC [8]; and Bacula, an enterprise ready network backup tool which require GCC. [9]
|
||||
|
||||
### Optimizing Everything
|
||||
|
||||
For the research and development of the scientific codes used in High Performance Computing (HPC), GCC offers mature C, C++, and Fortran front ends as well as support for OpenMP and OpenACC APIs for directive-based parallel programming. Because GCC offers portability across computing environments, it enables code to be more easily targeted and tested across a variety of new and legacy client and server platforms. GCC offers full support for OpenMP 4.0 for C, C++ and Fortran compilers and full support for OpenMP 4.5 for C and C++ compilers. For OpenACC, GCC supports most of the 2.5 specification and performance optimizations and is the only non-commercial, nonacademic compiler to provide [OpenACC][1] support.
|
||||
|
||||
Code performance is an important parameter to this community and GCC offers a solid performance base. A Nov. 2017 paper published by Colfax Research evaluates C++ compilers for the speed of compiled code parallelized with OpenMP 4.x directives and for the speed of compilation time. Figure 1 plots the relative performance of the computational kernels when compiled by the different compilers and run with a single thread. The performance values are normalized so that the performance of G++ is equal to 1.0.
|
||||
|
||||
![performance][3]
|
||||
|
||||
Figure 1. Relative performance of each kernel as compiled by the different compilers. (single-threaded, higher is better).
|
||||
|
||||
[Used with permission][4]
|
||||
|
||||
The paper summarizes “the GNU compiler also does very well in our tests. G++ produces the second fastest code in three out of six cases and is amongst the fastest compiler in terms of compile time.” [10]
|
||||
|
||||
### Who Is Using GCC?
|
||||
|
||||
In The State of Developer Ecosystem Survey in 2018 by JetBrains, out of 6,000 developers who took the survey GCC is regularly used by 66% of C++ programmers and 73% of C programmers. [11] Here is a quick summary of the benefits of GCC that make it so popular with the developer community.
|
||||
|
||||
* For developers required to write code for a variety of new and legacy computing platforms and operating environments, GCC delivers support for the broadest range of hardware and operating environments. Compilers offered by hardware vendors focus mainly on support for their products and other open source compilers are much more limited in the hardware and operating systems supported. [12]
|
||||
|
||||
* There is a wide variety of GCC-based prebuilt toolchains, which has particular appeal to embedded systems developers. This includes the GNU ARM Embedded toolchains and 138 pre-compiled cross compiler toolchains available on the Bootlin web site. [13] While other open source compilers, such as Clang/LLVM, can replace GCC in existing cross compiling toolchains, these would need to be completely rebuilt by the developer. [14]
|
||||
|
||||
* GCC delivers to application developers trusted, stable performance from a mature compiler platform. The GCC 8/9 vs. LLVM Clang 6/7 Compiler Benchmarks On AMD EPYC article provides results of 49 benchmarks ran across the four tested compilers at three optimization levels. Coming in first 34% of the time was GCC 8.2 RC1 using "-O3 -march=native" level, while at the same optimization level LLVM Clang 6.0 came in second with wins 20% of the time. [15]
|
||||
|
||||
* GCC delivers improved diagnostics for compile time debugging [16] and accurate and useful information for runtime debugging. GCC is tightly integrated with GDB, a mature and feature complete tool which offers ‘non-stop’ debugging that can stop a single thread at a breakpoint.
|
||||
|
||||
* GCC is a well supported platform with an active, committed community that supports the current and two previous releases. With releases schedule yearly this provides two years of support for a version.
|
||||
|
||||
|
||||
|
||||
|
||||
### GCC: Continuing to Optimize Linux, the Internet, and Everything
|
||||
|
||||
GCC continues to move forward as a world-class compiler. The most current version of GCC is 8.2, which was released in July 2018 and added hardware support for upcoming Intel CPUs, more ARM CPUs and improved performance for AMD’s ZEN CPU. Initial C17 support has been added along with initial work towards C++2A. Diagnostics have continued to be enhanced including better emitted diagnostics, with improved locations, location ranges, and fix-it hints, particularly in the C++ front end. A blog written by David Malcolm of Red Hat in March 2018 provides an overview of usability improvements in GCC 8. [17]
|
||||
|
||||
New hardware platforms continue to rely on the GCC toolchain for software development, such as RISC-V, a free and open ISA that is of interest to machine learning, Artificial Intelligence (AI), and IoT market segments. GCC continues to be a critical component in the continuing development of Linux systems. The Clear Linux Project for Intel Architecture, an emerging distribution built for cloud, client, and IoT use cases, provides a good example of how GCC compiler technology is being used and improved to boost the performance and security of a Linux-based system. GCC is also being used for application development for Microsoft's Azure Sphere, a Linux-based operating system for IoT applications that initially supports the ARM based MediaTek MT3620 processor. In terms of developing the next generation of programmers, GCC is also a core component of the Windows toolchain for Raspberry PI, the low-cost embedded board running Debian-based GNU/Linux that is used to promote the teaching of basic computer science in schools and developing countries.
|
||||
|
||||
GCC was first released on March 22, 1987 by Richard Stallman, the founder of the GNU Project and was considered a significant breakthrough since it was the first portable ANSI C optimizing compiler released as free software. GCC is maintained by a community of programmers from all over the world under the direction of a steering committee that ensures broad, representative oversight of the project. GCC’s community approach is one of its strengths, resulting in a large and diverse community of developers and users that contribute to and provide support for the project. According to Open Hub, GCC “is one of the largest open-source teams in the world, and is in the top 2% of all project teams on Open Hub.” [18]
|
||||
|
||||
There has been a lot of discussion about the licensing of GCC, most of which confuses rather than enlightens. GCC is distributed under the GNU General Public License version 3 or later with the Runtime Library Exception. This is a copyleft license, which means that derivative work can only be distributed under the same license terms. GPLv3 is intended to protect GCC from being made proprietary and requires that changes to GCC code are made available freely and openly. To the ‘end user’ the compiler is just the same as any other; using GCC makes no difference to any licensing choices you might make for your own code. [19]
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/blog/2018/10/gcc-optimizing-linux-internet-and-everything
|
||||
|
||||
作者：[Margaret Lewis][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/margaret-lewis
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.openacc.org/tools
|
||||
[2]: /files/images/gccjpg-0
|
||||
[3]: https://www.linux.com/sites/lcom/files/styles/rendered_file/public/gcc_0.jpg?itok=HbGnRqWX (performance)
|
||||
[4]: https://www.linux.com/licenses/category/used-permission
|
||||
@ -0,0 +1,105 @@
|
||||
Talk over text: Conversational interface design and usability
|
||||
======
|
||||
To make conversational interfaces more human-centered, we must free our thinking from the trappings of web and mobile design.
|
||||
|
||||
|
||||
|
||||
Conversational interfaces are unique among the screen-based and physically manipulated user interfaces that characterize the range of digital experiences we encounter on a daily basis. As [Conversational Design][1] author Erika Hall eloquently writes, "Conversation is not a new interface. It's the oldest interface." And the conversation, the most human interaction of all, lies at the nexus of the aural and verbal rather than the visual and physical. This makes it particularly challenging for machines to meet the high expectations we tend to have when it comes to typical human conversations.
|
||||
|
||||
How do we design for conversational interfaces, which run the gamut from omnichannel chatbots on our websites and mobile apps to mono-channel voice assistants on physical devices such as the Amazon Echo and Google Home? What recommendations do other experts on conversational design and usability have when it comes to crafting the most robust chatbot or voice interface possible? In this overview, we focus on three areas: information architecture, design, and usability testing.
|
||||
|
||||
### Information architecture: Trees, not sitemaps
|
||||
|
||||
Consider the websites we visit and the visual interfaces we use regularly. Each has a navigational tool, whether it is a list of links or a series of buttons, that helps us gain some understanding of the interface. In a web-optimized information architecture, we can see the entire hierarchy of a website and its contents in the form of such navigation bars and sitemaps.
|
||||
|
||||
On the other hand, in a conversational information architecture—whether articulated in a chatbot or a voice assistant—the structure of our interactions must be provided to us in a simple and straightforward way. For instance, in lieu of a navigation bar that has links to pages like About, Menu, Order, and Locations with further links underneath, we can create a conversational means of describing how to navigate the options we wish to pursue.
|
||||
|
||||
Consider the differences between the two examples of navigation below.
|
||||
|
||||
| **Web-based navigation:** | **Conversational navigation:** |
|
||||
| Present all options in the navigation bar | Present only certain top-level options to access deeper options |
|
||||
|-------------------------------------------|-----------------------------------------------------------------|
|
||||
| • Floss's Pizza | • "To learn more about us, say About" |
|
||||
| • About | • "To hear our menu, say Menu" |
|
||||
| ◦ Team | • "To place an order, say Order" |
|
||||
| ◦ Our story | • "To find out where we are, say Where" |
|
||||
| • Menu | |
|
||||
| ◦ Pizzas | |
|
||||
| ◦ Pastas | |
|
||||
| ◦ Platters | |
|
||||
| • Order | |
|
||||
| ◦ Pickup | |
|
||||
| ◦ Delivery | |
|
||||
| • Where we are | |
|
||||
| ◦ Area map • "Welcome to Floss's Pizza!" | |
|
||||
|
||||
In a conversational context, an appropriate information architecture that focuses on decision trees is of paramount importance, because one of the biggest issues many conversational interfaces face is excessive verbosity. By avoiding information overload, prizing structural simplicity, and prescribing one-word directions, your users can traverse conversational interfaces without any additional visual aid.
|
||||
|
||||
### Design: Finessing flows and language
|
||||
|
||||
![Well-designed language example][3]
|
||||
|
||||
An example of well-designed language that encapsulates Hall's conversational key moments.
|
||||
|
||||
In her book Conversational Design, Hall emphasizes the need for all conversational interfaces to adhere to conversational maxims outlined by Paul Grice and advanced by Robin Lakoff. These conversational maxims highlight the characteristics every conversational interface should have to succeed: quantity (just enough information but not too much), quality (truthfulness), relation (relevance), manner (concision, orderliness, and lack of ambiguity), and politeness (Lakoff's addition).
|
||||
|
||||
In the process, Hall spotlights four key moments that build trust with users of conversational interfaces and give them all of the information they need to interact successfully with the conversational experience, whether it is a chatbot or a voice assistant.
|
||||
|
||||
* **Introduction:** Invite the user's interest and encourage trust with a friendly but brief greeting that welcomes them to an unfamiliar interface.
|
||||
|
||||
* **Orientation:** Offer system options, such as how to exit out of certain interactions, and provide a list of options that help the user achieve their goal.
|
||||
|
||||
* **Action:** After each response from the user, offer a new set of tasks and corresponding controls for the user to proceed with further interaction.
|
||||
|
||||
* **Guidance:** Provide feedback to the user after every response and give clear instructions.
|
||||
|
||||
|
||||
|
||||
|
||||
Taken as a whole, these key moments indicate that good conversational design obligates us to consider how we write machine utterances to be both inviting and informative and to structure our decision flows in such a way that they flow naturally to the user. In other words, rather than visual design chops or an eye for style, conversational design requires us to be good writers and thoughtful architects of decision trees.
|
||||
|
||||
![Decision flow example ][5]
|
||||
|
||||
An example decision flow that adheres to Hall's key moments.
|
||||
|
||||
One metaphor I use on a regular basis to conceive of each point in a conversational interface that presents a choice to the user is the dichotomous key. In tree science, dichotomous keys are used to identify trees in their natural habitat through certain salient characteristics. What makes dichotomous keys special, however, is the fact that each card in a dichotomous key only offers two choices (hence the moniker "dichotomous") with a clearly defined characteristic that cannot be mistaken for another. Eventually, after enough dichotomous choices have been made, we can winnow down the available options to the correct genus of tree.
|
||||
|
||||
We should design conversational interfaces in the same way, with particular attention given to disambiguation and decision-making that never verges on too much complexity. Because conversational interfaces require deeply nested hierarchical structures to reach certain outcomes, we can never be too helpful in the instructions and options we offer our users.
|
||||
|
||||
### Usability testing: Dialogues, not dialogs
|
||||
|
||||
Conversational usability is a relatively unexplored and less-understood area because it is frequently based on verbal and aural interactions rather than visual or physical ones. Whereas chatbots can be evaluated for their usability using traditional means such as think-aloud, voice assistants and other voice-driven interfaces have no such luxury.
|
||||
|
||||
For voice interfaces, we are unable to pursue approaches involving eye-tracking or think-aloud, since these interfaces are purely aural and users' utterances outside of responses to interface prompts can introduce bad data. For this reason, when our Acquia Labs team built [Ask GeorgiaGov][6], the first Alexa skill for residents of the state of Georgia, we chose retrospective probing (RP) for our usability tests.
|
||||
|
||||
In retrospective probing, the conversational interaction proceeds until the completion of the task, at which point the user is asked about their impressions of the interface. Retrospective probing is well-positioned for voice interfaces because it allows the conversation to proceed unimpeded by interruptions such as think-aloud feedback. Nonetheless, it does come with the disadvantage of suffering from our notoriously unreliable memories, as it forces us to recollect past interactions rather than ones we completed immediately before recollection.
|
||||
|
||||
### Challenges and opportunities
|
||||
|
||||
Conversational interfaces are here to stay in our rapidly expanding spectrum of digital experiences. Though they enrich the range of ways we have to engage users, they also present unprecedented challenges when it comes to information architecture, design, and usability testing. With the help of previous work such as Grice's conversational maxims and Hall's key moments, we can design and build effective conversational interfaces by focusing on strong writing and well-considered decision flows.
|
||||
|
||||
The fact that conversation is the oldest and most human of interfaces is also edifying when we approach other user interfaces that lack visual or physical manipulation. As Hall writes, "The ideal interface is an interface that's not noticeable at all." Whether or not we will eventually reach the utopian outcome of conversational interfaces that feel completely natural to the human ear, we can make conversational interfaces more human-centered by freeing our thinking from the trappings of web and mobile.
|
||||
|
||||
Preston So will present [Talk Over Text: Conversational Interface Design and Usability][7] at [All Things Open][8], October 21-23 in Raleigh, North Carolina.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/10/conversational-interface-design-and-usability
|
||||
|
||||
作者：[Preston So][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/prestonso
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://abookapart.com/products/conversational-design
|
||||
[2]: /file/411001
|
||||
[3]: https://opensource.com/sites/default/files/uploads/conversational-interfaces_1.png (Well-designed language example)
|
||||
[4]: /file/411006
|
||||
[5]: https://opensource.com/sites/default/files/uploads/conversational-interfaces_2.png (Decision flow example )
|
||||
[6]: https://www.acquia.com/blog/ask-georgiagov-alexa-skill-citizens-georgia-acquia-labs/12/10/2017/3312516
|
||||
[7]: https://allthingsopen.org/talk/talk-over-text-conversational-interface-design-and-usability/
|
||||
[8]: https://allthingsopen.org/
|
||||
@ -0,0 +1,147 @@
|
||||
How to level up your organization's security expertise
|
||||
======
|
||||
These best practices will make your employees more savvy and your organization more secure.
|
||||
|
||||
|
||||
IT security is critical to every company these days. In the words of former FBI director Robert Mueller: “There are only two types of companies: Those that have been hacked, and those that will be.”
|
||||
|
||||
At the same time, IT security is constantly evolving. We all know we need to keep up with the latest trends in cybersecurity and security tooling, but how can we do that without sacrificing our ability to keep moving forward on our business priorities?
|
||||
|
||||
No single person in your organization can handle all of the security work alone; your entire development and operations team will need to develop an awareness of security tooling and best practices, just like they all need to build skills in open source and in agile software delivery. There are a number of best practices that can help you level up the overall security expertise in your company through basic and intermediate education, subject matter experts, and knowledge-sharing.
|
||||
|
||||
### Basic education: Annual cybersecurity education and security contact information
|
||||
|
||||
At IBM, we all complete an online cybersecurity training class each year. I recommend this as a best practice for other companies as well. The online training is taught at a basic level, and it doesn’t assume that anyone has a technical background. Topics include social engineering, phishing and spearfishing attacks, problematic websites, viruses and worms, and so on. We learn how to avoid situations that may put ourselves or our systems at risk, how to recognize signs of an attempted security breach, and how to report a problem if we notice something that seems suspicious. This online education serves the purpose of raising the overall security awareness and readiness of the organization at a low per-person cost. A nice side effect of this education is that this basic knowledge can be applied to our personal lives, and we can share what we learned with our family and friends as well.
|
||||
|
||||
In addition to the general cybersecurity education, all employees should have annual training on data security and privacy regulations and how to comply with those.
|
||||
|
||||
Finally, we make it easy to find the Corporate Security Incident Response team by sharing the link to its website in prominent places, including Slack, and setting up suggested matches to ensure that a search of our internal website will send people to the right place:
|
||||
|
||||
|
||||
|
||||
### Intermediate education: Learn from your tools
|
||||
|
||||
Another great source of security expertise is through pre-built security tools. For example, we have set up a set of automated security tests that run against our web services using IBM AppScan, and the reports it generates include background knowledge about the vulnerabilities it finds, the severity of the threat, how to determine if your application is susceptible to the vulnerability, and how to fix the problem, with code examples.
|
||||
|
||||
Similarly, the free [npm audit command-line tool from npm, Inc.][1] will scan your open source Node.js modules and report any known vulnerabilities it finds. This tool also generates educational audit reports that include the severity of the threat, the vulnerable package, and versions with the vulnerability, an alternative package or versions that do not have the vulnerability, dependencies, and a link to more detailed information about the vulnerability. Here’s an example of a report from npm audit:
|
||||
|
||||
| High | Regular Expression Denial of Service |
|
||||
| --------------| ----------------------------------------- |
|
||||
| Package | minimath |
|
||||
| --------------| ----------------------------------------- |
|
||||
| Dependency of | gulp [dev] |
|
||||
| --------------| ----------------------------------------- |
|
||||
| Path | gulp > vinyl-fs > glob-stream > minimatch |
|
||||
| --------------| ----------------------------------------- |
|
||||
| More info | https://nodesecurity.io/advisories/118 |
|
||||
|
||||
Any good network-level security tool will also give you information on the types of attacks the tool is blocking and how it recognizes likely attacks. This information is available in the marketing materials online as well as the tool’s console and reports if you have access to those.
|
||||
|
||||
Each of your development teams or squads should have at least one subject matter expert who takes the time to read and fully understand the vulnerability reports that are relevant to you. This is often the technical lead, but it could be anyone who is interested in learning more about security. Your local subject matter expert will be able to recognize similar security holes in the future earlier in the development and deployment process.
|
||||
|
||||
Using the npm audit example above, a developer who reads and understands security advisory #118 from this report will be more likely to notice changes that may allow for a Regular Expression Denial of Service when reviewing code in the future. The team’s subject matter expert should also develop the skills needed to determine which of the vulnerability reports don’t actually apply to his or her specific project.
|
||||
|
||||
### Intermediate education: Conferences
|
||||
|
||||
Let’s not forget the value of attending security-related conferences, such as the [OWASP AppSec Conferences][2]. Conferences provide a great way for members of your team to focus on learning for a few days and bring back some of the newest ideas in the field. The “hallway track” of a conference, where we can learn from other practitioners, is also a valuable source of information. As much as most of us dislike being “sold to,” the sponsor hall at a conference is a good place to casually check out new security tools to see which ones you might be interested in evaluating later.
|
||||
|
||||
If your organization is big enough, ask your DevOps and security tool vendors to come to you! If you’ve already procured some great tools, but adoption isn’t going as quickly as you would like, many vendors would be happy to provide your teams with some additional practical training. It’s in their best interests to increase the adoption of their tools (making you more likely to continue paying for their services and to increase your license count), just like it’s in your best interests to maximize the value you get out of the tools you’re paying for. We recently hosted a [Toolbox@IBM][3] \+ DevSecOps summit at our largest sites (those with a couple thousand IT professionals). More than a dozen vendors sponsored each event, came onsite, set up booths, and gave conference talks, just like they would at a technical conference. We also had several of our own presenters speaking about DevOps and security best practices that were working well for them, and we had booths set up by our Corporate Information Security Office, agile coaching, onsite tech support, and internal toolchain teams. We had several hundred attendees at each site. It was great for our technical community because we could focus on the tools that we had already procured, learn how other teams in our company were using them, and make connections to help each other in the future.
|
||||
|
||||
When you send someone to a conference, it’s important to set the expectation that they will come back and share what they’ve learned with the team. We usually do this via an informal brown-bag lunch-and-learn, where people are encouraged to discuss new ideas interactively.
|
||||
|
||||
### Subject-matter experts and knowledge-sharing: The secure engineering guild
|
||||
|
||||
In the IBM Digital Business Group, we’ve adopted the squad model as described by [Spotify][4] and tweaked it to make it work for us. One sometimes-forgotten aspect of the squad model is the guild. Guilds are centers of excellence, focused around one topic or skill set, with members from many squads. Guild members learn together, share best practices with each other and their broader teams, and work to advance the state of the art. If you would like to establish your own secure engineering guild, here are some tips that have worked for me in setting up guilds in the past:
|
||||
|
||||
**Step 1: Advertise and recruit**
|
||||
|
||||
Your co-workers are busy people, so for many of them, a secure engineering guild could feel like just one more thing they have to cram into the week that doesn’t involve writing code. It’s important from the outset that the guild has a value proposition that will benefit its members as well as the organization.
|
||||
|
||||
Zane Lackey from [Signal Sciences][5] gave me some excellent advice: It’s important to call out the truth. In the past, he said, security initiatives may have been more of a hindrance or even a blocker to getting work done. Your secure engineering guild needs to focus on ways to make your engineering team’s lives easier and more efficient instead. You need to find ways to automate more of the busywork related to security and to make your development teams more self-sufficient so you don’t have to rely on security “gates” or hurdles late in the development process.
|
||||
|
||||
Here are some things that may attract people to your guild:
|
||||
|
||||
* Learn about security vulnerabilities and what you can do to combat them
|
||||
* Become a subject matter expert
|
||||
* Participate in penetration testing
|
||||
* Evaluate and pilot new security tools
|
||||
* Add “Secure Engineering Guild” to your resume
|
||||
|
||||
|
||||
|
||||
Here are some additional guild recruiting tips:
|
||||
|
||||
* Reach out directly to your security experts and ask them to join: security architects, network security administrators, people from your corporate security department, and so on.
|
||||
|
||||
* Bring in an external speaker who can get people excited about secure engineering. Advertise it as “sponsored by the Secure Engineering Guild” and collect names and contact information for people who want to join your guild, both before and after the talk.
|
||||
|
||||
* Get executive support for the program. Perhaps one of your VPs will write a blog post extolling the virtues of secure engineering skills and asking people to join the guild (or perhaps you can draft the blog post for her or him to edit and publish). You can combine that blog post with advertising the external speaker if the timing allows.
|
||||
|
||||
* Ask your management team to nominate someone from each squad to join the guild. This hardline approach is important if you have an urgent need to drive rapid improvement in your security posture.
|
||||
|
||||
|
||||
|
||||
|
||||
**Step 2: Build a team**
|
||||
|
||||
Guild meetings should be structured for action. It’s important to keep an agenda so people know what you plan to cover in each meeting, but leave time at the end for members to bring up any topics they want to discuss. Also be sure to take note of action items, and assign an owner and a target date for each of them. Finally, keep meeting minutes and send a brief summary out after each meeting.
|
||||
|
||||
Your first few guild meetings are your best opportunity to set off on the right foot, with a bit of team-building. I like to run a little design thinking exercise where you ask team members to share their ideas for the guild’s mission statement, vote on their favorites, and use those to craft a simple and exciting mission statement. The mission statement should include three components: WHO will benefit, WHAT the guild will do, and the WOW factor. The exercise itself is valuable because you can learn why people have decided to volunteer to be a part of the guild in the first place, and what they hope will come of it.
|
||||
|
||||
Another thing I like to do from the outset is ask people what they’re hoping to achieve as a guild. The guild should learn together, have fun, and do real work. Once you have those ideas out on the table, start putting owners and target dates next to those goals.
|
||||
|
||||
* Would they like to run a book club? Get someone to suggest a book and set up book club meetings.
|
||||
|
||||
* Would they like to share useful articles and blogs? Get someone to set up a Slack channel and invite everyone to it, or set up a shared document where people can contribute their favorite resources.
|
||||
|
||||
* Would they like to pilot a new tool? Get someone to set up a free trial, try it out for their own team, and report back in a few weeks.
|
||||
|
||||
* Would they like to continue a series of talks? Get someone to create a list of topics and speakers and send out the invitations.
|
||||
|
||||
|
||||
|
||||
|
||||
If a few goals end up without owners or dates, that’s OK; just start a to-do list or backlog for people to refer to when they’ve completed their first task.
|
||||
|
||||
Finally, survey the team to find the best time and day of the week for ongoing meetings and set those up. I recommend starting with weekly 30-minute meetings and adjust as needed.
|
||||
|
||||
**Step 3: Keep the energy going, or reboot**
|
||||
|
||||
As the months go on, your guild could start to lose energy. Here are some ways to keep the excitement going or reboot a guild that’s losing energy.
|
||||
|
||||
* Don’t be an echo chamber. Invite people in from various parts of the organization to talk for a few minutes about what they’re doing with respect to security engineering, and where they have concerns or see gaps.
|
||||
|
||||
* Show measurable progress. If you’ve been assigning owners to action items and completing them all along, you’ve certainly made progress, but if you look at it only from week to week, the progress can feel small or insignificant. Once per quarter, take a step back and write a blog about all you’ve accomplished and send it out to your organization. Showing off what you’ve accomplished makes the team proud of what they’ve accomplished, and it’s another opportunity to recruit even more people for your guild.
|
||||
|
||||
* Don’t be afraid to take on a large project. The guild should not be an ivory tower; it should get things done. Your guild may, for example, decide to roll out a new security tool that you love across a large organization. With a little bit of project management and a lot of executive support, you can and should tackle cross-squad projects. The guild members can and should be responsible for getting stories from the large projects prioritized in their own squads’ backlogs and completed in a timely manner.
|
||||
|
||||
* Periodically brainstorm the next set of action items. As time goes by, the most critical or pressing needs of your organization will likely change. People will be more motivated to work on the things they consider most important and urgent.
|
||||
|
||||
* Reward the extra work. You might offer an executive-sponsored cash award for the most impactful secure engineering projects. You might also have the guild itself choose someone to send to a security conference now and then.
|
||||
|
||||
|
||||
|
||||
|
||||
### Go forth, and make your company more secure
|
||||
|
||||
A more secure company starts with a more educated team. Building upon that expertise, a secure engineering guild can drive real changes by developing and sharing best practices, finding the right owners for each action item, and driving them to closure. I hope you found a few tips here that will help you level up the security expertise in your organization. Please add your own helpful tips in the comments.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/10/how-level-security-expertise-your-organization
|
||||
|
||||
作者：[Ann Marie Fred][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/annmarie99
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.npmjs.com/about
|
||||
[2]: https://www.owasp.org/index.php/Category:OWASP_AppSec_Conference
|
||||
[3]: mailto:Toolbox@IBM
|
||||
[4]: https://medium.com/project-management-learnings/spotify-squad-framework-part-i-8f74bcfcd761
|
||||
[5]: https://www.signalsciences.com/
|
||||
@ -1,7 +1,3 @@
|
||||
# sober-wang 翻译中
|
||||
|
||||
|
||||
|
||||
30 Best Sources For Linux / *BSD / Unix Documentation On the We
|
||||
======
|
||||
|
||||
|
||||
@ -1,495 +0,0 @@
|
||||
Translating By houbaron
|
||||
|
||||
Five things that make Go fast
|
||||
============================================================
|
||||
|
||||
_Anthony Starks has remixed my original Google Present based slides using his fantastic Deck presentation tool. You can check out his remix over on his blog,[mindchunk.blogspot.com.au/2014/06/remixing-with-deck][5]._
|
||||
|
||||
* * *
|
||||
|
||||
I was recently invited to give a talk at Gocon, a fantastic Go conference held semi-annually in Tokyo, Japan. [Gocon 2014][6] was an entirely community-run one day event combining training and an afternoon of presentations surrounding the theme of <q style="border: 0px; vertical-align: baseline; quotes: none;">Go in production</q>.
|
||||
|
||||
The following is the text of my presentation. The original text was structured to force me to speak slowly and clearly, so I have taken the liberty of editing it slightly to be more readable.
|
||||
|
||||
I want to thank [Bill Kennedy][7], Minux Ma, and especially [Josh Bleecher Snyder][8], for their assistance in preparing this talk.
|
||||
|
||||
* * *
|
||||
|
||||
Good afternoon.
|
||||
|
||||
My name is David.
|
||||
|
||||
I am delighted to be here at Gocon today. I have wanted to come to this conference for two years and I am very grateful to the organisers for extending me the opportunity to present to you today.
|
||||
|
||||
[][9]
|
||||
I want to begin my talk with a question.
|
||||
|
||||
Why are people choosing to use Go ?
|
||||
|
||||
When people talk about their decision to learn Go, or use it in their product, they have a variety of answers, but there always three that are at the top of their list
|
||||
|
||||
[][10]
|
||||
These are the top three.
|
||||
|
||||
The first, Concurrency.
|
||||
|
||||
Go’s concurrency primitives are attractive to programmers who come from single threaded scripting languages like Nodejs, Ruby, or Python, or from languages like C++ or Java with their heavyweight threading model.
|
||||
|
||||
Ease of deployment.
|
||||
|
||||
We have heard today from experienced Gophers who appreciate the simplicity of deploying Go applications.
|
||||
|
||||
[][11]
|
||||
|
||||
This leaves Performance.
|
||||
|
||||
I believe an important reason why people choose to use Go is because it is _fast_ .
|
||||
|
||||
[][12]
|
||||
|
||||
For my talk today I want to discuss five features that contribute to Go’s performance.
|
||||
|
||||
I will also share with you the details of how Go implements these features.
|
||||
|
||||
[][13]
|
||||
|
||||
The first feature I want to talk about is Go’s efficient treatment and storage of values.
|
||||
|
||||
[][14]
|
||||
|
||||
This is an example of a value in Go. When compiled, `gocon` consumes exactly four bytes of memory.
|
||||
|
||||
Let’s compare Go with some other languages
|
||||
|
||||
[][15]
|
||||
|
||||
Due to the overhead of the way Python represents variables, storing the same value using Python consumes six times more memory.
|
||||
|
||||
This extra memory is used by Python to track type information, do reference counting, etc
|
||||
|
||||
Let’s look at another example:
|
||||
|
||||
[][16]
|
||||
|
||||
Similar to Go, the Java `int` type consumes 4 bytes of memory to store this value.
|
||||
|
||||
However, to use this value in a collection like a `List` or `Map`, the compiler must convert it into an `Integer` object.
|
||||
|
||||
[][17]
|
||||
|
||||
So an integer in Java frequently looks more like this and consumes between 16 and 24 bytes of memory.
|
||||
|
||||
Why is this important ? Memory is cheap and plentiful, why should this overhead matter ?
|
||||
|
||||
[][18]
|
||||
|
||||
This is a graph showing CPU clock speed vs memory bus speed.
|
||||
|
||||
Notice how the gap between CPU clock speed and memory bus speed continues to widen.
|
||||
|
||||
The difference between the two is effectively how much time the CPU spends waiting for memory.
|
||||
|
||||
[][19]
|
||||
|
||||
Since the late 1960’s CPU designers have understood this problem.
|
||||
|
||||
Their solution is a cache, an area of smaller, faster memory which is inserted between the CPU and main memory.
|
||||
|
||||
[][20]
|
||||
|
||||
This is a `Location` type which holds the location of some object in three dimensional space. It is written in Go, so each `Location` consumes exactly 24 bytes of storage.
|
||||
|
||||
We can use this type to construct an array type of 1,000 `Location`s, which consumes exactly 24,000 bytes of memory.
|
||||
|
||||
Inside the array, the `Location` structures are stored sequentially, rather than as pointers to 1,000 Location structures stored randomly.
|
||||
|
||||
This is important because now all 1,000 `Location` structures are in the cache in sequence, packed tightly together.
|
||||
|
||||
[][21]
|
||||
|
||||
Go lets you create compact data structures, avoiding unnecessary indirection.
|
||||
|
||||
Compact data structures utilise the cache better.
|
||||
|
||||
Better cache utilisation leads to better performance.
|
||||
|
||||
[][22]
|
||||
|
||||
Function calls are not free.
|
||||
|
||||
[][23]
|
||||
|
||||
Three things happen when a function is called.
|
||||
|
||||
A new stack frame is created, and the details of the caller recorded.
|
||||
|
||||
Any registers which may be overwritten during the function call are saved to the stack.
|
||||
|
||||
The processor computes the address of the function and executes a branch to that new address.
|
||||
|
||||
[][24]
|
||||
|
||||
Because function calls are very common operations, CPU designers have worked hard to optimise this procedure, but they cannot eliminate the overhead.
|
||||
|
||||
Depending on what the function does, this overhead may be trivial or significant.
|
||||
|
||||
A solution to reducing function call overhead is an optimisation technique called Inlining.
|
||||
|
||||
[][25]
|
||||
|
||||
The Go compiler inlines a function by treating the body of the function as if it were part of the caller.
|
||||
|
||||
Inlining has a cost; it increases binary size.
|
||||
|
||||
It only makes sense to inline when the overhead of calling a function is large relative to the work the function does, so only simple functions are candidates for inlining.
|
||||
|
||||
Complicated functions are usually not dominated by the overhead of calling them and are therefore not inlined.
|
||||
|
||||
[][26]
|
||||
|
||||
This example shows the function `Double` calling `util.Max`.
|
||||
|
||||
To reduce the overhead of the call to `util.Max`, the compiler can inline `util.Max` into `Double`, resulting in something like this
|
||||
|
||||
[][27]
|
||||
|
||||
After inlining there is no longer a call to `util.Max`, but the behaviour of `Double` is unchanged.
|
||||
|
||||
Inlining isn’t exclusive to Go. Almost every compiled or JITed language performs this optimisation. But how does inlining in Go work?
|
||||
|
||||
The Go implementation is very simple. When a package is compiled, any small function that is suitable for inlining is marked and then compiled as usual.
|
||||
|
||||
Then both the source of the function and the compiled version are stored.
|
||||
|
||||
[][28]
|
||||
|
||||
This slide shows the contents of util.a. The source has been transformed a little to make it easier for the compiler to process quickly.
|
||||
|
||||
When the compiler compiles Double it sees that `util.Max` is inlinable, and the source of `util.Max`is available.
|
||||
|
||||
Rather than insert a call to the compiled version of `util.Max`, it can substitute the source of the original function.
|
||||
|
||||
Having the source of the function enables other optimizations.
|
||||
|
||||
[][29]
|
||||
|
||||
In this example, although the function Test always returns false, Expensive cannot know that without executing it.
|
||||
|
||||
When `Test` is inlined, we get something like this
|
||||
|
||||
[][30]
|
||||
|
||||
The compiler now knows that the expensive code is unreachable.
|
||||
|
||||
Not only does this save the cost of calling Test, it saves compiling or running any of the expensive code that is now unreachable.
|
||||
|
||||
The Go compiler can automatically inline functions across files and even across packages. This includes code that calls inlinable functions from the standard library.
|
||||
|
||||
[][31]
|
||||
|
||||
Mandatory garbage collection makes Go a simpler and safer language.
|
||||
|
||||
This does not imply that garbage collection makes Go slow, or that garbage collection is the ultimate arbiter of the speed of your program.
|
||||
|
||||
What it does mean is memory allocated on the heap comes at a cost. It is a debt that costs CPU time every time the GC runs until that memory is freed.
|
||||
|
||||
[][32]
|
||||
|
||||
There is however another place to allocate memory, and that is the stack.
|
||||
|
||||
Unlike C, which forces you to choose if a value will be stored on the heap, via `malloc`, or on the stack, by declaring it inside the scope of the function, Go implements an optimisation called _escape analysis_ .
|
||||
|
||||
[][33]
|
||||
|
||||
Escape analysis determines whether any references to a value escape the function in which the value is declared.
|
||||
|
||||
If no references escape, the value may be safely stored on the stack.
|
||||
|
||||
Values stored on the stack do not need to be allocated or freed.
|
||||
|
||||
Lets look at some examples
|
||||
|
||||
[][34]
|
||||
|
||||
`Sum` adds the numbers between 1 and 100 and returns the result. This is a rather unusual way to do this, but it illustrates how Escape Analysis works.
|
||||
|
||||
Because the numbers slice is only referenced inside `Sum`, the compiler will arrange to store the 100 integers for that slice on the stack, rather than the heap.
|
||||
|
||||
There is no need to garbage collect `numbers`, it is automatically freed when `Sum` returns.
|
||||
|
||||
[][35]
|
||||
|
||||
This second example is also a little contrived. In `CenterCursor` we create a new `Cursor` and store a pointer to it in c.
|
||||
|
||||
Then we pass `c` to the `Center()` function which moves the `Cursor` to the center of the screen.
|
||||
|
||||
Then finally we print the X and Y locations of that `Cursor`.
|
||||
|
||||
Even though `c` was allocated with the `new` function, it will not be stored on the heap, because no reference `c` escapes the `CenterCursor` function.
|
||||
|
||||
[][36]
|
||||
|
||||
Go’s optimisations are always enabled by default. You can see the compiler’s escape analysis and inlining decisions with the `-gcflags=-m` switch.
|
||||
|
||||
Because escape analysis is performed at compile time, not run time, stack allocation will always be faster than heap allocation, no matter how efficient your garbage collector is.
|
||||
|
||||
I will talk more about the stack in the remaining sections of this talk.
|
||||
|
||||
[][37]
|
||||
|
||||
Go has goroutines. These are the foundations for concurrency in Go.
|
||||
|
||||
I want to step back for a moment and explore the history that leads us to goroutines.
|
||||
|
||||
In the beginning computers ran one process at a time. Then in the 60’s the idea of multiprocessing, or time sharing became popular.
|
||||
|
||||
In a time-sharing system the operating systems must constantly switch the attention of the CPU between these processes by recording the state of the current process, then restoring the state of another.
|
||||
|
||||
This is called _process switching_ .
|
||||
|
||||
[][38]
|
||||
|
||||
There are three main costs of a process switch.
|
||||
|
||||
First is the kernel needs to store the contents of all the CPU registers for that process, then restore the values for another process.
|
||||
|
||||
The kernel also needs to flush the CPU’s mappings from virtual memory to physical memory as these are only valid for the current process.
|
||||
|
||||
Finally there is the cost of the operating system context switch, and the overhead of the scheduler function to choose the next process to occupy the CPU.
|
||||
|
||||
[][39]
|
||||
|
||||
There are a surprising number of registers in a modern processor. I have difficulty fitting them on one slide, which should give you a clue how much time it takes to save and restore them.
|
||||
|
||||
Because a process switch can occur at any point in a process’ execution, the operating system needs to store the contents of all of these registers because it does not know which are currently in use.
|
||||
|
||||
[][40]
|
||||
|
||||
This lead to the development of threads, which are conceptually the same as processes, but share the same memory space.
|
||||
|
||||
As threads share address space, they are lighter than processes so are faster to create and faster to switch between.
|
||||
|
||||
[][41]
|
||||
|
||||
Goroutines take the idea of threads a step further.
|
||||
|
||||
Goroutines are cooperatively scheduled, rather than relying on the kernel to manage their time sharing.
|
||||
|
||||
The switch between goroutines only happens at well defined points, when an explicit call is made to the Go runtime scheduler.
|
||||
|
||||
The compiler knows the registers which are in use and saves them automatically.
|
||||
|
||||
[][42]
|
||||
|
||||
While goroutines are cooperatively scheduled, this scheduling is handled for you by the runtime.
|
||||
|
||||
Places where Goroutines may yield to others are:
|
||||
|
||||
* Channel send and receive operations, if those operations would block.
|
||||
|
||||
* The Go statement, although there is no guarantee that new goroutine will be scheduled immediately.
|
||||
|
||||
* Blocking syscalls like file and network operations.
|
||||
|
||||
* After being stopped for a garbage collection cycle.
|
||||
|
||||
[][43]
|
||||
|
||||
This an example to illustrate some of the scheduling points described in the previous slide.
|
||||
|
||||
The thread, depicted by the arrow, starts on the left in the `ReadFile` function. It encounters `os.Open`, which blocks the thread while waiting for the file operation to complete, so the scheduler switches the thread to the goroutine on the right hand side.
|
||||
|
||||
Execution continues until the read from the `c` chan blocks, and by this time the `os.Open` call has completed so the scheduler switches the thread back the left hand side and continues to the `file.Read` function, which again blocks on file IO.
|
||||
|
||||
The scheduler switches the thread back to the right hand side for another channel operation, which has unblocked during the time the left hand side was running, but it blocks again on the channel send.
|
||||
|
||||
Finally the thread switches back to the left hand side as the `Read` operation has completed and data is available.
|
||||
|
||||
[][44]
|
||||
|
||||
This slide shows the low level `runtime.Syscall` function which is the base for all functions in the os package.
|
||||
|
||||
Any time your code results in a call to the operating system, it will go through this function.
|
||||
|
||||
The call to `entersyscall` informs the runtime that this thread is about to block.
|
||||
|
||||
This allows the runtime to spin up a new thread which will service other goroutines while this current thread blocked.
|
||||
|
||||
This results in relatively few operating system threads per Go process, with the Go runtime taking care of assigning a runnable Goroutine to a free operating system thread.
|
||||
|
||||
[][45]
|
||||
|
||||
In the previous section I discussed how goroutines reduce the overhead of managing many, sometimes hundreds of thousands of concurrent threads of execution.
|
||||
|
||||
There is another side to the goroutine story, and that is stack management, which leads me to my final topic.
|
||||
|
||||
[][46]
|
||||
|
||||
This is a diagram of the memory layout of a process. The key thing we are interested is the location of the heap and the stack.
|
||||
|
||||
Traditionally inside the address space of a process, the heap is at the bottom of memory, just above the program (text) and grows upwards.
|
||||
|
||||
The stack is located at the top of the virtual address space, and grows downwards.
|
||||
|
||||
[][47]
|
||||
|
||||
Because the heap and stack overwriting each other would be catastrophic, the operating system usually arranges to place an area of unwritable memory between the stack and the heap to ensure that if they did collide, the program will abort.
|
||||
|
||||
This is called a guard page, and effectively limits the stack size of a process, usually in the order of several megabytes.
|
||||
|
||||
[][48]
|
||||
|
||||
We’ve discussed that threads share the same address space, so for each thread, it must have its own stack.
|
||||
|
||||
Because it is hard to predict the stack requirements of a particular thread, a large amount of memory is reserved for each thread’s stack along with a guard page.
|
||||
|
||||
The hope is that this is more than will ever be needed and the guard page will never be hit.
|
||||
|
||||
The downside is that as the number of threads in your program increases, the amount of available address space is reduced.
|
||||
|
||||
[][49]
|
||||
|
||||
We’ve seen that the Go runtime schedules a large number of goroutines onto a small number of threads, but what about the stack requirements of those goroutines ?
|
||||
|
||||
Instead of using guard pages, the Go compiler inserts a check as part of every function call to check if there is sufficient stack for the function to run. If there is not, the runtime can allocate more stack space.
|
||||
|
||||
Because of this check, a goroutines initial stack can be made much smaller, which in turn permits Go programmers to treat goroutines as cheap resources.
|
||||
|
||||
[][50]
|
||||
|
||||
This is a slide that shows how stacks are managed in Go 1.2.
|
||||
|
||||
When `G` calls to `H` there is not enough space for `H` to run, so the runtime allocates a new stack frame from the heap, then runs `H` on that new stack segment. When `H` returns, the stack area is returned to the heap before returning to `G`.
|
||||
|
||||
[][51]
|
||||
|
||||
This method of managing the stack works well in general, but for certain types of code, usually recursive code, it can cause the inner loop of your program to straddle one of these stack boundaries.
|
||||
|
||||
For example, in the inner loop of your program, function `G` may call `H` many times in a loop,
|
||||
|
||||
Each time this will cause a stack split. This is known as the hot split problem.
|
||||
|
||||
[][52]
|
||||
|
||||
To solve hot splits, Go 1.3 has adopted a new stack management method.
|
||||
|
||||
Instead of adding and removing additional stack segments, if the stack of a goroutine is too small, a new, larger, stack will be allocated.
|
||||
|
||||
The old stack’s contents are copied to the new stack, then the goroutine continues with its new larger stack.
|
||||
|
||||
After the first call to `H` the stack will be large enough that the check for available stack space will always succeed.
|
||||
|
||||
This resolves the hot split problem.
|
||||
|
||||
[][53]
|
||||
|
||||
Values, Inlining, Escape Analysis, Goroutines, and segmented/copying stacks.
|
||||
|
||||
These are the five features that I chose to speak about today, but they are by no means the only things that makes Go a fast programming language, just as there more that three reasons that people cite as their reason to learn Go.
|
||||
|
||||
As powerful as these five features are individually, they do not exist in isolation.
|
||||
|
||||
For example, the way the runtime multiplexes goroutines onto threads would not be nearly as efficient without growable stacks.
|
||||
|
||||
Inlining reduces the cost of the stack size check by combining smaller functions into larger ones.
|
||||
|
||||
Escape analysis reduces the pressure on the garbage collector by automatically moving allocations from the heap to the stack.
|
||||
|
||||
Escape analysis is also provides better cache locality.
|
||||
|
||||
Without growable stacks, escape analysis might place too much pressure on the stack.
|
||||
|
||||
[][54]
|
||||
|
||||
* Thank you to the Gocon organisers for permitting me to speak today
|
||||
* twitter / web / email details
|
||||
* thanks to @offbymany, @billkennedy_go, and Minux for their assistance in preparing this talk.
|
||||
|
||||
### Related Posts:
|
||||
|
||||
1. [Hear me speak about Go performance at OSCON][1]
|
||||
|
||||
2. [Why is a Goroutine’s stack infinite ?][2]
|
||||
|
||||
3. [A whirlwind tour of Go’s runtime environment variables][3]
|
||||
|
||||
4. [Performance without the event loop][4]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
作者简介：
|
||||
|
||||
David is a programmer and author from Sydney Australia.
|
||||
|
||||
Go contributor since February 2011, committer since April 2012.
|
||||
|
||||
Contact information
|
||||
|
||||
* dave@cheney.net
|
||||
* twitter: @davecheney
|
||||
|
||||
----------------------
|
||||
|
||||
via: https://dave.cheney.net/2014/06/07/five-things-that-make-go-fast
|
||||
|
||||
作者：[Dave Cheney ][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://dave.cheney.net/
|
||||
[1]:https://dave.cheney.net/2015/05/31/hear-me-speak-about-go-performance-at-oscon
|
||||
[2]:https://dave.cheney.net/2013/06/02/why-is-a-goroutines-stack-infinite
|
||||
[3]:https://dave.cheney.net/2015/11/29/a-whirlwind-tour-of-gos-runtime-environment-variables
|
||||
[4]:https://dave.cheney.net/2015/08/08/performance-without-the-event-loop
|
||||
[5]:http://mindchunk.blogspot.com.au/2014/06/remixing-with-deck.html
|
||||
[6]:http://ymotongpoo.hatenablog.com/entry/2014/06/01/124350
|
||||
[7]:http://www.goinggo.net/
|
||||
[8]:https://twitter.com/offbymany
|
||||
[9]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-1.jpg
|
||||
[10]:https://dave.cheney.net/2014/06/07/five-things-that-make-go-fast/gocon-2014-2
|
||||
[11]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-3.jpg
|
||||
[12]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-4.jpg
|
||||
[13]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-5.jpg
|
||||
[14]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-6.jpg
|
||||
[15]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-7.jpg
|
||||
[16]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-8.jpg
|
||||
[17]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-9.jpg
|
||||
[18]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-10.jpg
|
||||
[19]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-11.jpg
|
||||
[20]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-12.jpg
|
||||
[21]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-13.jpg
|
||||
[22]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-14.jpg
|
||||
[23]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-15.jpg
|
||||
[24]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-16.jpg
|
||||
[25]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-17.jpg
|
||||
[26]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-18.jpg
|
||||
[27]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-19.jpg
|
||||
[28]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-20.jpg
|
||||
[29]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-21.jpg
|
||||
[30]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-22.jpg
|
||||
[31]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-23.jpg
|
||||
[32]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-24.jpg
|
||||
[33]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-25.jpg
|
||||
[34]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-26.jpg
|
||||
[35]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-27.jpg
|
||||
[36]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-28.jpg
|
||||
[37]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-30.jpg
|
||||
[38]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-29.jpg
|
||||
[39]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-31.jpg
|
||||
[40]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-32.jpg
|
||||
[41]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-33.jpg
|
||||
[42]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-34.jpg
|
||||
[43]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-35.jpg
|
||||
[44]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-36.jpg
|
||||
[45]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-37.jpg
|
||||
[46]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-39.jpg
|
||||
[47]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-40.jpg
|
||||
[48]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-41.jpg
|
||||
[49]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-42.jpg
|
||||
[50]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-43.jpg
|
||||
[51]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-44.jpg
|
||||
[52]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-45.jpg
|
||||
[53]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-46.jpg
|
||||
[54]:https://dave.cheney.net/wp-content/uploads/2014/06/Gocon-2014-47.jpg
|
||||
@ -0,0 +1,639 @@
|
||||
BriFuture is translating this article
|
||||
|
||||
# Compiling Lisp to JavaScript From Scratch in 350
|
||||
|
||||
In this article we will look at a from-scratch implementation of a compiler from a simple LISP-like calculator language to JavaScript. The complete source code can be found [here][7].
|
||||
|
||||
We will:
|
||||
|
||||
1. Define our language and write a simple program in it
|
||||
|
||||
2. Implement a simple parser combinator library
|
||||
|
||||
3. Implement a parser for our language
|
||||
|
||||
4. Implement a pretty printer for our language
|
||||
|
||||
5. Define a subset of JavaScript for our usage
|
||||
|
||||
6. Implement a code translator to the JavaScript subset we defined
|
||||
|
||||
7. Glue it all together
|
||||
|
||||
Let's start!
|
||||
|
||||
### 1\. Defining the language
|
||||
|
||||
The main attraction of lisps is that their syntax already represent a tree, this is why they are so easy to parse. We'll see that soon. But first let's define our language. Here's a BNF description of our language's syntax:
|
||||
|
||||
```
|
||||
program ::= expr
|
||||
expr ::= <integer> | <name> | ([<expr>])
|
||||
```
|
||||
|
||||
Basically, our language let's us define one expression at the top level which it will evaluate. An expression is composed of either an integer, for example `5`, a variable, for example `x`, or a list of expressions, for example `(add x 1)`.
|
||||
|
||||
An integer evaluate to itself, a variable evaluates to what it's bound in the current environment, and a list evaluates to a function call where the first argument is the function and the rest are the arguments to the function.
|
||||
|
||||
We have some built-in special forms in our language so we can do more interesting stuff:
|
||||
|
||||
* let expression let's us introduce new variables in the environment of the body of the let. The syntax is:
|
||||
|
||||
```
|
||||
let ::= (let ([<letarg>]) <body>)
|
||||
letargs ::= (<name> <expr>)
|
||||
body ::= <expr>
|
||||
```
|
||||
|
||||
* lambda expression: evaluates to an anonymous function definition. The syntax is:
|
||||
|
||||
```
|
||||
lambda ::= (lambda ([<name>]) <body>)
|
||||
```
|
||||
|
||||
We also have a few built in functions: `add`, `mul`, `sub`, `div` and `print`.
|
||||
|
||||
Let's see a quick example of a program written in our language:
|
||||
|
||||
```
|
||||
(let
|
||||
((compose
|
||||
(lambda (f g)
|
||||
(lambda (x) (f (g x)))))
|
||||
(square
|
||||
(lambda (x) (mul x x)))
|
||||
(add1
|
||||
(lambda (x) (add x 1))))
|
||||
(print ((compose square add1) 5)))
|
||||
```
|
||||
|
||||
This program defines 3 functions: `compose`, `square` and `add1`. And then prints the result of the computation:`((compose square add1) 5)`
|
||||
|
||||
I hope this is enough information about the language. Let's start implementing it!
|
||||
|
||||
We can define the language in Haskell like this:
|
||||
|
||||
```
|
||||
type Name = String
|
||||
|
||||
data Expr
|
||||
= ATOM Atom
|
||||
| LIST [Expr]
|
||||
deriving (Eq, Read, Show)
|
||||
|
||||
data Atom
|
||||
= Int Int
|
||||
| Symbol Name
|
||||
deriving (Eq, Read, Show)
|
||||
```
|
||||
|
||||
We can parse programs in the language we defined to an `Expr`. Also, we are giving the new data types `Eq`, `Read`and `Show` instances to aid in testing and debugging. You'll be able to use those in the REPL for example to verify all this actually works.
|
||||
|
||||
The reason we did not define `lambda`, `let` and the other built-in functions as part of the syntax is because we can get away with it in this case. These functions are just a more specific case of a `LIST`. So I decided to leave this to a later phase.
|
||||
|
||||
Usually, you would like to define these special cases in the abstract syntax - to improve error messages, to unable static analysis and optimizations and such, but we won't do that here so this is enough for us.
|
||||
|
||||
Another thing you would like to do usually is add some annotation to the syntax. For example the location: Which file did this `Expr` come from and which row and col in the file. You can use this in later stages to print the location of errors, even if they are not in the parser stage.
|
||||
|
||||
* _Exercise 1_ : Add a `Program` data type to include multiple `Expr` sequentially
|
||||
|
||||
* _Exercise 2_ : Add location annotation to the syntax tree.
|
||||
|
||||
### 2\. Implement a simple parser combinator library
|
||||
|
||||
First thing we are going to do is define an Embedded Domain Specific Language (or EDSL) which we will use to define our languages' parser. This is often referred to as parser combinator library. The reason we are doing it is strictly for learning purposes, Haskell has great parsing libraries and you should definitely use them when building real software, or even when just experimenting. One such library is [megaparsec][8].
|
||||
|
||||
First let's talk about the idea behind our parser library implementation. In it's essence, our parser is a function that takes some input, might consume some or all of the input, and returns the value it managed to parse and the rest of the input it didn't parse yet, or throws an error if it failed. Let's write that down.
|
||||
|
||||
```
|
||||
newtype Parser a
|
||||
= Parser (ParseString -> Either ParseError (a, ParseString))
|
||||
|
||||
data ParseString
|
||||
= ParseString Name (Int, Int) String
|
||||
|
||||
data ParseError
|
||||
= ParseError ParseString Error
|
||||
|
||||
type Error = String
|
||||
|
||||
```
|
||||
|
||||
Here we defined three main new types.
|
||||
|
||||
First, `Parser a`, is the parsing function we described before.
|
||||
|
||||
Second, `ParseString` is our input or state we carry along. It has three significant parts:
|
||||
|
||||
* `Name`: This is the name of the source
|
||||
|
||||
* `(Int, Int)`: This is the current location in the source
|
||||
|
||||
* `String`: This is the remaining string left to parse
|
||||
|
||||
Third, `ParseError` contains the current state of the parser and an error message.
|
||||
|
||||
Now we want our parser to be flexible, so we will define a few instances for common type classes for it. These instances will allow us to combine small parsers to make bigger parsers (hence the name 'parser combinators').
|
||||
|
||||
The first one is a `Functor` instance. We want a `Functor` instance because we want to be able to define a parser using another parser simply by applying a function on the parsed value. We will see an example of this when we define the parser for our language.
|
||||
|
||||
```
|
||||
instance Functor Parser where
|
||||
fmap f (Parser parser) =
|
||||
Parser (\str -> first f <$> parser str)
|
||||
```
|
||||
|
||||
The second instance is an `Applicative` instance. One common use case for this instance instance is to lift a pure function on multiple parsers.
|
||||
|
||||
```
|
||||
instance Applicative Parser where
|
||||
pure x = Parser (\str -> Right (x, str))
|
||||
(Parser p1) <*> (Parser p2) =
|
||||
Parser $
|
||||
\str -> do
|
||||
(f, rest) <- p1 str
|
||||
(x, rest') <- p2 rest
|
||||
pure (f x, rest')
|
||||
|
||||
```
|
||||
|
||||
(Note: _We will also implement a Monad instance so we can use do notation here._ )
|
||||
|
||||
The third instance is an `Alternative` instance. We want to be able to supply an alternative parser in case one fails.
|
||||
|
||||
```
|
||||
instance Alternative Parser where
|
||||
empty = Parser (`throwErr` "Failed consuming input")
|
||||
(Parser p1) <|> (Parser p2) =
|
||||
Parser $
|
||||
\pstr -> case p1 pstr of
|
||||
Right result -> Right result
|
||||
Left _ -> p2 pstr
|
||||
```
|
||||
|
||||
The forth instance is a `Monad` instance. So we'll be able to chain parsers.
|
||||
|
||||
```
|
||||
instance Monad Parser where
|
||||
(Parser p1) >>= f =
|
||||
Parser $
|
||||
\str -> case p1 str of
|
||||
Left err -> Left err
|
||||
Right (rs, rest) ->
|
||||
case f rs of
|
||||
Parser parser -> parser rest
|
||||
|
||||
```
|
||||
|
||||
Next, let's define a way to run a parser and a utility function for failure:
|
||||
|
||||
```
|
||||
|
||||
runParser :: String -> String -> Parser a -> Either ParseError (a, ParseString)
|
||||
runParser name str (Parser parser) = parser $ ParseString name (0,0) str
|
||||
|
||||
throwErr :: ParseString -> String -> Either ParseError a
|
||||
throwErr ps@(ParseString name (row,col) _) errMsg =
|
||||
Left $ ParseError ps $ unlines
|
||||
[ "*** " ++ name ++ ": " ++ errMsg
|
||||
, "* On row " ++ show row ++ ", column " ++ show col ++ "."
|
||||
]
|
||||
|
||||
```
|
||||
|
||||
Now we'll start implementing the combinators which are the API and heart of the EDSL.
|
||||
|
||||
First, we'll define `oneOf`. `oneOf` will succeed if one of the characters in the list supplied to it is the next character of the input and will fail otherwise.
|
||||
|
||||
```
|
||||
oneOf :: [Char] -> Parser Char
|
||||
oneOf chars =
|
||||
Parser $ \case
|
||||
ps@(ParseString name (row, col) str) ->
|
||||
case str of
|
||||
[] -> throwErr ps "Cannot read character of empty string"
|
||||
(c:cs) ->
|
||||
if c `elem` chars
|
||||
then Right (c, ParseString name (row, col+1) cs)
|
||||
else throwErr ps $ unlines ["Unexpected character " ++ [c], "Expecting one of: " ++ show chars]
|
||||
```
|
||||
|
||||
`optional` will stop a parser from throwing an error. It will just return `Nothing` on failure.
|
||||
|
||||
```
|
||||
optional :: Parser a -> Parser (Maybe a)
|
||||
optional (Parser parser) =
|
||||
Parser $
|
||||
\pstr -> case parser pstr of
|
||||
Left _ -> Right (Nothing, pstr)
|
||||
Right (x, rest) -> Right (Just x, rest)
|
||||
```
|
||||
|
||||
`many` will try to run a parser repeatedly until it fails. When it does, it'll return a list of successful parses. `many1`will do the same, but will throw an error if it fails to parse at least once.
|
||||
|
||||
```
|
||||
many :: Parser a -> Parser [a]
|
||||
many parser = go []
|
||||
where go cs = (parser >>= \c -> go (c:cs)) <|> pure (reverse cs)
|
||||
|
||||
many1 :: Parser a -> Parser [a]
|
||||
many1 parser =
|
||||
(:) <$> parser <*> many parser
|
||||
|
||||
```
|
||||
|
||||
These next few parsers use the combinators we defined to make more specific parsers:
|
||||
|
||||
```
|
||||
char :: Char -> Parser Char
|
||||
char c = oneOf [c]
|
||||
|
||||
string :: String -> Parser String
|
||||
string = traverse char
|
||||
|
||||
space :: Parser Char
|
||||
space = oneOf " \n"
|
||||
|
||||
spaces :: Parser String
|
||||
spaces = many space
|
||||
|
||||
spaces1 :: Parser String
|
||||
spaces1 = many1 space
|
||||
|
||||
withSpaces :: Parser a -> Parser a
|
||||
withSpaces parser =
|
||||
spaces *> parser <* spaces
|
||||
|
||||
parens :: Parser a -> Parser a
|
||||
parens parser =
|
||||
(withSpaces $ char '(')
|
||||
*> withSpaces parser
|
||||
<* (spaces *> char ')')
|
||||
|
||||
sepBy :: Parser a -> Parser b -> Parser [b]
|
||||
sepBy sep parser = do
|
||||
frst <- optional parser
|
||||
rest <- many (sep *> parser)
|
||||
pure $ maybe rest (:rest) frst
|
||||
|
||||
```
|
||||
|
||||
Now we have everything we need to start defining a parser for our language.
|
||||
|
||||
* _Exercise_ : implement an EOF (end of file/input) parser combinator.
|
||||
|
||||
### 3\. Implementing a parser for our language
|
||||
|
||||
To define our parser, we'll use the top-bottom method.
|
||||
|
||||
```
|
||||
parseExpr :: Parser Expr
|
||||
parseExpr = fmap ATOM parseAtom <|> fmap LIST parseList
|
||||
|
||||
parseList :: Parser [Expr]
|
||||
parseList = parens $ sepBy spaces1 parseExpr
|
||||
|
||||
parseAtom :: Parser Atom
|
||||
parseAtom = parseSymbol <|> parseInt
|
||||
|
||||
parseSymbol :: Parser Atom
|
||||
parseSymbol = fmap Symbol parseName
|
||||
|
||||
```
|
||||
|
||||
Notice that these four function are a very high-level description of our language. This demonstrate why Haskell is so nice for parsing. Still, after defining the high-level parts, we still need to define the lower-level `parseName` and `parseInt`.
|
||||
|
||||
What characters can we use as names in our language? Let's decide to use lowercase letters, digits and underscores, where the first character must be a letter.
|
||||
|
||||
```
|
||||
parseName :: Parser Name
|
||||
parseName = do
|
||||
c <- oneOf ['a'..'z']
|
||||
cs <- many $ oneOf $ ['a'..'z'] ++ "0123456789" ++ "_"
|
||||
pure (c:cs)
|
||||
```
|
||||
|
||||
For integers, we want a sequence of digits optionally preceding by '-':
|
||||
|
||||
```
|
||||
parseInt :: Parser Atom
|
||||
parseInt = do
|
||||
sign <- optional $ char '-'
|
||||
num <- many1 $ oneOf "0123456789"
|
||||
let result = read $ maybe num (:num) sign of
|
||||
pure $ Int result
|
||||
```
|
||||
|
||||
Lastly, we'll define a function to run a parser and get back an `Expr` or an error message.
|
||||
|
||||
```
|
||||
runExprParser :: Name -> String -> Either String Expr
|
||||
runExprParser name str =
|
||||
case runParser name str (withSpaces parseExpr) of
|
||||
Left (ParseError _ errMsg) -> Left errMsg
|
||||
Right (result, _) -> Right result
|
||||
```
|
||||
|
||||
* _Exercise 1_ : Write a parser for the `Program` type you defined in the first section
|
||||
|
||||
* _Exercise 2_ : Rewrite `parseName` in Applicative style
|
||||
|
||||
* _Exercise 3_ : Find a way to handle the overflow case in `parseInt` instead of using `read`.
|
||||
|
||||
### 4\. Implement a pretty printer for our language
|
||||
|
||||
One more thing we'd like to do is be able to print our programs as source code. This is useful for better error messages.
|
||||
|
||||
```
|
||||
printExpr :: Expr -> String
|
||||
printExpr = printExpr' False 0
|
||||
|
||||
printAtom :: Atom -> String
|
||||
printAtom = \case
|
||||
Symbol s -> s
|
||||
Int i -> show i
|
||||
|
||||
printExpr' :: Bool -> Int -> Expr -> String
|
||||
printExpr' doindent level = \case
|
||||
ATOM a -> indent (bool 0 level doindent) (printAtom a)
|
||||
LIST (e:es) ->
|
||||
indent (bool 0 level doindent) $
|
||||
concat
|
||||
[ "("
|
||||
, printExpr' False (level + 1) e
|
||||
, bool "\n" "" (null es)
|
||||
, intercalate "\n" $ map (printExpr' True (level + 1)) es
|
||||
, ")"
|
||||
]
|
||||
|
||||
indent :: Int -> String -> String
|
||||
indent tabs e = concat (replicate tabs " ") ++ e
|
||||
```
|
||||
|
||||
* _Exercise_ : Write a pretty printer for the `Program` type you defined in the first section
|
||||
|
||||
Okay, we wrote around 200 lines so far of what's typically called the front-end of the compiler. We have around 150 more lines to go and three more tasks: We need to define a subset of JS for our usage, define the translator from our language to that subset, and glue the whole thing together. Let's go!
|
||||
|
||||
### 5\. Define a subset of JavaScript for our usage
|
||||
|
||||
First, we'll define the subset of JavaScript we are going to use:
|
||||
|
||||
```
|
||||
data JSExpr
|
||||
= JSInt Int
|
||||
| JSSymbol Name
|
||||
| JSBinOp JSBinOp JSExpr JSExpr
|
||||
| JSLambda [Name] JSExpr
|
||||
| JSFunCall JSExpr [JSExpr]
|
||||
| JSReturn JSExpr
|
||||
deriving (Eq, Show, Read)
|
||||
|
||||
type JSBinOp = String
|
||||
```
|
||||
|
||||
This data type represent a JavaScript expression. We have two atoms - `JSInt` and `JSSymbol` to which we'll translate our languages' `Atom`, We have `JSBinOp` to represent a binary operation such as `+` or `*`, we have `JSLambda`for anonymous functions same as our `lambda expression`, We have `JSFunCall` which we'll use both for calling functions and introducing new names as in `let`, and we have `JSReturn` to return values from functions as that's required in JavaScript.
|
||||
|
||||
This `JSExpr` type is an **abstract representation** of a JavaScript expression. We will translate our own `Expr`which is an abstract representation of our languages' expression to `JSExpr` and from there to JavaScript. But in order to do that we need to take this `JSExpr` and produce JavaScript code from it. We'll do that by pattern matching on `JSExpr` recursively and emit JS code as a `String`. This is basically the same thing we did in `printExpr`. We'll also track the scoping of elements so we can indent the generated code in a nice way.
|
||||
|
||||
```
|
||||
printJSOp :: JSBinOp -> String
|
||||
printJSOp op = op
|
||||
|
||||
printJSExpr :: Bool -> Int -> JSExpr -> String
|
||||
printJSExpr doindent tabs = \case
|
||||
JSInt i -> show i
|
||||
JSSymbol name -> name
|
||||
JSLambda vars expr -> (if doindent then indent tabs else id) $ unlines
|
||||
["function(" ++ intercalate ", " vars ++ ") {"
|
||||
,indent (tabs+1) $ printJSExpr False (tabs+1) expr
|
||||
] ++ indent tabs "}"
|
||||
JSBinOp op e1 e2 -> "(" ++ printJSExpr False tabs e1 ++ " " ++ printJSOp op ++ " " ++ printJSExpr False tabs e2 ++ ")"
|
||||
JSFunCall f exprs -> "(" ++ printJSExpr False tabs f ++ ")(" ++ intercalate ", " (fmap (printJSExpr False tabs) exprs) ++ ")"
|
||||
JSReturn expr -> (if doindent then indent tabs else id) $ "return " ++ printJSExpr False tabs expr ++ ";"
|
||||
```
|
||||
|
||||
* _Exercise 1_ : Add a `JSProgram` type that will hold multiple `JSExpr` and create a function `printJSExprProgram` to generate code for it.
|
||||
|
||||
* _Exercise 2_ : Add a new type of `JSExpr` - `JSIf`, and generate code for it.
|
||||
|
||||
### 6\. Implement a code translator to the JavaScript subset we defined
|
||||
|
||||
We are almost there. In this section we'll create a function to translate `Expr` to `JSExpr`.
|
||||
|
||||
The basic idea is simple, we'll translate `ATOM` to `JSSymbol` or `JSInt` and `LIST` to either a function call or a special case we'll translate later.
|
||||
|
||||
```
|
||||
type TransError = String
|
||||
|
||||
translateToJS :: Expr -> Either TransError JSExpr
|
||||
translateToJS = \case
|
||||
ATOM (Symbol s) -> pure $ JSSymbol s
|
||||
ATOM (Int i) -> pure $ JSInt i
|
||||
LIST xs -> translateList xs
|
||||
|
||||
translateList :: [Expr] -> Either TransError JSExpr
|
||||
translateList = \case
|
||||
[] -> Left "translating empty list"
|
||||
ATOM (Symbol s):xs
|
||||
| Just f <- lookup s builtins ->
|
||||
f xs
|
||||
f:xs ->
|
||||
JSFunCall <$> translateToJS f <*> traverse translateToJS xs
|
||||
|
||||
```
|
||||
|
||||
`builtins` is a list of special cases to translate, like `lambda` and `let`. Every case gets the list of arguments for it, verify that its syntactically valid and translates it to the equivalent `JSExpr`.
|
||||
|
||||
```
|
||||
type Builtin = [Expr] -> Either TransError JSExpr
|
||||
type Builtins = [(Name, Builtin)]
|
||||
|
||||
builtins :: Builtins
|
||||
builtins =
|
||||
[("lambda", transLambda)
|
||||
,("let", transLet)
|
||||
,("add", transBinOp "add" "+")
|
||||
,("mul", transBinOp "mul" "*")
|
||||
,("sub", transBinOp "sub" "-")
|
||||
,("div", transBinOp "div" "/")
|
||||
,("print", transPrint)
|
||||
]
|
||||
|
||||
```
|
||||
|
||||
In our case, we treat built-in special forms as special and not first class, so will not be able to use them as first class functions and such.
|
||||
|
||||
We'll translate a Lambda to an anonymous function:
|
||||
|
||||
```
|
||||
transLambda :: [Expr] -> Either TransError JSExpr
|
||||
transLambda = \case
|
||||
[LIST vars, body] -> do
|
||||
vars' <- traverse fromSymbol vars
|
||||
JSLambda vars' <$> (JSReturn <$> translateToJS body)
|
||||
|
||||
vars ->
|
||||
Left $ unlines
|
||||
["Syntax error: unexpected arguments for lambda."
|
||||
,"expecting 2 arguments, the first is the list of vars and the second is the body of the lambda."
|
||||
,"In expression: " ++ show (LIST $ ATOM (Symbol "lambda") : vars)
|
||||
]
|
||||
|
||||
fromSymbol :: Expr -> Either String Name
|
||||
fromSymbol (ATOM (Symbol s)) = Right s
|
||||
fromSymbol e = Left $ "cannot bind value to non symbol type: " ++ show e
|
||||
|
||||
```
|
||||
|
||||
We'll translate let to a definition of a function with the relevant named arguments and call it with the values, Thus introducing the variables in that scope:
|
||||
|
||||
```
|
||||
transLet :: [Expr] -> Either TransError JSExpr
|
||||
transLet = \case
|
||||
[LIST binds, body] -> do
|
||||
(vars, vals) <- letParams binds
|
||||
vars' <- traverse fromSymbol vars
|
||||
JSFunCall . JSLambda vars' <$> (JSReturn <$> translateToJS body) <*> traverse translateToJS vals
|
||||
where
|
||||
letParams :: [Expr] -> Either Error ([Expr],[Expr])
|
||||
letParams = \case
|
||||
[] -> pure ([],[])
|
||||
LIST [x,y] : rest -> ((x:) *** (y:)) <$> letParams rest
|
||||
x : _ -> Left ("Unexpected argument in let list in expression:\n" ++ printExpr x)
|
||||
|
||||
vars ->
|
||||
Left $ unlines
|
||||
["Syntax error: unexpected arguments for let."
|
||||
,"expecting 2 arguments, the first is the list of var/val pairs and the second is the let body."
|
||||
,"In expression:\n" ++ printExpr (LIST $ ATOM (Symbol "let") : vars)
|
||||
]
|
||||
```
|
||||
|
||||
We'll translate an operation that can work on multiple arguments to a chain of binary operations. For example: `(add 1 2 3)` will become `1 + (2 + 3)`
|
||||
|
||||
```
|
||||
transBinOp :: Name -> Name -> [Expr] -> Either TransError JSExpr
|
||||
transBinOp f _ [] = Left $ "Syntax error: '" ++ f ++ "' expected at least 1 argument, got: 0"
|
||||
transBinOp _ _ [x] = translateToJS x
|
||||
transBinOp _ f list = foldl1 (JSBinOp f) <$> traverse translateToJS list
|
||||
```
|
||||
|
||||
And we'll translate a `print` as a call to `console.log`
|
||||
|
||||
```
|
||||
transPrint :: [Expr] -> Either TransError JSExpr
|
||||
transPrint [expr] = JSFunCall (JSSymbol "console.log") . (:[]) <$> translateToJS expr
|
||||
transPrint xs = Left $ "Syntax error. print expected 1 arguments, got: " ++ show (length xs)
|
||||
|
||||
```
|
||||
|
||||
Notice that we could have skipped verifying the syntax if we'd parse those as special cases of `Expr`.
|
||||
|
||||
* _Exercise 1_ : Translate `Program` to `JSProgram`
|
||||
|
||||
* _Exercise 2_ : add a special case for `if Expr Expr Expr` and translate it to the `JSIf` case you implemented in the last exercise
|
||||
|
||||
### 7\. Glue it all together
|
||||
|
||||
Finally, we are going to glue this all together. We'll:
|
||||
|
||||
1. Read a file
|
||||
|
||||
2. Parse it to `Expr`
|
||||
|
||||
3. Translate it to `JSExpr`
|
||||
|
||||
4. Emit JavaScript code to the standard output
|
||||
|
||||
We'll also enable a few flags for testing:
|
||||
|
||||
* `--e` will parse and print the abstract representation of the expression (`Expr`)
|
||||
|
||||
* `--pp` will parse and pretty print
|
||||
|
||||
* `--jse` will parse, translate and print the abstract representation of the resulting JS (`JSExpr`)
|
||||
|
||||
* `--ppc` will parse, pretty print and compile
|
||||
|
||||
```
|
||||
main :: IO ()
|
||||
main = getArgs >>= \case
|
||||
[file] ->
|
||||
printCompile =<< readFile file
|
||||
["--e",file] ->
|
||||
either putStrLn print . runExprParser "--e" =<< readFile file
|
||||
["--pp",file] ->
|
||||
either putStrLn (putStrLn . printExpr) . runExprParser "--pp" =<< readFile file
|
||||
["--jse",file] ->
|
||||
either print (either putStrLn print . translateToJS) . runExprParser "--jse" =<< readFile file
|
||||
["--ppc",file] ->
|
||||
either putStrLn (either putStrLn putStrLn) . fmap (compile . printExpr) . runExprParser "--ppc" =<< readFile file
|
||||
_ ->
|
||||
putStrLn $ unlines
|
||||
["Usage: runghc Main.hs [ --e, --pp, --jse, --ppc ] <filename>"
|
||||
,"--e print the Expr"
|
||||
,"--pp pretty print Expr"
|
||||
,"--jse print the JSExpr"
|
||||
,"--ppc pretty print Expr and then compile"
|
||||
]
|
||||
|
||||
printCompile :: String -> IO ()
|
||||
printCompile = either putStrLn putStrLn . compile
|
||||
|
||||
compile :: String -> Either Error String
|
||||
compile str = printJSExpr False 0 <$> (translateToJS =<< runExprParser "compile" str)
|
||||
|
||||
```
|
||||
|
||||
That's it. We have a compiler from our language to JS. Again, you can view the full source file [here][9].
|
||||
|
||||
Running our compiler with the example from the first section yields this JavaScript code:
|
||||
|
||||
```
|
||||
$ runhaskell Lisp.hs example.lsp
|
||||
(function(compose, square, add1) {
|
||||
return (console.log)(((compose)(square, add1))(5));
|
||||
})(function(f, g) {
|
||||
return function(x) {
|
||||
return (f)((g)(x));
|
||||
};
|
||||
}, function(x) {
|
||||
return (x * x);
|
||||
}, function(x) {
|
||||
return (x + 1);
|
||||
})
|
||||
```
|
||||
|
||||
If you have node.js installed on your computer, you can run this code by running:
|
||||
|
||||
```
|
||||
$ runhaskell Lisp.hs example.lsp | node -p
|
||||
36
|
||||
undefined
|
||||
```
|
||||
|
||||
* _Final exercise_ : instead of compiling an expression, compile a program of multiple expressions.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://gilmi.me/blog/post/2016/10/14/lisp-to-js
|
||||
|
||||
作者：[ Gil Mizrahi ][a]
|
||||
选题：[oska874][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://gilmi.me/home
|
||||
[b]:https://github.com/oska874
|
||||
[1]:https://gilmi.me/blog/authors/Gil
|
||||
[2]:https://gilmi.me/blog/tags/compilers
|
||||
[3]:https://gilmi.me/blog/tags/fp
|
||||
[4]:https://gilmi.me/blog/tags/haskell
|
||||
[5]:https://gilmi.me/blog/tags/lisp
|
||||
[6]:https://gilmi.me/blog/tags/parsing
|
||||
[7]:https://gist.github.com/soupi/d4ff0727ccb739045fad6cdf533ca7dd
|
||||
[8]:https://mrkkrp.github.io/megaparsec/
|
||||
[9]:https://gist.github.com/soupi/d4ff0727ccb739045fad6cdf533ca7dd
|
||||
[10]:https://gilmi.me/blog/post/2016/10/14/lisp-to-js
|
||||
@ -1,202 +0,0 @@
|
||||
BriFuture is translating this article
|
||||
|
||||
The user’s home dashboard in our app, AlignHow we built our first full-stack JavaScript web app in three weeks
|
||||
============================================================
|
||||
|
||||
|
||||
|
||||
### A simple step-by-step guide to go from idea to deployed app
|
||||
|
||||
My three months of coding bootcamp at the Grace Hopper Program have come to a close, and the title of this article is actually not quite true — I’ve now built _three_ full-stack apps: [an e-commerce store from scratch][3], a [personal hackathon project][4] of my choice, and finally, a three-week capstone project. That capstone project was by far the most intensive— a three week journey with two teammates — and it is my proudest achievement from bootcamp. It is the first robust, complex app I have ever fully built and designed.
|
||||
|
||||
As most developers know, even when you “know how to code”, it can be really overwhelming to embark on the creation of your first full-stack app. The JavaScript ecosystem is incredibly vast: with package managers, modules, build tools, transpilers, databases, libraries, and decisions to be made about all of them, it’s no wonder that so many budding coders never build anything beyond Codecademy tutorials. That’s why I want to walk you through a step-by-step guide of the decisions and steps my team took to create our live app, Align.
|
||||
|
||||
* * *
|
||||
|
||||
First, some context. Align is a web app that uses an intuitive timeline interface to help users set long-term goals and manage them over time.Our stack includes Firebase for back-end services and React on the front end. My teammates and I explain more in this short video:
|
||||
|
||||
[video](https://youtu.be/YacM6uYP2Jo)
|
||||
|
||||
Demoing Align @ Demo Day Live // July 10, 2017
|
||||
|
||||
So how did we go from Day 1, when we were assigned our teams, to the final live app? Here’s a rundown of the steps we took:
|
||||
|
||||
* * *
|
||||
|
||||
### Step 1: Ideate
|
||||
|
||||
The first step was to figure out what exactly we wanted to build. In my past life as a consultant at IBM, I led ideation workshops with corporate leaders. Pulling from that, I suggested to my group the classic post-it brainstorming strategy, in which we all scribble out as many ideas as we can — even ‘stupid ones’ — so that people’s brains keep moving and no one avoids voicing ideas out of fear.
|
||||
|
||||
|
||||
|
||||
After generating a few dozen app ideas, we sorted them into categories to gain a better understanding of what themes we were collectively excited about. In our group, we saw a clear trend towards ideas surrounding self-improvement, goal-setting, nostalgia, and personal development. From that, we eventually honed in on a specific idea: a personal dashboard for setting and managing long-term goals, with elements of memory-keeping and data visualization over time.
|
||||
|
||||
From there, we created a set of user stories — descriptions of features we wanted to have, from an end-user perspective — to elucidate what exactly we wanted our app to do.
|
||||
|
||||
### Step 2: Wireframe UX/UI
|
||||
|
||||
Next, on a white board, we drew out the basic views we envisioned in our app. We incorporated our set of user stories to understand how these views would work in a skeletal app framework.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
These sketches ensured we were all on the same page, and provided a visual blueprint going forward of what exactly we were all working towards.
|
||||
|
||||
### Step 3: Choose a data structure and type of database
|
||||
|
||||
It was now time to design our data structure. Based on our wireframes and user stories, we created a list in a Google doc of the models we would need and what attributes each should include. We knew we needed a ‘goal’ model, a ‘user’ model, a ‘milestone’ model, and a ‘checkin’ model, as well as eventually a ‘resource’ model, and an ‘upload’ model.
|
||||
|
||||
|
||||
|
||||
Our initial sketch of our data models
|
||||
|
||||
After informally sketching the models out, we needed to choose a _type _ of database: ‘relational’ vs. ‘non-relational’ (a.k.a. ‘SQL’ vs. ‘NoSQL’). Whereas SQL databases are table-based and need predefined schema, NoSQL databases are document-based and have dynamic schema for unstructured data.
|
||||
|
||||
For our use case, it didn’t matter much whether we used a SQL or a No-SQL database, so we ultimately chose Google’s cloud NoSQL database Firebasefor other reasons:
|
||||
|
||||
1. It could hold user image uploads in its cloud storage
|
||||
|
||||
2. It included WebSocket integration for real-time updating
|
||||
|
||||
3. It could handle our user authentication and offer easy OAuth integration
|
||||
|
||||
Once we chose a database, it was time to understand the relations between our data models. Since Firebase is NoSQL, we couldn’t create join tables or set up formal relations like _“Checkins belongTo Goals”_ . Instead, we needed to figure out what the JSON tree would look like, and how the objects would be nested (or not). Ultimately, we structured our model like this:
|
||||
|
||||
** 此处有Canvas,请手动处理 **
|
||||
|
||||
|
||||
Our final Firebase data scheme for the Goal object. Note that Milestones & Checkins are nested under Goals.
|
||||
|
||||
_(Note: Firebase prefers shallow, normalized data structures for efficiency, but for our use case, it made most sense to nest it, since we would never be pulling a Goal from the database without its child Milestones and Checkins.)_
|
||||
|
||||
### Step 4: Set up Github and an agile workflow
|
||||
|
||||
We knew from the start that staying organized and practicing agile development would serve us well. We set up a Github repo, on which weprevented merging to master to force ourselves to review each other’s code.
|
||||
|
||||
|
||||
|
||||
|
||||
We also created an agile board on [Waffle.io][5], which is free and has easy integration with Github. On the Waffle board, we listed our user stories as well as bugs we knew we needed to fix. Later, when we started coding, we would each create git branches for the user story we were currently working on, moving it from swim lane to swim lane as we made progress.
|
||||
|
||||
|
||||
|
||||
|
||||
We also began holding “stand-up” meetings each morning to discuss the previous day’s progress and any blockers each of us were encountering. This meeting often decided the day’s flow — who would be pair programming, and who would work on an issue solo.
|
||||
|
||||
I highly recommend some sort of structured workflow like this, as it allowed us to clearly define our priorities and make efficient progress without any interpersonal conflict.
|
||||
|
||||
### Step 5: Choose & download a boilerplate
|
||||
|
||||
Because the JavaScript ecosystem is so complicated, we opted not to build our app from absolute ground zero. It felt unnecessary to spend valuable time wiring up our Webpack build scripts and loaders, and our symlink that pointed to our project directory. My team chose the [Firebones][6] skeleton because it fit our use case, but there are many open-source skeleton options available to choose from.
|
||||
|
||||
### Step 6: Write back-end API routes (or Firebase listeners)
|
||||
|
||||
If we weren’t using a cloud-based database, this would have been the time to start writing our back-end Express routes to make requests to our database. But since we were using Firebase, which is already in the cloud and has a different way of communicating with code, we just worked to set up our first successful database listener.
|
||||
|
||||
To ensure our listener was working, we coded out a basic user form for creating a Goal, and saw that, indeed, when we filled out the form, our database was live-updating. We were connected!
|
||||
|
||||
### Step 7: Build a “Proof Of Concept”
|
||||
|
||||
Our next step was to create a “proof of concept” for our app, or a prototype of the most difficult fundamental features to implement, demonstrating that our app _could _ eventuallyexist. For us, this meant finding a front-end library to satisfactorily render timelines, and connecting it to Firebase successfully to display some seed data in our database.
|
||||
|
||||
|
||||
|
||||
Basic Victory.JS timelines
|
||||
|
||||
We found Victory.JS, a React library built on D3, and spent a day reading the documentation and putting together a very basic example of a _VictoryLine_ component and a _VictoryScatter_ component to visually display data from the database. Indeed, it worked! We were ready to build.
|
||||
|
||||
### Step 8: Code out the features
|
||||
|
||||
Finally, it was time to build out all the exciting functionality of our app. This is a giant step that will obviously vary widely depending on the app you’re personally building. We looked at our wireframes and started coding out the individual user stories in our Waffle. This often included touching both front-end and back-end code (for example, creating a front-end form and also connecting it to the database). Our features ranged from major to minor, and included things like:
|
||||
|
||||
* ability to create new goals, milestones, and checkins
|
||||
|
||||
* ability to delete goals, milestones, and checkins
|
||||
|
||||
* ability to change a timeline’s name, color, and details
|
||||
|
||||
* ability to zoom in on timelines
|
||||
|
||||
* ability to add links to resources
|
||||
|
||||
* ability to upload media
|
||||
|
||||
* ability to bubble up resources and media from milestones and checkins to their associated goals
|
||||
|
||||
* rich text editor integration
|
||||
|
||||
* user signup / authentication / OAuth
|
||||
|
||||
* popover to view timeline options
|
||||
|
||||
* loading screens
|
||||
|
||||
For obvious reasons, this step took up the bulk of our time — this phase is where most of the meaty code happened, and each time we finished a feature, there were always more to build out!
|
||||
|
||||
### Step 9: Choose and code the design scheme
|
||||
|
||||
Once we had an MVP of the functionality we desired in our app, it was time to clean it up and make it pretty. My team used Material-UI for components like form fields, menus, and login tabs, which ensured everything looked sleek, polished, and coherent without much in-depth design knowledge.
|
||||
|
||||
|
||||
|
||||
This was one of my favorite features to code out. Its beauty is so satisfying!
|
||||
|
||||
We spent a while choosing a color scheme and editing the CSS, which provided us a nice break from in-the-trenches coding. We also designed alogo and uploaded a favicon.
|
||||
|
||||
### Step 10: Find and squash bugs
|
||||
|
||||
While we should have been using test-driven development from the beginning, time constraints left us with precious little time for anything but features. This meant that we spent the final two days simulating every user flow we could think of and hunting our app for bugs.
|
||||
|
||||
|
||||
|
||||
|
||||
This process was not the most systematic, but we found plenty of bugs to keep us busy, including a bug in which the loading screen would last indefinitely in certain situations, and one in which the resource component had stopped working entirely. Fixing bugs can be annoying, but when it finally works, it’s extremely satisfying.
|
||||
|
||||
### Step 11: Deploy the live app
|
||||
|
||||
The final step was to deploy our app so it would be available live! Because we were using Firebase to store our data, we deployed to Firebase Hosting, which was intuitive and simple. If your back end uses a different database, you can use Heroku or DigitalOcean. Generally, deployment directions are readily available on the hosting site.
|
||||
|
||||
We also bought a cheap domain name on Namecheap.com to make our app more polished and easy to find.
|
||||
|
||||
|
||||
|
||||
* * *
|
||||
|
||||
And that was it — we were suddenly the co-creators of a real live full-stack app that someone could use! If we had a longer runway, Step 12 would have been to run A/B testing on users, so we could better understand how actual users interact with our app and what they’d like to see in a V2.
|
||||
|
||||
For now, however, we’re happy with the final product, and with the immeasurable knowledge and understanding we gained throughout this process. Check out Align [here][7]!
|
||||
|
||||
|
||||
|
||||
Team Align: Sara Kladky (left), Melanie Mohn (center), and myself.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://medium.com/ladies-storm-hackathons/how-we-built-our-first-full-stack-javascript-web-app-in-three-weeks-8a4668dbd67c?imm_mid=0f581a&cmp=em-web-na-na-newsltr_20170816
|
||||
|
||||
作者：[Sophia Ciocca ][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://medium.com/@sophiaciocca?source=post_header_lockup
|
||||
[1]:https://medium.com/@sophiaciocca?source=post_header_lockup
|
||||
[2]:https://medium.com/@sophiaciocca?source=post_header_lockup
|
||||
[3]:https://github.com/limitless-leggings/limitless-leggings
|
||||
[4]:https://www.youtube.com/watch?v=qyLoInHNjoc
|
||||
[5]:http://www.waffle.io/
|
||||
[6]:https://github.com/FullstackAcademy/firebones
|
||||
[7]:https://align.fun/
|
||||
[8]:https://github.com/align-capstone/align
|
||||
[9]:https://github.com/sophiaciocca
|
||||
[10]:https://github.com/Kladky
|
||||
[11]:https://github.com/melaniemohn
|
||||
@ -1,223 +0,0 @@
|
||||
translating by dianbanjiu Managing users on Linux systems
|
||||
======
|
||||
Your Linux users may not be raging bulls, but keeping them happy is always a challenge as it involves managing their accounts, monitoring their access rights, tracking down the solutions to problems they run into, and keeping them informed about important changes on the systems they use. Here are some of the tasks and tools that make the job a little easier.
|
||||
|
||||
### Configuring accounts
|
||||
|
||||
Adding and removing accounts is the easier part of managing users, but there are still a lot of options to consider. Whether you use a desktop tool or go with command line options, the process is largely automated. You can set up a new user with a command as simple as **adduser jdoe** and a number of things will happen. John 's account will be created using the next available UID and likely populated with a number of files that help to configure his account. When you run the adduser command with a single argument (the new username), it will prompt for some additional information and explain what it is doing.
|
||||
```
|
||||
$ sudo adduser jdoe
|
||||
Adding user `jdoe' ...
|
||||
Adding new group `jdoe' (1001) ...
|
||||
Adding new user `jdoe' (1001) with group `jdoe' ...
|
||||
Creating home directory `/home/jdoe' ...
|
||||
Copying files from `/etc/skel' …
|
||||
Enter new UNIX password:
|
||||
Retype new UNIX password:
|
||||
passwd: password updated successfully
|
||||
Changing the user information for jdoe
|
||||
Enter the new value, or press ENTER for the default
|
||||
Full Name []: John Doe
|
||||
Room Number []:
|
||||
Work Phone []:
|
||||
Home Phone []:
|
||||
Other []:
|
||||
Is the information correct? [Y/n] Y
|
||||
|
||||
```
|
||||
|
||||
As you can see, adduser adds the user's information (to the /etc/passwd and /etc/shadow files), creates the new home directory and populates it with some files from /etc/skel, prompts for you to assign the initial password and identifying information, and then verifies that it's got everything right. If you answer "n" for no at the final "Is the information correct?" prompt, it will run back through all of your previous answers, allowing you to change any that you might want to change.
|
||||
|
||||
Once an account is set up, you might want to verify that it looks as you'd expect. However, a better strategy is to ensure that the choices being made "automagically" match what you want to see _before_ you add your first account. The defaults are defaults for good reason, but it 's useful to know where they're defined in case you want some to be different - for example, if you don't want home directories in /home, you don't want user UIDs to start with 1000, or you don't want the files in home directories to be readable by _everyone_ on the system.
|
||||
|
||||
Some of the details of how the adduser command works are configured in the /etc/adduser.conf file. This file contains a lot of settings that determine how new accounts are configured and will look something like this. Note that the comments and blanks lines are omitted in the output below so that we can focus more easily on just the settings.
|
||||
```
|
||||
$ cat /etc/adduser.conf | grep -v "^#" | grep -v "^$"
|
||||
DSHELL=/bin/bash
|
||||
DHOME=/home
|
||||
GROUPHOMES=no
|
||||
LETTERHOMES=no
|
||||
SKEL=/etc/skel
|
||||
FIRST_SYSTEM_UID=100
|
||||
LAST_SYSTEM_UID=999
|
||||
FIRST_SYSTEM_GID=100
|
||||
LAST_SYSTEM_GID=999
|
||||
FIRST_UID=1000
|
||||
LAST_UID=29999
|
||||
FIRST_GID=1000
|
||||
LAST_GID=29999
|
||||
USERGROUPS=yes
|
||||
USERS_GID=100
|
||||
DIR_MODE=0755
|
||||
SETGID_HOME=no
|
||||
QUOTAUSER=""
|
||||
SKEL_IGNORE_REGEX="dpkg-(old|new|dist|save)"
|
||||
|
||||
```
|
||||
|
||||
As you can see, we've got a default shell (DSHELL), the starting value for UIDs (FIRST_UID), the location for home directories (DHOME) and the source location for startup files (SKEL) that will be added to each account as it is set up - along with a number of additional settings. This file also specifies the permissions to be assigned to home directories (DIR_MODE).
|
||||
|
||||
One of the more important settings is DIR_MODE, which determines the permissions that are used for each user's home directory. Given this setting, the permissions assigned to a directory that the user creates will be 755. Given this setting, home directories will be set up with rwxr-xr-x permissions. Users will be able to read other users' files, but not modify or remove them. If you want to be more restrictive, you can change this setting to 750 (no access by anyone outside the user's group) or even 700 (no access but the user himself).
|
||||
|
||||
Any user account settings can be manually changed after the accounts are set up. For example, you can edit the /etc/passwd file or chmod home directory, but configuring the /etc/adduser.conf file _before_ you start adding accounts on a new server will ensure some consistency and save you some time and trouble over the long run.
|
||||
|
||||
Changes to the /etc/adduser.conf file will affect all accounts that are set up subsequent to those changes. If you want to set up some specific account differently, you've also got the option of providing account configuration options as arguments with the adduser command in addition to the username. Maybe you want to assign a different shell for some user, request a specific UID, or disable logins altogether. The man page for the adduser command will display some of your choices for configuring an individual account.
|
||||
```
|
||||
adduser [options] [--home DIR] [--shell SHELL] [--no-create-home]
|
||||
[--uid ID] [--firstuid ID] [--lastuid ID] [--ingroup GROUP | --gid ID]
|
||||
[--disabled-password] [--disabled-login] [--gecos GECOS]
|
||||
[--add_extra_groups] [--encrypt-home] user
|
||||
|
||||
```
|
||||
|
||||
These days probably every Linux system is, by default, going to put each user into his or her own group. As an admin, you might elect to do things differently. You might find that putting users in shared groups works better for your site, electing to use adduser's --gid option to select a specific group. Users can, of course, always be members of multiple groups, so you have some options on how to manage groups -- both primary and secondary.
|
||||
|
||||
### Dealing with user passwords
|
||||
|
||||
Since it's always a bad idea to know someone else's password, admins will generally use a temporary password when they set up an account and then run a command that will force the user to change his password on his first login. Here's an example:
|
||||
```
|
||||
$ sudo chage -d 0 jdoe
|
||||
|
||||
```
|
||||
|
||||
When the user logs in, he will see something like this:
|
||||
```
|
||||
WARNING: Your password has expired.
|
||||
You must change your password now and login again!
|
||||
Changing password for jdoe.
|
||||
(current) UNIX password:
|
||||
|
||||
```
|
||||
|
||||
### Adding users to secondary groups
|
||||
|
||||
To add a user to a secondary group, you might use the usermod command as shown below -- to add the user to the group and then verify that the change was made.
|
||||
```
|
||||
$ sudo usermod -a -G sudo jdoe
|
||||
$ sudo grep sudo /etc/group
|
||||
sudo:x:27:shs,jdoe
|
||||
|
||||
```
|
||||
|
||||
Keep in mind that some groups -- like the sudo or wheel group -- imply certain privileges. More on this in a moment.
|
||||
|
||||
### Removing accounts, adding groups, etc.
|
||||
|
||||
Linux systems also provide commands to remove accounts, add new groups, remove groups, etc. The **deluser** command, for example, will remove the user login entries from the /etc/passwd and /etc/shadow files but leave her home directory intact unless you add the --remove-home or --remove-all-files option. The **addgroup** command adds a group, but will give it the next group id in the sequence (i.e., likely in the user group range) unless you use the --gid option.
|
||||
```
|
||||
$ sudo addgroup testgroup --gid=131
|
||||
Adding group `testgroup' (GID 131) ...
|
||||
Done.
|
||||
|
||||
```
|
||||
|
||||
### Managing privileged accounts
|
||||
|
||||
Some Linux systems have a wheel group that gives members the ability to run commands as root. In this case, the /etc/sudoers file references this group. On Debian systems, this group is called sudo, but it works the same way and you'll see a reference like this in the /etc/sudoers file:
|
||||
```
|
||||
%sudo ALL=(ALL:ALL) ALL
|
||||
|
||||
```
|
||||
|
||||
This setting basically means that anyone in the wheel or sudo group can run all commands with the power of root once they preface them with the sudo command.
|
||||
|
||||
You can also add more limited privileges to the sudoers file -- maybe to give particular users the ability to run one or two commands as root. If you do, you should also periodically review the /etc/sudoers file to gauge how much privilege users have and very that the privileges provided are still required.
|
||||
|
||||
In the command shown below, we're looking at the active lines in the /etc/sudoers file. The most interesting lines in this file include the path set for commands that can be run using the sudo command and the two groups that are allowed to run commands via sudo. As was just mentioned, individuals can be given permissions by being directly included in the sudoers file, but it is generally better practice to define privileges through group memberships.
|
||||
```
|
||||
# cat /etc/sudoers | grep -v "^#" | grep -v "^$"
|
||||
Defaults env_reset
|
||||
Defaults mail_badpass
|
||||
Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"
|
||||
root ALL=(ALL:ALL) ALL
|
||||
%admin ALL=(ALL) ALL <== admin group
|
||||
%sudo ALL=(ALL:ALL) ALL <== sudo group
|
||||
|
||||
```
|
||||
|
||||
### Checking on logins
|
||||
|
||||
To see when a user last logged in, you can use a command like this one:
|
||||
```
|
||||
# last jdoe
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 08:44 - 11:48 (00:04)
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 13:43 - 18:44 (00:00)
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 19:42 - 19:43 (00:00)
|
||||
|
||||
```
|
||||
|
||||
If you want to see when each of your users last logged in, you can run the last command through a loop like this one:
|
||||
```
|
||||
$ for user in `ls /home`; do last $user | head -1; done
|
||||
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 19:42 - 19:43 (00:03)
|
||||
|
||||
rocket pts/18 192.168.0.11 Thu Sep 14 13:02 - 13:02 (00:00)
|
||||
shs pts/17 192.168.0.11 Thu Sep 14 12:45 still logged in
|
||||
|
||||
|
||||
```
|
||||
|
||||
This command will only show you users who have logged on since the current wtmp file became active. The blank lines indicate that some users have never logged in since that time, but doesn't call them out. A better command would be this one that clear displays the users who have not logged in at all in this time period:
|
||||
```
|
||||
$ for user in `ls /home`; do echo -n "$user ";last $user | head -1 | awk '{print substr($0,40)}'; done
|
||||
dhayes
|
||||
jdoe pts/18 192.168.0.11 Thu Sep 14 19:42 - 19:43
|
||||
peanut pts/19 192.168.0.29 Mon Sep 11 09:15 - 17:11
|
||||
rocket pts/18 192.168.0.11 Thu Sep 14 13:02 - 13:02
|
||||
shs pts/17 192.168.0.11 Thu Sep 14 12:45 still logged
|
||||
tsmith
|
||||
|
||||
```
|
||||
|
||||
That command is a lot to type, but could be turned into a script to make it a lot easier to use.
|
||||
```
|
||||
#!/bin/bash
|
||||
|
||||
for user in `ls /home`
|
||||
do
|
||||
echo -n "$user ";last $user | head -1 | awk '{print substr($0,40)}'
|
||||
done
|
||||
|
||||
```
|
||||
|
||||
Sometimes this kind of information can alert you to changes in users' roles that suggest they may no longer need the accounts in question.
|
||||
|
||||
### Communicating with users
|
||||
|
||||
Linux systems provide a number of ways to communicate with your users. You can add messages to the /etc/motd file that will be displayed when a user logs into a server using a terminal connection. You can also message users with commands such as write (message to single user) or wall (write to all logled in users.
|
||||
```
|
||||
$ wall System will go down in one hour
|
||||
|
||||
Broadcast message from shs@stinkbug (pts/17) (Thu Sep 14 14:04:16 2017):
|
||||
|
||||
System will go down in one hour
|
||||
|
||||
```
|
||||
|
||||
Important messages should probably be delivered through multiple channels as it's difficult to predict what users will actually notice. Together, message-of-the-day (motd), wall, and email notifications might stand of chance of getting most of your users' attention.
|
||||
|
||||
### Paying attention to log files
|
||||
|
||||
Paying attention to log files can also help you understand user activity. In particular, the /var/log/auth.log file will show you user login and logout activity, creation of new groups, etc. The /var/log/messages or /var/log/syslog files will tell you more about system activity.
|
||||
|
||||
### Tracking problems and requests
|
||||
|
||||
Whether or not you install a ticketing application on your Linux system, it's important to track the problems that your users run into and the requests that they make. Your users won't be happy if some portion of their requests fall through the proverbial cracks. Even a paper log could be helpful or, better yet, a spreadsheet that allows you to notice what issues are still outstanding and what the root cause of the problems turned out to be. Ensuring that problems and requests are addressed is important and logs can also help you remember what you had to do to address a problem that re-emerges many months or even years later.
|
||||
|
||||
### Wrap-up
|
||||
|
||||
Managing user accounts on a busy server depends in part on starting out with well configured defaults and in part on monitoring user activities and problems encountered. Users are likely to be happy if they feel you are responsive to their concerns and know what to expect when system upgrades are needed.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3225109/linux/managing-users-on-linux-systems.html
|
||||
|
||||
作者：[Sandra Henry-Stocker][a]
|
||||
译者：[runningwater](https://github.com/runningwater)
|
||||
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/
|
||||
@ -1,4 +1,3 @@
|
||||
translating by ljgibbslf
|
||||
How to use a here documents to write data to a file in bash script
|
||||
======
|
||||
|
||||
|
||||
@ -1,4 +1,3 @@
|
||||
Yoliver istranslating.
|
||||
Excellent Business Software Alternatives For Linux
|
||||
-------
|
||||
|
||||
|
||||
@ -1,3 +1,6 @@
|
||||
Translating by MjSeven
|
||||
|
||||
|
||||
# [Improve your Bash scripts with Argbash][1]
|
||||
|
||||
|
||||
|
||||
@ -1,3 +1,5 @@
|
||||
translating by Flowsnow
|
||||
|
||||
Peeking into your Linux packages
|
||||
======
|
||||
Do you ever wonder how many _thousands_ of packages are installed on your Linux system? And, yes, I said "thousands." Even a fairly modest Linux system is likely to have well over a thousand packages installed. And there are many ways to get details on what they are.
|
||||
|
||||
@ -1,3 +1,6 @@
|
||||
**translating by [ivo-wang](https://github.com/ivo-wang)**
|
||||
|
||||
|
||||
10 keys to quick game development
|
||||
======
|
||||
|
||||
|
||||
@ -1,140 +0,0 @@
|
||||
The Best Linux Distributions for 2018
|
||||
============================================================
|
||||
|
||||
|
||||
Jack Wallen shares his picks for the best Linux distributions for 2018.[Creative Commons Zero][6]Pixabay
|
||||
|
||||
It’s a new year and the landscape of possibility is limitless for Linux. Whereas 2017 brought about some big changes to a number of Linux distributions, I believe 2018 will bring serious stability and market share growth—for both the server and the desktop.
|
||||
|
||||
For those who might be looking to migrate to the open source platform (or those looking to switch it up), what are the best choices for the coming year? If you hop over to [Distrowatch][14], you’ll find a dizzying array of possibilities, some of which are on the rise, and some that are seeing quite the opposite effect.
|
||||
|
||||
So, which Linux distributions will 2018 favor? I have my thoughts. In fact, I’m going to share them with you now.
|
||||
|
||||
Similar to what I did for[ last year’s list][15], I’m going to make this task easier and break down the list, as follows: sysadmin, lightweight distribution, desktop, distro with more to prove, IoT, and server. These categories should cover the needs of any type of Linux user.
|
||||
|
||||
With that said, let’s get to the list of best Linux distributions for 2018.
|
||||
|
||||
### Best distribution for sysadmins
|
||||
|
||||
[Debian][16] isn’t often seen on “best of” lists. It should be. Why? If you consider that Debian is the foundation for Ubuntu (which is, in turn, the foundation for so many distributions), it’s pretty easy to understand why this distribution should find its way on many a list. But why for administrators? I’ve considered this for two very important reasons:
|
||||
|
||||
* Ease of use
|
||||
|
||||
* Extreme stability
|
||||
|
||||
Because Debian uses the dpkg and apt package managers, it makes for an incredibly easy to use environment. And because Debian offers one of the the most stable Linux platforms, it makes for an ideal environment for so many things: Desktops, servers, testing, development. Although Debian may not include the plethora of applications found in last years winner (for this category), [Parrot Linux][17], it is very easy to add any/all the necessary applications you need to get the job done. And because Debian can be installed with your choice of desktop (Cinnamon, GNOME, KDE, LXDE, Mate, or Xfce), you can be sure the interface will meet your needs.
|
||||
|
||||
|
||||
|
||||
Figure 1: The GNOME desktop running on top of Debian 9.3.[Used with permission][1]
|
||||
|
||||
At the moment, Debian is listed at #2 on Distrowatch. Download it, install it, and then make it serve a specific purpose. It may not be flashy, but Debian is a sysadmin dream come true.
|
||||
|
||||
### Best lightweight distribution
|
||||
|
||||
Lightweight distribution serve a very specific purpose—giving new life to older, lesser-powered machines. But that doesn’t mean these particular distributions should only be considered for your older hardware. If speed is your ultimate need, you might want to see just how fast this category of distribution will run on your modern machine.
|
||||
|
||||
Topping the list of lightweight distributions for 2018 is [Lubuntu][18]. Although there are plenty of options in this category, few come even close to the next-to-zero learning curve found on this distribution. And although Lubuntu’s footprint isn’t quite as small as Puppy Linux, thanks to it being a member of the Ubuntu family, the ease of use gained with this distribution makes up for it. But fear not, Lubuntu won’t bog down your older hardware.The requirements are:
|
||||
|
||||
* CPU: Pentium 4 or Pentium M or AMD K8
|
||||
|
||||
* For local applications, Lubuntu can function with 512MB of RAM. For online usage (Youtube, Google+, Google Drive, and Facebook), 1GB of RAM is recommended.
|
||||
|
||||
Lubuntu makes use of the LXDE desktop (Figure 2), which means users new to Linux won’t have the slightest problem working with this distribution. The short list of included apps (such as Abiword, Gnumeric, and Firefox) are all lightning fast and user-friendly.
|
||||
|
||||
### [lubuntu.jpg][8]
|
||||
|
||||
|
||||
Figure 2: The Lubuntu LXDE desktop in action.[Used with permission][2]
|
||||
|
||||
Lubntu can make short and easy work of breathing life into hardware that is up to ten years old.
|
||||
|
||||
### Best desktop distribution
|
||||
|
||||
For the second year in a row, [Elementary OS][19] tops my list of best Desktop distribution. For many, the leader on the Desktop is [Linux Mint][20] (which is a very fine flavor). However, for my money, it’s hard to beat the ease of use and stability of Elementary OS. Case in point, I was certain the release of [Ubuntu][21] 17.10 would have me migrating back to Canonical’s distribution. Very soon after migrating to the new GNOME-Friendly Ubuntu, I found myself missing the look, feel, and reliability of Elementary OS (Figure 3). After two weeks with Ubuntu, I was back to Elementary OS.
|
||||
|
||||
### [elementaros.jpg][9]
|
||||
|
||||
|
||||
Figure 3: The Pantheon desktop is a work of art as a desktop.[Used with permission][3]
|
||||
|
||||
Anyone that has given Elementary OS a go immediately feels right at home. The Pantheon desktop is a perfect combination of slickness and user-friendliness. And with each update, it only gets better.
|
||||
|
||||
Although Elementary OS stands at #6 on the Distrowatch page hit ranking, I predict it will find itself climbing to at least the third spot by the end of 2018\. The Elementary developers are very much in tune with what users want. They listen and they evolve. However, the current state of this distribution is so good, it seems all they could do to better it is a bit of polish here and there. Anyone looking for a desktop that offers a unified look and feel throughout the UI, Elementary OS is hard to beat. If you need a desktop that offers an outstanding ratio of reliability and ease of use, Elementary OS is your distribution.
|
||||
|
||||
### Best distro for those with something to prove
|
||||
|
||||
For the longest time [Gentoo][22] sat on top of the “show us your skills” distribution list. However, I think it’s time Gentoo took a backseat to the true leader of “something to prove”: [Linux From Scratch][23]. You may not think this fair, as LFS isn’t actually a distribution, but a project that helps users create their own Linux distribution. But, seriously, if you want to go a very long way to proving your Linux knowledge, what better way than to create your own distribution? From the LFS project, you can build a custom Linux system, from the ground up... entirely from source code. So, if you really have something to prove, download the [Linux From Scratch Book][24] and start building.
|
||||
|
||||
### Best distribution for IoT
|
||||
|
||||
For the second year in a row [Ubuntu Core][25] wins, hands down. Ubuntu Core is a tiny, transactional version of Ubuntu, built specifically for embedded and IoT devices. What makes Ubuntu Core so perfect for IoT is that it places the focus on snap packages—universal packages that can be installed onto a platform, without interfering with the base system. These snap packages contain everything they need to run (including dependencies), so there is no worry the installation will break the operating system (or any other installed software). Also, snaps are very easy to upgrade and run in an isolated sandbox, making them a great solution for IoT.
|
||||
|
||||
Another area of security built into Ubuntu Core is the login mechanism. Ubuntu Core works with Ubuntu One ssh keys, such that the only way to log into the system is via uploaded ssh keys to a [Ubuntu One account][26] (Figure 4). This makes for a heightened security for your IoT devices.
|
||||
|
||||
### [ubuntucore.jpg][10]
|
||||
|
||||
|
||||
Figure 4:The Ubuntu Core screen indicating a remote access enabled via Ubuntu One user.[Used with permission][4]
|
||||
|
||||
### Best server distribution
|
||||
|
||||
This where things get a bit confusing. The primary reason is support. If you need commercial support your best choice might be, at first blush, [Red Hat Enterprise Linux][27]. Red Hat has proved itself, year after year, to not only be one of the strongest enterprise server platforms on the planet, but the single most profitable open source businesses (with over $2 billion in annual revenue).
|
||||
|
||||
However, Red Hat isn’t far and away the only server distribution. In fact, Red Hat doesn’t even dominate every aspect of Enterprise server computing. If you look at cloud statistics on Amazon’s Elastic Compute Cloud alone, Ubuntu blows away Red Hat Enterprise Linux. According to [The Cloud Market][28], EC2 statistics show RHEL at under 100k deployments, whereas Ubuntu is over 200k deployments. That’s significant.
|
||||
|
||||
The end result is that Ubuntu has pretty much taken over as the leader in the cloud. And if you combine that with Ubuntu’s ease of working with and managing containers, it starts to become clear that Ubuntu Server is the clear winner for the Server category. And, if you need commercial support, Canonical has you covered, with [Ubuntu Advantage][29].
|
||||
|
||||
The one caveat to Ubuntu Server is that it defaults to a text-only interface (Figure 5). You can install a GUI, if needed, but working with the Ubuntu Server command line is pretty straightforward (and something every Linux administrator should know).
|
||||
|
||||
### [ubuntuserver.jpg][11]
|
||||
|
||||
|
||||
Figure 5: The Ubuntu server login, informing of updates.[Used with permission][5]
|
||||
|
||||
### The choice is yours
|
||||
|
||||
As I said before, these choices are all very subjective … but if you’re looking for a great place to start, give these distributions a try. Each one can serve a very specific purpose and do it better than most. Although you may not agree with my particular picks, chances are you’ll agree that Linux offers amazing possibilities on every front. And, stay tuned for more “best distro” picks next week.
|
||||
|
||||
_Learn more about Linux through the free ["Introduction to Linux" ][13]course from The Linux Foundation and edX._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/blog/learn/intro-to-linux/2018/1/best-linux-distributions-2018
|
||||
|
||||
作者：[JACK WALLEN ][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.linux.com/users/jlwallen
|
||||
[1]:https://www.linux.com/licenses/category/used-permission
|
||||
[2]:https://www.linux.com/licenses/category/used-permission
|
||||
[3]:https://www.linux.com/licenses/category/used-permission
|
||||
[4]:https://www.linux.com/licenses/category/used-permission
|
||||
[5]:https://www.linux.com/licenses/category/used-permission
|
||||
[6]:https://www.linux.com/licenses/category/creative-commons-zero
|
||||
[7]:https://www.linux.com/files/images/debianjpg
|
||||
[8]:https://www.linux.com/files/images/lubuntujpg-2
|
||||
[9]:https://www.linux.com/files/images/elementarosjpg
|
||||
[10]:https://www.linux.com/files/images/ubuntucorejpg
|
||||
[11]:https://www.linux.com/files/images/ubuntuserverjpg-1
|
||||
[12]:https://www.linux.com/files/images/linux-distros-2018jpg
|
||||
[13]:https://training.linuxfoundation.org/linux-courses/system-administration-training/introduction-to-linux
|
||||
[14]:https://distrowatch.com/
|
||||
[15]:https://www.linux.com/news/learn/sysadmin/best-linux-distributions-2017
|
||||
[16]:https://www.debian.org/
|
||||
[17]:https://www.parrotsec.org/
|
||||
[18]:http://lubuntu.me/
|
||||
[19]:https://elementary.io/
|
||||
[20]:https://linuxmint.com/
|
||||
[21]:https://www.ubuntu.com/
|
||||
[22]:https://www.gentoo.org/
|
||||
[23]:http://www.linuxfromscratch.org/
|
||||
[24]:http://www.linuxfromscratch.org/lfs/download.html
|
||||
[25]:https://www.ubuntu.com/core
|
||||
[26]:https://login.ubuntu.com/
|
||||
[27]:https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux
|
||||
[28]:http://thecloudmarket.com/stats#/by_platform_definition
|
||||
[29]:https://buy.ubuntu.com/?_ga=2.177313893.113132429.1514825043-1939188204.1510782993
|
||||
@ -1,4 +1,3 @@
|
||||
imquanquan Translating
|
||||
Trying Other Go Versions
|
||||
============================================================
|
||||
|
||||
@ -110,4 +109,4 @@ via: https://pocketgophers.com/trying-other-versions/
|
||||
[8]:https://pocketgophers.com/trying-other-versions/#trying-a-specific-release
|
||||
[9]:https://pocketgophers.com/guide-to-json/
|
||||
[10]:https://pocketgophers.com/trying-other-versions/#trying-any-release
|
||||
[11]:https://pocketgophers.com/trying-other-versions/#trying-a-source-build-e-g-tip
|
||||
[11]:https://pocketgophers.com/trying-other-versions/#trying-a-source-build-e-g-tip
|
||||
@ -1,292 +0,0 @@
|
||||
Rock Solid React.js Foundations: A Beginner’s Guide
|
||||
============================================================
|
||||
** 此处有Canvas,请手动处理 **
|
||||
|
||||
|
||||
React.js crash course
|
||||
|
||||
I’ve been working with React and React-Native for the last couple of months. I have already released two apps in production, [Kiven Aa][1] (React) and [Pollen Chat][2] (React Native). When I started learning React, I was searching for something (a blog, a video, a course, whatever) that didn’t only teach me how to write apps in React. I also wanted it to prepare me for interviews.
|
||||
|
||||
Most of the material I found, concentrated on one or the other. So, this post is aimed towards the audience who is looking for a perfect mix of theory and hands-on. I will give you a little bit of theory so that you understand what is happening under the hood and then I will show you how to write some React.js code.
|
||||
|
||||
If you prefer video, I have this entire course up on YouTube as well. Please check that out.
|
||||
|
||||
|
||||
Let’s dive in…
|
||||
|
||||
> React.js is a JavaScript library for building user interfaces
|
||||
|
||||
You can build all sorts of single page applications. For example, chat messengers and e-commerce portals where you want to show changes on the user interface in real-time.
|
||||
|
||||
### Everything’s a component
|
||||
|
||||
A React app is comprised of components, _a lot of them_ , nested into one another. _But what are components, you may ask?_
|
||||
|
||||
A component is a reusable piece of code, which defines how certain features should look and behave on the UI. For example, a button is a component.
|
||||
|
||||
Let’s look at the following calculator, which you see on Google when you try to calculate something like 2+2 = 4 –1 = 3 (quick maths!)
|
||||
|
||||
|
||||
|
||||
Red markers denote components
|
||||
|
||||
As you can see in the image above, the calculator has many areas — like the _result display window_ and the _numpad_ . All of these can be separate components or one giant component. It depends on how comfortable one is in breaking down and abstracting away things in React
|
||||
|
||||
You write code for all such components separately. Then combine those under one container, which in turn is a React component itself. This way you can create reusable components and your final app will be a collection of separate components working together.
|
||||
|
||||
The following is one such way you can write the calculator, shown above, in React.
|
||||
|
||||
```
|
||||
<Calculator>
|
||||
<DisplayWindow />
|
||||
<NumPad>
|
||||
<Key number={1}/>
|
||||
<Key number={2}/>
|
||||
.
|
||||
.
|
||||
.
|
||||
<Key number={9}/>
|
||||
</NumPad>
|
||||
</Calculator>
|
||||
|
||||
```
|
||||
|
||||
Yes! It looks like HTML code, but it isn’t. We will explore more about it in the later sections.
|
||||
|
||||
### Setting up our Playground
|
||||
|
||||
This tutorial focuses on React’s fundamentals. It is not primarily geared towards React for Web or [React Native][3] (for building mobile apps). So, we will use an online editor so as to avoid web or native specific configurations before even learning what React can do.
|
||||
|
||||
I’ve already set up an environment for you on [codepen.io][4]. Just follow the link and read all the comments in HTML and JavaScript (JS) tabs.
|
||||
|
||||
### Controlling Components
|
||||
|
||||
We’ve learned that a React app is a collection of various components, structured as a nested tree. Thus, we require some sort of mechanism to pass data from one component to other.
|
||||
|
||||
#### Enter “props”
|
||||
|
||||
We can pass arbitrary data to our component using a `props` object. Every component in React gets this `props` object.
|
||||
|
||||
Before learning how to use this `props` object, let’s learn about functional components.
|
||||
|
||||
#### a) Functional component
|
||||
|
||||
A functional component in React consumes arbitrary data that you pass to it using `props` object. It returns an object which describes what UI React should render. Functional components are also known as Stateless components.
|
||||
|
||||
Let’s write our first functional component.
|
||||
|
||||
```
|
||||
function Hello(props) {
|
||||
return <div>{props.name}</div>
|
||||
}
|
||||
```
|
||||
|
||||
It’s that simple. We just passed `props` as an argument to a plain JavaScript function and returned, _umm, well, what was that? That _ `_<div>{props.name}</div>_` _thing!_ It’s JSX (JavaScript Extended). We will learn more about it in a later section.
|
||||
|
||||
This above function will render the following HTML in the browser.
|
||||
|
||||
```
|
||||
<!-- If the "props" object is: {name: 'rajat'} -->
|
||||
<div>
|
||||
rajat
|
||||
</div>
|
||||
```
|
||||
|
||||
|
||||
> Read the section below about JSX, where I have explained how did we get this HTML from our JSX code.
|
||||
|
||||
How can you use this functional component in your React app? Glad you asked! It’s as simple as the following.
|
||||
|
||||
```
|
||||
<Hello name='rajat' age={26}/>
|
||||
```
|
||||
|
||||
The attribute `name` in the above code becomes `props.name` inside our `Hello`component. The attribute `age` becomes `props.age` and so on.
|
||||
|
||||
> Remember! You can nest one React component inside other React components.
|
||||
|
||||
Let’s use this `Hello` component in our codepen playground. Replace the `div`inside `ReactDOM.render()` with our `Hello` component, as follows, and see the changes in the bottom window.
|
||||
|
||||
```
|
||||
function Hello(props) {
|
||||
return <div>{props.name}</div>
|
||||
}
|
||||
|
||||
ReactDOM.render(<Hello name="rajat"/>, document.getElementById('root'));
|
||||
```
|
||||
|
||||
|
||||
> But what if your component has some internal state. For instance, like the following counter component, which has an internal count variable, which changes on + and — key presses.
|
||||
|
||||
A React component with an internal state
|
||||
|
||||
#### b) Class-based component
|
||||
|
||||
The class-based component has an additional property `state` , which you can use to hold a component’s private data. We can rewrite our `Hello` component using class notation as follows. Since these components have a state, these are also known as Stateful components.
|
||||
|
||||
```
|
||||
class Counter extends React.Component {
|
||||
// this method should be present in your component
|
||||
render() {
|
||||
return (
|
||||
<div>
|
||||
{this.props.name}
|
||||
</div>
|
||||
);
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
We extend `React.Component` class of React library to make class-based components in React. Learn more about JavaScript classes [here][5].
|
||||
|
||||
The `render()` method must be present in your class as React looks for this method in order to know what UI it should render on screen.
|
||||
|
||||
To use this sort of internal state, we first have to initialize the `state` object in the constructor of the component class, in the following way.
|
||||
|
||||
```
|
||||
class Counter extends React.Component {
|
||||
constructor() {
|
||||
super();
|
||||
|
||||
// define the internal state of the component
|
||||
this.state = {name: 'rajat'}
|
||||
}
|
||||
|
||||
render() {
|
||||
return (
|
||||
<div>
|
||||
{this.state.name}
|
||||
</div>
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
// Usage:
|
||||
// In your react app: <Counter />
|
||||
```
|
||||
|
||||
Similarly, the `props` can be accessed inside our class-based component using `this.props` object.
|
||||
|
||||
To set the state, you use `React.Component`'s `setState()`. We will see an example of this, in the last part of this tutorial.
|
||||
|
||||
> Tip: Never call `setState()` inside `render()` function, as `setState()` causes component to re-render and this will result in endless loop.
|
||||
|
||||
|
||||
|
||||
A class-based component has an optional property “state”.
|
||||
|
||||
_Apart from _ `_state_` _, a class-based component has some life-cycle methods like _ `_componentWillMount()._` _ These you can use to do stuff, like initializing the _ `_state_` _and all but that is out of the scope of this post._
|
||||
|
||||
### JSX
|
||||
|
||||
JSX is a short form of _JavaScript Extended_ and it is a way to write `React`components. Using JSX, you get the full power of JavaScript inside XML like tags.
|
||||
|
||||
You put JavaScript expressions inside `{}`. The following are some valid JSX examples.
|
||||
|
||||
```
|
||||
<button disabled={true}>Press me!</button>
|
||||
|
||||
<button disabled={true}>Press me {3+1} times!</button>;
|
||||
|
||||
<div className='container'><Hello /></div>
|
||||
|
||||
```
|
||||
|
||||
The way it works is you write JSX to describe what your UI should look like. A [transpiler][6] like `Babel` converts that code into a bunch of `React.createElement()` calls. The React library then uses those `React.createElement()` calls to construct a tree-like structure of DOM elements. In case of React for Web or Native views in case of React Native. It keeps it in the memory.
|
||||
|
||||
React then calculates how it can effectively mimic this tree in the memory of the UI displayed to the user. This process is known as [reconciliation][7]. After that calculation is done, React makes the changes to the actual UI on the screen.
|
||||
|
||||
** 此处有Canvas,请手动处理 **
|
||||
|
||||
|
||||
How React converts your JSX into a tree which describes your app’s UI
|
||||
|
||||
You can use [Babel’s online REPL][8] to see what React actually outputs when you write some JSX.
|
||||
|
||||
|
||||
|
||||
Use Babel REPL to transform JSX into plain JavaScript
|
||||
|
||||
> Since JSX is just a syntactic sugar over plain `React.createElement()` calls, React can be used without JSX.
|
||||
|
||||
Now we have every concept in place, so we are well positioned to write a `counter` component that we saw earlier as a GIF.
|
||||
|
||||
The code is as follows and I hope that you already know how to render that in our playground.
|
||||
|
||||
```
|
||||
class Counter extends React.Component {
|
||||
constructor(props) {
|
||||
super(props);
|
||||
|
||||
this.state = {count: this.props.start || 0}
|
||||
|
||||
// the following bindings are necessary to make `this` work in the callback
|
||||
this.inc = this.inc.bind(this);
|
||||
this.dec = this.dec.bind(this);
|
||||
}
|
||||
|
||||
inc() {
|
||||
this.setState({
|
||||
count: this.state.count + 1
|
||||
});
|
||||
}
|
||||
|
||||
dec() {
|
||||
this.setState({
|
||||
count: this.state.count - 1
|
||||
});
|
||||
}
|
||||
|
||||
render() {
|
||||
return (
|
||||
<div>
|
||||
<button onClick={this.inc}>+</button>
|
||||
<button onClick={this.dec}>-</button>
|
||||
<div>{this.state.count}</div>
|
||||
</div>
|
||||
);
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
The following are some salient points about the above code.
|
||||
|
||||
1. JSX uses `camelCasing` hence `button`'s attribute is `onClick`, not `onclick`, as we use in HTML.
|
||||
|
||||
2. Binding is necessary for `this` to work on callbacks. See line #8 and 9 in the code above.
|
||||
|
||||
The final interactive code is located [here][9].
|
||||
|
||||
With that, we’ve reached the conclusion of our React crash course. I hope I have shed some light on how React works and how you can use React to build bigger apps, using smaller and reusable components.
|
||||
|
||||
* * *
|
||||
|
||||
If you have any queries or doubts, hit me up on Twitter [@rajat1saxena][10] or write to me at [rajat@raynstudios.com][11].
|
||||
|
||||
* * *
|
||||
|
||||
#### Please recommend this post, if you liked it and share it with your network. Follow me for more tech related posts and consider subscribing to my channel [Rayn Studios][12] on YouTube. Thanks a lot.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://medium.freecodecamp.org/rock-solid-react-js-foundations-a-beginners-guide-c45c93f5a923
|
||||
|
||||
作者：[Rajat Saxena ][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://medium.freecodecamp.org/@rajat1saxena
|
||||
[1]:https://kivenaa.com/
|
||||
[2]:https://play.google.com/store/apps/details?id=com.pollenchat.android
|
||||
[3]:https://facebook.github.io/react-native/
|
||||
[4]:https://codepen.io/raynesax/pen/MrNmBM
|
||||
[5]:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes
|
||||
[6]:https://en.wikipedia.org/wiki/Source-to-source_compiler
|
||||
[7]:https://reactjs.org/docs/reconciliation.html
|
||||
[8]:https://babeljs.io/repl
|
||||
[9]:https://codepen.io/raynesax/pen/QaROqK
|
||||
[10]:https://twitter.com/rajat1saxena
|
||||
[11]:mailto:rajat@raynstudios.com
|
||||
[12]:https://www.youtube.com/channel/UCUmQhjjF9bsIaVDJUHSIIKw
|
||||
@ -1,4 +1,3 @@
|
||||
Zafiry translating...
|
||||
Writing eBPF tracing tools in Rust
|
||||
============================================================
|
||||
|
||||
|
||||
@ -1,3 +1,5 @@
|
||||
translating by Flowsnow
|
||||
|
||||
Build a bikesharing app with Redis and Python
|
||||
======
|
||||
|
||||
|
||||
@ -1,5 +1,3 @@
|
||||
Translating by shipsw
|
||||
|
||||
Python ChatOps libraries: Opsdroid and Errbot
|
||||
======
|
||||
|
||||
@ -1,147 +0,0 @@
|
||||
A Desktop GUI Application For NPM
|
||||
======
|
||||
|
||||
|
||||
|
||||
NPM, short for **N** ode **P** ackage **M** anager, is a command line package manager for installing NodeJS packages, or modules. We already have have published a guide that described how to [**manage NodeJS packages using NPM**][1]. As you may noticed, managing NodeJS packages or modules using Npm is not a big deal. However, if you’re not compatible with CLI-way, there is a desktop GUI application named **NDM** which can be used for managing NodeJS applications/modules. NDM, stands for **N** PM **D** esktop **M** anager, is a free, open source graphical front-end for NPM that allows us to install, update, remove NodeJS packages via a simple graphical window.
|
||||
|
||||
In this brief tutorial, we are going to learn about Ndm in Linux.
|
||||
|
||||
### Install NDM
|
||||
|
||||
NDM is available in AUR, so you can install it using any AUR helpers on Arch Linux and its derivatives like Antergos and Manjaro Linux.
|
||||
|
||||
Using [**Pacaur**][2]:
|
||||
```
|
||||
$ pacaur -S ndm
|
||||
|
||||
```
|
||||
|
||||
Using [**Packer**][3]:
|
||||
```
|
||||
$ packer -S ndm
|
||||
|
||||
```
|
||||
|
||||
Using [**Trizen**][4]:
|
||||
```
|
||||
$ trizen -S ndm
|
||||
|
||||
```
|
||||
|
||||
Using [**Yay**][5]:
|
||||
```
|
||||
$ yay -S ndm
|
||||
|
||||
```
|
||||
|
||||
Using [**Yaourt**][6]:
|
||||
```
|
||||
$ yaourt -S ndm
|
||||
|
||||
```
|
||||
|
||||
On RHEL based systems like CentOS, run the following command to install NDM.
|
||||
```
|
||||
$ echo "[fury] name=ndm repository baseurl=https://repo.fury.io/720kb/ enabled=1 gpgcheck=0" | sudo tee /etc/yum.repos.d/ndm.repo && sudo yum update &&
|
||||
|
||||
```
|
||||
|
||||
On Debian, Ubuntu, Linux Mint:
|
||||
```
|
||||
$ echo "deb [trusted=yes] https://apt.fury.io/720kb/ /" | sudo tee /etc/apt/sources.list.d/ndm.list && sudo apt-get update && sudo apt-get install ndm
|
||||
|
||||
```
|
||||
|
||||
NDM can also be installed using **Linuxbrew**. First, install Linuxbrew as described in the following link.
|
||||
|
||||
After installing Linuxbrew, you can install NDM using the following commands:
|
||||
```
|
||||
$ brew update
|
||||
|
||||
$ brew install ndm
|
||||
|
||||
```
|
||||
|
||||
On other Linux distributions, go to the [**NDM releases page**][7], download the latest version, compile and install it yourself.
|
||||
|
||||
### NDM Usage
|
||||
|
||||
Launch NDM wither from the Menu or using application launcher. This is how NDM’s default interface looks like.
|
||||
|
||||
![][9]
|
||||
|
||||
From here, you can install NodeJS packages/modules either locally or globally.
|
||||
|
||||
**Install NodeJS packages locally**
|
||||
|
||||
To install a package locally, first choose project directory by clicking on the **“Add projects”** button from the Home screen and select the directory where you want to keep your project files. For example, I have chosen a directory named **“demo”** as my project directory.
|
||||
|
||||
Click on the project directory (i.e **demo** ) and then, click **Add packages** button.
|
||||
|
||||
![][10]
|
||||
|
||||
Type the package name you want to install and hit the **Install** button.
|
||||
|
||||
![][11]
|
||||
|
||||
Once installed, the packages will be listed under the project’s directory. Simply click on the directory to view the list of installed packages locally.
|
||||
|
||||
![][12]
|
||||
|
||||
Similarly, you can create separate project directories and install NodeJS modules in them. To view the list of installed modules on a project, click on the project directory, and you will the packages on the right side.
|
||||
|
||||
**Install NodeJS packages globally**
|
||||
|
||||
To install NodeJS packages globally, click on the **Globals** button on the left from the main interface. Then, click “Add packages” button, type the name of the package and hit “Install” button.
|
||||
|
||||
**Manage packages**
|
||||
|
||||
Click on any installed packages and you will see various options on the top, such as
|
||||
|
||||
1. Version (to view the installed version),
|
||||
2. Latest (to install latest available version),
|
||||
3. Update (to update the currently selected package),
|
||||
4. Uninstall (to remove the selected package) etc.
|
||||
|
||||
|
||||
|
||||
![][13]
|
||||
|
||||
NDM has two more options namely **“Update npm”** which is used to update the node package manager to latest available version, and **Doctor** that runs a set of checks to ensure that your npm installation has what it needs to manage your packages/modules.
|
||||
|
||||
### Conclusion
|
||||
|
||||
NDM makes the process of installing, updating, removing NodeJS packages easier! You don’t need to memorize the commands to perform those tasks. NDM lets us to do them all with a few mouse clicks via simple graphical window. For those who are lazy to type commands, NDM is perfect companion to manage NodeJS packages.
|
||||
|
||||
Cheers!
|
||||
|
||||
**Resource:**
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/ndm-a-desktop-gui-application-for-npm/
|
||||
|
||||
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]:https://www.ostechnix.com/manage-nodejs-packages-using-npm/
|
||||
[2]:https://www.ostechnix.com/install-pacaur-arch-linux/
|
||||
[3]:https://www.ostechnix.com/install-packer-arch-linux-2/
|
||||
[4]:https://www.ostechnix.com/trizen-lightweight-aur-package-manager-arch-based-systems/
|
||||
[5]:https://www.ostechnix.com/yay-found-yet-another-reliable-aur-helper/
|
||||
[6]:https://www.ostechnix.com/install-yaourt-arch-linux/
|
||||
[7]:https://github.com/720kb/ndm/releases
|
||||
[8]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[9]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-1.png
|
||||
[10]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-5-1.png
|
||||
[11]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-6.png
|
||||
[12]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-7.png
|
||||
[13]:http://www.ostechnix.com/wp-content/uploads/2018/04/ndm-8.png
|
||||
@ -1,5 +1,3 @@
|
||||
translated by cyleft
|
||||
|
||||
How to Enable Click to Minimize On Ubuntu
|
||||
============================================================
|
||||
|
||||
|
||||
@ -1,3 +1,4 @@
|
||||
Translating by qhwdw
|
||||
Complete Sed Command Guide [Explained with Practical Examples]
|
||||
======
|
||||
In a previous article, I showed the [basic usage of Sed][1], the stream editor, on a practical use case. Today, be prepared to gain more insight about Sed as we will take an in-depth tour of the sed execution model. This will be also an opportunity to make an exhaustive review of all Sed commands and to dive into their details and subtleties. So, if you are ready, launch a terminal, [download the test files][2] and sit comfortably before your keyboard: we will start our exploration right now!
|
||||
|
||||
@ -1,3 +1,5 @@
|
||||
translating by Flowsnow
|
||||
|
||||
How To Rename Multiple Files At Once In Linux
|
||||
======
|
||||
|
||||
|
||||
@ -1,320 +0,0 @@
|
||||
Install Oracle VirtualBox On Ubuntu 18.04 LTS Headless Server
|
||||
======
|
||||
|
||||
|
||||
|
||||
This step by step tutorial walk you through how to install **Oracle VirtualBox** on Ubuntu 18.04 LTS headless server. And, this guide also describes how to manage the VirtualBox headless instances using **phpVirtualBox** , a web-based front-end tool for VirtualBox. The steps described below might also work on Debian, and other Ubuntu derivatives such as Linux Mint. Let us get started.
|
||||
|
||||
### Prerequisites
|
||||
|
||||
Before installing Oracle VirtualBox, we need to do the following prerequisites in our Ubuntu 18.04 LTS server.
|
||||
|
||||
First of all, update the Ubuntu server by running the following commands one by one.
|
||||
```
|
||||
$ sudo apt update
|
||||
|
||||
$ sudo apt upgrade
|
||||
|
||||
$ sudo apt dist-upgrade
|
||||
|
||||
```
|
||||
|
||||
Next, install the following necessary packages:
|
||||
```
|
||||
$ sudo apt install build-essential dkms unzip wget
|
||||
|
||||
```
|
||||
|
||||
After installing all updates and necessary prerequisites, restart the Ubuntu server.
|
||||
```
|
||||
$ sudo reboot
|
||||
|
||||
```
|
||||
|
||||
### Install Oracle VirtualBox on Ubuntu 18.04 LTS server
|
||||
|
||||
Add Oracle VirtualBox official repository. To do so, edit **/etc/apt/sources.list** file:
|
||||
```
|
||||
$ sudo nano /etc/apt/sources.list
|
||||
|
||||
```
|
||||
|
||||
Add the following lines.
|
||||
|
||||
Here, I will be using Ubuntu 18.04 LTS, so I have added the following repository.
|
||||
```
|
||||
deb http://download.virtualbox.org/virtualbox/debian bionic contrib
|
||||
|
||||
```
|
||||
|
||||
![][2]
|
||||
|
||||
Replace the word **‘bionic’** with your Ubuntu distribution’s code name, such as ‘xenial’, ‘vivid’, ‘utopic’, ‘trusty’, ‘raring’, ‘quantal’, ‘precise’, ‘lucid’, ‘jessie’, ‘wheezy’, or ‘squeeze**‘.**
|
||||
|
||||
Then, run the following command to add the Oracle public key:
|
||||
```
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
|
||||
|
||||
```
|
||||
|
||||
For VirtualBox older versions, add the following key:
|
||||
```
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
|
||||
|
||||
```
|
||||
|
||||
Next, update the software sources using command:
|
||||
```
|
||||
$ sudo apt update
|
||||
|
||||
```
|
||||
|
||||
Finally, install latest Oracle VirtualBox latest version using command:
|
||||
```
|
||||
$ sudo apt install virtualbox-5.2
|
||||
|
||||
```
|
||||
|
||||
### Adding users to VirtualBox group
|
||||
|
||||
We need to create and add our system user to the **vboxusers** group. You can either create a separate user and assign it to vboxusers group or use the existing user. I don’t want to create a new user, so I added my existing user to this group. Please note that if you use a separate user for virtualbox, you must log out and log in to that particular user and do the rest of the steps.
|
||||
|
||||
I am going to use my username named **sk** , so, I ran the following command to add it to the vboxusers group.
|
||||
```
|
||||
$ sudo usermod -aG vboxusers sk
|
||||
|
||||
```
|
||||
|
||||
Now, run the following command to check if virtualbox kernel modules are loaded or not.
|
||||
```
|
||||
$ sudo systemctl status vboxdrv
|
||||
|
||||
```
|
||||
|
||||
![][3]
|
||||
|
||||
As you can see in the above screenshot, the vboxdrv module is loaded and running!
|
||||
|
||||
For older Ubuntu versions, run:
|
||||
```
|
||||
$ sudo /etc/init.d/vboxdrv status
|
||||
|
||||
```
|
||||
|
||||
If the virtualbox module doesn’t start, run the following command to start it.
|
||||
```
|
||||
$ sudo /etc/init.d/vboxdrv setup
|
||||
|
||||
```
|
||||
|
||||
Great! We have successfully installed VirtualBox and started virtualbox module. Now, let us go ahead and install Oracle VirtualBox extension pack.
|
||||
|
||||
### Install VirtualBox Extension pack
|
||||
|
||||
The VirtualBox Extension pack provides the following functionalities to the VirtualBox guests.
|
||||
|
||||
* The virtual USB 2.0 (EHCI) device
|
||||
* VirtualBox Remote Desktop Protocol (VRDP) support
|
||||
* Host webcam passthrough
|
||||
* Intel PXE boot ROM
|
||||
* Experimental support for PCI passthrough on Linux hosts
|
||||
|
||||
|
||||
|
||||
Download the latest Extension pack for VirtualBox 5.2.x from [**here**][4].
|
||||
```
|
||||
$ wget https://download.virtualbox.org/virtualbox/5.2.14/Oracle_VM_VirtualBox_Extension_Pack-5.2.14.vbox-extpack
|
||||
|
||||
```
|
||||
|
||||
Install Extension pack using command:
|
||||
```
|
||||
$ sudo VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-5.2.14.vbox-extpack
|
||||
|
||||
```
|
||||
|
||||
Congratulations! We have successfully installed Oracle VirtualBox with extension pack in Ubuntu 16.04 LTS server. It is time to deploy virtual machines. Refer the [**virtualbox official guide**][5] to start creating and managing virtual machines in command line.
|
||||
|
||||
Not everyone is command line expert. Some of you might want to create and use virtual machines graphically. No worries! Here is where **phpVirtualBox** comes in handy!!
|
||||
|
||||
### About phpVirtualBox
|
||||
|
||||
**phpVirtualBox** is a free, web-based front-end to Oracle VirtualBox. It is written using PHP language. Using phpVirtualBox, we can easily create, delete, manage and administer virtual machines via a web browser from any remote system on the network.
|
||||
|
||||
### Install phpVirtualBox in Ubuntu 18.04 LTS
|
||||
|
||||
Since it is a web-based tool, we need to install Apache web server, PHP and some php modules.
|
||||
|
||||
To do so, run:
|
||||
```
|
||||
$ sudo apt install apache2 php php-mysql libapache2-mod-php php-soap php-xml
|
||||
|
||||
```
|
||||
|
||||
Then, Download the phpVirtualBox 5.2.x version from the [**releases page**][6]. Please note that we have installed VirtualBox 5.2, so we must install phpVirtualBox version 5.2 as well.
|
||||
|
||||
To download it, run:
|
||||
```
|
||||
$ wget https://github.com/phpvirtualbox/phpvirtualbox/archive/5.2-0.zip
|
||||
|
||||
```
|
||||
|
||||
Extract the downloaded archive with command:
|
||||
```
|
||||
$ unzip 5.2-0.zip
|
||||
|
||||
```
|
||||
|
||||
This command will extract the contents of 5.2.0.zip file into a folder named “phpvirtualbox-5.2-0”. Now, copy or move the contents of this folder to your apache web server root folder.
|
||||
```
|
||||
$ sudo mv phpvirtualbox-5.2-0/ /var/www/html/phpvirtualbox
|
||||
|
||||
```
|
||||
|
||||
Assign the proper permissions to the phpvirtualbox folder.
|
||||
```
|
||||
$ sudo chmod 777 /var/www/html/phpvirtualbox/
|
||||
|
||||
```
|
||||
|
||||
Next, let us configure phpVirtualBox.
|
||||
|
||||
Copy the sample config file as shown below.
|
||||
```
|
||||
$ sudo cp /var/www/html/phpvirtualbox/config.php-example /var/www/html/phpvirtualbox/config.php
|
||||
|
||||
```
|
||||
|
||||
Edit phpVirtualBox **config.php** file:
|
||||
```
|
||||
$ sudo nano /var/www/html/phpvirtualbox/config.php
|
||||
|
||||
```
|
||||
|
||||
Find the following lines and replace the username and password with your system user (The same username that we used in “Adding users to VirtualBox group” section).
|
||||
|
||||
In my case, my Ubuntu system username is **sk** , and its password is **ubuntu**.
|
||||
```
|
||||
var $username = 'sk';
|
||||
var $password = 'ubuntu';
|
||||
|
||||
```
|
||||
|
||||
![][7]
|
||||
|
||||
Save and close the file.
|
||||
|
||||
Next, create a new file called **/etc/default/virtualbox** :
|
||||
```
|
||||
$ sudo nano /etc/default/virtualbox
|
||||
|
||||
```
|
||||
|
||||
Add the following line. Replace ‘sk’ with your own username.
|
||||
```
|
||||
VBOXWEB_USER=sk
|
||||
|
||||
```
|
||||
|
||||
Finally, Reboot your system or simply restart the following services to complete the configuration.
|
||||
```
|
||||
$ sudo systemctl restart vboxweb-service
|
||||
|
||||
$ sudo systemctl restart vboxdrv
|
||||
|
||||
$ sudo systemctl restart apache2
|
||||
|
||||
```
|
||||
|
||||
### Adjust firewall to allow Apache web server
|
||||
|
||||
By default, the apache web browser can’t be accessed from remote systems if you have enabled the UFW firewall in Ubuntu 18.04 LTS. You must allow the http and https traffic via UFW by following the below steps.
|
||||
|
||||
First, let us view which applications have installed a profile using command:
|
||||
```
|
||||
$ sudo ufw app list
|
||||
Available applications:
|
||||
Apache
|
||||
Apache Full
|
||||
Apache Secure
|
||||
OpenSSH
|
||||
|
||||
```
|
||||
|
||||
As you can see, Apache and OpenSSH applications have installed UFW profiles.
|
||||
|
||||
If you look into the **“Apache Full”** profile, you will see that it enables traffic to the ports **80** and **443** :
|
||||
```
|
||||
$ sudo ufw app info "Apache Full"
|
||||
Profile: Apache Full
|
||||
Title: Web Server (HTTP,HTTPS)
|
||||
Description: Apache v2 is the next generation of the omnipresent Apache web
|
||||
server.
|
||||
|
||||
Ports:
|
||||
80,443/tcp
|
||||
|
||||
```
|
||||
|
||||
Now, run the following command to allow incoming HTTP and HTTPS traffic for this profile:
|
||||
```
|
||||
$ sudo ufw allow in "Apache Full"
|
||||
Rules updated
|
||||
Rules updated (v6)
|
||||
|
||||
```
|
||||
|
||||
If you want to allow https traffic, but only http (80) traffic, run:
|
||||
```
|
||||
$ sudo ufw app info "Apache"
|
||||
|
||||
```
|
||||
|
||||
### Access phpVirtualBox Web console
|
||||
|
||||
Now, go to any remote system that has graphical web browser.
|
||||
|
||||
In the address bar, type: **<http://IP-address-of-virtualbox-headless-server/phpvirtualbox>**.
|
||||
|
||||
In my case, I navigated to this link – **<http://192.168.225.22/phpvirtualbox>**
|
||||
|
||||
You should see the following screen. Enter the phpVirtualBox administrative user credentials.
|
||||
|
||||
The default username and phpVirtualBox is **admin** / **admin**.
|
||||
|
||||
![][8]
|
||||
|
||||
Congratulations! You will now be greeted with phpVirtualBox dashboard.
|
||||
|
||||
![][9]
|
||||
|
||||
Now, start creating your VMs and manage them from phpvirtualbox dashboard. As I mentioned earlier, You can access the phpVirtualBox from any system in the same network. All you need is a web browser and the username and password of phpVirtualBox.
|
||||
|
||||
If you haven’t enabled virtualization support in the BISO of host system (not the guest), phpVirtualBox allows you to create 32-bit guests only. To install 64-bit guest systems, you must enable virtualization in your host system’s BIOS. Look for an option that is something like “virtualization” or “hypervisor” in your bios and make sure it is enabled.
|
||||
|
||||
That’s it. Hope this helps. If you find this guide useful, please share it on your social networks and support us.
|
||||
|
||||
More good stuffs to come. Stay tuned!
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/install-oracle-virtualbox-ubuntu-16-04-headless-server/
|
||||
|
||||
作者：[SK][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.ostechnix.com/author/sk/
|
||||
[1]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[2]:http://www.ostechnix.com/wp-content/uploads/2016/07/Add-VirtualBox-repository.png
|
||||
[3]:http://www.ostechnix.com/wp-content/uploads/2016/07/vboxdrv-service.png
|
||||
[4]:https://www.virtualbox.org/wiki/Downloads
|
||||
[5]:http://www.virtualbox.org/manual/ch08.html
|
||||
[6]:https://github.com/phpvirtualbox/phpvirtualbox/releases
|
||||
[7]:http://www.ostechnix.com/wp-content/uploads/2016/07/phpvirtualbox-config.png
|
||||
[8]:http://www.ostechnix.com/wp-content/uploads/2016/07/phpvirtualbox-1.png
|
||||
[9]:http://www.ostechnix.com/wp-content/uploads/2016/07/phpvirtualbox-2.png
|
||||
@ -1,332 +0,0 @@
|
||||
Setup Headless Virtualization Server Using KVM In Ubuntu 18.04 LTS
|
||||
======
|
||||
|
||||
|
||||
|
||||
We already have covered [**setting up Oracle VirtualBox on Ubuntu 18.04**][1] headless server. In this tutorial, we will be discussing how to setup headless virtualization server using **KVM** and how to manage the guest machines from a remote client. As you may know already, KVM ( **K** ernel-based **v** irtual **m** achine) is an open source, full virtualization for Linux. Using KVM, we can easily turn any Linux server in to a complete virtualization environment in minutes and deploy different kind of VMs such as GNU/Linux, *BSD, Windows etc.
|
||||
|
||||
### Setup Headless Virtualization Server Using KVM
|
||||
|
||||
I tested this guide on Ubuntu 18.04 LTS server, however this tutorial will work on other Linux distributions such as Debian, CentOS, RHEL and Scientific Linux. This method will be perfectly suitable for those who wants to setup a simple virtualization environment in a Linux server that doesn’t have any graphical environment.
|
||||
|
||||
For the purpose of this guide, I will be using two systems.
|
||||
|
||||
**KVM virtualization server:**
|
||||
|
||||
* **Host OS** – Ubuntu 18.04 LTS minimal server (No GUI)
|
||||
* **IP Address of Host OS** : 192.168.225.22/24
|
||||
* **Guest OS** (Which we are going to host on Ubuntu 18.04) : Ubuntu 16.04 LTS server
|
||||
|
||||
|
||||
|
||||
**Remote desktop client :**
|
||||
|
||||
* **OS** – Arch Linux
|
||||
|
||||
|
||||
|
||||
### Install KVM
|
||||
|
||||
First, let us check if our system supports hardware virtualization. To do so, run the following command from the Terminal:
|
||||
```
|
||||
$ egrep -c '(vmx|svm)' /proc/cpuinfo
|
||||
|
||||
```
|
||||
|
||||
If the result is **zero (0)** , the system doesn’t support hardware virtualization or the virtualization is disabled in the Bios. Go to your bios and check for the virtualization option and enable it.
|
||||
|
||||
if the result is **1** or **more** , the system will support hardware virtualization. However, you still need to enable the virtualization option in Bios before running the above commands.
|
||||
|
||||
Alternatively, you can use the following command to verify it. You need to install kvm first as described below, in order to use this command.
|
||||
```
|
||||
$ kvm-ok
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
INFO: /dev/kvm exists
|
||||
KVM acceleration can be used
|
||||
|
||||
```
|
||||
|
||||
If you got the following error instead, you still can run guest machines in KVM, but the performance will be very poor.
|
||||
```
|
||||
INFO: Your CPU does not support KVM extensions
|
||||
INFO: For more detailed results, you should run this as root
|
||||
HINT: sudo /usr/sbin/kvm-ok
|
||||
|
||||
```
|
||||
|
||||
Also, there are other ways to find out if your CPU supports Virtualization or not. Refer the following guide for more details.
|
||||
|
||||
Next, Install KVM and other required packages to setup a virtualization environment in Linux.
|
||||
|
||||
On Ubuntu and other DEB based systems, run:
|
||||
```
|
||||
$ sudo apt-get install qemu-kvm libvirt-bin virtinst bridge-utils cpu-checker
|
||||
|
||||
```
|
||||
|
||||
Once KVM installed, start libvertd service (If it is not started already):
|
||||
```
|
||||
$ sudo systemctl enable libvirtd
|
||||
|
||||
$ sudo systemctl start libvirtd
|
||||
|
||||
```
|
||||
|
||||
### Create Virtual machines
|
||||
|
||||
All virtual machine files and other related files will be stored under **/var/lib/libvirt/**. The default path of ISO images is **/var/lib/libvirt/boot/**.
|
||||
|
||||
First, let us see if there is any virtual machines. To view the list of available virtual machines, run:
|
||||
```
|
||||
$ sudo virsh list --all
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
Id Name State
|
||||
----------------------------------------------------
|
||||
|
||||
```
|
||||
|
||||
![][3]
|
||||
|
||||
As you see above, there is no virtual machine available right now.
|
||||
|
||||
Now, let us crate one.
|
||||
|
||||
For example, let us create Ubuntu 16.04 Virtual machine with 512 MB RAM, 1 CPU core, 8 GB Hdd.
|
||||
```
|
||||
$ sudo virt-install --name Ubuntu-16.04 --ram=512 --vcpus=1 --cpu host --hvm --disk path=/var/lib/libvirt/images/ubuntu-16.04-vm1,size=8 --cdrom /var/lib/libvirt/boot/ubuntu-16.04-server-amd64.iso --graphics vnc
|
||||
|
||||
```
|
||||
|
||||
Please make sure you have Ubuntu 16.04 ISO image in path **/var/lib/libvirt/boot/** or any other path you have given in the above command.
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
WARNING Graphics requested but DISPLAY is not set. Not running virt-viewer.
|
||||
WARNING No console to launch for the guest, defaulting to --wait -1
|
||||
|
||||
Starting install...
|
||||
Creating domain... | 0 B 00:00:01
|
||||
Domain installation still in progress. Waiting for installation to complete.
|
||||
Domain has shutdown. Continuing.
|
||||
Domain creation completed.
|
||||
Restarting guest.
|
||||
|
||||
```
|
||||
|
||||
![][4]
|
||||
|
||||
Let us break down the above command and see what each option do.
|
||||
|
||||
* **–name** : This option defines the name of the virtual name. In our case, the name of VM is **Ubuntu-16.04**.
|
||||
* **–ram=512** : Allocates 512MB RAM to the VM.
|
||||
* **–vcpus=1** : Indicates the number of CPU cores in the VM.
|
||||
* **–cpu host** : Optimizes the CPU properties for the VM by exposing the host’s CPU’s configuration to the guest.
|
||||
* **–hvm** : Request the full hardware virtualization.
|
||||
* **–disk path** : The location to save VM’s hdd and it’s size. In our example, I have allocated 8GB hdd size.
|
||||
* **–cdrom** : The location of installer ISO image. Please note that you must have the actual ISO image in this location.
|
||||
* **–graphics vnc** : Allows VNC access to the VM from a remote client.
|
||||
|
||||
|
||||
|
||||
### Access Virtual machines using VNC client
|
||||
|
||||
Now, go to the remote Desktop system. SSH to the Ubuntu server(Virtualization server) as shown below.
|
||||
|
||||
Here, **sk** is my Ubuntu server’s user name and **192.168.225.22** is its IP address.
|
||||
|
||||
Run the following command to find out the VNC port number. We need this to access the Vm from a remote system.
|
||||
```
|
||||
$ sudo virsh dumpxml Ubuntu-16.04 | grep vnc
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
<graphics type='vnc' port='5900' autoport='yes' listen='127.0.0.1'>
|
||||
|
||||
```
|
||||
|
||||
![][5]
|
||||
|
||||
Note down the port number **5900**. Install any VNC client application. For this guide, I will be using TigerVnc. TigerVNC is available in the Arch Linux default repositories. To install it on Arch based systems, run:
|
||||
```
|
||||
$ sudo pacman -S tigervnc
|
||||
|
||||
```
|
||||
|
||||
Type the following SSH port forwarding command from your remote client system that has VNC client application installed.
|
||||
|
||||
Again, **192.168.225.22** is my Ubuntu server’s (virtualization server) IP address.
|
||||
|
||||
Then, open the VNC client from your Arch Linux (client).
|
||||
|
||||
Type **localhost:5900** in the VNC server field and click **Connect** button.
|
||||
|
||||
![][6]
|
||||
|
||||
Then start installing the Ubuntu VM as the way you do in the physical system.
|
||||
|
||||
![][7]
|
||||
|
||||
![][8]
|
||||
|
||||
Similarly, you can setup as many as virtual machines depending upon server hardware specifications.
|
||||
|
||||
Alternatively, you can use **virt-viewer** utility in order to install operating system in the guest machines. virt-viewer is available in the most Linux distribution’s default repositories. After installing virt-viewer, run the following command to establish VNC access to the VM.
|
||||
```
|
||||
$ sudo virt-viewer --connect=qemu+ssh://192.168.225.22/system --name Ubuntu-16.04
|
||||
|
||||
```
|
||||
|
||||
### Manage virtual machines
|
||||
|
||||
Managing VMs from the command-line using virsh management user interface is very interesting and fun. The commands are very easy to remember. Let us see some examples.
|
||||
|
||||
To view the list of running VMs, run:
|
||||
```
|
||||
$ sudo virsh list
|
||||
|
||||
```
|
||||
|
||||
Or,
|
||||
```
|
||||
$ sudo virsh list --all
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
Id Name State
|
||||
----------------------------------------------------
|
||||
2 Ubuntu-16.04 running
|
||||
|
||||
```
|
||||
|
||||
![][9]
|
||||
|
||||
To start a VM, run:
|
||||
```
|
||||
$ sudo virsh start Ubuntu-16.04
|
||||
|
||||
```
|
||||
|
||||
Alternatively, you can use the VM id to start it.
|
||||
|
||||
![][10]
|
||||
|
||||
As you see in the above output, Ubuntu 16.04 virtual machine’s Id is 2. So, in order to start it, just specify its Id like below.
|
||||
```
|
||||
$ sudo virsh start 2
|
||||
|
||||
```
|
||||
|
||||
To restart a VM, run:
|
||||
```
|
||||
$ sudo virsh reboot Ubuntu-16.04
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
Domain Ubuntu-16.04 is being rebooted
|
||||
|
||||
```
|
||||
|
||||
![][11]
|
||||
|
||||
To pause a running VM, run:
|
||||
```
|
||||
$ sudo virsh suspend Ubuntu-16.04
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
Domain Ubuntu-16.04 suspended
|
||||
|
||||
```
|
||||
|
||||
To resume the suspended VM, run:
|
||||
```
|
||||
$ sudo virsh resume Ubuntu-16.04
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
Domain Ubuntu-16.04 resumed
|
||||
|
||||
```
|
||||
|
||||
To shutdown a VM, run:
|
||||
```
|
||||
$ sudo virsh shutdown Ubuntu-16.04
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
Domain Ubuntu-16.04 is being shutdown
|
||||
|
||||
```
|
||||
|
||||
To completely remove a VM, run:
|
||||
```
|
||||
$ sudo virsh undefine Ubuntu-16.04
|
||||
|
||||
$ sudo virsh destroy Ubuntu-16.04
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
```
|
||||
Domain Ubuntu-16.04 destroyed
|
||||
|
||||
```
|
||||
|
||||
![][12]
|
||||
|
||||
For more options, I recommend you to look into the man pages.
|
||||
```
|
||||
$ man virsh
|
||||
|
||||
```
|
||||
|
||||
That’s all for now folks. Start playing with your new virtualization environment. KVM virtualization will be opt for research & development and testing purposes, but not limited to. If you have sufficient hardware, you can use it for large production environments. Have fun and don’t forget to leave your valuable comments in the comment section below.
|
||||
|
||||
Cheers!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/setup-headless-virtualization-server-using-kvm-ubuntu/
|
||||
|
||||
作者：[SK][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.ostechnix.com/author/sk/
|
||||
[1]:https://www.ostechnix.com/install-oracle-virtualbox-ubuntu-16-04-headless-server/
|
||||
[2]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[3]:http://www.ostechnix.com/wp-content/uploads/2016/11/sk@ubuntuserver-_001.png
|
||||
[4]:http://www.ostechnix.com/wp-content/uploads/2016/11/sk@ubuntuserver-_008-1.png
|
||||
[5]:http://www.ostechnix.com/wp-content/uploads/2016/11/sk@ubuntuserver-_002.png
|
||||
[6]:http://www.ostechnix.com/wp-content/uploads/2016/11/VNC-Viewer-Connection-Details_005.png
|
||||
[7]:http://www.ostechnix.com/wp-content/uploads/2016/11/QEMU-Ubuntu-16.04-TigerVNC_006.png
|
||||
[8]:http://www.ostechnix.com/wp-content/uploads/2016/11/QEMU-Ubuntu-16.04-TigerVNC_007.png
|
||||
[9]:http://www.ostechnix.com/wp-content/uploads/2016/11/sk@ubuntuserver-_010-1.png
|
||||
[10]:http://www.ostechnix.com/wp-content/uploads/2016/11/sk@ubuntuserver-_010-2.png
|
||||
[11]:http://www.ostechnix.com/wp-content/uploads/2016/11/sk@ubuntuserver-_011-1.png
|
||||
[12]:http://www.ostechnix.com/wp-content/uploads/2016/11/sk@ubuntuserver-_012.png
|
||||
207
sources/tech/20180715 Why is Python so slow.md
Normal file
207
sources/tech/20180715 Why is Python so slow.md
Normal file
@ -0,0 +1,207 @@
|
||||
HankChow translating
|
||||
|
||||
Why is Python so slow?
|
||||
============================================================
|
||||
|
||||
Python is booming in popularity. It is used in DevOps, Data Science, Web Development and Security.
|
||||
|
||||
It does not, however, win any medals for speed.
|
||||
|
||||
|
||||
|
||||
|
||||
> How does Java compare in terms of speed to C or C++ or C# or Python? The answer depends greatly on the type of application you’re running. No benchmark is perfect, but The Computer Language Benchmarks Game is [a good starting point][5].
|
||||
|
||||
I’ve been referring to the Computer Language Benchmarks Game for over a decade; compared with other languages like Java, C#, Go, JavaScript, C++, Python is [one of the slowest][6]. This includes [JIT][7] (C#, Java) and [AOT][8] (C, C++) compilers, as well as interpreted languages like JavaScript.
|
||||
|
||||
_NB: When I say “Python”, I’m talking about the reference implementation of the language, CPython. I will refer to other runtimes in this article._
|
||||
|
||||
> I want to answer this question: When Python completes a comparable application 2–10x slower than another language, _why is it slow_ and can’t we _make it faster_ ?
|
||||
|
||||
Here are the top theories:
|
||||
|
||||
* “ _It’s the GIL (Global Interpreter Lock)_ ”
|
||||
|
||||
* “ _It’s because its interpreted and not compiled_ ”
|
||||
|
||||
* “ _It’s because its a dynamically typed language_ ”
|
||||
|
||||
Which one of these reasons has the biggest impact on performance?
|
||||
|
||||
### “It’s the GIL”
|
||||
|
||||
Modern computers come with CPU’s that have multiple cores, and sometimes multiple processors. In order to utilise all this extra processing power, the Operating System defines a low-level structure called a thread, where a process (e.g. Chrome Browser) can spawn multiple threads and have instructions for the system inside. That way if one process is particularly CPU-intensive, that load can be shared across the cores and this effectively makes most applications complete tasks faster.
|
||||
|
||||
My Chrome Browser, as I’m writing this article, has 44 threads open. Keep in mind that the structure and API of threading are different between POSIX-based (e.g. Mac OS and Linux) and Windows OS. The operating system also handles the scheduling of threads.
|
||||
|
||||
IF you haven’t done multi-threaded programming before, a concept you’ll need to quickly become familiar with locks. Unlike a single-threaded process, you need to ensure that when changing variables in memory, multiple threads don’t try and access/change the same memory address at the same time.
|
||||
|
||||
When CPython creates variables, it allocates the memory and then counts how many references to that variable exist, this is a concept known as reference counting. If the number of references is 0, then it frees that piece of memory from the system. This is why creating a “temporary” variable within say, the scope of a for loop, doesn’t blow up the memory consumption of your application.
|
||||
|
||||
The challenge then becomes when variables are shared within multiple threads, how CPython locks the reference count. There is a “global interpreter lock” that carefully controls thread execution. The interpreter can only execute one operation at a time, regardless of how many threads it has.
|
||||
|
||||
#### What does this mean to the performance of Python application?
|
||||
|
||||
If you have a single-threaded, single interpreter application. It will make no difference to the speed. Removing the GIL would have no impact on the performance of your code.
|
||||
|
||||
If you wanted to implement concurrency within a single interpreter (Python process) by using threading, and your threads were IO intensive (e.g. Network IO or Disk IO), you would see the consequences of GIL-contention.
|
||||
|
||||
|
||||
From David Beazley’s GIL visualised post [http://dabeaz.blogspot.com/2010/01/python-gil-visualized.html][1]
|
||||
|
||||
If you have a web-application (e.g. Django) and you’re using WSGI, then each request to your web-app is a separate Python interpreter, so there is only 1 lock _per_ request. Because the Python interpreter is slow to start, some WSGI implementations have a “Daemon Mode” [which keep Python process(es) on the go for you.][9]
|
||||
|
||||
#### What about other Python runtimes?
|
||||
|
||||
[PyPy has a GIL][10] and it is typically >3x faster than CPython.
|
||||
|
||||
[Jython does not have a GIL][11] because a Python thread in Jython is represented by a Java thread and benefits from the JVM memory-management system.
|
||||
|
||||
#### How does JavaScript do this?
|
||||
|
||||
Well, firstly all Javascript engines [use mark-and-sweep Garbage Collection][12]. As stated, the primary need for the GIL is CPython’s memory-management algorithm.
|
||||
|
||||
JavaScript does not have a GIL, but it’s also single-threaded so it doesn’t require one. JavaScript’s event-loop and Promise/Callback pattern are how asynchronous-programming is achieved in place of concurrency. Python has a similar thing with the asyncio event-loop.
|
||||
|
||||
### “It’s because its an interpreted language”
|
||||
|
||||
I hear this a lot and I find it a gross-simplification of the way CPython actually works. If at a terminal you wrote `python myscript.py` then CPython would start a long sequence of reading, lexing, parsing, compiling, interpreting and executing that code.
|
||||
|
||||
If you’re interested in how that process works, I’ve written about it before:
|
||||
|
||||
[Modifying the Python language in 6 minutes
|
||||
This week I raised my first pull-request to the CPython core project, which was declined :-( but as to not completely…hackernoon.com][13][][14]
|
||||
|
||||
An important point in that process is the creation of a `.pyc` file, at the compiler stage, the bytecode sequence is written to a file inside `__pycache__/`on Python 3 or in the same directory in Python 2\. This doesn’t just apply to your script, but all of the code you imported, including 3rd party modules.
|
||||
|
||||
So most of the time (unless you write code which you only ever run once?), Python is interpreting bytecode and executing it locally. Compare that with Java and C#.NET:
|
||||
|
||||
> Java compiles to an “Intermediate Language” and the Java Virtual Machine reads the bytecode and just-in-time compiles it to machine code. The .NET CIL is the same, the .NET Common-Language-Runtime, CLR, uses just-in-time compilation to machine code.
|
||||
|
||||
So, why is Python so much slower than both Java and C# in the benchmarks if they all use a virtual machine and some sort of Bytecode? Firstly, .NET and Java are JIT-Compiled.
|
||||
|
||||
JIT or Just-in-time compilation requires an intermediate language to allow the code to be split into chunks (or frames). Ahead of time (AOT) compilers are designed to ensure that the CPU can understand every line in the code before any interaction takes place.
|
||||
|
||||
The JIT itself does not make the execution any faster, because it is still executing the same bytecode sequences. However, JIT enables optimizations to be made at runtime. A good JIT optimizer will see which parts of the application are being executed a lot, call these “hot spots”. It will then make optimizations to those bits of code, by replacing them with more efficient versions.
|
||||
|
||||
This means that when your application does the same thing again and again, it can be significantly faster. Also, keep in mind that Java and C# are strongly-typed languages so the optimiser can make many more assumptions about the code.
|
||||
|
||||
PyPy has a JIT and as mentioned in the previous section, is significantly faster than CPython. This performance benchmark article goes into more detail —
|
||||
|
||||
[Which is the fastest version of Python?
|
||||
Of course, “it depends”, but what does it depend on and how can you assess which is the fastest version of Python for…hackernoon.com][15][][16]
|
||||
|
||||
#### So why doesn’t CPython use a JIT?
|
||||
|
||||
There are downsides to JITs: one of those is startup time. CPython startup time is already comparatively slow, PyPy is 2–3x slower to start than CPython. The Java Virtual Machine is notoriously slow to boot. The .NET CLR gets around this by starting at system-startup, but the developers of the CLR also develop the Operating System on which the CLR runs.
|
||||
|
||||
If you have a single Python process running for a long time, with code that can be optimized because it contains “hot spots”, then a JIT makes a lot of sense.
|
||||
|
||||
However, CPython is a general-purpose implementation. So if you were developing command-line applications using Python, having to wait for a JIT to start every time the CLI was called would be horribly slow.
|
||||
|
||||
CPython has to try and serve as many use cases as possible. There was the possibility of [plugging a JIT into CPython][17] but this project has largely stalled.
|
||||
|
||||
> If you want the benefits of a JIT and you have a workload that suits it, use PyPy.
|
||||
|
||||
### “It’s because its a dynamically typed language”
|
||||
|
||||
In a “Statically-Typed” language, you have to specify the type of a variable when it is declared. Those would include C, C++, Java, C#, Go.
|
||||
|
||||
In a dynamically-typed language, there are still the concept of types, but the type of a variable is dynamic.
|
||||
|
||||
```
|
||||
a = 1
|
||||
a = "foo"
|
||||
```
|
||||
|
||||
In this toy-example, Python creates a second variable with the same name and a type of `str` and deallocates the memory created for the first instance of `a`
|
||||
|
||||
Statically-typed languages aren’t designed as such to make your life hard, they are designed that way because of the way the CPU operates. If everything eventually needs to equate to a simple binary operation, you have to convert objects and types down to a low-level data structure.
|
||||
|
||||
Python does this for you, you just never see it, nor do you need to care.
|
||||
|
||||
Not having to declare the type isn’t what makes Python slow, the design of the Python language enables you to make almost anything dynamic. You can replace the methods on objects at runtime, you can monkey-patch low-level system calls to a value declared at runtime. Almost anything is possible.
|
||||
|
||||
It’s this design that makes it incredibly hard to optimise Python.
|
||||
|
||||
To illustrate my point, I’m going to use a syscall tracing tool that works in Mac OS called Dtrace. CPython distributions do not come with DTrace builtin, so you have to recompile CPython. I’m using 3.6.6 for my demo
|
||||
|
||||
```
|
||||
wget https://github.com/python/cpython/archive/v3.6.6.zip
|
||||
unzip v3.6.6.zip
|
||||
cd v3.6.6
|
||||
./configure --with-dtrace
|
||||
make
|
||||
```
|
||||
|
||||
Now `python.exe` will have Dtrace tracers throughout the code. [Paul Ross wrote an awesome Lightning Talk on Dtrace][19]. You can [download DTrace starter files][20] for Python to measure function calls, execution time, CPU time, syscalls, all sorts of fun. e.g.
|
||||
|
||||
`sudo dtrace -s toolkit/<tracer>.d -c ‘../cpython/python.exe script.py’`
|
||||
|
||||
The `py_callflow` tracer shows all the function calls in your application
|
||||
|
||||
|
||||
|
||||
|
||||
So, does Python’s dynamic typing make it slow?
|
||||
|
||||
* Comparing and converting types is costly, every time a variable is read, written to or referenced the type is checked
|
||||
|
||||
* It is hard to optimise a language that is so dynamic. The reason many alternatives to Python are so much faster is that they make compromises to flexibility in the name of performance
|
||||
|
||||
* Looking at [Cython][2], which combines C-Static Types and Python to optimise code where the types are known[ can provide ][3]an 84x performanceimprovement.
|
||||
|
||||
### Conclusion
|
||||
|
||||
> Python is primarily slow because of its dynamic nature and versatility. It can be used as a tool for all sorts of problems, where more optimised and faster alternatives are probably available.
|
||||
|
||||
There are, however, ways of optimising your Python applications by leveraging async, understanding the profiling tools, and consider using multiple-interpreters.
|
||||
|
||||
For applications where startup time is unimportant and the code would benefit a JIT, consider PyPy.
|
||||
|
||||
For parts of your code where performance is critical and you have more statically-typed variables, consider using [Cython][4].
|
||||
|
||||
#### Further reading
|
||||
|
||||
Jake VDP’s excellent article (although slightly dated) [https://jakevdp.github.io/blog/2014/05/09/why-python-is-slow/][21]
|
||||
|
||||
Dave Beazley’s talk on the GIL [http://www.dabeaz.com/python/GIL.pdf][22]
|
||||
|
||||
All about JIT compilers [https://hacks.mozilla.org/2017/02/a-crash-course-in-just-in-time-jit-compilers/][23]
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://hackernoon.com/why-is-python-so-slow-e5074b6fe55b
|
||||
|
||||
作者：[Anthony Shaw][a]
|
||||
选题：[oska874][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://hackernoon.com/@anthonypjshaw?source=post_header_lockup
|
||||
[b]:https://github.com/oska874
|
||||
[1]:http://dabeaz.blogspot.com/2010/01/python-gil-visualized.html
|
||||
[2]:http://cython.org/
|
||||
[3]:http://notes-on-cython.readthedocs.io/en/latest/std_dev.html
|
||||
[4]:http://cython.org/
|
||||
[5]:http://algs4.cs.princeton.edu/faq/
|
||||
[6]:https://benchmarksgame-team.pages.debian.net/benchmarksgame/faster/python.html
|
||||
[7]:https://en.wikipedia.org/wiki/Just-in-time_compilation
|
||||
[8]:https://en.wikipedia.org/wiki/Ahead-of-time_compilation
|
||||
[9]:https://www.slideshare.net/GrahamDumpleton/secrets-of-a-wsgi-master
|
||||
[10]:http://doc.pypy.org/en/latest/faq.html#does-pypy-have-a-gil-why
|
||||
[11]:http://www.jython.org/jythonbook/en/1.0/Concurrency.html#no-global-interpreter-lock
|
||||
[12]:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Memory_Management
|
||||
[13]:https://hackernoon.com/modifying-the-python-language-in-7-minutes-b94b0a99ce14
|
||||
[14]:https://hackernoon.com/modifying-the-python-language-in-7-minutes-b94b0a99ce14
|
||||
[15]:https://hackernoon.com/which-is-the-fastest-version-of-python-2ae7c61a6b2b
|
||||
[16]:https://hackernoon.com/which-is-the-fastest-version-of-python-2ae7c61a6b2b
|
||||
[17]:https://www.slideshare.net/AnthonyShaw5/pyjion-a-jit-extension-system-for-cpython
|
||||
[18]:https://github.com/python/cpython/archive/v3.6.6.zip
|
||||
[19]:https://github.com/paulross/dtrace-py#the-lightning-talk
|
||||
[20]:https://github.com/paulross/dtrace-py/tree/master/toolkit
|
||||
[21]:https://jakevdp.github.io/blog/2014/05/09/why-python-is-slow/
|
||||
[22]:http://www.dabeaz.com/python/GIL.pdf
|
||||
[23]:https://hacks.mozilla.org/2017/02/a-crash-course-in-just-in-time-jit-compilers/
|
||||
@ -1,988 +0,0 @@
|
||||
75 Most Used Essential Linux Applications of 2018
|
||||
======
|
||||
|
||||
**2018** has been an awesome year for a lot of applications, especially those that are both free and open source. And while various Linux distributions come with a number of default apps, users are free to take them out and use any of the free or paid alternatives of their choice.
|
||||
|
||||
Today, we bring you a [list of Linux applications][3] that have been able to make it to users’ Linux installations almost all the time despite the butt-load of other alternatives.
|
||||
|
||||
To simply put, any app on this list is among the most used in its category, and if you haven’t already tried it out you are probably missing out. Enjoy!
|
||||
|
||||
### Backup Tools
|
||||
|
||||
#### Rsync
|
||||
|
||||
[Rsync][4] is an open source bandwidth-friendly utility tool for performing swift incremental file transfers and it is available for free.
|
||||
```
|
||||
$ rsync [OPTION...] SRC... [DEST]
|
||||
|
||||
```
|
||||
|
||||
To know more examples and usage, read our article “[10 Practical Examples of Rsync Command][5]” to learn more about it.
|
||||
|
||||
#### Timeshift
|
||||
|
||||
[Timeshift][6] provides users with the ability to protect their system by taking incremental snapshots which can be reverted to at a different date – similar to the function of Time Machine in Mac OS and System restore in Windows.
|
||||
|
||||
|
||||
|
||||
### BitTorrent Client
|
||||
|
||||
|
||||
|
||||
#### Deluge
|
||||
|
||||
[Deluge][7] is a beautiful cross-platform BitTorrent client that aims to perfect the **μTorrent** experience and make it available to users for free.
|
||||
|
||||
Install **Deluge** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:deluge-team/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install deluge
|
||||
|
||||
```
|
||||
|
||||
#### qBittorent
|
||||
|
||||
[qBittorent][8] is an open source BitTorrent protocol client that aims to provide a free alternative to torrent apps like μTorrent.
|
||||
|
||||
Install **qBittorent** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:qbittorrent-team/qbittorrent-stable
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install qbittorrent
|
||||
|
||||
```
|
||||
|
||||
#### Transmission
|
||||
|
||||
[Transmission][9] is also a BitTorrent client with awesome functionalities and a major focus on speed and ease of use. It comes preinstalled with many Linux distros.
|
||||
|
||||
Install **Transmission** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:transmissionbt/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install transmission-gtk transmission-cli transmission-common transmission-daemon
|
||||
|
||||
```
|
||||
|
||||
### Cloud Storage
|
||||
|
||||
|
||||
|
||||
#### Dropbox
|
||||
|
||||
The [Dropbox][10] team rebranded their cloud service earlier this year to provide an even better performance and app integration for their clients. It starts with 2GB of storage for free.
|
||||
|
||||
Install **Dropbox** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86" | tar xzf - [On 32-Bit]
|
||||
$ cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf - [On 64-Bit]
|
||||
$ ~/.dropbox-dist/dropboxd
|
||||
|
||||
```
|
||||
|
||||
#### Google Drive
|
||||
|
||||
[Google Drive][11] is Google’s cloud service solution and my guess is that it needs no introduction. Just like with **Dropbox** , you can sync files across all your connected devices. It starts with 15GB of storage for free and this includes Gmail, Google photos, Maps, etc.
|
||||
|
||||
Check out: [5 Google Drive Clients for Linux][12]
|
||||
|
||||
#### Mega
|
||||
|
||||
[Mega][13] stands out from the rest because apart from being extremely security-conscious, it gives free users 50GB to do as they wish! Its end-to-end encryption ensures that they can’t access your data, and if you forget your recovery key, you too wouldn’t be able to.
|
||||
|
||||
[**Download MEGA Cloud Storage for Ubuntu][14]
|
||||
|
||||
### Commandline Editors
|
||||
|
||||
|
||||
|
||||
#### Vim
|
||||
|
||||
[Vim][15] is an open source clone of vi text editor developed to be customizable and able to work with any type of text.
|
||||
|
||||
Install **Vim** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jonathonf/vim
|
||||
$ sudo apt update
|
||||
$ sudo apt install vim
|
||||
|
||||
```
|
||||
|
||||
#### Emacs
|
||||
|
||||
[Emacs][16] refers to a set of highly configurable text editors. The most popular variant, GNU Emacs, is written in Lisp and C to be self-documenting, extensible, and customizable.
|
||||
|
||||
Install **Emacs** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kelleyk/emacs
|
||||
$ sudo apt update
|
||||
$ sudo apt install emacs25
|
||||
|
||||
```
|
||||
|
||||
#### Nano
|
||||
|
||||
[Nano][17] is a feature-rich CLI text editor for power users and it has the ability to work with different terminals, among other functionalities.
|
||||
|
||||
Install **Nano** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:n-muench/programs-ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install nano
|
||||
|
||||
```
|
||||
|
||||
### Download Manager
|
||||
|
||||
|
||||
|
||||
#### Aria2
|
||||
|
||||
[Aria2][18] is an open source lightweight multi-source and multi-protocol command line-based downloader with support for Metalinks, torrents, HTTP/HTTPS, SFTP, etc.
|
||||
|
||||
Install **Aria2** on **Ubuntu** and **Debian** , using following command.
|
||||
```
|
||||
$ sudo apt-get install aria2
|
||||
|
||||
```
|
||||
|
||||
#### uGet
|
||||
|
||||
[uGet][19] has earned its title as the **#1** open source download manager for Linux distros and it features the ability to handle any downloading task you can throw at it including using multiple connections, using queues, categories, etc.
|
||||
|
||||
Install **uGet** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:plushuang-tw/uget-stable
|
||||
$ sudo apt update
|
||||
$ sudo apt install uget
|
||||
|
||||
```
|
||||
|
||||
#### XDM
|
||||
|
||||
[XDM][20], **Xtreme Download Manager** is an open source downloader written in Java. Like any good download manager, it can work with queues, torrents, browsers, and it also includes a video grabber and a smart scheduler.
|
||||
|
||||
Install **XDM** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:noobslab/apps
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install xdman
|
||||
|
||||
```
|
||||
|
||||
### Email Clients
|
||||
|
||||
|
||||
|
||||
#### Thunderbird
|
||||
|
||||
[Thunderbird][21] is among the most popular email applications. It is free, open source, customizable, feature-rich, and above all, easy to install.
|
||||
|
||||
Install **Thunderbird** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install thunderbird
|
||||
|
||||
```
|
||||
|
||||
#### Geary
|
||||
|
||||
[Geary][22] is an open source email client based on WebKitGTK+. It is free, open-source, feature-rich, and adopted by the GNOME project.
|
||||
|
||||
Install **Geary** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:geary-team/releases
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install geary
|
||||
|
||||
```
|
||||
|
||||
#### Evolution
|
||||
|
||||
[Evolution][23] is a free and open source email client for managing emails, meeting schedules, reminders, and contacts.
|
||||
|
||||
Install **Evolution** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:gnome3-team/gnome3-staging
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install evolution
|
||||
|
||||
```
|
||||
|
||||
### Finance Software
|
||||
|
||||
|
||||
|
||||
#### GnuCash
|
||||
|
||||
[GnuCash][24] is a free, cross-platform, and open source software for financial accounting tasks for personal and small to mid-size businesses.
|
||||
|
||||
Install **GnuCash** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo sh -c 'echo "deb http://archive.getdeb.net/ubuntu $(lsb_release -sc)-getdeb apps" >> /etc/apt/sources.list.d/getdeb.list'
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gnucash
|
||||
|
||||
```
|
||||
|
||||
#### KMyMoney
|
||||
|
||||
[KMyMoney][25] is a finance manager software that provides all important features found in the commercially-available, personal finance managers.
|
||||
|
||||
Install **KMyMoney** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:claydoh/kmymoney2-kde4
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install kmymoney
|
||||
|
||||
```
|
||||
|
||||
### IDE Editors
|
||||
|
||||
|
||||
|
||||
#### Eclipse IDE
|
||||
|
||||
[Eclipse][26] is the most widely used Java IDE containing a base workspace and an impossible-to-overemphasize configurable plug-in system for personalizing its coding environment.
|
||||
|
||||
For installation, read our article “[How to Install Eclipse Oxygen IDE in Debian and Ubuntu][27]”
|
||||
|
||||
#### Netbeans IDE
|
||||
|
||||
A fan-favourite, [Netbeans][28] enables users to easily build applications for mobile, desktop, and web platforms using Java, PHP, HTML5, JavaScript, and C/C++, among other languages.
|
||||
|
||||
For installation, read our article “[How to Install Netbeans Oxygen IDE in Debian and Ubuntu][29]”
|
||||
|
||||
#### Brackets
|
||||
|
||||
[Brackets][30] is an advanced text editor developed by Adobe to feature visual tools, preprocessor support, and a design-focused user flow for web development. In the hands of an expert, it can serve as an IDE in its own right.
|
||||
|
||||
Install **Brackets** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:webupd8team/brackets
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install brackets
|
||||
|
||||
```
|
||||
|
||||
#### Atom IDE
|
||||
|
||||
[Atom IDE][31] is a more robust version of Atom text editor achieved by adding a number of extensions and libraries to boost its performance and functionalities. It is, in a sense, Atom on steroids.
|
||||
|
||||
Install **Atom** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install atom --classic
|
||||
|
||||
```
|
||||
|
||||
#### Light Table
|
||||
|
||||
[Light Table][32] is a self-proclaimed next-generation IDE developed to offer awesome features like data value flow stats and coding collaboration.
|
||||
|
||||
Install **Light Table** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:dr-akulavich/lighttable
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install lighttable-installer
|
||||
|
||||
```
|
||||
|
||||
#### Visual Studio Code
|
||||
|
||||
[Visual Studio Code][33] is a source code editor created by Microsoft to offer users the best-advanced features in a text editor including syntax highlighting, code completion, debugging, performance statistics and graphs, etc.
|
||||
|
||||
[**Download Visual Studio Code for Ubuntu][34]
|
||||
|
||||
### Instant Messaging
|
||||
|
||||
|
||||
|
||||
#### Pidgin
|
||||
|
||||
[Pidgin][35] is an open source instant messaging app that supports virtually all chatting platforms and can have its abilities extended using extensions.
|
||||
|
||||
Install **Pidgin** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jonathonf/backports
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install pidgin
|
||||
|
||||
```
|
||||
|
||||
#### Skype
|
||||
|
||||
[Skype][36] needs no introduction and its awesomeness is available for any interested Linux user.
|
||||
|
||||
Install **Skype** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install snapd
|
||||
$ sudo snap install skype --classic
|
||||
|
||||
```
|
||||
|
||||
#### Empathy
|
||||
|
||||
[Empathy][37] is a messaging app with support for voice, video chat, text, and file transfers over multiple several protocols. It also allows you to add other service accounts to it and interface with all of them through it.
|
||||
|
||||
Install **Empathy** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install empathy
|
||||
|
||||
```
|
||||
|
||||
### Linux Antivirus
|
||||
|
||||
#### ClamAV/ClamTk
|
||||
|
||||
[ClamAV][38] is an open source and cross-platform command line antivirus app for detecting Trojans, viruses, and other malicious codes. [ClamTk][39] is its GUI front-end.
|
||||
|
||||
Install **ClamAV/ClamTk** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install clamav
|
||||
$ sudo apt-get install clamtk
|
||||
|
||||
```
|
||||
|
||||
### Linux Desktop Environments
|
||||
|
||||
#### Cinnamon
|
||||
|
||||
[Cinnamon][40] is a free and open-source derivative of **GNOME3** and it follows the traditional desktop metaphor conventions.
|
||||
|
||||
Install **Cinnamon** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:embrosyn/cinnamon
|
||||
$ sudo apt update
|
||||
$ sudo apt install cinnamon-desktop-environment lightdm
|
||||
|
||||
```
|
||||
|
||||
#### Mate
|
||||
|
||||
The [Mate][41] Desktop Environment is a derivative and continuation of **GNOME2** developed to offer an attractive UI on Linux using traditional metaphors.
|
||||
|
||||
Install **Mate** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install ubuntu-mate-desktop
|
||||
|
||||
```
|
||||
|
||||
#### GNOME
|
||||
|
||||
[GNOME][42] is a Desktop Environment comprised of several free and open-source applications and can run on any Linux distro and on most BSD derivatives.
|
||||
|
||||
Install **Gnome** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install ubuntu-desktop
|
||||
|
||||
```
|
||||
|
||||
#### KDE
|
||||
|
||||
[KDE][43] is developed by the KDE community to provide users with a graphical solution to interfacing with their system and performing several computing tasks.
|
||||
|
||||
Install **KDE** desktop on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install tasksel
|
||||
$ sudo apt update
|
||||
$ sudo tasksel install kubuntu-desktop
|
||||
|
||||
```
|
||||
|
||||
### Linux Maintenance Tools
|
||||
|
||||
#### GNOME Tweak Tool
|
||||
|
||||
The [GNOME Tweak Tool][44] is the most popular tool for customizing and tweaking GNOME3 and GNOME Shell settings.
|
||||
|
||||
Install **GNOME Tweak Tool** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt install gnome-tweak-tool
|
||||
|
||||
```
|
||||
|
||||
#### Stacer
|
||||
|
||||
[Stacer][45] is a free, open-source app for monitoring and optimizing Linux systems.
|
||||
|
||||
Install **Stacer** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:oguzhaninan/stacer
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install stacer
|
||||
|
||||
```
|
||||
|
||||
#### BleachBit
|
||||
|
||||
[BleachBit][46] is a free disk space cleaner that also works as a privacy manager and system optimizer.
|
||||
|
||||
[**Download BleachBit for Ubuntu][47]
|
||||
|
||||
### Linux Terminals
|
||||
|
||||
#### GNOME Terminal
|
||||
|
||||
[GNOME Terminal][48] is GNOME’s default terminal emulator.
|
||||
|
||||
Install **Gnome Terminal** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install gnome-terminal
|
||||
|
||||
```
|
||||
|
||||
#### Konsole
|
||||
|
||||
[Konsole][49] is a terminal emulator for KDE.
|
||||
|
||||
Install **Konsole** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install konsole
|
||||
|
||||
```
|
||||
|
||||
#### Terminator
|
||||
|
||||
[Terminator][50] is a feature-rich GNOME Terminal-based terminal app built with a focus on arranging terminals, among other functions.
|
||||
|
||||
Install **Terminator** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install terminator
|
||||
|
||||
```
|
||||
|
||||
#### Guake
|
||||
|
||||
[Guake][51] is a lightweight drop-down terminal for the GNOME Desktop Environment.
|
||||
|
||||
Install **Guake** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install guake
|
||||
|
||||
```
|
||||
|
||||
### Multimedia Editors
|
||||
|
||||
#### Ardour
|
||||
|
||||
[Ardour][52] is a beautiful Digital Audio Workstation (DAW) for recording, editing, and mixing audio professionally.
|
||||
|
||||
Install **Ardour** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:dobey/audiotools
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install ardour
|
||||
|
||||
```
|
||||
|
||||
#### Audacity
|
||||
|
||||
[Audacity][53] is an easy-to-use cross-platform and open source multi-track audio editor and recorder; arguably the most famous of them all.
|
||||
|
||||
Install **Audacity** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:ubuntuhandbook1/audacity
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install audacity
|
||||
|
||||
```
|
||||
|
||||
#### GIMP
|
||||
|
||||
[GIMP][54] is the most popular open source Photoshop alternative and it is for a reason. It features various customization options, 3rd-party plugins, and a helpful user community.
|
||||
|
||||
Install **Gimp** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:otto-kesselgulasch/gimp
|
||||
$ sudo apt update
|
||||
$ sudo apt install gimp
|
||||
|
||||
```
|
||||
|
||||
#### Krita
|
||||
|
||||
[Krita][55] is an open source painting app that can also serve as an image manipulating tool and it features a beautiful UI with a reliable performance.
|
||||
|
||||
Install **Krita** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kritalime/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install krita
|
||||
|
||||
```
|
||||
|
||||
#### Lightworks
|
||||
|
||||
[Lightworks][56] is a powerful, flexible, and beautiful tool for editing videos professionally. It comes feature-packed with hundreds of amazing effects and presets that allow it to handle any editing task that you throw at it and it has 25 years of experience to back up its claims.
|
||||
|
||||
[**Download Lightworks for Ubuntu][57]
|
||||
|
||||
#### OpenShot
|
||||
|
||||
[OpenShot][58] is an award-winning free and open source video editor known for its excellent performance and powerful capabilities.
|
||||
|
||||
Install **Openshot** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:openshot.developers/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install openshot-qt
|
||||
|
||||
```
|
||||
|
||||
#### PiTiV
|
||||
|
||||
[Pitivi][59] is a beautiful video editor that features a beautiful code base, awesome community, is easy to use, and allows for hassle-free collaboration.
|
||||
|
||||
Install **PiTiV** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ flatpak install --user https://flathub.org/repo/appstream/org.pitivi.Pitivi.flatpakref
|
||||
$ flatpak install --user http://flatpak.pitivi.org/pitivi.flatpakref
|
||||
$ flatpak run org.pitivi.Pitivi//stable
|
||||
|
||||
```
|
||||
|
||||
### Music Players
|
||||
|
||||
#### Rhythmbox
|
||||
|
||||
[Rhythmbox][60] posses the ability to perform all music tasks you throw at it and has so far proved to be a reliable music player that it ships with Ubuntu.
|
||||
|
||||
Install **Rhythmbox** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:fossfreedom/rhythmbox
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install rhythmbox
|
||||
|
||||
```
|
||||
|
||||
#### Lollypop
|
||||
|
||||
[Lollypop][61] is a beautiful, relatively new, open source music player featuring a number of advanced options like online radio, scrubbing support and party mode. Yet, it manages to keep everything simple and easy to manage.
|
||||
|
||||
Install **Lollypop** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:gnumdk/lollypop
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install lollypop
|
||||
|
||||
```
|
||||
|
||||
#### Amarok
|
||||
|
||||
[Amarok][62] is a robust music player with an intuitive UI and tons of advanced features bundled into a single unit. It also allows users to discover new music based on their genre preferences.
|
||||
|
||||
Install **Amarok** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install amarok
|
||||
|
||||
```
|
||||
|
||||
#### Clementine
|
||||
|
||||
[Clementine][63] is an Amarok-inspired music player that also features a straight-forward UI, advanced control features, and the ability to let users search for and discover new music.
|
||||
|
||||
Install **Clementine** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:me-davidsansome/clementine
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install clementine
|
||||
|
||||
```
|
||||
|
||||
#### Cmus
|
||||
|
||||
[Cmus][64] is arguably the most efficient CLI music player, Cmus is fast and reliable, and its functionality can be increased using extensions.
|
||||
|
||||
Install **Cmus** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:jmuc/cmus
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install cmus
|
||||
|
||||
```
|
||||
|
||||
### Office Suites
|
||||
|
||||
#### Calligra Suite
|
||||
|
||||
The [Calligra Suite][65] provides users with a set of 8 applications which cover working with office, management, and graphics tasks.
|
||||
|
||||
Install **Calligra Suite** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install calligra
|
||||
|
||||
```
|
||||
|
||||
#### LibreOffice
|
||||
|
||||
[LibreOffice][66] the most actively developed office suite in the open source community, LibreOffice is known for its reliability and its functions can be increased using extensions.
|
||||
|
||||
Install **LibreOffice** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:libreoffice/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install libreoffice
|
||||
|
||||
```
|
||||
|
||||
#### WPS Office
|
||||
|
||||
[WPS Office][67] is a beautiful office suite alternative with a more modern UI.
|
||||
|
||||
[**Download WPS Office for Ubuntu][68]
|
||||
|
||||
### Screenshot Tools
|
||||
|
||||
#### Shutter
|
||||
|
||||
[Shutter][69] allows users to take screenshots of their desktop and then edit them using filters and other effects coupled with the option to upload and share them online.
|
||||
|
||||
Install **Shutter** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository -y ppa:shutter/ppa
|
||||
$ sudo apt update
|
||||
$ sudo apt install shutter
|
||||
|
||||
```
|
||||
|
||||
#### Kazam
|
||||
|
||||
[Kazam][70] screencaster captures screen content to output a video and audio file supported by any video player with VP8/WebM and PulseAudio support.
|
||||
|
||||
Install **Kazam** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:kazam-team/unstable-series
|
||||
$ sudo apt update
|
||||
$ sudo apt install kazam python3-cairo python3-xlib
|
||||
|
||||
```
|
||||
|
||||
#### Gnome Screenshot
|
||||
|
||||
[Gnome Screenshot][71] was once bundled with Gnome utilities but is now a standalone app. It can be used to take screencasts in a format that is easily shareable.
|
||||
|
||||
Install **Gnome Screenshot** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gnome-screenshot
|
||||
|
||||
```
|
||||
|
||||
### Screen Recorders
|
||||
|
||||
#### SimpleScreenRecorder
|
||||
|
||||
[SimpleScreenRecorder][72] was created to be better than the screen-recording apps available at the time of its creation and has now turned into one of the most efficient and easy-to-use screen recorders for Linux distros.
|
||||
|
||||
Install **SimpleScreenRecorder** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install simplescreenrecorder
|
||||
|
||||
```
|
||||
|
||||
#### recordMyDesktop
|
||||
|
||||
[recordMyDesktop][73] is an open source session recorder that is also capable of recording desktop session audio.
|
||||
|
||||
Install **recordMyDesktop** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gtk-recordmydesktop
|
||||
|
||||
```
|
||||
|
||||
### Text Editors
|
||||
|
||||
#### Atom
|
||||
|
||||
[Atom][74] is a modern and customizable text editor created and maintained by GitHub. It is ready for use right out of the box and can have its functionality enhanced and its UI customized using extensions and themes.
|
||||
|
||||
Install **Atom** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install atom --classic
|
||||
|
||||
```
|
||||
|
||||
#### Sublime Text
|
||||
|
||||
[Sublime Text][75] is easily among the most awesome text editors to date. It is customizable, lightweight (even when bulldozed with a lot of data files and extensions), flexible, and remains free to use forever.
|
||||
|
||||
Install **Sublime Text** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install snapd
|
||||
$ sudo snap install sublime-text
|
||||
|
||||
```
|
||||
|
||||
#### Geany
|
||||
|
||||
[Geany][76] is a memory-friendly text editor with basic IDE features designed to exhibit shot load times and extensible functions using libraries.
|
||||
|
||||
Install **Geany** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install geany
|
||||
|
||||
```
|
||||
|
||||
#### Gedit
|
||||
|
||||
[Gedit][77] is famous for its simplicity and it comes preinstalled with many Linux distros because of its function as an excellent general purpose text editor.
|
||||
|
||||
Install **Gedit** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install gedit
|
||||
|
||||
```
|
||||
|
||||
### To-Do List Apps
|
||||
|
||||
#### Evernote
|
||||
|
||||
[Evernote][78] is a cloud-based note-taking productivity app designed to work perfectly with different types of notes including to-do lists and reminders.
|
||||
|
||||
There is no any official evernote app for Linux, so check out other third party [6 Evernote Alternative Clients for Linux][79].
|
||||
|
||||
#### Everdo
|
||||
|
||||
[Everdo][78] is a beautiful, security-conscious, low-friction Getting-Things-Done app productivity app for handling to-dos and other note types. If Evernote comes off to you in an unpleasant way, Everdo is a perfect alternative.
|
||||
|
||||
[**Download Everdo for Ubuntu][80]
|
||||
|
||||
#### Taskwarrior
|
||||
|
||||
[Taskwarrior][81] is an open source and cross-platform command line app for managing tasks. It is famous for its speed and distraction-free environment.
|
||||
|
||||
Install **Taskwarrior** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install taskwarrior
|
||||
|
||||
```
|
||||
|
||||
### Video Players
|
||||
|
||||
#### Banshee
|
||||
|
||||
[Banshee][82] is an open source multi-format-supporting media player that was first developed in 2005 and has only been getting better since.
|
||||
|
||||
Install **Banshee** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:banshee-team/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install banshee
|
||||
|
||||
```
|
||||
|
||||
#### VLC
|
||||
|
||||
[VLC][83] is my favourite video player and it’s so awesome that it can play almost any audio and video format you throw at it. You can also use it to play internet radio, record desktop sessions, and stream movies online.
|
||||
|
||||
Install **VLC** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:videolan/stable-daily
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install vlc
|
||||
|
||||
```
|
||||
|
||||
#### Kodi
|
||||
|
||||
[Kodi][84] is among the world’s most famous media players and it comes as a full-fledged media centre app for playing all things media whether locally or remotely.
|
||||
|
||||
Install **Kodi** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo apt-get install software-properties-common
|
||||
$ sudo add-apt-repository ppa:team-xbmc/ppa
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install kodi
|
||||
|
||||
```
|
||||
|
||||
#### SMPlayer
|
||||
|
||||
[SMPlayer][85] is a GUI for the award-winning **MPlayer** and it is capable of handling all popular media formats; coupled with the ability to stream from YouTube, Chromcast, and download subtitles.
|
||||
|
||||
Install **SMPlayer** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:rvm/smplayer
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install smplayer
|
||||
|
||||
```
|
||||
|
||||
### Virtualization Tools
|
||||
|
||||
#### VirtualBox
|
||||
|
||||
[VirtualBox][86] is an open source app created for general-purpose OS virtualization and it can be run on servers, desktops, and embedded systems.
|
||||
|
||||
Install **VirtualBox** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
|
||||
$ wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install virtualbox-5.2
|
||||
$ virtualbox
|
||||
|
||||
```
|
||||
|
||||
#### VMWare
|
||||
|
||||
[VMware][87] is a digital workspace that provides platform virtualization and cloud computing services to customers and is reportedly the first to successfully virtualize x86 architecture systems. One of its products, VMware workstations allows users to run multiple OSes in a virtual memory.
|
||||
|
||||
For installation, read our article “[How to Install VMware Workstation Pro on Ubuntu][88]“.
|
||||
|
||||
### Web Browsers
|
||||
|
||||
#### Chrome
|
||||
|
||||
[Google Chrome][89] is undoubtedly the most popular browser. Known for its speed, simplicity, security, and beauty following Google’s Material Design trend, Chrome is a browser that web developers cannot do without. It is also free to use and open source.
|
||||
|
||||
Install **Google Chrome** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
|
||||
$ sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
|
||||
$ sudo apt-get update
|
||||
$ sudo apt-get install google-chrome-stable
|
||||
|
||||
```
|
||||
|
||||
#### Firefox
|
||||
|
||||
[Firefox Quantum][90] is a beautiful, speed, task-ready, and customizable browser capable of any browsing task that you throw at it. It is also free, open source, and packed with developer-friendly tools that are easy for even beginners to get up and running with.
|
||||
|
||||
Install **Firefox Quantum** on **Ubuntu** and **Debian** , using following commands.
|
||||
```
|
||||
$ sudo add-apt-repository ppa:mozillateam/firefox-next
|
||||
$ sudo apt update && sudo apt upgrade
|
||||
$ sudo apt install firefox
|
||||
|
||||
```
|
||||
|
||||
#### Vivaldi
|
||||
|
||||
[Vivaldi][91] is a free and open source Chrome-based project that aims to perfect Chrome’s features with a couple of more feature additions. It is known for its colourful panels, memory-friendly performance, and flexibility.
|
||||
|
||||
[**Download Vivaldi for Ubuntu][91]
|
||||
|
||||
That concludes our list for today. Did I skip a famous title? Tell me about it in the comments section below.
|
||||
|
||||
Don’t forget to share this post and to subscribe to our newsletter to get the latest publications from FossMint.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.fossmint.com/most-used-linux-applications/
|
||||
|
||||
作者：[Martins D. Okoi][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.fossmint.com/author/dillivine/
|
||||
[1]:https://plus.google.com/share?url=https://www.fossmint.com/most-used-linux-applications/ (Share on Google+)
|
||||
[2]:https://www.linkedin.com/shareArticle?mini=true&url=https://www.fossmint.com/most-used-linux-applications/ (Share on LinkedIn)
|
||||
[3]:https://www.fossmint.com/awesome-linux-software/
|
||||
[4]:https://rsync.samba.org/
|
||||
[5]:https://www.tecmint.com/rsync-local-remote-file-synchronization-commands/
|
||||
[6]:https://github.com/teejee2008/timeshift
|
||||
[7]:https://deluge-torrent.org/
|
||||
[8]:https://www.qbittorrent.org/
|
||||
[9]:https://transmissionbt.com/
|
||||
[10]:https://www.dropbox.com/
|
||||
[11]:https://www.google.com/drive/
|
||||
[12]:https://www.fossmint.com/best-google-drive-clients-for-linux/
|
||||
[13]:https://mega.nz/
|
||||
[14]:https://mega.nz/sync!linux
|
||||
[15]:https://www.vim.org/
|
||||
[16]:https://www.gnu.org/s/emacs/
|
||||
[17]:https://www.nano-editor.org/
|
||||
[18]:https://aria2.github.io/
|
||||
[19]:http://ugetdm.com/
|
||||
[20]:http://xdman.sourceforge.net/
|
||||
[21]:https://www.thunderbird.net/
|
||||
[22]:https://github.com/GNOME/geary
|
||||
[23]:https://github.com/GNOME/evolution
|
||||
[24]:https://www.gnucash.org/
|
||||
[25]:https://kmymoney.org/
|
||||
[26]:https://www.eclipse.org/ide/
|
||||
[27]:https://www.tecmint.com/install-eclipse-oxygen-ide-in-ubuntu-debian/
|
||||
[28]:https://netbeans.org/
|
||||
[29]:https://www.tecmint.com/install-netbeans-ide-in-ubuntu-debian-linux-mint/
|
||||
[30]:http://brackets.io/
|
||||
[31]:https://ide.atom.io/
|
||||
[32]:http://lighttable.com/
|
||||
[33]:https://code.visualstudio.com/
|
||||
[34]:https://code.visualstudio.com/download
|
||||
[35]:https://www.pidgin.im/
|
||||
[36]:https://www.skype.com/
|
||||
[37]:https://wiki.gnome.org/Apps/Empathy
|
||||
[38]:https://www.clamav.net/
|
||||
[39]:https://dave-theunsub.github.io/clamtk/
|
||||
[40]:https://github.com/linuxmint/cinnamon-desktop
|
||||
[41]:https://mate-desktop.org/
|
||||
[42]:https://www.gnome.org/
|
||||
[43]:https://www.kde.org/plasma-desktop
|
||||
[44]:https://github.com/nzjrs/gnome-tweak-tool
|
||||
[45]:https://github.com/oguzhaninan/Stacer
|
||||
[46]:https://www.bleachbit.org/
|
||||
[47]:https://www.bleachbit.org/download
|
||||
[48]:https://github.com/GNOME/gnome-terminal
|
||||
[49]:https://konsole.kde.org/
|
||||
[50]:https://gnometerminator.blogspot.com/p/introduction.html
|
||||
[51]:http://guake-project.org/
|
||||
[52]:https://ardour.org/
|
||||
[53]:https://www.audacityteam.org/
|
||||
[54]:https://www.gimp.org/
|
||||
[55]:https://krita.org/en/
|
||||
[56]:https://www.lwks.com/
|
||||
[57]:https://www.lwks.com/index.php?option=com_lwks&view=download&Itemid=206
|
||||
[58]:https://www.openshot.org/
|
||||
[59]:http://www.pitivi.org/
|
||||
[60]:https://wiki.gnome.org/Apps/Rhythmbox
|
||||
[61]:https://gnumdk.github.io/lollypop-web/
|
||||
[62]:https://amarok.kde.org/en
|
||||
[63]:https://www.clementine-player.org/
|
||||
[64]:https://cmus.github.io/
|
||||
[65]:https://www.calligra.org/tour/calligra-suite/
|
||||
[66]:https://www.libreoffice.org/
|
||||
[67]:https://www.wps.com/
|
||||
[68]:http://wps-community.org/downloads
|
||||
[69]:http://shutter-project.org/
|
||||
[70]:https://launchpad.net/kazam
|
||||
[71]:https://gitlab.gnome.org/GNOME/gnome-screenshot
|
||||
[72]:http://www.maartenbaert.be/simplescreenrecorder/
|
||||
[73]:http://recordmydesktop.sourceforge.net/about.php
|
||||
[74]:https://atom.io/
|
||||
[75]:https://www.sublimetext.com/
|
||||
[76]:https://www.geany.org/
|
||||
[77]:https://wiki.gnome.org/Apps/Gedit
|
||||
[78]:https://everdo.net/
|
||||
[79]:https://www.fossmint.com/evernote-alternatives-for-linux/
|
||||
[80]:https://everdo.net/linux/
|
||||
[81]:https://taskwarrior.org/
|
||||
[82]:http://banshee.fm/
|
||||
[83]:https://www.videolan.org/
|
||||
[84]:https://kodi.tv/
|
||||
[85]:https://www.smplayer.info/
|
||||
[86]:https://www.virtualbox.org/wiki/VirtualBox
|
||||
[87]:https://www.vmware.com/
|
||||
[88]:https://www.tecmint.com/install-vmware-workstation-in-linux/
|
||||
[89]:https://www.google.com/chrome/
|
||||
[90]:https://www.mozilla.org/en-US/firefox/
|
||||
[91]:https://vivaldi.com/
|
||||
@ -1,284 +0,0 @@
|
||||
Building a network attached storage device with a Raspberry Pi
|
||||
======
|
||||
|
||||
|
||||
|
||||
In this three-part series, I'll explain how to set up a simple, useful NAS (network attached storage) system. I use this kind of setup to store my files on a central system, creating incremental backups automatically every night. To mount the disk on devices that are located in the same network, NFS is installed. To access files offline and share them with friends, I use [Nextcloud][1].
|
||||
|
||||
This article will cover the basic setup of software and hardware to mount the data disk on a remote device. In the second article, I will discuss a backup strategy and set up a cron job to create daily backups. In the third and last article, we will install Nextcloud, a tool for easy file access to devices synced offline as well as online using a web interface. It supports multiple users and public file-sharing so you can share pictures with friends, for example, by sending a password-protected link.
|
||||
|
||||
The target architecture of our system looks like this:
|
||||
|
||||
|
||||
### Hardware
|
||||
|
||||
Let's get started with the hardware you need. You might come up with a different shopping list, so consider this one an example.
|
||||
|
||||
The computing power is delivered by a [Raspberry Pi 3][2], which comes with a quad-core CPU, a gigabyte of RAM, and (somewhat) fast ethernet. Data will be stored on two USB hard drives (I use 1-TB disks); one is used for the everyday traffic, the other is used to store backups. Be sure to use either active USB hard drives or a USB hub with an additional power supply, as the Raspberry Pi will not be able to power two USB drives.
|
||||
|
||||
### Software
|
||||
|
||||
The operating system with the highest visibility in the community is [Raspbian][3] , which is excellent for custom projects. There are plenty of [guides][4] that explain how to install Raspbian on a Raspberry Pi, so I won't go into details here. The latest official supported version at the time of this writing is [Raspbian Stretch][5] , which worked fine for me.
|
||||
|
||||
At this point, I will assume you have configured your basic Raspbian and are able to connect to the Raspberry Pi by `ssh`.
|
||||
|
||||
### Prepare the USB drives
|
||||
|
||||
To achieve good performance reading from and writing to the USB hard drives, I recommend formatting them with ext4. To do so, you must first find out which disks are attached to the Raspberry Pi. You can find the disk devices in `/dev/sd/<x>`. Using the command `fdisk -l`, you can find out which two USB drives you just attached. Please note that all data on the USB drives will be lost as soon as you follow these steps.
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo fdisk -l
|
||||
|
||||
|
||||
|
||||
<...>
|
||||
|
||||
|
||||
|
||||
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 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: 0xe8900690
|
||||
|
||||
|
||||
|
||||
Device Boot Start End Sectors Size Id Type
|
||||
|
||||
/dev/sda1 2048 1953525167 1953523120 931.5G 83 Linux
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
Disk /dev/sdb: 931.5 GiB, 1000204886016 bytes, 1953525168 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: 0x6aa4f598
|
||||
|
||||
|
||||
|
||||
Device Boot Start End Sectors Size Id Type
|
||||
|
||||
/dev/sdb1 * 2048 1953521663 1953519616 931.5G 83 Linux
|
||||
|
||||
```
|
||||
|
||||
As those devices are the only 1TB disks attached to the Raspberry Pi, we can easily see that `/dev/sda` and `/dev/sdb` are the two USB drives. The partition table at the end of each disk shows how it should look after the following steps, which create the partition table and format the disks. To do this, repeat the following steps for each of the two devices by replacing `sda` with `sdb` the second time (assuming your devices are also listed as `/dev/sda` and `/dev/sdb` in `fdisk`).
|
||||
|
||||
First, delete the partition table of the disk and create a new one containing only one partition. In `fdisk`, you can use interactive one-letter commands to tell the program what to do. Simply insert them after the prompt `Command (m for help):` as follows (you can also use the `m` command anytime to get more information):
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo fdisk /dev/sda
|
||||
|
||||
|
||||
|
||||
Welcome to fdisk (util-linux 2.29.2).
|
||||
|
||||
Changes will remain in memory only, until you decide to write them.
|
||||
|
||||
Be careful before using the write command.
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
Command (m for help): o
|
||||
|
||||
Created a new DOS disklabel with disk identifier 0x9c310964.
|
||||
|
||||
|
||||
|
||||
Command (m for help): n
|
||||
|
||||
Partition type
|
||||
|
||||
p primary (0 primary, 0 extended, 4 free)
|
||||
|
||||
e extended (container for logical partitions)
|
||||
|
||||
Select (default p): p
|
||||
|
||||
Partition number (1-4, default 1):
|
||||
|
||||
First sector (2048-1953525167, default 2048):
|
||||
|
||||
Last sector, +sectors or +size{K,M,G,T,P} (2048-1953525167, default 1953525167):
|
||||
|
||||
|
||||
|
||||
Created a new partition 1 of type 'Linux' and of size 931.5 GiB.
|
||||
|
||||
|
||||
|
||||
Command (m for help): p
|
||||
|
||||
|
||||
|
||||
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 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: 0x9c310964
|
||||
|
||||
|
||||
|
||||
Device Boot Start End Sectors Size Id Type
|
||||
|
||||
/dev/sda1 2048 1953525167 1953523120 931.5G 83 Linux
|
||||
|
||||
|
||||
|
||||
Command (m for help): w
|
||||
|
||||
The partition table has been altered.
|
||||
|
||||
Syncing disks.
|
||||
|
||||
```
|
||||
|
||||
Now we will format the newly created partition `/dev/sda1` using the ext4 filesystem:
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo mkfs.ext4 /dev/sda1
|
||||
|
||||
mke2fs 1.43.4 (31-Jan-2017)
|
||||
|
||||
Discarding device blocks: done
|
||||
|
||||
|
||||
|
||||
<...>
|
||||
|
||||
|
||||
|
||||
Allocating group tables: done
|
||||
|
||||
Writing inode tables: done
|
||||
|
||||
Creating journal (1024 blocks): done
|
||||
|
||||
Writing superblocks and filesystem accounting information: done
|
||||
|
||||
```
|
||||
|
||||
After repeating the above steps, let's label the new partitions according to their usage in your system:
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo e2label /dev/sda1 data
|
||||
|
||||
pi@raspberrypi:~ $ sudo e2label /dev/sdb1 backup
|
||||
|
||||
```
|
||||
|
||||
Now let's get those disks mounted to store some data. My experience, based on running this setup for over a year now, is that USB drives are not always available to get mounted when the Raspberry Pi boots up (for example, after a power outage), so I recommend using autofs to mount them when needed.
|
||||
|
||||
First install autofs and create the mount point for the storage:
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo apt install autofs
|
||||
|
||||
pi@raspberrypi:~ $ sudo mkdir /nas
|
||||
|
||||
```
|
||||
|
||||
Then mount the devices by adding the following line to `/etc/auto.master`:
|
||||
```
|
||||
/nas /etc/auto.usb
|
||||
|
||||
```
|
||||
|
||||
Create the file `/etc/auto.usb` if not existing with the following content, and restart the autofs service:
|
||||
```
|
||||
data -fstype=ext4,rw :/dev/disk/by-label/data
|
||||
|
||||
backup -fstype=ext4,rw :/dev/disk/by-label/backup
|
||||
|
||||
pi@raspberrypi3:~ $ sudo service autofs restart
|
||||
|
||||
```
|
||||
|
||||
Now you should be able to access the disks at `/nas/data` and `/nas/backup`, respectively. Clearly, the content will not be too thrilling, as you just erased all the data from the disks. Nevertheless, you should be able to verify the devices are mounted by executing the following commands:
|
||||
```
|
||||
pi@raspberrypi3:~ $ cd /nas/data
|
||||
|
||||
pi@raspberrypi3:/nas/data $ cd /nas/backup
|
||||
|
||||
pi@raspberrypi3:/nas/backup $ mount
|
||||
|
||||
<...>
|
||||
|
||||
/etc/auto.usb on /nas type autofs (rw,relatime,fd=6,pgrp=463,timeout=300,minproto=5,maxproto=5,indirect)
|
||||
|
||||
<...>
|
||||
|
||||
/dev/sda1 on /nas/data type ext4 (rw,relatime,data=ordered)
|
||||
|
||||
/dev/sdb1 on /nas/backup type ext4 (rw,relatime,data=ordered)
|
||||
|
||||
```
|
||||
|
||||
First move into the directories to make sure autofs mounts the devices. Autofs tracks access to the filesystems and mounts the needed devices on the go. Then the `mount` command shows that the two devices are actually mounted where we wanted them.
|
||||
|
||||
Setting up autofs is a bit fault-prone, so do not get frustrated if mounting doesn't work on the first try. Give it another chance, search for more detailed resources (there is plenty of documentation online), or leave a comment.
|
||||
|
||||
### Mount network storage
|
||||
|
||||
Now that you have set up the basic network storage, we want it to be mounted on a remote Linux machine. We will use the network file system (NFS) for this. First, install the NFS server on the Raspberry Pi:
|
||||
```
|
||||
pi@raspberrypi:~ $ sudo apt install nfs-kernel-server
|
||||
|
||||
```
|
||||
|
||||
Next we need to tell the NFS server to expose the `/nas/data` directory, which will be the only device accessible from outside the Raspberry Pi (the other one will be used for backups only). To export the directory, edit the file `/etc/exports` and add the following line to allow all devices with access to the NAS to mount your storage:
|
||||
```
|
||||
/nas/data *(rw,sync,no_subtree_check)
|
||||
|
||||
```
|
||||
|
||||
For more information about restricting the mount to single devices and so on, refer to `man exports`. In the configuration above, anyone will be able to mount your data as long as they have access to the ports needed by NFS: `111` and `2049`. I use the configuration above and allow access to my home network only for ports 22 and 443 using the routers firewall. That way, only devices in the home network can reach the NFS server.
|
||||
|
||||
To mount the storage on a Linux computer, run the commands:
|
||||
```
|
||||
you@desktop:~ $ sudo mkdir /nas/data
|
||||
|
||||
you@desktop:~ $ sudo mount -t nfs <raspberry-pi-hostname-or-ip>:/nas/data /nas/data
|
||||
|
||||
```
|
||||
|
||||
Again, I recommend using autofs to mount this network device. For extra help, check out [How to use autofs to mount NFS shares][6].
|
||||
|
||||
Now you are able to access files stored on your own RaspberryPi-powered NAS from remote devices using the NFS mount. In the next part of this series, I will cover how to automatically back up your data to the second hard drive using `rsync`. To save space on the device while still doing daily backups, you will learn how to create incremental backups with `rsync`.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/7/network-attached-storage-Raspberry-Pi
|
||||
|
||||
作者：[Manuel Dewald][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/ntlx
|
||||
[1]:https://nextcloud.com/
|
||||
[2]:https://www.raspberrypi.org/products/raspberry-pi-3-model-b/
|
||||
[3]:https://www.raspbian.org/
|
||||
[4]:https://www.raspberrypi.org/documentation/installation/installing-images/
|
||||
[5]:https://www.raspberrypi.org/blog/raspbian-stretch/
|
||||
[6]:https://opensource.com/article/18/6/using-autofs-mount-nfs-shares
|
||||
@ -1,5 +1,3 @@
|
||||
pinewall translating
|
||||
|
||||
How to analyze your system with perf and Python
|
||||
======
|
||||
|
||||
|
||||
@ -1,148 +0,0 @@
|
||||
5 Essential Tools for Linux Development
|
||||
======
|
||||
|
||||
|
||||
|
||||
Linux has become a mainstay for many sectors of work, play, and personal life. We depend upon it. With Linux, technology is expanding and evolving faster than anyone could have imagined. That means Linux development is also happening at an exponential rate. Because of this, more and more developers will be hopping on board the open source and Linux dev train in the immediate, near, and far-off future. For that, people will need tools. Fortunately, there are a ton of dev tools available for Linux; so many, in fact, that it can be a bit intimidating to figure out precisely what you need (especially if you’re coming from another platform).
|
||||
|
||||
To make that easier, I thought I’d help narrow down the selection a bit for you. But instead of saying you should use Tool X and Tool Y, I’m going to narrow it down to five categories and then offer up an example for each. Just remember, for most categories, there are several available options. And, with that said, let’s get started.
|
||||
|
||||
### Containers
|
||||
|
||||
Let’s face it, in this day and age you need to be working with containers. Not only are they incredibly easy to deploy, they make for great development environments. If you regularly develop for a specific platform, why not do so by creating a container image that includes all of the tools you need to make the process quick and easy. With that image available, you can then develop and roll out numerous instances of whatever software or service you need.
|
||||
|
||||
Using containers for development couldn’t be easier than it is with [Docker][1]. The advantages of using containers (and Docker) are:
|
||||
|
||||
* Consistent development environment.
|
||||
|
||||
* You can trust it will “just work” upon deployment.
|
||||
|
||||
* Makes it easy to build across platforms.
|
||||
|
||||
* Docker images available for all types of development environments and languages.
|
||||
|
||||
* Deploying single containers or container clusters is simple.
|
||||
|
||||
|
||||
|
||||
|
||||
Thanks to [Docker Hub][2], you’ll find images for nearly any platform, development environment, server, service… just about anything you need. Using images from Docker Hub means you can skip over the creation of the development environment and go straight to work on developing your app, server, API, or service.
|
||||
|
||||
Docker is easily installable of most every Linux platform. For example: To install Docker on Ubuntu, you only have to open a terminal window and issue the command:
|
||||
```
|
||||
sudo apt-get install docker.io
|
||||
|
||||
```
|
||||
|
||||
With Docker installed, you’re ready to start pulling down specific images, developing, and deploying (Figure 1).
|
||||
|
||||
![Docker images][4]
|
||||
|
||||
Figure 1: Docker images ready to deploy.
|
||||
|
||||
[Used with permission][5]
|
||||
|
||||
### Version control system
|
||||
|
||||
If you’re working on a large project or with a team on a project, you’re going to need a version control system. Why? Because you need to keep track of your code, where your code is, and have an easy means of making commits and merging code from others. Without such a tool, your projects would be nearly impossible to manage. For Linux users, you cannot beat the ease of use and widespread deployment of [Git][6] and [GitHub][7]. If you’re new to their worlds, Git is the version control system that you install on your local machine and GitHub is the remote repository you use to upload (and then manage) your projects. Git can be installed on most Linux distributions. For example, on a Debian-based system, the install is as simple as:
|
||||
```
|
||||
sudo apt-get install git
|
||||
|
||||
```
|
||||
|
||||
Once installed, you are ready to start your journey with version control (Figure 2).
|
||||
|
||||
![Git installed][9]
|
||||
|
||||
Figure 2: Git is installed and available for many important tasks.
|
||||
|
||||
[Used with permission][5]
|
||||
|
||||
Github requires you to create an account. You can use it for free for non-commercial projects, or you can pay for commercial project housing (for more information check out the price matrix [here][10]).
|
||||
|
||||
### Text editor
|
||||
|
||||
Let’s face it, developing on Linux would be a bit of a challenge without a text editor. Of course what a text editor is varies, depending upon who you ask. One person might say vim, emacs, or nano, whereas another might go full-on GUI with their editor. But since we’re talking development, we need a tool that can meet the needs of the modern day developer. And before I mention a couple of text editors, I will say this: Yes, I know that vim is a serious workhorse for serious developers and, if you know it well vim will meet and exceed all of your needs. However, getting up to speed enough that it won’t be in your way, can be a bit of a hurdle for some developers (especially those new to Linux). Considering my goal is to always help win over new users (and not just preach to an already devout choir), I’m taking the GUI route here.
|
||||
|
||||
As far as text editors are concerned, you cannot go wrong with the likes of [Bluefish][11]. Bluefish can be found in most standard repositories and features project support, multi-threaded support for remote files, search and replace, open files recursively, snippets sidebar, integrates with make, lint, weblint, xmllint, unlimited undo/redo, in-line spell checker, auto-recovery, full screen editing, syntax highlighting (Figure 3), support for numerous languages, and much more.
|
||||
|
||||
![Bluefish][13]
|
||||
|
||||
Figure 3: Bluefish running on Ubuntu Linux 18.04.
|
||||
|
||||
[Used with permission][5]
|
||||
|
||||
### IDE
|
||||
|
||||
Integrated Development Environment (IDE) is a piece of software that includes a comprehensive set of tools that enable a one-stop-shop environment for developing. IDEs not only enable you to code your software, but document and build them as well. There are a number of IDEs for Linux, but one in particular is not only included in the standard repositories it is also very user-friendly and powerful. That tool in question is [Geany][14]. Geany features syntax highlighting, code folding, symbol name auto-completion, construct completion/snippets, auto-closing of XML and HTML tags, call tips, many supported filetypes, symbol lists, code navigation, build system to compile and execute your code, simple project management, and a built-in plugin system.
|
||||
|
||||
Geany can be easily installed on your system. For example, on a Debian-based distribution, issue the command:
|
||||
```
|
||||
sudo apt-get install geany
|
||||
|
||||
```
|
||||
|
||||
Once installed, you’re ready to start using this very powerful tool that includes a user-friendly interface (Figure 4) that has next to no learning curve.
|
||||
|
||||
![Geany][16]
|
||||
|
||||
Figure 4: Geany is ready to serve as your IDE.
|
||||
|
||||
[Used with permission][5]
|
||||
|
||||
### diff tool
|
||||
|
||||
There will be times when you have to compare two files to find where they differ. This could be two different copies of what was the same file (only one compiles and the other doesn’t). When that happens, you don’t want to have to do that manually. Instead, you want to employ the power of tool like [Meld][17]. Meld is a visual diff and merge tool targeted at developers. With Meld you can make short shrift out of discovering the differences between two files. Although you can use a command line diff tool, when efficiency is the name of the game, you can’t beat Meld.
|
||||
|
||||
Meld allows you to open a comparison between to files and it will highlight the differences between each. Meld also allows you to merge comparisons either from the right or the left (as the files are opened side by side - Figure 5).
|
||||
|
||||
![Comparing two files][19]
|
||||
|
||||
Figure 5: Comparing two files with a simple difference.
|
||||
|
||||
[Used with permission][5]
|
||||
|
||||
Meld can be installed from most standard repositories. On a Debian-based system, the installation command is:
|
||||
```
|
||||
sudo apt-get install meld
|
||||
|
||||
```
|
||||
|
||||
### Working with efficiency
|
||||
|
||||
These five tools not only enable you to get your work done, they help to make it quite a bit more efficient. Although there are a ton of developer tools available for Linux, you’re going to want to make sure you have one for each of the above categories (maybe even starting with the suggestions I’ve made).
|
||||
|
||||
Learn more about Linux through the free ["Introduction to Linux" ][20]course from The Linux Foundation and edX.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.linux.com/learn/intro-to-linux/2018/8/5-essential-tools-linux-development
|
||||
|
||||
作者：[Jack Wallen][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.linux.com/users/jlwallen
|
||||
[1]:https://www.docker.com/
|
||||
[2]:https://hub.docker.com/
|
||||
[3]:/files/images/5devtools1jpg
|
||||
[4]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_1.jpg?itok=V1Bsbkg9 (Docker images)
|
||||
[5]:/licenses/category/used-permission
|
||||
[6]:https://git-scm.com/
|
||||
[7]:https://github.com/
|
||||
[8]:/files/images/5devtools2jpg
|
||||
[9]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_2.jpg?itok=YJjhe4O6 (Git installed)
|
||||
[10]:https://github.com/pricing
|
||||
[11]:http://bluefish.openoffice.nl/index.html
|
||||
[12]:/files/images/5devtools3jpg
|
||||
[13]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_3.jpg?itok=66A7Svme (Bluefish)
|
||||
[14]:https://www.geany.org/
|
||||
[15]:/files/images/5devtools4jpg
|
||||
[16]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_4.jpg?itok=jRcA-0ue (Geany)
|
||||
[17]:http://meldmerge.org/
|
||||
[18]:/files/images/5devtools5jpg
|
||||
[19]:https://www.linux.com/sites/lcom/files/styles/rendered_file/public/5devtools_5.jpg?itok=eLkfM9oZ (Comparing two files)
|
||||
[20]:https://training.linuxfoundation.org/linux-courses/system-administration-training/introduction-to-linux
|
||||
@ -1,84 +0,0 @@
|
||||
translating by lujun9972
|
||||
How to Create M3U Playlists in Linux [Quick Tip]
|
||||
======
|
||||
**Brief: A quick tip on how to create M3U playlists in Linux terminal from unordered files to play them in a sequence.**
|
||||
|
||||
![Create M3U playlists in Linux Terminal][1]
|
||||
|
||||
I am a fan of foreign tv series and it’s not always easy to get them on DVD or on streaming services like [Netflix][2]. Thankfully, you can find some of them on YouTube and [download them from YouTube][3].
|
||||
|
||||
Now there comes a problem. Your files might not be sorted in a particular order. In GNU/Linux files are not naturally sort ordered by number sequencing so I had to make a .m3u playlist so [MPV video player][4] would play the videos in sequence and not out of sequence.
|
||||
|
||||
Also sometimes the numbers are in the middle or the end like ‘My Web Series S01E01.mkv’ as an example. The episode information here is in the middle of the filename, the ‘S01E01’ which tells us, humans, which is the first episode and which needs to come in next.
|
||||
|
||||
So what I did was to generate an m3u playlist in the video directory and tell MPV to play the .m3u playlist and it would take care of playing them in the sequence.
|
||||
|
||||
### What is an M3U file?
|
||||
|
||||
[M3U][5] is basically a text file that contains filenames in a specific order. When a player like MPV or VLC opens an M3U file, it tries to play the specified files in the given sequence.
|
||||
|
||||
### Creating M3U to play audio/video files in a sequence
|
||||
|
||||
In my case, I used the following command:
|
||||
```
|
||||
$/home/shirish/Videos/web-series-video/$ ls -1v |grep .mkv > /tmp/1.m3u && mv /tmp/1.m3u .
|
||||
|
||||
```
|
||||
|
||||
Let’s break it down a bit and see each bit as to what it means –
|
||||
|
||||
**ls -1v** = This is using the plain ls or listing entries in the directory. The -1 means list one file per line. while -v natural sort of (version) numbers within text
|
||||
|
||||
**| grep .mkv** = It’s basically telling `ls` to look for files which are ending in .mkv . It could be .mp4 or any other media file format that you want.
|
||||
|
||||
It’s usually a good idea to do a dry run by running the command on the console:
|
||||
```
|
||||
ls -1v |grep .mkv
|
||||
My Web Series S01E01 [Episode 1 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E02 [Episode 2 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E03 [Episode 3 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E04 [Episode 4 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E05 [Episode 5 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E06 [Episode 6 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E07 [Episode 7 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
My Web Series S01E08 [Episode 8 Name] Multi 480p WEBRip x264 - xRG.mkv
|
||||
|
||||
```
|
||||
|
||||
This tells me that what I’m trying to do is correct. Now just have to make that the output is in the form of a .m3u playlist which is the next part.
|
||||
```
|
||||
ls -1v |grep .mkv > /tmp/web_playlist.m3u && mv /tmp/web_playlist.m3u .
|
||||
|
||||
```
|
||||
|
||||
This makes the .m3u generate in the current directory. The .m3u playlist is nothing but a .txt file with the same contents as above with the .m3u extension. You can edit it manually as well and add the exact filenames in an order you desire.
|
||||
|
||||
After that you just have to do something like this:
|
||||
```
|
||||
mpv web_playlist.m3u
|
||||
|
||||
```
|
||||
|
||||
The great thing about MPV and the playlists, in general, is that you don’t have to binge-watch. You can see however much you want to do in one sitting and see the rest in the next session or the session after that.
|
||||
|
||||
I hope to do articles featuring MPV as well as how to make mkv files embedding subtitles in a media file but that’s in the future.
|
||||
|
||||
Note: It’s FOSS doesn’t encourage piracy.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/create-m3u-playlist-linux/
|
||||
|
||||
作者：[Shirsh][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://itsfoss.com/author/shirish/
|
||||
[1]:https://4bds6hergc-flywheel.netdna-ssl.com/wp-content/uploads/2018/08/Create-M3U-Playlists.jpeg
|
||||
[2]:https://itsfoss.com/netflix-open-source-ai/
|
||||
[3]:https://itsfoss.com/download-youtube-linux/
|
||||
[4]:https://itsfoss.com/mpv-video-player/
|
||||
[5]:https://en.wikipedia.org/wiki/M3U
|
||||
@ -1,190 +0,0 @@
|
||||
How To Lock The Keyboard And Mouse, But Not The Screen In Linux
|
||||
======
|
||||
|
||||
|
||||
|
||||
My 4-years-old niece is a curious-kid. She loves “Avatar” movie very much. When the Avatar movie is on, she became so focused and her eyes are glued to the screen. But the problem is she often touches a key in the keyboard or move the mouse or click the mouse button while watching the movie. Sometimes, she accidentally close or pause the movie by pressing a key in the keyboard. So I was looking for a way to lock down both the keyboard and mouse, but not the screen. Luckily, I came across a perfect solution in Ubuntu forum. If you don’t want your cat or puppy walking on your keyboard or your kid messing up with the keyboard and mouse while you watching something important on the screen, I suggest you to try **“xtrlock”** utility. It is a simple, yet useful utility to lock the X display till the user enters their password at the keyboard. In this brief tutorial, I will show you how to lock the keyboard and mouse, but not the screen in Linux. This trick will work on all Linux operating systems.
|
||||
|
||||
### Install xtrlock
|
||||
|
||||
The xtrlock package is available in the default repositories of most Linux operating systems. So, you can install it using your distribution’s package manager.
|
||||
|
||||
On **Arch Linux** and derivatives, run the following command to install it.
|
||||
```
|
||||
$ sudo pacman -S xtrlock
|
||||
|
||||
```
|
||||
|
||||
On **Fedora** :
|
||||
```
|
||||
$ sudo dnf install xtrlock
|
||||
|
||||
```
|
||||
|
||||
On **RHEL, CentOS** :
|
||||
```
|
||||
$ sudo yum install xtrlock
|
||||
|
||||
```
|
||||
|
||||
On **SUSE/openSUSE** :
|
||||
```
|
||||
$ sudo zypper install xtrlock
|
||||
|
||||
```
|
||||
|
||||
On **Debian, Ubuntu, Linux Mint** :
|
||||
```
|
||||
$ sudo apt-get install xtrlock
|
||||
|
||||
```
|
||||
|
||||
### Lock the Keyboard and Mouse, but not the Screen using xtrlock
|
||||
|
||||
Once xtrlock installed, create a keyboard shortcut. You need this to lock the keyboard and mouse using the key combination of your choice.
|
||||
|
||||
Create a new file called **lockkbmouse** in **/usr/local/bin**.
|
||||
```
|
||||
$ sudo vi /usr/local/bin/lockkbmouse
|
||||
|
||||
```
|
||||
|
||||
Add the following lines into it.
|
||||
```
|
||||
#!/bin/bash
|
||||
sleep 1 && xtrlock
|
||||
|
||||
```
|
||||
|
||||
Save the file and close the file.
|
||||
|
||||
Make it as executable using the following command:
|
||||
```
|
||||
$ sudo chmod a+x /usr/local/bin/lockkbmouse
|
||||
|
||||
```
|
||||
|
||||
Next, we need to create keyboard a shortcut.
|
||||
|
||||
**In Arch Linux MATE desktop:**
|
||||
|
||||
Go to **System - > Preferences -> Hardware -> keyboard Shortcuts**.
|
||||
|
||||
Click **Add** to create a new shortcut.
|
||||
|
||||
![][2]
|
||||
|
||||
Enter the name for your shortcut and add the following line in the command box, and click **Apply** button.
|
||||
```
|
||||
bash -c "sleep 1 && xtrlock"
|
||||
|
||||
```
|
||||
|
||||
![][3]
|
||||
|
||||
To assign the shortcut key, just select or double click on it and type the key combination of your choice. For example, I use **Alt+k**.
|
||||
|
||||
![][4]
|
||||
|
||||
To clear the key combination, press BACKSPACE key. Once you finished, close the Keyboard Settings window.
|
||||
|
||||
**In Ubuntu GNOME DE:**
|
||||
|
||||
Go to **System Settings - > Devices -> Keyboard**. Click the **+** symbol at the end.
|
||||
|
||||
Enter the name for your shortcut and add the following line in the command box, and click **Add** button.
|
||||
```
|
||||
bash -c "sleep 1 && xtrlock"
|
||||
|
||||
```
|
||||
|
||||
![][5]
|
||||
|
||||
Next, assign the shortcut key to the newly created shortcut. To do so, just select or double click on it and click on **“Set shortcut”** button.
|
||||
|
||||
![][6]
|
||||
|
||||
You will now see the following screen.
|
||||
|
||||
![][7]
|
||||
|
||||
Type the key combination of your choice. For example, I use **Alt+k**.
|
||||
|
||||
![][8]
|
||||
|
||||
To clear the key combination, press BACKSPACE key. The shortcut key has been assigned. Once you finished, close the Keyboard Settings window.
|
||||
|
||||
From now on, whenever you press the keyboard shortcut key (ALT+k in our case), the mouse pointer will turn into a a padlock. Now, the keyboard and mouse have been locked, so you can freely watch the movies or whatever you want to. Even your kid or pet touches some keys on the keyboard or clicks a mouse button, they won’t work.
|
||||
|
||||
Here is xtrclock in action.
|
||||
|
||||
![][9]
|
||||
|
||||
Do you see the a small lock button? It means that the keyboard and mouse have been locked. Even if you move the lock button, nothing will happen. The task in the background will keep running until you unlock your screen and manually close the running task.
|
||||
|
||||
### Unlock keyboard and mouse
|
||||
|
||||
To unlock the keyboard and mouse, simply type your password and hit “Enter”. You will not see the password as you type it. Just type the password anyway and hit ENTER key. The mouse and keyboard will start to work after you entered the correct password. If you entered an incorrect password, you will hear a bell sound. Press **ESC** key to clear the incorrect password and re-enter the correct password again. To remove one character of a partially typed password, press either **BACKSPACE** or **DELETE** keys.
|
||||
|
||||
### What if I permanently get locked out of the screen?
|
||||
|
||||
The xtrclock tool may not work on some DEs, for example GDM. It may permanently lock you out of the screen. Please test it in a virtual machine and then try it in your personal or official desktop if it really works. I tested this on Arch Linux MATE desktop and Ubuntu 18.04 GNOME desktop. It worked just fine.
|
||||
|
||||
Just in case, you are locked out of the screen permanently, switch to the TTY (CTRL+ALT+F2) then run:
|
||||
```
|
||||
$ sudo killall xtrlock
|
||||
|
||||
```
|
||||
|
||||
Alternatively, you can use the **chvt** command to switch between TTY and X session.
|
||||
|
||||
For example, to switch to TTY1, run:
|
||||
```
|
||||
$ sudo chvt 1
|
||||
|
||||
```
|
||||
|
||||
To switch back to the X session again, type:
|
||||
```
|
||||
$ sudo chvt 7
|
||||
|
||||
```
|
||||
|
||||
Different distros uses different key combinations to switch between TTYs. Please refer your distribution’s official website for more details.
|
||||
|
||||
For more details about xtrlock, refer man pages.
|
||||
```
|
||||
$ man xtrlock
|
||||
|
||||
```
|
||||
|
||||
And, that’s all for now. Hope this helps. If you find our guides useful, please spend a moment to share them on your social, professional networks and support OSTechNix.
|
||||
|
||||
**Resource:**
|
||||
|
||||
* [**Ubuntu forum**][10]
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/lock-keyboard-mouse-not-screen-linux/
|
||||
|
||||
作者：[SK][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.ostechnix.com/author/sk/
|
||||
[1]:data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
|
||||
[2]:http://www.ostechnix.com/wp-content/uploads/2017/09/Keyboard-Shortcuts_001.png
|
||||
[3]:http://www.ostechnix.com/wp-content/uploads/2017/09/Keyboard-Shortcuts_002.png
|
||||
[4]:http://www.ostechnix.com/wp-content/uploads/2017/09/Keyboard-Shortcuts_003.png
|
||||
[5]:http://www.ostechnix.com/wp-content/uploads/2018/01/Add-xtrlock-shortcut.png
|
||||
[6]:http://www.ostechnix.com/wp-content/uploads/2018/01/set-shortcut-key-1.png
|
||||
[7]:http://www.ostechnix.com/wp-content/uploads/2018/01/set-shortcut-key-2.png
|
||||
[8]:http://www.ostechnix.com/wp-content/uploads/2018/01/set-shortcut-key-3.png
|
||||
[9]:http://www.ostechnix.com/wp-content/uploads/2018/01/xtrclock-1.png
|
||||
[10]:https://ubuntuforums.org/showthread.php?t=993800
|
||||
@ -1,170 +0,0 @@
|
||||
A checklist for submitting your first Linux kernel patch
|
||||
======
|
||||
|
||||
|
||||
|
||||
One of the biggest—and the fastest moving—open source projects, the Linux kernel, is composed of about 53,600 files and nearly 20-million lines of code. With more than 15,600 programmers contributing to the project worldwide, the Linux kernel follows a maintainer model for collaboration.
|
||||
|
||||
|
||||
|
||||
In this article, I'll provide a quick checklist of steps involved with making your first kernel contribution, and look at what you should know before submitting a patch. For a more in-depth look at the submission process for contributing your first patch, read the [KernelNewbies First Kernel Patch tutorial][1].
|
||||
|
||||
### Contributing to the kernel
|
||||
|
||||
#### Step 1: Prepare your system.
|
||||
|
||||
Steps in this article assume you have the following tools on your system:
|
||||
|
||||
+ Text editor
|
||||
+ Email client
|
||||
+ Version control system (e.g., git)
|
||||
|
||||
#### Step 2: Download the Linux kernel code repository`:`
|
||||
```
|
||||
git clone -b staging-testing
|
||||
|
||||
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
|
||||
|
||||
```
|
||||
|
||||
### Copy your current config: ````
|
||||
```
|
||||
cp /boot/config-`uname -r`* .config
|
||||
|
||||
```
|
||||
|
||||
### Step 3: Build/install your kernel.
|
||||
```
|
||||
make -jX
|
||||
|
||||
sudo make modules_install install
|
||||
|
||||
```
|
||||
|
||||
### Step 4: Make a branch and switch to it.
|
||||
```
|
||||
git checkout -b first-patch
|
||||
|
||||
```
|
||||
|
||||
### Step 5: Update your kernel to point to the latest code base.
|
||||
```
|
||||
git fetch origin
|
||||
|
||||
git rebase origin/staging-testing
|
||||
|
||||
```
|
||||
|
||||
### Step 6: Make a change to the code base.
|
||||
|
||||
Recompile using `make` command to ensure that your change does not produce errors.
|
||||
|
||||
### Step 7: Commit your changes and create a patch.
|
||||
```
|
||||
git add <file>
|
||||
|
||||
git commit -s -v
|
||||
|
||||
git format-patch -o /tmp/ HEAD^
|
||||
|
||||
```
|
||||
|
||||
|
||||
|
||||
The subject consists of the path to the file name separated by colons, followed by what the patch does in the imperative tense. After a blank line comes the description of the patch and the mandatory signed off tag and, lastly, a diff of your patch.
|
||||
|
||||
Here is another example of a simple patch:
|
||||
|
||||
|
||||
|
||||
Next, send the patch [using email from the command line][2] (in this case, Mutt): ``
|
||||
```
|
||||
mutt -H /tmp/0001-<whatever your filename is>
|
||||
|
||||
```
|
||||
|
||||
To know the list of maintainers to whom to send the patch, use the [get_maintainer.pl script][11].
|
||||
|
||||
|
||||
### What to know before submitting your first patch
|
||||
|
||||
* [Greg Kroah-Hartman][3]'s [staging tree][4] is a good place to submit your [first patch][1] as he accepts easy patches from new contributors. When you get familiar with the patch-sending process, you could send subsystem-specific patches with increased complexity.
|
||||
|
||||
* You also could start with correcting coding style issues in the code. To learn more, read the [Linux kernel coding style documentation][5].
|
||||
|
||||
* The script [checkpatch.pl][6] detects coding style errors for you. For example, run:
|
||||
```
|
||||
perl scripts/checkpatch.pl -f drivers/staging/android/* | less
|
||||
|
||||
```
|
||||
|
||||
* You could complete TODOs left incomplete by developers:
|
||||
```
|
||||
find drivers/staging -name TODO
|
||||
```
|
||||
|
||||
* [Coccinelle][7] is a helpful tool for pattern matching.
|
||||
|
||||
* Read the [kernel mailing archives][8].
|
||||
|
||||
* Go through the [linux.git log][9] to see commits by previous authors for inspiration.
|
||||
|
||||
* Note: Do not top-post to communicate with the reviewer of your patch! Here's an example:
|
||||
|
||||
**Wrong way:**
|
||||
|
||||
Chris,
|
||||
_Yes let’s schedule the meeting tomorrow, on the second floor._
|
||||
> On Fri, Apr 26, 2013 at 9:25 AM, Chris wrote:
|
||||
> Hey John, I had some questions:
|
||||
> 1\. Do you want to schedule the meeting tomorrow?
|
||||
> 2\. On which floor in the office?
|
||||
> 3\. What time is suitable to you?
|
||||
|
||||
(Notice that the last question was unintentionally left unanswered in the reply.)
|
||||
|
||||
**Correct way:**
|
||||
|
||||
Chris,
|
||||
See my answers below...
|
||||
> On Fri, Apr 26, 2013 at 9:25 AM, Chris wrote:
|
||||
> Hey John, I had some questions:
|
||||
> 1\. Do you want to schedule the meeting tomorrow?
|
||||
_Yes tomorrow is fine._
|
||||
> 2\. On which floor in the office?
|
||||
_Let's keep it on the second floor._
|
||||
> 3\. What time is suitable to you?
|
||||
_09:00 am would be alright._
|
||||
|
||||
(All questions were answered, and this way saves reading time.)
|
||||
|
||||
* The [Eudyptula challenge][10] is a great way to learn kernel basics.
|
||||
|
||||
|
||||
To learn more, read the [KernelNewbies First Kernel Patch tutorial][1]. After that, if you still have any questions, ask on the [kernelnewbies mailing list][12] or in the [#kernelnewbies IRC channel][13].
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/18/8/first-linux-kernel-patch
|
||||
|
||||
作者：[Sayli Karnik][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/sayli
|
||||
[1]:https://kernelnewbies.org/FirstKernelPatch
|
||||
[2]:https://opensource.com/life/15/8/top-4-open-source-command-line-email-clients
|
||||
[3]:https://twitter.com/gregkh
|
||||
[4]:https://www.kernel.org/doc/html/v4.15/process/2.Process.html
|
||||
[5]:https://www.kernel.org/doc/html/v4.10/process/coding-style.html
|
||||
[6]:https://github.com/torvalds/linux/blob/master/scripts/checkpatch.pl
|
||||
[7]:http://coccinelle.lip6.fr/
|
||||
[8]:linux-kernel@vger.kernel.org
|
||||
[9]:https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/
|
||||
[10]:http://eudyptula-challenge.org/
|
||||
[11]:https://github.com/torvalds/linux/blob/master/scripts/get_maintainer.pl
|
||||
[12]:https://kernelnewbies.org/MailingList
|
||||
[13]:https://kernelnewbies.org/IRC
|
||||
@ -1,139 +0,0 @@
|
||||
What Stable Kernel Should I Use?
|
||||
======
|
||||
I get a lot of questions about people asking me about what stable kernel should they be using for their product/device/laptop/server/etc. all the time. Especially given the now-extended length of time that some kernels are being supported by me and others, this isn’t always a very obvious thing to determine. So this post is an attempt to write down my opinions on the matter. Of course, you are free to use what ever kernel version you want, but here’s what I recommend.
|
||||
|
||||
As always, the opinions written here are my own, I speak for no one but myself.
|
||||
|
||||
### What kernel to pick
|
||||
|
||||
Here’s the my short list of what kernel you should use, raked from best to worst options. I’ll go into the details of all of these below, but if you just want the summary of all of this, here it is:
|
||||
|
||||
Hierarchy of what kernel to use, from best solution to worst:
|
||||
|
||||
* Supported kernel from your favorite Linux distribution
|
||||
* Latest stable release
|
||||
* Latest LTS release
|
||||
* Older LTS release that is still being maintained
|
||||
|
||||
|
||||
|
||||
What kernel to never use:
|
||||
|
||||
* Unmaintained kernel release
|
||||
|
||||
|
||||
|
||||
To give numbers to the above, today, as of August 24, 2018, the front page of kernel.org looks like this:
|
||||
|
||||
![][1]
|
||||
|
||||
So, based on the above list that would mean that:
|
||||
|
||||
* 4.18.5 is the latest stable release
|
||||
* 4.14.67 is the latest LTS release
|
||||
* 4.9.124, 4.4.152, and 3.16.57 are the older LTS releases that are still being maintained
|
||||
* 4.17.19 and 3.18.119 are “End of Life” kernels that have had a release in the past 60 days, and as such stick around on the kernel.org site for those who still might want to use them.
|
||||
|
||||
|
||||
|
||||
Quite easy, right?
|
||||
|
||||
Ok, now for some justification for all of this:
|
||||
|
||||
### Distribution kernels
|
||||
|
||||
The best solution for almost all Linux users is to just use the kernel from your favorite Linux distribution. Personally, I prefer the community based Linux distributions that constantly roll along with the latest updated kernel and it is supported by that developer community. Distributions in this category are Fedora, openSUSE, Arch, Gentoo, CoreOS, and others.
|
||||
|
||||
All of these distributions use the latest stable upstream kernel release and make sure that any needed bugfixes are applied on a regular basis. That is the one of the most solid and best kernel that you can use when it comes to having the latest fixes ([remember all fixes are security fixes][2]) in it.
|
||||
|
||||
There are some community distributions that take a bit longer to move to a new kernel release, but eventually get there and support the kernel they currently have quite well. Those are also great to use, and examples of these are Debian and Ubuntu.
|
||||
|
||||
Just because I did not list your favorite distro here does not mean its kernel is not good. Look on the web site for the distro and make sure that the kernel package is constantly updated with the latest security patches, and all should be well.
|
||||
|
||||
Lots of people seem to like the old, “traditional” model of a distribution and use RHEL, SLES, CentOS or the “LTS” Ubuntu release. Those distros pick a specific kernel version and then camp out on it for years, if not decades. They do loads of work backporting the latest bugfixes and sometimes new features to these kernels, all in a Quixote quest to keep the version number from never being changed, despite having many thousands of changes on top of that older kernel version. This work is a truly thankless job, and the developers assigned to these tasks do some wonderful work in order to achieve these goals. If you like never seeing your kernel version number change, then use these distributions. They usually cost some money to use, but the support you get from these companies is worth it when something goes wrong.
|
||||
|
||||
So again, the best kernel you can use is one that someone else supports, and you can turn to for help. Use that support, usually you are already paying for it (for the enterprise distributions), and those companies know what they are doing.
|
||||
|
||||
But, if you do not want to trust someone else to manage your kernel for you, or you have hardware that a distribution does not support, then you want to run the Latest stable release:
|
||||
|
||||
### Latest stable release
|
||||
|
||||
This kernel is the latest one from the Linux kernel developer community that they declare as “stable”. About every three months, the community releases a new stable kernel that contains all of the newest hardware support, the latest performance improvements, as well as the latest bugfixes for all parts of the kernel. Over the next 3 months, bugfixes that go into the next kernel release to be made are backported into this stable release, so that any users of this kernel are sure to get them as soon as possible.
|
||||
|
||||
This is usually the kernel that most community distributions use as well, so you can be sure it is tested and has a large audience of users. Also, the kernel community (all 4000+ developers) are willing to help support users of this release, as it is the latest one that they made.
|
||||
|
||||
After 3 months, a new kernel is released and you should move to it to ensure that you stay up to date, as support for this kernel is usually dropped a few weeks after the newer release happens.
|
||||
|
||||
If you have new hardware that is purchased after the last LTS release came out, you almost are guaranteed to have to run this kernel in order to have it supported. So for desktops or new servers, this is usually the recommended kernel to be running.
|
||||
|
||||
### Latest LTS release
|
||||
|
||||
If your hardware relies on a vendors out-of-tree patch in order to make it work properly (like almost all embedded devices these days), then the next best kernel to be using is the latest LTS release. That release gets all of the latest kernel fixes that goes into the stable releases where applicable, and lots of users test and use it.
|
||||
|
||||
Note, no new features and almost no new hardware support is ever added to these kernels, so if you need to use a new device, it is better to use the latest stable release, not this release.
|
||||
|
||||
Also this release is common for users that do not like to worry about “major” upgrades happening on them every 3 months. So they stick to this release and upgrade every year instead, which is a fine practice to follow.
|
||||
|
||||
The downsides of using this release is that you do not get the performance improvements that happen in newer kernels, except when you update to the next LTS kernel, potentially a year in the future. That could be significant for some workloads, so be very aware of this.
|
||||
|
||||
Also, if you have problems with this kernel release, the first thing that any developer whom you report the issue to is going to ask you to do is, “does the latest stable release have this problem?” So you will need to be aware that support might not be as easy to get as with the latest stable releases.
|
||||
|
||||
Now if you are stuck with a large patchset and can not update to a new LTS kernel once a year, perhaps you want the older LTS releases:
|
||||
|
||||
### Older LTS release
|
||||
|
||||
These releases have traditionally been supported by the community for 2 years, sometimes longer for when a major distribution relies on this (like Debian or SLES). However in the past year, thanks to a lot of suport and investment in testing and infrastructure from Google, Linaro, Linaro member companies, [kernelci.org][3], and others, these kernels are starting to be supported for much longer.
|
||||
|
||||
Here’s the latest LTS releases and how long they will be supported for, as shown at [kernel.org/category/releases.html][4] on August 24, 2018:
|
||||
|
||||
![][5]
|
||||
|
||||
The reason that Google and other companies want to have these kernels live longer is due to the crazy (some will say broken) development model of almost all SoC chips these days. Those devices start their development lifecycle a few years before the chip is released, however that code is never merged upstream, resulting in a brand new chip being released based on a 2 year old kernel. These SoC trees usually have over 2 million lines added to them, making them something that I have started calling “Linux-like” kernels.
|
||||
|
||||
If the LTS releases stop happening after 2 years, then support from the community instantly stops, and no one ends up doing bugfixes for them. This results in millions of very insecure devices floating around in the world, not something that is good for any ecosystem.
|
||||
|
||||
Because of this dependency, these companies now require new devices to constantly update to the latest LTS releases as they happen for their specific release version (i.e. every 4.9.y release that happens). An example of this is the Android kernel requirements for new devices shipping for the “O” and now “P” releases specified the minimum kernel version allowed, and Android security releases might start to require those “.y” releases to happen more frequently on devices.
|
||||
|
||||
I will note that some manufacturers are already doing this today. Sony is one great example of this, updating to the latest 4.4.y release on many of their new phones for their quarterly security release. Another good example is the small company Essential which has been tracking the 4.4.y releases faster than anyone that I know of.
|
||||
|
||||
There is one huge caveat when using a kernel like this. The number of security fixes that get backported are not as great as with the latest LTS release, because the traditional model of the devices that use these older LTS kernels is a much more reduced user model. These kernels are not to be used in any type of “general computing” model where you have untrusted users or virtual machines, as the ability to do some of the recent Spectre-type fixes for older releases is greatly reduced, if present at all in some branches.
|
||||
|
||||
So again, only use older LTS releases in a device that you fully control, or lock down with a very strong security model (like Android enforces using SELinux and application isolation). Never use these releases on a server with untrusted users, programs, or virtual machines.
|
||||
|
||||
Also, support from the community for these older LTS releases is greatly reduced even from the normal LTS releases, if available at all. If you use these kernels, you really are on your own, and need to be able to support the kernel yourself, or rely on you SoC vendor to provide that support for you (note that almost none of them do provide that support, so beware…)
|
||||
|
||||
### Unmaintained kernel release
|
||||
|
||||
Surprisingly, many companies do just grab a random kernel release, slap it into their product and proceed to ship it in hundreds of thousands of units without a second thought. One crazy example of this would be the Lego Mindstorm systems that shipped a random -rc release of a kernel in their device for some unknown reason. A -rc release is a development release that not even the Linux kernel developers feel is ready for everyone to use just yet, let alone millions of users.
|
||||
|
||||
You are of course free to do this if you want, but note that you really are on your own here. The community can not support you as no one is watching all kernel versions for specific issues, so you will have to rely on in-house support for everything that could go wrong. Which for some companies and systems, could be just fine, but be aware of the “hidden” cost this might cause if you do not plan for this up front.
|
||||
|
||||
### Summary
|
||||
|
||||
So, here’s a short list of different types of devices, and what I would recommend for their kernels:
|
||||
|
||||
* Laptop / Desktop: Latest stable release
|
||||
* Server: Latest stable release or latest LTS release
|
||||
* Embedded device: Latest LTS release or older LTS release if the security model used is very strong and tight.
|
||||
|
||||
|
||||
|
||||
And as for me, what do I run on my machines? My laptops run the latest development kernel (i.e. Linus’s development tree) plus whatever kernel changes I am currently working on and my servers run the latest stable release. So despite being in charge of the LTS releases, I don’t run them myself, except in testing systems. I rely on the development and latest stable releases to ensure that my machines are running the fastest and most secure releases that we know how to create at this point in time.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://kroah.com/log/blog/2018/08/24/what-stable-kernel-should-i-use/
|
||||
|
||||
作者：[Greg Kroah-Hartman][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]:http://kroah.com
|
||||
[1]:https://s3.amazonaws.com/kroah.com/images/kernel.org_2018_08_24.png
|
||||
[2]:http://kroah.com/log/blog/2018/02/05/linux-kernel-release-model/
|
||||
[3]:https://kernelci.org/
|
||||
[4]:https://www.kernel.org/category/releases.html
|
||||
[5]:https://s3.amazonaws.com/kroah.com/images/kernel.org_releases_2018_08_24.png
|
||||
@ -1,89 +0,0 @@
|
||||
translating by lujun9972
|
||||
4 tips for better tmux sessions
|
||||
======
|
||||
|
||||
|
||||
|
||||
The tmux utility, a terminal multiplexer, lets you treat your terminal as a multi-paned window into your system. You can arrange the configuration, run different processes in each, and generally make better use of your screen. We introduced some readers to this powerful tool [in this earlier article][1]. Here are some tips that will help you get more out of tmux if you’re getting started.
|
||||
|
||||
This article assumes your current prefix key is Ctrl+b. If you’ve remapped that prefix, simply substitute your prefix in its place.
|
||||
|
||||
### Set your terminal to automatically use tmux
|
||||
|
||||
One of the biggest benefits of tmux is being able to disconnect and reconnect to sesions at wilI. This makes remote login sessions more powerful. Have you ever lost a connection and wished you could get back the work you were doing on the remote system? With tmux this problem is solved.
|
||||
|
||||
However, you may sometimes find yourself doing work on a remote system, and realize you didn’t start a session. One way to avoid this is to have tmux start or attach every time you login to a system with in interactive shell.
|
||||
|
||||
Add this to your remote system’s ~/.bash_profile file:
|
||||
|
||||
```
|
||||
if [ -z "$TMUX" ]; then
|
||||
tmux attach -t default || tmux new -s default
|
||||
fi
|
||||
```
|
||||
|
||||
Then logout of the remote system, and log back in with SSH. You’ll find you’re in a tmux session named default. This session will be regenerated at next login if you exit it. But more importantly, if you detach from it as normal, your work is waiting for you next time you login — especially useful if your connection is interrupted.
|
||||
|
||||
Of course you can add this to your local system as well. Note that terminals inside most GUIs won’t use the default session automatically, because they aren’t login shells. While you can change that behavior, it may result in nesting that makes the session less usable, so proceed with caution.
|
||||
|
||||
### Use zoom to focus on a single process
|
||||
|
||||
While the point of tmux is to offer multiple windows, panes, and processes in a single session, sometimes you need to focus. If you’re in a process and need more space, or to focus on a single task, the zoom command works well. It expands the current pane to take up the entire current window space.
|
||||
|
||||
Zoom can be useful in other situations too. For instance, imagine you’re using a terminal window in a graphical desktop. Panes can make it harder to copy and paste multiple lines from inside your tmux session. If you zoom the pane, you can do a clean copy/paste of multiple lines of data with ease.
|
||||
|
||||
To zoom into the current pane, hit Ctrl+b, z. When you’re finished with the zoom function, hit the same key combo to unzoom the pane.
|
||||
|
||||
### Bind some useful commands
|
||||
|
||||
By default tmux has numerous commands available. But it’s helpful to have some of the more common operations bound to keys you can easily remember. Here are some examples you can add to your ~/.tmux.conf file to make sessions more enjoyable:
|
||||
|
||||
```
|
||||
bind r source-file ~/.tmux.conf \; display "Reloaded config"
|
||||
```
|
||||
|
||||
This command rereads the commands and bindings in your config file. Once you add this binding, exit any tmux sessions and then restart one. Now after you make any other future changes, simply run Ctrl+b, r and the changes will be part of your existing session.
|
||||
|
||||
```
|
||||
bind V split-window -h
|
||||
bind H split-window
|
||||
```
|
||||
|
||||
These commands make it easier to split the current window across a vertical axis (note that’s Shift+V) or across a horizontal axis (Shift+H).
|
||||
|
||||
If you want to see how all keys are bound, use Ctrl+B, ? to see a list. You may see keys bound in copy-mode first, for when you’re working with copy and paste inside tmux. The prefix mode bindings are where you’ll see ones you’ve added above. Feel free to experiment with your own!
|
||||
|
||||
### Use powerline for great justice
|
||||
|
||||
[As reported in a previous Fedora Magazine article][2], the powerline utility is a fantastic addition to your shell. But it also has capabilities when used with tmux. Because tmux takes over the entire terminal space, the powerline window can provide more than just a better shell prompt.
|
||||
|
||||
[][3]
|
||||
|
||||
If you haven’t already, follow the instructions in the [Magazine’s powerline article][4] to install that utility. Then, install the addon [using sudo][5]:
|
||||
|
||||
```
|
||||
sudo dnf install tmux-powerline
|
||||
```
|
||||
|
||||
Now restart your session, and you’ll see a spiffy new status line at the bottom. Depending on the terminal width, the default status line now shows your current session ID, open windows, system information, date and time, and hostname. If you change directory into a git-controlled project, you’ll see the branch and color-coded status as well.
|
||||
|
||||
Of course, this status bar is highly configurable as well. Enjoy your new supercharged tmux session, and have fun experimenting with it.
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/4-tips-better-tmux-sessions/
|
||||
|
||||
作者：[Paul W. Frields][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
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/
|
||||
[1]:https://fedoramagazine.org/use-tmux-more-powerful-terminal/
|
||||
[2]:https://fedoramagazine.org/add-power-terminal-powerline/
|
||||
[3]:https://fedoramagazine.org/wp-content/uploads/2018/08/Screenshot-from-2018-08-25-19-36-53.png
|
||||
[4]:https://fedoramagazine.org/add-power-terminal-powerline/
|
||||
[5]:https://fedoramagazine.org/howto-use-sudo/
|
||||
@ -1,50 +0,0 @@
|
||||
translating by lujun9972
|
||||
Solve "error: failed to commit transaction (conflicting files)" In Arch Linux
|
||||
======
|
||||
|
||||
|
||||
|
||||
It’s been a month since I upgraded my Arch Linux desktop. Today, I tried to update my Arch Linux system, and ran into an error that said **“error: failed to commit transaction (conflicting files) stfl: /usr/lib/libstfl.so.0 exists in filesystem”**. It looks like one library (/usr/lib/libstfl.so.0) that exists on my filesystem and pacman can’t upgrade it. If you’re encountered with the same error, here is a quick fix to resolve it.
|
||||
|
||||
### Solve “error: failed to commit transaction (conflicting files)” In Arch Linux
|
||||
|
||||
You have three options.
|
||||
|
||||
1. Simply ignore the problematic **stfl** library from being upgraded and try to update the system again. Refer this guide to know [**how to ignore package from being upgraded**][1].
|
||||
|
||||
2. Overwrite the package using command:
|
||||
```
|
||||
$ sudo pacman -Syu --overwrite /usr/lib/libstfl.so.0
|
||||
```
|
||||
|
||||
3. Remove stfl library file manually and try to upgrade the system again. Please make sure the intended package is not a dependency to any important package. and check the archlinux.org whether are mentions of this conflict.
|
||||
```
|
||||
$ sudo rm /usr/lib/libstfl.so.0
|
||||
```
|
||||
|
||||
Now, try to update the system:
|
||||
```
|
||||
$ sudo pacman -Syu
|
||||
```
|
||||
|
||||
I chose the third option and just deleted the file and upgraded my Arch Linux system. It works now!
|
||||
|
||||
Hope this helps. More good stuffs to come. Stay tuned!
|
||||
|
||||
Cheers!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/how-to-solve-error-failed-to-commit-transaction-conflicting-files-in-arch-linux/
|
||||
|
||||
作者：[SK][a]
|
||||
选题：[lujun9972](https://github.com/lujun9972)
|
||||
译者：[lujun9972](https://github.com/lujun9972)
|
||||
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/
|
||||
[1]:https://www.ostechnix.com/safely-ignore-package-upgraded-arch-linux/
|
||||
@ -1,3 +1,4 @@
|
||||
translating by sd886393
|
||||
4 open source monitoring tools
|
||||
======
|
||||
|
||||
|
||||
201
sources/tech/20180907 6.828 lab tools guide.md
Normal file
201
sources/tech/20180907 6.828 lab tools guide.md
Normal file
@ -0,0 +1,201 @@
|
||||
6.828 lab tools guide
|
||||
======
|
||||
### 6.828 lab tools guide
|
||||
|
||||
Familiarity with your environment is crucial for productive development and debugging. This page gives a brief overview of the JOS environment and useful GDB and QEMU commands. Don't take our word for it, though. Read the GDB and QEMU manuals. These are powerful tools that are worth knowing how to use.
|
||||
|
||||
#### Debugging tips
|
||||
|
||||
##### Kernel
|
||||
|
||||
GDB is your friend. Use the qemu-gdb target (or its `qemu-gdb-nox` variant) to make QEMU wait for GDB to attach. See the GDB reference below for some commands that are useful when debugging kernels.
|
||||
|
||||
If you're getting unexpected interrupts, exceptions, or triple faults, you can ask QEMU to generate a detailed log of interrupts using the -d argument.
|
||||
|
||||
To debug virtual memory issues, try the QEMU monitor commands info mem (for a high-level overview) or info pg (for lots of detail). Note that these commands only display the _current_ page table.
|
||||
|
||||
(Lab 4+) To debug multiple CPUs, use GDB's thread-related commands like thread and info threads.
|
||||
|
||||
##### User environments (lab 3+)
|
||||
|
||||
GDB also lets you debug user environments, but there are a few things you need to watch out for, since GDB doesn't know that there's a distinction between multiple user environments, or between user and kernel.
|
||||
|
||||
You can start JOS with a specific user environment using make run- _name_ (or you can edit `kern/init.c` directly). To make QEMU wait for GDB to attach, use the run- _name_ -gdb variant.
|
||||
|
||||
You can symbolically debug user code, just like you can kernel code, but you have to tell GDB which symbol table to use with the symbol-file command, since it can only use one symbol table at a time. The provided `.gdbinit` loads the kernel symbol table, `obj/kern/kernel`. The symbol table for a user environment is in its ELF binary, so you can load it using symbol-file obj/user/ _name_. _Don't_ load symbols from any `.o` files, as those haven't been relocated by the linker (libraries are statically linked into JOS user binaries, so those symbols are already included in each user binary). Make sure you get the _right_ user binary; library functions will be linked at different EIPs in different binaries and GDB won't know any better!
|
||||
|
||||
(Lab 4+) Since GDB is attached to the virtual machine as a whole, it sees clock interrupts as just another control transfer. This makes it basically impossible to step through user code because a clock interrupt is virtually guaranteed the moment you let the VM run again. The stepi command works because it suppresses interrupts, but it only steps one assembly instruction. Breakpoints generally work, but watch out because you can hit the same EIP in a different environment (indeed, a different binary altogether!).
|
||||
|
||||
#### Reference
|
||||
|
||||
##### JOS makefile
|
||||
|
||||
The JOS GNUmakefile includes a number of phony targets for running JOS in various ways. All of these targets configure QEMU to listen for GDB connections (the `*-gdb` targets also wait for this connection). To start once QEMU is running, simply run gdb from your lab directory. We provide a `.gdbinit` file that automatically points GDB at QEMU, loads the kernel symbol file, and switches between 16-bit and 32-bit mode. Exiting GDB will shut down QEMU.
|
||||
|
||||
* make qemu
|
||||
Build everything and start QEMU with the VGA console in a new window and the serial console in your terminal. To exit, either close the VGA window or press `Ctrl-c` or `Ctrl-a x` in your terminal.
|
||||
* make qemu-nox
|
||||
Like `make qemu`, but run with only the serial console. To exit, press `Ctrl-a x`. This is particularly useful over SSH connections to Athena dialups because the VGA window consumes a lot of bandwidth.
|
||||
* make qemu-gdb
|
||||
Like `make qemu`, but rather than passively accepting GDB connections at any time, this pauses at the first machine instruction and waits for a GDB connection.
|
||||
* make qemu-nox-gdb
|
||||
A combination of the `qemu-nox` and `qemu-gdb` targets.
|
||||
* make run- _name_
|
||||
(Lab 3+) Run user program _name_. For example, `make run-hello` runs `user/hello.c`.
|
||||
* make run- _name_ -nox, run- _name_ -gdb, run- _name_ -gdb-nox,
|
||||
(Lab 3+) Variants of `run-name` that correspond to the variants of the `qemu` target.
|
||||
|
||||
|
||||
|
||||
The makefile also accepts a few useful variables:
|
||||
|
||||
* make V=1 ...
|
||||
Verbose mode. Print out every command being executed, including arguments.
|
||||
* make V=1 grade
|
||||
Stop after any failed grade test and leave the QEMU output in `jos.out` for inspection.
|
||||
* make QEMUEXTRA=' _args_ ' ...
|
||||
Specify additional arguments to pass to QEMU.
|
||||
|
||||
|
||||
|
||||
##### JOS obj/
|
||||
|
||||
The JOS GNUmakefile includes a number of phony targets for running JOS in various ways. All of these targets configure QEMU to listen for GDB connections (thetargets also wait for this connection). To start once QEMU is running, simply runfrom your lab directory. We provide afile that automatically points GDB at QEMU, loads the kernel symbol file, and switches between 16-bit and 32-bit mode. Exiting GDB will shut down QEMU.The makefile also accepts a few useful variables:
|
||||
|
||||
When building JOS, the makefile also produces some additional output files that may prove useful while debugging:
|
||||
|
||||
* `obj/boot/boot.asm`, `obj/kern/kernel.asm`, `obj/user/hello.asm`, etc.
|
||||
Assembly code listings for the bootloader, kernel, and user programs.
|
||||
* `obj/kern/kernel.sym`, `obj/user/hello.sym`, etc.
|
||||
Symbol tables for the kernel and user programs.
|
||||
* `obj/boot/boot.out`, `obj/kern/kernel`, `obj/user/hello`, etc
|
||||
Linked ELF images of the kernel and user programs. These contain symbol information that can be used by GDB.
|
||||
|
||||
|
||||
|
||||
##### GDB
|
||||
|
||||
See the [GDB manual][1] for a full guide to GDB commands. Here are some particularly useful commands for 6.828, some of which don't typically come up outside of OS development.
|
||||
|
||||
* Ctrl-c
|
||||
Halt the machine and break in to GDB at the current instruction. If QEMU has multiple virtual CPUs, this halts all of them.
|
||||
* c (or continue)
|
||||
Continue execution until the next breakpoint or `Ctrl-c`.
|
||||
* si (or stepi)
|
||||
Execute one machine instruction.
|
||||
* b function or b file:line (or breakpoint)
|
||||
Set a breakpoint at the given function or line.
|
||||
* b * _addr_ (or breakpoint)
|
||||
Set a breakpoint at the EIP _addr_.
|
||||
* set print pretty
|
||||
Enable pretty-printing of arrays and structs.
|
||||
* info registers
|
||||
Print the general purpose registers, `eip`, `eflags`, and the segment selectors. For a much more thorough dump of the machine register state, see QEMU's own `info registers` command.
|
||||
* x/ _N_ x _addr_
|
||||
Display a hex dump of _N_ words starting at virtual address _addr_. If _N_ is omitted, it defaults to 1. _addr_ can be any expression.
|
||||
* x/ _N_ i _addr_
|
||||
Display the _N_ assembly instructions starting at _addr_. Using `$eip` as _addr_ will display the instructions at the current instruction pointer.
|
||||
* symbol-file _file_
|
||||
(Lab 3+) Switch to symbol file _file_. When GDB attaches to QEMU, it has no notion of the process boundaries within the virtual machine, so we have to tell it which symbols to use. By default, we configure GDB to use the kernel symbol file, `obj/kern/kernel`. If the machine is running user code, say `hello.c`, you can switch to the hello symbol file using `symbol-file obj/user/hello`.
|
||||
|
||||
|
||||
|
||||
QEMU represents each virtual CPU as a thread in GDB, so you can use all of GDB's thread-related commands to view or manipulate QEMU's virtual CPUs.
|
||||
|
||||
* thread _n_
|
||||
GDB focuses on one thread (i.e., CPU) at a time. This command switches that focus to thread _n_ , numbered from zero.
|
||||
* info threads
|
||||
List all threads (i.e., CPUs), including their state (active or halted) and what function they're in.
|
||||
|
||||
|
||||
|
||||
##### QEMU
|
||||
|
||||
QEMU includes a built-in monitor that can inspect and modify the machine state in useful ways. To enter the monitor, press Ctrl-a c in the terminal running QEMU. Press Ctrl-a c again to switch back to the serial console.
|
||||
|
||||
For a complete reference to the monitor commands, see the [QEMU manual][2]. Here are some particularly useful commands:
|
||||
|
||||
* xp/ _N_ x _paddr_
|
||||
Display a hex dump of _N_ words starting at _physical_ address _paddr_. If _N_ is omitted, it defaults to 1. This is the physical memory analogue of GDB's `x` command.
|
||||
|
||||
* info registers
|
||||
Display a full dump of the machine's internal register state. In particular, this includes the machine's _hidden_ segment state for the segment selectors and the local, global, and interrupt descriptor tables, plus the task register. This hidden state is the information the virtual CPU read from the GDT/LDT when the segment selector was loaded. Here's the CS when running in the JOS kernel in lab 1 and the meaning of each field:
|
||||
```
|
||||
CS =0008 10000000 ffffffff 10cf9a00 DPL=0 CS32 [-R-]
|
||||
```
|
||||
|
||||
* `CS =0008`
|
||||
The visible part of the code selector. We're using segment 0x8. This also tells us we're referring to the global descriptor table (0x8 &4=0), and our CPL (current privilege level) is 0x8&3=0.
|
||||
* `10000000`
|
||||
The base of this segment. Linear address = logical address + 0x10000000.
|
||||
* `ffffffff`
|
||||
The limit of this segment. Linear addresses above 0xffffffff will result in segment violation exceptions.
|
||||
* `10cf9a00`
|
||||
The raw flags of this segment, which QEMU helpfully decodes for us in the next few fields.
|
||||
* `DPL=0`
|
||||
The privilege level of this segment. Only code running with privilege level 0 can load this segment.
|
||||
* `CS32`
|
||||
This is a 32-bit code segment. Other values include `DS` for data segments (not to be confused with the DS register), and `LDT` for local descriptor tables.
|
||||
* `[-R-]`
|
||||
This segment is read-only.
|
||||
* info mem
|
||||
(Lab 2+) Display mapped virtual memory and permissions. For example,
|
||||
```
|
||||
ef7c0000-ef800000 00040000 urw
|
||||
efbf8000-efc00000 00008000 -rw
|
||||
|
||||
```
|
||||
|
||||
tells us that the 0x00040000 bytes of memory from 0xef7c0000 to 0xef800000 are mapped read/write and user-accessible, while the memory from 0xefbf8000 to 0xefc00000 is mapped read/write, but only kernel-accessible.
|
||||
|
||||
* info pg
|
||||
(Lab 2+) Display the current page table structure. The output is similar to `info mem`, but distinguishes page directory entries and page table entries and gives the permissions for each separately. Repeated PTE's and entire page tables are folded up into a single line. For example,
|
||||
```
|
||||
VPN range Entry Flags Physical page
|
||||
[00000-003ff] PDE[000] -------UWP
|
||||
[00200-00233] PTE[200-233] -------U-P 00380 0037e 0037d 0037c 0037b 0037a ..
|
||||
[00800-00bff] PDE[002] ----A--UWP
|
||||
[00800-00801] PTE[000-001] ----A--U-P 0034b 00349
|
||||
[00802-00802] PTE[002] -------U-P 00348
|
||||
|
||||
```
|
||||
|
||||
This shows two page directory entries, spanning virtual addresses 0x00000000 to 0x003fffff and 0x00800000 to 0x00bfffff, respectively. Both PDE's are present, writable, and user and the second PDE is also accessed. The second of these page tables maps three pages, spanning virtual addresses 0x00800000 through 0x00802fff, of which the first two are present, user, and accessed and the third is only present and user. The first of these PTE's maps physical page 0x34b.
|
||||
|
||||
|
||||
|
||||
|
||||
QEMU also takes some useful command line arguments, which can be passed into the JOS makefile using the
|
||||
|
||||
* make QEMUEXTRA='-d int' ...
|
||||
Log all interrupts, along with a full register dump, to `qemu.log`. You can ignore the first two log entries, "SMM: enter" and "SMM: after RMS", as these are generated before entering the boot loader. After this, log entries look like
|
||||
```
|
||||
4: v=30 e=0000 i=1 cpl=3 IP=001b:00800e2e pc=00800e2e SP=0023:eebfdf28 EAX=00000005
|
||||
EAX=00000005 EBX=00001002 ECX=00200000 EDX=00000000
|
||||
ESI=00000805 EDI=00200000 EBP=eebfdf60 ESP=eebfdf28
|
||||
...
|
||||
|
||||
```
|
||||
|
||||
The first line describes the interrupt. The `4:` is just a log record counter. `v` gives the vector number in hex. `e` gives the error code. `i=1` indicates that this was produced by an `int` instruction (versus a hardware interrupt). The rest of the line should be self-explanatory. See info registers for a description of the register dump that follows.
|
||||
|
||||
Note: If you're running a pre-0.15 version of QEMU, the log will be written to `/tmp` instead of the current directory.
|
||||
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://pdos.csail.mit.edu/6.828/2018/labguide.html
|
||||
|
||||
作者：[csail.mit][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://pdos.csail.mit.edu
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: http://sourceware.org/gdb/current/onlinedocs/gdb/
|
||||
[2]: http://wiki.qemu.org/download/qemu-doc.html#pcsys_005fmonitor
|
||||
247
sources/tech/20180911 Tools Used in 6.828.md
Normal file
247
sources/tech/20180911 Tools Used in 6.828.md
Normal file
@ -0,0 +1,247 @@
|
||||
Tools Used in 6.828
|
||||
======
|
||||
### Tools Used in 6.828
|
||||
|
||||
You'll use two sets of tools in this class: an x86 emulator, QEMU, for running your kernel; and a compiler toolchain, including assembler, linker, C compiler, and debugger, for compiling and testing your kernel. This page has the information you'll need to download and install your own copies. This class assumes familiarity with Unix commands throughout.
|
||||
|
||||
We highly recommend using a Debathena machine, such as athena.dialup.mit.edu, to work on the labs. If you use the MIT Athena machines that run Linux, then all the software tools you will need for this course are located in the 6.828 locker: just type 'add -f 6.828' to get access to them.
|
||||
|
||||
If you don't have access to a Debathena machine, we recommend you use a virtual machine with Linux. If you really want to, you can build and install the tools on your own machine. We have instructions below for Linux and MacOS computers.
|
||||
|
||||
It should be possible to get this development environment running under windows with the help of [Cygwin][1]. Install cygwin, and be sure to install the flex and bison packages (they are under the development header).
|
||||
|
||||
For an overview of useful commands in the tools used in 6.828, see the [lab tools guide][2].
|
||||
|
||||
#### Compiler Toolchain
|
||||
|
||||
A "compiler toolchain" is the set of programs, including a C compiler, assemblers, and linkers, that turn code into executable binaries. You'll need a compiler toolchain that generates code for 32-bit Intel architectures ("x86" architectures) in the ELF binary format.
|
||||
|
||||
##### Test Your Compiler Toolchain
|
||||
|
||||
Modern Linux and BSD UNIX distributions already provide a toolchain suitable for 6.828. To test your distribution, try the following commands:
|
||||
|
||||
```
|
||||
% objdump -i
|
||||
|
||||
```
|
||||
|
||||
The second line should say `elf32-i386`.
|
||||
|
||||
```
|
||||
% gcc -m32 -print-libgcc-file-name
|
||||
|
||||
```
|
||||
|
||||
The command should print something like `/usr/lib/gcc/i486-linux-gnu/version/libgcc.a` or `/usr/lib/gcc/x86_64-linux-gnu/version/32/libgcc.a`
|
||||
|
||||
If both these commands succeed, you're all set, and don't need to compile your own toolchain.
|
||||
|
||||
If the gcc command fails, you may need to install a development environment. On Ubuntu Linux, try this:
|
||||
|
||||
```
|
||||
% sudo apt-get install -y build-essential gdb
|
||||
|
||||
```
|
||||
|
||||
On 64-bit machines, you may need to install a 32-bit support library. The symptom is that linking fails with error messages like "`__udivdi3` not found" and "`__muldi3` not found". On Ubuntu Linux, try this to fix the problem:
|
||||
|
||||
```
|
||||
% sudo apt-get install gcc-multilib
|
||||
|
||||
```
|
||||
|
||||
##### Using a Virtual Machine
|
||||
|
||||
Otherwise, the easiest way to get a compatible toolchain is to install a modern Linux distribution on your computer. With platform virtualization, Linux can cohabitate with your normal computing environment. Installing a Linux virtual machine is a two step process. First, you download the virtualization platform.
|
||||
|
||||
* [**VirtualBox**][3] (free for Mac, Linux, Windows) — [Download page][3]
|
||||
* [VMware Player][4] (free for Linux and Windows, registration required)
|
||||
* [VMware Fusion][5] (Downloadable from IS&T for free).
|
||||
|
||||
|
||||
|
||||
VirtualBox is a little slower and less flexible, but free!
|
||||
|
||||
Once the virtualization platform is installed, download a boot disk image for the Linux distribution of your choice.
|
||||
|
||||
* [Ubuntu Desktop][6] is what we use.
|
||||
|
||||
|
||||
|
||||
This will download a file named something like `ubuntu-10.04.1-desktop-i386.iso`. Start up your virtualization platform and create a new (32-bit) virtual machine. Use the downloaded Ubuntu image as a boot disk; the procedure differs among VMs but is pretty simple. Type `objdump -i`, as above, to verify that your toolchain is now set up. You will do your work inside the VM.
|
||||
|
||||
##### Building Your Own Compiler Toolchain
|
||||
|
||||
This will take longer to set up, but give slightly better performance than a virtual machine, and lets you work in your own familiar environment (Unix/MacOS). Fast-forward to the end for MacOS instructions.
|
||||
|
||||
###### Linux
|
||||
|
||||
You can use your own tool chain by adding the following line to `conf/env.mk`:
|
||||
|
||||
```
|
||||
GCCPREFIX=
|
||||
|
||||
```
|
||||
|
||||
We assume that you are installing the toolchain into `/usr/local`. You will need a fair amount of disk space to compile the tools (around 1GiB). If you don't have that much space, delete each directory after its `make install` step.
|
||||
|
||||
Download the following packages:
|
||||
|
||||
+ ftp://ftp.gmplib.org/pub/gmp-5.0.2/gmp-5.0.2.tar.bz2
|
||||
+ https://www.mpfr.org/mpfr-3.1.2/mpfr-3.1.2.tar.bz2
|
||||
+ http://www.multiprecision.org/downloads/mpc-0.9.tar.gz
|
||||
+ http://ftpmirror.gnu.org/binutils/binutils-2.21.1.tar.bz2
|
||||
+ http://ftpmirror.gnu.org/gcc/gcc-4.6.4/gcc-core-4.6.4.tar.bz2
|
||||
+ http://ftpmirror.gnu.org/gdb/gdb-7.3.1.tar.bz2
|
||||
|
||||
(You may also use newer versions of these packages.) Unpack and build the packages. The `green bold` text shows you how to install into `/usr/local`, which is what we recommend. To install into a different directory, $PFX, note the differences in lighter type ([hide][7]). If you have problems, see below.
|
||||
|
||||
```
|
||||
export PATH=$PFX/bin:$PATH
|
||||
export LD_LIBRARY_PATH=$PFX/lib:$LD_LIBRARY_PATH
|
||||
|
||||
tar xjf gmp-5.0.2.tar.bz2
|
||||
cd gmp-5.0.2
|
||||
./configure --prefix=$PFX
|
||||
make
|
||||
make install # This step may require privilege (sudo make install)
|
||||
cd ..
|
||||
|
||||
tar xjf mpfr-3.1.2.tar.bz2
|
||||
cd mpfr-3.1.2
|
||||
./configure --prefix=$PFX --with-gmp=$PFX
|
||||
make
|
||||
make install # This step may require privilege (sudo make install)
|
||||
cd ..
|
||||
|
||||
tar xzf mpc-0.9.tar.gz
|
||||
cd mpc-0.9
|
||||
./configure --prefix=$PFX --with-gmp=$PFX --with-mpfr=$PFX
|
||||
make
|
||||
make install # This step may require privilege (sudo make install)
|
||||
cd ..
|
||||
|
||||
|
||||
tar xjf binutils-2.21.1.tar.bz2
|
||||
cd binutils-2.21.1
|
||||
./configure --prefix=$PFX --target=i386-jos-elf --disable-werror
|
||||
make
|
||||
make install # This step may require privilege (sudo make install)
|
||||
cd ..
|
||||
|
||||
i386-jos-elf-objdump -i
|
||||
# Should produce output like:
|
||||
# BFD header file version (GNU Binutils) 2.21.1
|
||||
# elf32-i386
|
||||
# (header little endian, data little endian)
|
||||
# i386...
|
||||
|
||||
|
||||
tar xjf gcc-core-4.6.4.tar.bz2
|
||||
cd gcc-4.6.4
|
||||
mkdir build # GCC will not compile correctly unless you build in a separate directory
|
||||
cd build
|
||||
../configure --prefix=$PFX --with-gmp=$PFX --with-mpfr=$PFX --with-mpc=$PFX \
|
||||
--target=i386-jos-elf --disable-werror \
|
||||
--disable-libssp --disable-libmudflap --with-newlib \
|
||||
--without-headers --enable-languages=c MAKEINFO=missing
|
||||
make all-gcc
|
||||
make install-gcc # This step may require privilege (sudo make install-gcc)
|
||||
make all-target-libgcc
|
||||
make install-target-libgcc # This step may require privilege (sudo make install-target-libgcc)
|
||||
cd ../..
|
||||
|
||||
i386-jos-elf-gcc -v
|
||||
# Should produce output like:
|
||||
# Using built-in specs.
|
||||
# COLLECT_GCC=i386-jos-elf-gcc
|
||||
# COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/i386-jos-elf/4.6.4/lto-wrapper
|
||||
# Target: i386-jos-elf
|
||||
|
||||
|
||||
tar xjf gdb-7.3.1.tar.bz2
|
||||
cd gdb-7.3.1
|
||||
./configure --prefix=$PFX --target=i386-jos-elf --program-prefix=i386-jos-elf- \
|
||||
--disable-werror
|
||||
make all
|
||||
make install # This step may require privilege (sudo make install)
|
||||
cd ..
|
||||
|
||||
```
|
||||
|
||||
###### Linux troubleshooting
|
||||
|
||||
* Q. I can't run `make install` because I don't have root permission on this machine.
|
||||
A. Our instructions assume you are installing into the `/usr/local` directory. However, this may not be allowed in your environment. If you can only install code into your home directory, that's OK. In the instructions above, replace `--prefix=/usr/local` with `--prefix=$HOME` (and [click here][7] to update the instructions further). You will also need to change your `PATH` and `LD_LIBRARY_PATH` environment variables, to inform your shell where to find the tools. For example:
|
||||
```
|
||||
export PATH=$HOME/bin:$PATH
|
||||
export LD_LIBRARY_PATH=$HOME/lib:$LD_LIBRARY_PATH
|
||||
```
|
||||
|
||||
Enter these lines in your `~/.bashrc` file so you don't need to type them every time you log in.
|
||||
|
||||
|
||||
|
||||
* Q. My build fails with an inscrutable message about "library not found".
|
||||
A. You need to set your `LD_LIBRARY_PATH`. The environment variable must include the `PREFIX/lib` directory (for instance, `/usr/local/lib`).
|
||||
|
||||
|
||||
|
||||
#### MacOS
|
||||
|
||||
First begin by installing developer tools on Mac OSX:
|
||||
`xcode-select --install`
|
||||
|
||||
First begin by installing developer tools on Mac OSX:
|
||||
|
||||
You can install the qemu dependencies from homebrew, however do not install qemu itself as you will need the 6.828 patched version.
|
||||
|
||||
`brew install $(brew deps qemu)`
|
||||
|
||||
The gettext utility does not add installed binaries to the path, so you will need to run
|
||||
|
||||
`PATH=${PATH}:/usr/local/opt/gettext/bin make install`
|
||||
|
||||
when installing qemu below.
|
||||
|
||||
### QEMU Emulator
|
||||
|
||||
[QEMU][8] is a modern and fast PC emulator. QEMU version 2.3.0 is set up on Athena for x86 machines in the 6.828 locker (`add -f 6.828`)
|
||||
|
||||
Unfortunately, QEMU's debugging facilities, while powerful, are somewhat immature, so we highly recommend you use our patched version of QEMU instead of the stock version that may come with your distribution. The version installed on Athena is already patched. To build your own patched version of QEMU:
|
||||
|
||||
1. Clone the IAP 6.828 QEMU git repository `git clone https://github.com/mit-pdos/6.828-qemu.git qemu`
|
||||
2. On Linux, you may need to install several libraries. We have successfully built 6.828 QEMU on Debian/Ubuntu 16.04 after installing the following packages: libsdl1.2-dev, libtool-bin, libglib2.0-dev, libz-dev, and libpixman-1-dev.
|
||||
3. Configure the source code (optional arguments are shown in square brackets; replace PFX with a path of your choice)
|
||||
1. Linux: `./configure --disable-kvm --disable-werror [--prefix=PFX] [--target-list="i386-softmmu x86_64-softmmu"]`
|
||||
2. OS X: `./configure --disable-kvm --disable-werror --disable-sdl [--prefix=PFX] [--target-list="i386-softmmu x86_64-softmmu"]` The `prefix` argument specifies where to install QEMU; without it QEMU will install to `/usr/local` by default. The `target-list` argument simply slims down the architectures QEMU will build support for.
|
||||
4. Run `make && make install`
|
||||
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://pdos.csail.mit.edu/6.828/2018/tools.html
|
||||
|
||||
作者：[csail.mit][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://pdos.csail.mit.edu
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: http://www.cygwin.com
|
||||
[2]: labguide.html
|
||||
[3]: http://www.oracle.com/us/technologies/virtualization/oraclevm/
|
||||
[4]: http://www.vmware.com/products/player/
|
||||
[5]: http://www.vmware.com/products/fusion/
|
||||
[6]: http://www.ubuntu.com/download/desktop
|
||||
[7]:
|
||||
[8]: http://www.nongnu.org/qemu/
|
||||
[9]: mailto:6828-staff@lists.csail.mit.edu
|
||||
[10]: https://i.creativecommons.org/l/by/3.0/us/88x31.png
|
||||
[11]: https://creativecommons.org/licenses/by/3.0/us/
|
||||
[12]: https://pdos.csail.mit.edu/6.828/2018/index.html
|
||||
@ -0,0 +1,616 @@
|
||||
Lab 1: PC Bootstrap and GCC Calling Conventions
|
||||
======
|
||||
### Lab 1: Booting a PC
|
||||
|
||||
#### Introduction
|
||||
|
||||
This lab is split into three parts. The first part concentrates on getting familiarized with x86 assembly language, the QEMU x86 emulator, and the PC's power-on bootstrap procedure. The second part examines the boot loader for our 6.828 kernel, which resides in the `boot` directory of the `lab` tree. Finally, the third part delves into the initial template for our 6.828 kernel itself, named JOS, which resides in the `kernel` directory.
|
||||
|
||||
##### Software Setup
|
||||
|
||||
The files you will need for this and subsequent lab assignments in this course are distributed using the [Git][1] version control system. To learn more about Git, take a look at the [Git user's manual][2], or, if you are already familiar with other version control systems, you may find this [CS-oriented overview of Git][3] useful.
|
||||
|
||||
The URL for the course Git repository is <https://pdos.csail.mit.edu/6.828/2018/jos.git>. To install the files in your Athena account, you need to _clone_ the course repository, by running the commands below. You must use an x86 Athena machine; that is, `uname -a` should mention `i386 GNU/Linux` or `i686 GNU/Linux` or `x86_64 GNU/Linux`. You can log into a public Athena host with `ssh -X athena.dialup.mit.edu`.
|
||||
|
||||
```
|
||||
athena% mkdir ~/6.828
|
||||
athena% cd ~/6.828
|
||||
athena% add git
|
||||
athena% git clone https://pdos.csail.mit.edu/6.828/2018/jos.git lab
|
||||
Cloning into lab...
|
||||
athena% cd lab
|
||||
athena%
|
||||
|
||||
```
|
||||
|
||||
Git allows you to keep track of the changes you make to the code. For example, if you are finished with one of the exercises, and want to checkpoint your progress, you can _commit_ your changes by running:
|
||||
|
||||
```
|
||||
athena% git commit -am 'my solution for lab1 exercise 9'
|
||||
Created commit 60d2135: my solution for lab1 exercise 9
|
||||
1 files changed, 1 insertions(+), 0 deletions(-)
|
||||
athena%
|
||||
|
||||
```
|
||||
|
||||
You can keep track of your changes by using the git diff command. Running git diff will display the changes to your code since your last commit, and git diff origin/lab1 will display the changes relative to the initial code supplied for this lab. Here, `origin/lab1` is the name of the git branch with the initial code you downloaded from our server for this assignment.
|
||||
|
||||
We have set up the appropriate compilers and simulators for you on Athena. To use them, run add -f 6.828. You must run this command every time you log in (or add it to your `~/.environment` file). If you get obscure errors while compiling or running `qemu`, double check that you added the course locker.
|
||||
|
||||
If you are working on a non-Athena machine, you'll need to install `qemu` and possibly `gcc` following the directions on the [tools page][4]. We've made several useful debugging changes to `qemu` and some of the later labs depend on these patches, so you must build your own. If your machine uses a native ELF toolchain (such as Linux and most BSD's, but notably _not_ OS X), you can simply install `gcc` from your package manager. Otherwise, follow the directions on the tools page.
|
||||
|
||||
##### Hand-In Procedure
|
||||
|
||||
You will turn in your assignments using the [submission website][5]. You need to request an API key from the submission website before you can turn in any assignments or labs.
|
||||
|
||||
The lab code comes with GNU Make rules to make submission easier. After committing your final changes to the lab, type make handin to submit your lab.
|
||||
|
||||
```
|
||||
athena% git commit -am "ready to submit my lab"
|
||||
[lab1 c2e3c8b] ready to submit my lab
|
||||
2 files changed, 18 insertions(+), 2 deletions(-)
|
||||
|
||||
athena% make handin
|
||||
git archive --prefix=lab1/ --format=tar HEAD | gzip > lab1-handin.tar.gz
|
||||
Get an API key for yourself by visiting https://6828.scripts.mit.edu/2018/handin.py/
|
||||
Please enter your API key: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
|
||||
% Total % Received % Xferd Average Speed Time Time Time Current
|
||||
Dload Upload Total Spent Left Speed
|
||||
100 50199 100 241 100 49958 414 85824 --:--:-- --:--:-- --:--:-- 85986
|
||||
athena%
|
||||
|
||||
```
|
||||
|
||||
make handin will store your API key in _myapi.key_. If you need to change your API key, just remove this file and let make handin generate it again ( _myapi.key_ must not include newline characters).
|
||||
|
||||
If use make handin and you have either uncomitted changes or untracked files, you will see output similar to the following:
|
||||
|
||||
```
|
||||
M hello.c
|
||||
?? bar.c
|
||||
?? foo.pyc
|
||||
Untracked files will not be handed in. Continue? [y/N]
|
||||
|
||||
```
|
||||
|
||||
Inspect the above lines and make sure all files that your lab solution needs are tracked i.e. not listed in a line that begins with ??.
|
||||
|
||||
In the case that make handin does not work properly, try fixing the problem with the curl or Git commands. Or you can run make tarball. This will make a tar file for you, which you can then upload via our [web interface][5].
|
||||
|
||||
You can run make grade to test your solutions with the grading program. The [web interface][5] uses the same grading program to assign your lab submission a grade. You should check the output of the grader (it may take a few minutes since the grader runs periodically) and ensure that you received the grade which you expected. If the grades don't match, your lab submission probably has a bug -- check the output of the grader (resp-lab*.txt) to see which particular test failed.
|
||||
|
||||
For Lab 1, you do not need to turn in answers to any of the questions below. (Do answer them for yourself though! They will help with the rest of the lab.)
|
||||
|
||||
#### Part 1: PC Bootstrap
|
||||
|
||||
The purpose of the first exercise is to introduce you to x86 assembly language and the PC bootstrap process, and to get you started with QEMU and QEMU/GDB debugging. You will not have to write any code for this part of the lab, but you should go through it anyway for your own understanding and be prepared to answer the questions posed below.
|
||||
|
||||
##### Getting Started with x86 assembly
|
||||
|
||||
If you are not already familiar with x86 assembly language, you will quickly become familiar with it during this course! The [PC Assembly Language Book][6] is an excellent place to start. Hopefully, the book contains mixture of new and old material for you.
|
||||
|
||||
_Warning:_ Unfortunately the examples in the book are written for the NASM assembler, whereas we will be using the GNU assembler. NASM uses the so-called _Intel_ syntax while GNU uses the _AT &T_ syntax. While semantically equivalent, an assembly file will differ quite a lot, at least superficially, depending on which syntax is used. Luckily the conversion between the two is pretty simple, and is covered in [Brennan's Guide to Inline Assembly][7].
|
||||
|
||||
Exercise 1. Familiarize yourself with the assembly language materials available on [the 6.828 reference page][8]. You don't have to read them now, but you'll almost certainly want to refer to some of this material when reading and writing x86 assembly.
|
||||
|
||||
We do recommend reading the section "The Syntax" in [Brennan's Guide to Inline Assembly][7]. It gives a good (and quite brief) description of the AT&T assembly syntax we'll be using with the GNU assembler in JOS.
|
||||
|
||||
Certainly the definitive reference for x86 assembly language programming is Intel's instruction set architecture reference, which you can find on [the 6.828 reference page][8] in two flavors: an HTML edition of the old [80386 Programmer's Reference Manual][9], which is much shorter and easier to navigate than more recent manuals but describes all of the x86 processor features that we will make use of in 6.828; and the full, latest and greatest [IA-32 Intel Architecture Software Developer's Manuals][10] from Intel, covering all the features of the most recent processors that we won't need in class but you may be interested in learning about. An equivalent (and often friendlier) set of manuals is [available from AMD][11]. Save the Intel/AMD architecture manuals for later or use them for reference when you want to look up the definitive explanation of a particular processor feature or instruction.
|
||||
|
||||
##### Simulating the x86
|
||||
|
||||
Instead of developing the operating system on a real, physical personal computer (PC), we use a program that faithfully emulates a complete PC: the code you write for the emulator will boot on a real PC too. Using an emulator simplifies debugging; you can, for example, set break points inside of the emulated x86, which is difficult to do with the silicon version of an x86.
|
||||
|
||||
In 6.828 we will use the [QEMU Emulator][12], a modern and relatively fast emulator. While QEMU's built-in monitor provides only limited debugging support, QEMU can act as a remote debugging target for the [GNU debugger][13] (GDB), which we'll use in this lab to step through the early boot process.
|
||||
|
||||
To get started, extract the Lab 1 files into your own directory on Athena as described above in "Software Setup", then type make (or gmake on BSD systems) in the `lab` directory to build the minimal 6.828 boot loader and kernel you will start with. (It's a little generous to call the code we're running here a "kernel," but we'll flesh it out throughout the semester.)
|
||||
|
||||
```
|
||||
athena% cd lab
|
||||
athena% make
|
||||
+ as kern/entry.S
|
||||
+ cc kern/entrypgdir.c
|
||||
+ cc kern/init.c
|
||||
+ cc kern/console.c
|
||||
+ cc kern/monitor.c
|
||||
+ cc kern/printf.c
|
||||
+ cc kern/kdebug.c
|
||||
+ cc lib/printfmt.c
|
||||
+ cc lib/readline.c
|
||||
+ cc lib/string.c
|
||||
+ ld obj/kern/kernel
|
||||
+ as boot/boot.S
|
||||
+ cc -Os boot/main.c
|
||||
+ ld boot/boot
|
||||
boot block is 380 bytes (max 510)
|
||||
+ mk obj/kern/kernel.img
|
||||
|
||||
```
|
||||
|
||||
(If you get errors like "undefined reference to `__udivdi3'", you probably don't have the 32-bit gcc multilib. If you're running Debian or Ubuntu, try installing the gcc-multilib package.)
|
||||
|
||||
Now you're ready to run QEMU, supplying the file `obj/kern/kernel.img`, created above, as the contents of the emulated PC's "virtual hard disk." This hard disk image contains both our boot loader (`obj/boot/boot`) and our kernel (`obj/kernel`).
|
||||
|
||||
```
|
||||
athena% make qemu
|
||||
|
||||
```
|
||||
|
||||
or
|
||||
|
||||
```
|
||||
athena% make qemu-nox
|
||||
|
||||
```
|
||||
|
||||
This executes QEMU with the options required to set the hard disk and direct serial port output to the terminal. Some text should appear in the QEMU window:
|
||||
|
||||
```
|
||||
Booting from Hard Disk...
|
||||
6828 decimal is XXX octal!
|
||||
entering test_backtrace 5
|
||||
entering test_backtrace 4
|
||||
entering test_backtrace 3
|
||||
entering test_backtrace 2
|
||||
entering test_backtrace 1
|
||||
entering test_backtrace 0
|
||||
leaving test_backtrace 0
|
||||
leaving test_backtrace 1
|
||||
leaving test_backtrace 2
|
||||
leaving test_backtrace 3
|
||||
leaving test_backtrace 4
|
||||
leaving test_backtrace 5
|
||||
Welcome to the JOS kernel monitor!
|
||||
Type 'help' for a list of commands.
|
||||
K>
|
||||
|
||||
```
|
||||
|
||||
Everything after '`Booting from Hard Disk...`' was printed by our skeletal JOS kernel; the `K>` is the prompt printed by the small _monitor_ , or interactive control program, that we've included in the kernel. If you used make qemu, these lines printed by the kernel will appear in both the regular shell window from which you ran QEMU and the QEMU display window. This is because for testing and lab grading purposes we have set up the JOS kernel to write its console output not only to the virtual VGA display (as seen in the QEMU window), but also to the simulated PC's virtual serial port, which QEMU in turn outputs to its own standard output. Likewise, the JOS kernel will take input from both the keyboard and the serial port, so you can give it commands in either the VGA display window or the terminal running QEMU. Alternatively, you can use the serial console without the virtual VGA by running make qemu-nox. This may be convenient if you are SSH'd into an Athena dialup. To quit qemu, type Ctrl+a x.
|
||||
|
||||
There are only two commands you can give to the kernel monitor, `help` and `kerninfo`.
|
||||
|
||||
```
|
||||
K> help
|
||||
help - display this list of commands
|
||||
kerninfo - display information about the kernel
|
||||
K> kerninfo
|
||||
Special kernel symbols:
|
||||
entry f010000c (virt) 0010000c (phys)
|
||||
etext f0101a75 (virt) 00101a75 (phys)
|
||||
edata f0112300 (virt) 00112300 (phys)
|
||||
end f0112960 (virt) 00112960 (phys)
|
||||
Kernel executable memory footprint: 75KB
|
||||
K>
|
||||
|
||||
```
|
||||
|
||||
The `help` command is obvious, and we will shortly discuss the meaning of what the `kerninfo` command prints. Although simple, it's important to note that this kernel monitor is running "directly" on the "raw (virtual) hardware" of the simulated PC. This means that you should be able to copy the contents of `obj/kern/kernel.img` onto the first few sectors of a _real_ hard disk, insert that hard disk into a real PC, turn it on, and see exactly the same thing on the PC's real screen as you did above in the QEMU window. (We don't recommend you do this on a real machine with useful information on its hard disk, though, because copying `kernel.img` onto the beginning of its hard disk will trash the master boot record and the beginning of the first partition, effectively causing everything previously on the hard disk to be lost!)
|
||||
|
||||
##### The PC's Physical Address Space
|
||||
|
||||
We will now dive into a bit more detail about how a PC starts up. A PC's physical address space is hard-wired to have the following general layout:
|
||||
|
||||
```
|
||||
+------------------+ <- 0xFFFFFFFF (4GB)
|
||||
| 32-bit |
|
||||
| memory mapped |
|
||||
| devices |
|
||||
| |
|
||||
/\/\/\/\/\/\/\/\/\/\
|
||||
|
||||
/\/\/\/\/\/\/\/\/\/\
|
||||
| |
|
||||
| Unused |
|
||||
| |
|
||||
+------------------+ <- depends on amount of RAM
|
||||
| |
|
||||
| |
|
||||
| Extended Memory |
|
||||
| |
|
||||
| |
|
||||
+------------------+ <- 0x00100000 (1MB)
|
||||
| BIOS ROM |
|
||||
+------------------+ <- 0x000F0000 (960KB)
|
||||
| 16-bit devices, |
|
||||
| expansion ROMs |
|
||||
+------------------+ <- 0x000C0000 (768KB)
|
||||
| VGA Display |
|
||||
+------------------+ <- 0x000A0000 (640KB)
|
||||
| |
|
||||
| Low Memory |
|
||||
| |
|
||||
+------------------+ <- 0x00000000
|
||||
|
||||
```
|
||||
|
||||
The first PCs, which were based on the 16-bit Intel 8088 processor, were only capable of addressing 1MB of physical memory. The physical address space of an early PC would therefore start at 0x00000000 but end at 0x000FFFFF instead of 0xFFFFFFFF. The 640KB area marked "Low Memory" was the _only_ random-access memory (RAM) that an early PC could use; in fact the very earliest PCs only could be configured with 16KB, 32KB, or 64KB of RAM!
|
||||
|
||||
The 384KB area from 0x000A0000 through 0x000FFFFF was reserved by the hardware for special uses such as video display buffers and firmware held in non-volatile memory. The most important part of this reserved area is the Basic Input/Output System (BIOS), which occupies the 64KB region from 0x000F0000 through 0x000FFFFF. In early PCs the BIOS was held in true read-only memory (ROM), but current PCs store the BIOS in updateable flash memory. The BIOS is responsible for performing basic system initialization such as activating the video card and checking the amount of memory installed. After performing this initialization, the BIOS loads the operating system from some appropriate location such as floppy disk, hard disk, CD-ROM, or the network, and passes control of the machine to the operating system.
|
||||
|
||||
When Intel finally "broke the one megabyte barrier" with the 80286 and 80386 processors, which supported 16MB and 4GB physical address spaces respectively, the PC architects nevertheless preserved the original layout for the low 1MB of physical address space in order to ensure backward compatibility with existing software. Modern PCs therefore have a "hole" in physical memory from 0x000A0000 to 0x00100000, dividing RAM into "low" or "conventional memory" (the first 640KB) and "extended memory" (everything else). In addition, some space at the very top of the PC's 32-bit physical address space, above all physical RAM, is now commonly reserved by the BIOS for use by 32-bit PCI devices.
|
||||
|
||||
Recent x86 processors can support _more_ than 4GB of physical RAM, so RAM can extend further above 0xFFFFFFFF. In this case the BIOS must arrange to leave a _second_ hole in the system's RAM at the top of the 32-bit addressable region, to leave room for these 32-bit devices to be mapped. Because of design limitations JOS will use only the first 256MB of a PC's physical memory anyway, so for now we will pretend that all PCs have "only" a 32-bit physical address space. But dealing with complicated physical address spaces and other aspects of hardware organization that evolved over many years is one of the important practical challenges of OS development.
|
||||
|
||||
##### The ROM BIOS
|
||||
|
||||
In this portion of the lab, you'll use QEMU's debugging facilities to investigate how an IA-32 compatible computer boots.
|
||||
|
||||
Open two terminal windows and cd both shells into your lab directory. In one, enter make qemu-gdb (or make qemu-nox-gdb). This starts up QEMU, but QEMU stops just before the processor executes the first instruction and waits for a debugging connection from GDB. In the second terminal, from the same directory you ran `make`, run make gdb. You should see something like this,
|
||||
|
||||
```
|
||||
athena% make gdb
|
||||
GNU gdb (GDB) 6.8-debian
|
||||
Copyright (C) 2008 Free Software Foundation, Inc.
|
||||
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
|
||||
This is free software: you are free to change and redistribute it.
|
||||
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
|
||||
and "show warranty" for details.
|
||||
This GDB was configured as "i486-linux-gnu".
|
||||
+ target remote localhost:26000
|
||||
The target architecture is assumed to be i8086
|
||||
[f000:fff0] 0xffff0: ljmp $0xf000,$0xe05b
|
||||
0x0000fff0 in ?? ()
|
||||
+ symbol-file obj/kern/kernel
|
||||
(gdb)
|
||||
|
||||
```
|
||||
|
||||
We provided a `.gdbinit` file that set up GDB to debug the 16-bit code used during early boot and directed it to attach to the listening QEMU. (If it doesn't work, you may have to add an `add-auto-load-safe-path` in your `.gdbinit` in your home directory to convince `gdb` to process the `.gdbinit` we provided. `gdb` will tell you if you have to do this.)
|
||||
|
||||
The following line:
|
||||
|
||||
```
|
||||
[f000:fff0] 0xffff0: ljmp $0xf000,$0xe05b
|
||||
|
||||
```
|
||||
|
||||
is GDB's disassembly of the first instruction to be executed. From this output you can conclude a few things:
|
||||
|
||||
* The IBM PC starts executing at physical address 0x000ffff0, which is at the very top of the 64KB area reserved for the ROM BIOS.
|
||||
* The PC starts executing with `CS = 0xf000` and `IP = 0xfff0`.
|
||||
* The first instruction to be executed is a `jmp` instruction, which jumps to the segmented address `CS = 0xf000` and `IP = 0xe05b`.
|
||||
|
||||
|
||||
|
||||
Why does QEMU start like this? This is how Intel designed the 8088 processor, which IBM used in their original PC. Because the BIOS in a PC is "hard-wired" to the physical address range 0x000f0000-0x000fffff, this design ensures that the BIOS always gets control of the machine first after power-up or any system restart - which is crucial because on power-up there _is_ no other software anywhere in the machine's RAM that the processor could execute. The QEMU emulator comes with its own BIOS, which it places at this location in the processor's simulated physical address space. On processor reset, the (simulated) processor enters real mode and sets CS to 0xf000 and the IP to 0xfff0, so that execution begins at that (CS:IP) segment address. How does the segmented address 0xf000:fff0 turn into a physical address?
|
||||
|
||||
To answer that we need to know a bit about real mode addressing. In real mode (the mode that PC starts off in), address translation works according to the formula: _physical address_ = 16 选题模板.txt 中文排版指北.md comic core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LCTT翻译规范.md LICENSE Makefile published README.md sign.md sources translated _segment_ \+ _offset_. So, when the PC sets CS to 0xf000 and IP to 0xfff0, the physical address referenced is:
|
||||
|
||||
```
|
||||
16 * 0xf000 + 0xfff0 # in hex multiplication by 16 is
|
||||
= 0xf0000 + 0xfff0 # easy--just append a 0.
|
||||
= 0xffff0
|
||||
|
||||
```
|
||||
|
||||
`0xffff0` is 16 bytes before the end of the BIOS (`0x100000`). Therefore we shouldn't be surprised that the first thing that the BIOS does is `jmp` backwards to an earlier location in the BIOS; after all how much could it accomplish in just 16 bytes?
|
||||
|
||||
Exercise 2. Use GDB's si (Step Instruction) command to trace into the ROM BIOS for a few more instructions, and try to guess what it might be doing. You might want to look at [Phil Storrs I/O Ports Description][14], as well as other materials on the [6.828 reference materials page][8]. No need to figure out all the details - just the general idea of what the BIOS is doing first.
|
||||
|
||||
When the BIOS runs, it sets up an interrupt descriptor table and initializes various devices such as the VGA display. This is where the "`Starting SeaBIOS`" message you see in the QEMU window comes from.
|
||||
|
||||
After initializing the PCI bus and all the important devices the BIOS knows about, it searches for a bootable device such as a floppy, hard drive, or CD-ROM. Eventually, when it finds a bootable disk, the BIOS reads the _boot loader_ from the disk and transfers control to it.
|
||||
|
||||
#### Part 2: The Boot Loader
|
||||
|
||||
Floppy and hard disks for PCs are divided into 512 byte regions called _sectors_. A sector is the disk's minimum transfer granularity: each read or write operation must be one or more sectors in size and aligned on a sector boundary. If the disk is bootable, the first sector is called the _boot sector_ , since this is where the boot loader code resides. When the BIOS finds a bootable floppy or hard disk, it loads the 512-byte boot sector into memory at physical addresses 0x7c00 through 0x7dff, and then uses a `jmp` instruction to set the CS:IP to `0000:7c00`, passing control to the boot loader. Like the BIOS load address, these addresses are fairly arbitrary - but they are fixed and standardized for PCs.
|
||||
|
||||
The ability to boot from a CD-ROM came much later during the evolution of the PC, and as a result the PC architects took the opportunity to rethink the boot process slightly. As a result, the way a modern BIOS boots from a CD-ROM is a bit more complicated (and more powerful). CD-ROMs use a sector size of 2048 bytes instead of 512, and the BIOS can load a much larger boot image from the disk into memory (not just one sector) before transferring control to it. For more information, see the ["El Torito" Bootable CD-ROM Format Specification][15].
|
||||
|
||||
For 6.828, however, we will use the conventional hard drive boot mechanism, which means that our boot loader must fit into a measly 512 bytes. The boot loader consists of one assembly language source file, `boot/boot.S`, and one C source file, `boot/main.c` Look through these source files carefully and make sure you understand what's going on. The boot loader must perform two main functions:
|
||||
|
||||
1. First, the boot loader switches the processor from real mode to _32-bit protected mode_ , because it is only in this mode that software can access all the memory above 1MB in the processor's physical address space. Protected mode is described briefly in sections 1.2.7 and 1.2.8 of [PC Assembly Language][6], and in great detail in the Intel architecture manuals. At this point you only have to understand that translation of segmented addresses (segment:offset pairs) into physical addresses happens differently in protected mode, and that after the transition offsets are 32 bits instead of 16.
|
||||
2. Second, the boot loader reads the kernel from the hard disk by directly accessing the IDE disk device registers via the x86's special I/O instructions. If you would like to understand better what the particular I/O instructions here mean, check out the "IDE hard drive controller" section on [the 6.828 reference page][8]. You will not need to learn much about programming specific devices in this class: writing device drivers is in practice a very important part of OS development, but from a conceptual or architectural viewpoint it is also one of the least interesting.
|
||||
|
||||
|
||||
|
||||
After you understand the boot loader source code, look at the file `obj/boot/boot.asm`. This file is a disassembly of the boot loader that our GNUmakefile creates _after_ compiling the boot loader. This disassembly file makes it easy to see exactly where in physical memory all of the boot loader's code resides, and makes it easier to track what's happening while stepping through the boot loader in GDB. Likewise, `obj/kern/kernel.asm` contains a disassembly of the JOS kernel, which can often be useful for debugging.
|
||||
|
||||
You can set address breakpoints in GDB with the `b` command. For example, b *0x7c00 sets a breakpoint at address 0x7C00. Once at a breakpoint, you can continue execution using the c and si commands: c causes QEMU to continue execution until the next breakpoint (or until you press Ctrl-C in GDB), and si _N_ steps through the instructions _`N`_ at a time.
|
||||
|
||||
To examine instructions in memory (besides the immediate next one to be executed, which GDB prints automatically), you use the x/i command. This command has the syntax x/ _N_ i _ADDR_ , where _N_ is the number of consecutive instructions to disassemble and _ADDR_ is the memory address at which to start disassembling.
|
||||
|
||||
Exercise 3. Take a look at the [lab tools guide][16], especially the section on GDB commands. Even if you're familiar with GDB, this includes some esoteric GDB commands that are useful for OS work.
|
||||
|
||||
Set a breakpoint at address 0x7c00, which is where the boot sector will be loaded. Continue execution until that breakpoint. Trace through the code in `boot/boot.S`, using the source code and the disassembly file `obj/boot/boot.asm` to keep track of where you are. Also use the `x/i` command in GDB to disassemble sequences of instructions in the boot loader, and compare the original boot loader source code with both the disassembly in `obj/boot/boot.asm` and GDB.
|
||||
|
||||
Trace into `bootmain()` in `boot/main.c`, and then into `readsect()`. Identify the exact assembly instructions that correspond to each of the statements in `readsect()`. Trace through the rest of `readsect()` and back out into `bootmain()`, and identify the begin and end of the `for` loop that reads the remaining sectors of the kernel from the disk. Find out what code will run when the loop is finished, set a breakpoint there, and continue to that breakpoint. Then step through the remainder of the boot loader.
|
||||
|
||||
Be able to answer the following questions:
|
||||
|
||||
* At what point does the processor start executing 32-bit code? What exactly causes the switch from 16- to 32-bit mode?
|
||||
* What is the _last_ instruction of the boot loader executed, and what is the _first_ instruction of the kernel it just loaded?
|
||||
* _Where_ is the first instruction of the kernel?
|
||||
* How does the boot loader decide how many sectors it must read in order to fetch the entire kernel from disk? Where does it find this information?
|
||||
|
||||
|
||||
|
||||
##### Loading the Kernel
|
||||
|
||||
We will now look in further detail at the C language portion of the boot loader, in `boot/main.c`. But before doing so, this is a good time to stop and review some of the basics of C programming.
|
||||
|
||||
Exercise 4. Read about programming with pointers in C. The best reference for the C language is _The C Programming Language_ by Brian Kernighan and Dennis Ritchie (known as 'K &R'). We recommend that students purchase this book (here is an [Amazon Link][17]) or find one of [MIT's 7 copies][18].
|
||||
|
||||
Read 5.1 (Pointers and Addresses) through 5.5 (Character Pointers and Functions) in K&R. Then download the code for [pointers.c][19], run it, and make sure you understand where all of the printed values come from. In particular, make sure you understand where the pointer addresses in printed lines 1 and 6 come from, how all the values in printed lines 2 through 4 get there, and why the values printed in line 5 are seemingly corrupted.
|
||||
|
||||
There are other references on pointers in C (e.g., [A tutorial by Ted Jensen][20] that cites K&R heavily), though not as strongly recommended.
|
||||
|
||||
_Warning:_ Unless you are already thoroughly versed in C, do not skip or even skim this reading exercise. If you do not really understand pointers in C, you will suffer untold pain and misery in subsequent labs, and then eventually come to understand them the hard way. Trust us; you don't want to find out what "the hard way" is.
|
||||
|
||||
To make sense out of `boot/main.c` you'll need to know what an ELF binary is. When you compile and link a C program such as the JOS kernel, the compiler transforms each C source ('`.c`') file into an _object_ ('`.o`') file containing assembly language instructions encoded in the binary format expected by the hardware. The linker then combines all of the compiled object files into a single _binary image_ such as `obj/kern/kernel`, which in this case is a binary in the ELF format, which stands for "Executable and Linkable Format".
|
||||
|
||||
Full information about this format is available in [the ELF specification][21] on [our reference page][8], but you will not need to delve very deeply into the details of this format in this class. Although as a whole the format is quite powerful and complex, most of the complex parts are for supporting dynamic loading of shared libraries, which we will not do in this class. The [Wikipedia page][22] has a short description.
|
||||
|
||||
For purposes of 6.828, you can consider an ELF executable to be a header with loading information, followed by several _program sections_ , each of which is a contiguous chunk of code or data intended to be loaded into memory at a specified address. The boot loader does not modify the code or data; it loads it into memory and starts executing it.
|
||||
|
||||
An ELF binary starts with a fixed-length _ELF header_ , followed by a variable-length _program header_ listing each of the program sections to be loaded. The C definitions for these ELF headers are in `inc/elf.h`. The program sections we're interested in are:
|
||||
|
||||
* `.text`: The program's executable instructions.
|
||||
* `.rodata`: Read-only data, such as ASCII string constants produced by the C compiler. (We will not bother setting up the hardware to prohibit writing, however.)
|
||||
* `.data`: The data section holds the program's initialized data, such as global variables declared with initializers like `int x = 5;`.
|
||||
|
||||
|
||||
|
||||
When the linker computes the memory layout of a program, it reserves space for _uninitialized_ global variables, such as `int x;`, in a section called `.bss` that immediately follows `.data` in memory. C requires that "uninitialized" global variables start with a value of zero. Thus there is no need to store contents for `.bss` in the ELF binary; instead, the linker records just the address and size of the `.bss` section. The loader or the program itself must arrange to zero the `.bss` section.
|
||||
|
||||
Examine the full list of the names, sizes, and link addresses of all the sections in the kernel executable by typing:
|
||||
|
||||
```
|
||||
athena% objdump -h obj/kern/kernel
|
||||
|
||||
(If you compiled your own toolchain, you may need to use i386-jos-elf-objdump)
|
||||
|
||||
```
|
||||
|
||||
You will see many more sections than the ones we listed above, but the others are not important for our purposes. Most of the others are to hold debugging information, which is typically included in the program's executable file but not loaded into memory by the program loader.
|
||||
|
||||
Take particular note of the "VMA" (or _link address_ ) and the "LMA" (or _load address_ ) of the `.text` section. The load address of a section is the memory address at which that section should be loaded into memory.
|
||||
|
||||
The link address of a section is the memory address from which the section expects to execute. The linker encodes the link address in the binary in various ways, such as when the code needs the address of a global variable, with the result that a binary usually won't work if it is executing from an address that it is not linked for. (It is possible to generate _position-independent_ code that does not contain any such absolute addresses. This is used extensively by modern shared libraries, but it has performance and complexity costs, so we won't be using it in 6.828.)
|
||||
|
||||
Typically, the link and load addresses are the same. For example, look at the `.text` section of the boot loader:
|
||||
|
||||
```
|
||||
athena% objdump -h obj/boot/boot.out
|
||||
|
||||
```
|
||||
|
||||
The boot loader uses the ELF _program headers_ to decide how to load the sections. The program headers specify which parts of the ELF object to load into memory and the destination address each should occupy. You can inspect the program headers by typing:
|
||||
|
||||
```
|
||||
athena% objdump -x obj/kern/kernel
|
||||
|
||||
```
|
||||
|
||||
The program headers are then listed under "Program Headers" in the output of objdump. The areas of the ELF object that need to be loaded into memory are those that are marked as "LOAD". Other information for each program header is given, such as the virtual address ("vaddr"), the physical address ("paddr"), and the size of the loaded area ("memsz" and "filesz").
|
||||
|
||||
Back in boot/main.c, the `ph->p_pa` field of each program header contains the segment's destination physical address (in this case, it really is a physical address, though the ELF specification is vague on the actual meaning of this field).
|
||||
|
||||
The BIOS loads the boot sector into memory starting at address 0x7c00, so this is the boot sector's load address. This is also where the boot sector executes from, so this is also its link address. We set the link address by passing `-Ttext 0x7C00` to the linker in `boot/Makefrag`, so the linker will produce the correct memory addresses in the generated code.
|
||||
|
||||
Exercise 5. Trace through the first few instructions of the boot loader again and identify the first instruction that would "break" or otherwise do the wrong thing if you were to get the boot loader's link address wrong. Then change the link address in `boot/Makefrag` to something wrong, run make clean, recompile the lab with make, and trace into the boot loader again to see what happens. Don't forget to change the link address back and make clean again afterward!
|
||||
|
||||
Look back at the load and link addresses for the kernel. Unlike the boot loader, these two addresses aren't the same: the kernel is telling the boot loader to load it into memory at a low address (1 megabyte), but it expects to execute from a high address. We'll dig in to how we make this work in the next section.
|
||||
|
||||
Besides the section information, there is one more field in the ELF header that is important to us, named `e_entry`. This field holds the link address of the _entry point_ in the program: the memory address in the program's text section at which the program should begin executing. You can see the entry point:
|
||||
|
||||
```
|
||||
athena% objdump -f obj/kern/kernel
|
||||
|
||||
```
|
||||
|
||||
You should now be able to understand the minimal ELF loader in `boot/main.c`. It reads each section of the kernel from disk into memory at the section's load address and then jumps to the kernel's entry point.
|
||||
|
||||
Exercise 6. We can examine memory using GDB's x command. The [GDB manual][23] has full details, but for now, it is enough to know that the command x/ _N_ x _ADDR_ prints _`N`_ words of memory at _`ADDR`_. (Note that both '`x`'s in the command are lowercase.) _Warning_ : The size of a word is not a universal standard. In GNU assembly, a word is two bytes (the 'w' in xorw, which stands for word, means 2 bytes).
|
||||
|
||||
Reset the machine (exit QEMU/GDB and start them again). Examine the 8 words of memory at 0x00100000 at the point the BIOS enters the boot loader, and then again at the point the boot loader enters the kernel. Why are they different? What is there at the second breakpoint? (You do not really need to use QEMU to answer this question. Just think.)
|
||||
|
||||
#### Part 3: The Kernel
|
||||
|
||||
We will now start to examine the minimal JOS kernel in a bit more detail. (And you will finally get to write some code!). Like the boot loader, the kernel begins with some assembly language code that sets things up so that C language code can execute properly.
|
||||
|
||||
##### Using virtual memory to work around position dependence
|
||||
|
||||
When you inspected the boot loader's link and load addresses above, they matched perfectly, but there was a (rather large) disparity between the _kernel's_ link address (as printed by objdump) and its load address. Go back and check both and make sure you can see what we're talking about. (Linking the kernel is more complicated than the boot loader, so the link and load addresses are at the top of `kern/kernel.ld`.)
|
||||
|
||||
Operating system kernels often like to be linked and run at very high _virtual address_ , such as 0xf0100000, in order to leave the lower part of the processor's virtual address space for user programs to use. The reason for this arrangement will become clearer in the next lab.
|
||||
|
||||
Many machines don't have any physical memory at address 0xf0100000, so we can't count on being able to store the kernel there. Instead, we will use the processor's memory management hardware to map virtual address 0xf0100000 (the link address at which the kernel code _expects_ to run) to physical address 0x00100000 (where the boot loader loaded the kernel into physical memory). This way, although the kernel's virtual address is high enough to leave plenty of address space for user processes, it will be loaded in physical memory at the 1MB point in the PC's RAM, just above the BIOS ROM. This approach requires that the PC have at least a few megabytes of physical memory (so that physical address 0x00100000 works), but this is likely to be true of any PC built after about 1990.
|
||||
|
||||
In fact, in the next lab, we will map the _entire_ bottom 256MB of the PC's physical address space, from physical addresses 0x00000000 through 0x0fffffff, to virtual addresses 0xf0000000 through 0xffffffff respectively. You should now see why JOS can only use the first 256MB of physical memory.
|
||||
|
||||
For now, we'll just map the first 4MB of physical memory, which will be enough to get us up and running. We do this using the hand-written, statically-initialized page directory and page table in `kern/entrypgdir.c`. For now, you don't have to understand the details of how this works, just the effect that it accomplishes. Up until `kern/entry.S` sets the `CR0_PG` flag, memory references are treated as physical addresses (strictly speaking, they're linear addresses, but boot/boot.S set up an identity mapping from linear addresses to physical addresses and we're never going to change that). Once `CR0_PG` is set, memory references are virtual addresses that get translated by the virtual memory hardware to physical addresses. `entry_pgdir` translates virtual addresses in the range 0xf0000000 through 0xf0400000 to physical addresses 0x00000000 through 0x00400000, as well as virtual addresses 0x00000000 through 0x00400000 to physical addresses 0x00000000 through 0x00400000. Any virtual address that is not in one of these two ranges will cause a hardware exception which, since we haven't set up interrupt handling yet, will cause QEMU to dump the machine state and exit (or endlessly reboot if you aren't using the 6.828-patched version of QEMU).
|
||||
|
||||
Exercise 7. Use QEMU and GDB to trace into the JOS kernel and stop at the `movl %eax, %cr0`. Examine memory at 0x00100000 and at 0xf0100000. Now, single step over that instruction using the stepi GDB command. Again, examine memory at 0x00100000 and at 0xf0100000. Make sure you understand what just happened.
|
||||
|
||||
What is the first instruction _after_ the new mapping is established that would fail to work properly if the mapping weren't in place? Comment out the `movl %eax, %cr0` in `kern/entry.S`, trace into it, and see if you were right.
|
||||
|
||||
##### Formatted Printing to the Console
|
||||
|
||||
Most people take functions like `printf()` for granted, sometimes even thinking of them as "primitives" of the C language. But in an OS kernel, we have to implement all I/O ourselves.
|
||||
|
||||
Read through `kern/printf.c`, `lib/printfmt.c`, and `kern/console.c`, and make sure you understand their relationship. It will become clear in later labs why `printfmt.c` is located in the separate `lib` directory.
|
||||
|
||||
Exercise 8. We have omitted a small fragment of code - the code necessary to print octal numbers using patterns of the form "%o". Find and fill in this code fragment.
|
||||
|
||||
Be able to answer the following questions:
|
||||
|
||||
1. Explain the interface between `printf.c` and `console.c`. Specifically, what function does `console.c` export? How is this function used by `printf.c`?
|
||||
|
||||
2. Explain the following from `console.c`:
|
||||
```
|
||||
1 if (crt_pos >= CRT_SIZE) {
|
||||
2 int i;
|
||||
3 memmove(crt_buf, crt_buf + CRT_COLS, (CRT_SIZE - CRT_COLS) 选题模板.txt 中文排版指北.md comic core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LCTT翻译规范.md LICENSE Makefile published README.md sign.md sources translated sizeof(uint16_t));
|
||||
4 for (i = CRT_SIZE - CRT_COLS; i < CRT_SIZE; i++)
|
||||
5 crt_buf[i] = 0x0700 | ' ';
|
||||
6 crt_pos -= CRT_COLS;
|
||||
7 }
|
||||
|
||||
```
|
||||
|
||||
3. For the following questions you might wish to consult the notes for Lecture 2. These notes cover GCC's calling convention on the x86.
|
||||
|
||||
Trace the execution of the following code step-by-step:
|
||||
```
|
||||
int x = 1, y = 3, z = 4;
|
||||
cprintf("x %d, y %x, z %d\n", x, y, z);
|
||||
|
||||
```
|
||||
|
||||
* In the call to `cprintf()`, to what does `fmt` point? To what does `ap` point?
|
||||
* List (in order of execution) each call to `cons_putc`, `va_arg`, and `vcprintf`. For `cons_putc`, list its argument as well. For `va_arg`, list what `ap` points to before and after the call. For `vcprintf` list the values of its two arguments.
|
||||
4. Run the following code.
|
||||
```
|
||||
unsigned int i = 0x00646c72;
|
||||
cprintf("H%x Wo%s", 57616, &i);
|
||||
|
||||
```
|
||||
|
||||
What is the output? Explain how this output is arrived at in the step-by-step manner of the previous exercise. [Here's an ASCII table][24] that maps bytes to characters.
|
||||
|
||||
The output depends on that fact that the x86 is little-endian. If the x86 were instead big-endian what would you set `i` to in order to yield the same output? Would you need to change `57616` to a different value?
|
||||
|
||||
[Here's a description of little- and big-endian][25] and [a more whimsical description][26].
|
||||
|
||||
5. In the following code, what is going to be printed after `'y='`? (note: the answer is not a specific value.) Why does this happen?
|
||||
```
|
||||
cprintf("x=%d y=%d", 3);
|
||||
|
||||
```
|
||||
|
||||
6. Let's say that GCC changed its calling convention so that it pushed arguments on the stack in declaration order, so that the last argument is pushed last. How would you have to change `cprintf` or its interface so that it would still be possible to pass it a variable number of arguments?
|
||||
|
||||
|
||||
|
||||
|
||||
Challenge Enhance the console to allow text to be printed in different colors. The traditional way to do this is to make it interpret [ANSI escape sequences][27] embedded in the text strings printed to the console, but you may use any mechanism you like. There is plenty of information on [the 6.828 reference page][8] and elsewhere on the web on programming the VGA display hardware. If you're feeling really adventurous, you could try switching the VGA hardware into a graphics mode and making the console draw text onto the graphical frame buffer.
|
||||
|
||||
##### The Stack
|
||||
|
||||
In the final exercise of this lab, we will explore in more detail the way the C language uses the stack on the x86, and in the process write a useful new kernel monitor function that prints a _backtrace_ of the stack: a list of the saved Instruction Pointer (IP) values from the nested `call` instructions that led to the current point of execution.
|
||||
|
||||
Exercise 9. Determine where the kernel initializes its stack, and exactly where in memory its stack is located. How does the kernel reserve space for its stack? And at which "end" of this reserved area is the stack pointer initialized to point to?
|
||||
|
||||
The x86 stack pointer (`esp` register) points to the lowest location on the stack that is currently in use. Everything _below_ that location in the region reserved for the stack is free. Pushing a value onto the stack involves decreasing the stack pointer and then writing the value to the place the stack pointer points to. Popping a value from the stack involves reading the value the stack pointer points to and then increasing the stack pointer. In 32-bit mode, the stack can only hold 32-bit values, and esp is always divisible by four. Various x86 instructions, such as `call`, are "hard-wired" to use the stack pointer register.
|
||||
|
||||
The `ebp` (base pointer) register, in contrast, is associated with the stack primarily by software convention. On entry to a C function, the function's _prologue_ code normally saves the previous function's base pointer by pushing it onto the stack, and then copies the current `esp` value into `ebp` for the duration of the function. If all the functions in a program obey this convention, then at any given point during the program's execution, it is possible to trace back through the stack by following the chain of saved `ebp` pointers and determining exactly what nested sequence of function calls caused this particular point in the program to be reached. This capability can be particularly useful, for example, when a particular function causes an `assert` failure or `panic` because bad arguments were passed to it, but you aren't sure _who_ passed the bad arguments. A stack backtrace lets you find the offending function.
|
||||
|
||||
Exercise 10. To become familiar with the C calling conventions on the x86, find the address of the `test_backtrace` function in `obj/kern/kernel.asm`, set a breakpoint there, and examine what happens each time it gets called after the kernel starts. How many 32-bit words does each recursive nesting level of `test_backtrace` push on the stack, and what are those words?
|
||||
|
||||
Note that, for this exercise to work properly, you should be using the patched version of QEMU available on the [tools][4] page or on Athena. Otherwise, you'll have to manually translate all breakpoint and memory addresses to linear addresses.
|
||||
|
||||
The above exercise should give you the information you need to implement a stack backtrace function, which you should call `mon_backtrace()`. A prototype for this function is already waiting for you in `kern/monitor.c`. You can do it entirely in C, but you may find the `read_ebp()` function in `inc/x86.h` useful. You'll also have to hook this new function into the kernel monitor's command list so that it can be invoked interactively by the user.
|
||||
|
||||
The backtrace function should display a listing of function call frames in the following format:
|
||||
|
||||
```
|
||||
Stack backtrace:
|
||||
ebp f0109e58 eip f0100a62 args 00000001 f0109e80 f0109e98 f0100ed2 00000031
|
||||
ebp f0109ed8 eip f01000d6 args 00000000 00000000 f0100058 f0109f28 00000061
|
||||
...
|
||||
|
||||
```
|
||||
|
||||
Each line contains an `ebp`, `eip`, and `args`. The `ebp` value indicates the base pointer into the stack used by that function: i.e., the position of the stack pointer just after the function was entered and the function prologue code set up the base pointer. The listed `eip` value is the function's _return instruction pointer_ : the instruction address to which control will return when the function returns. The return instruction pointer typically points to the instruction after the `call` instruction (why?). Finally, the five hex values listed after `args` are the first five arguments to the function in question, which would have been pushed on the stack just before the function was called. If the function was called with fewer than five arguments, of course, then not all five of these values will be useful. (Why can't the backtrace code detect how many arguments there actually are? How could this limitation be fixed?)
|
||||
|
||||
The first line printed reflects the _currently executing_ function, namely `mon_backtrace` itself, the second line reflects the function that called `mon_backtrace`, the third line reflects the function that called that one, and so on. You should print _all_ the outstanding stack frames. By studying `kern/entry.S` you'll find that there is an easy way to tell when to stop.
|
||||
|
||||
Here are a few specific points you read about in K&R Chapter 5 that are worth remembering for the following exercise and for future labs.
|
||||
|
||||
* If `int *p = (int*)100`, then `(int)p + 1` and `(int)(p + 1)` are different numbers: the first is `101` but the second is `104`. When adding an integer to a pointer, as in the second case, the integer is implicitly multiplied by the size of the object the pointer points to.
|
||||
* `p[i]` is defined to be the same as `*(p+i)`, referring to the i'th object in the memory pointed to by p. The above rule for addition helps this definition work when the objects are larger than one byte.
|
||||
* `&p[i]` is the same as `(p+i)`, yielding the address of the i'th object in the memory pointed to by p.
|
||||
|
||||
|
||||
|
||||
Although most C programs never need to cast between pointers and integers, operating systems frequently do. Whenever you see an addition involving a memory address, ask yourself whether it is an integer addition or pointer addition and make sure the value being added is appropriately multiplied or not.
|
||||
|
||||
Exercise 11. Implement the backtrace function as specified above. Use the same format as in the example, since otherwise the grading script will be confused. When you think you have it working right, run make grade to see if its output conforms to what our grading script expects, and fix it if it doesn't. _After_ you have handed in your Lab 1 code, you are welcome to change the output format of the backtrace function any way you like.
|
||||
|
||||
If you use `read_ebp()`, note that GCC may generate "optimized" code that calls `read_ebp()` _before_ `mon_backtrace()`'s function prologue, which results in an incomplete stack trace (the stack frame of the most recent function call is missing). While we have tried to disable optimizations that cause this reordering, you may want to examine the assembly of `mon_backtrace()` and make sure the call to `read_ebp()` is happening after the function prologue.
|
||||
|
||||
At this point, your backtrace function should give you the addresses of the function callers on the stack that lead to `mon_backtrace()` being executed. However, in practice you often want to know the function names corresponding to those addresses. For instance, you may want to know which functions could contain a bug that's causing your kernel to crash.
|
||||
|
||||
To help you implement this functionality, we have provided the function `debuginfo_eip()`, which looks up `eip` in the symbol table and returns the debugging information for that address. This function is defined in `kern/kdebug.c`.
|
||||
|
||||
Exercise 12. Modify your stack backtrace function to display, for each `eip`, the function name, source file name, and line number corresponding to that `eip`.
|
||||
|
||||
In `debuginfo_eip`, where do `__STAB_*` come from? This question has a long answer; to help you to discover the answer, here are some things you might want to do:
|
||||
|
||||
* look in the file `kern/kernel.ld` for `__STAB_*`
|
||||
* run objdump -h obj/kern/kernel
|
||||
* run objdump -G obj/kern/kernel
|
||||
* run gcc -pipe -nostdinc -O2 -fno-builtin -I. -MD -Wall -Wno-format -DJOS_KERNEL -gstabs -c -S kern/init.c, and look at init.s.
|
||||
* see if the bootloader loads the symbol table in memory as part of loading the kernel binary
|
||||
|
||||
|
||||
|
||||
Complete the implementation of `debuginfo_eip` by inserting the call to `stab_binsearch` to find the line number for an address.
|
||||
|
||||
Add a `backtrace` command to the kernel monitor, and extend your implementation of `mon_backtrace` to call `debuginfo_eip` and print a line for each stack frame of the form:
|
||||
|
||||
```
|
||||
K> backtrace
|
||||
Stack backtrace:
|
||||
ebp f010ff78 eip f01008ae args 00000001 f010ff8c 00000000 f0110580 00000000
|
||||
kern/monitor.c:143: monitor+106
|
||||
ebp f010ffd8 eip f0100193 args 00000000 00001aac 00000660 00000000 00000000
|
||||
kern/init.c:49: i386_init+59
|
||||
ebp f010fff8 eip f010003d args 00000000 00000000 0000ffff 10cf9a00 0000ffff
|
||||
kern/entry.S:70: <unknown>+0
|
||||
K>
|
||||
|
||||
```
|
||||
|
||||
Each line gives the file name and line within that file of the stack frame's `eip`, followed by the name of the function and the offset of the `eip` from the first instruction of the function (e.g., `monitor+106` means the return `eip` is 106 bytes past the beginning of `monitor`).
|
||||
|
||||
Be sure to print the file and function names on a separate line, to avoid confusing the grading script.
|
||||
|
||||
Tip: printf format strings provide an easy, albeit obscure, way to print non-null-terminated strings like those in STABS tables. `printf("%.*s", length, string)` prints at most `length` characters of `string`. Take a look at the printf man page to find out why this works.
|
||||
|
||||
You may find that some functions are missing from the backtrace. For example, you will probably see a call to `monitor()` but not to `runcmd()`. This is because the compiler in-lines some function calls. Other optimizations may cause you to see unexpected line numbers. If you get rid of the `-O2` from `GNUMakefile`, the backtraces may make more sense (but your kernel will run more slowly).
|
||||
|
||||
**This completes the lab.** In the `lab` directory, commit your changes with git commit and type make handin to submit your code.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://pdos.csail.mit.edu/6.828/2018/labs/lab1/
|
||||
|
||||
作者：[csail.mit][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]:
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: http://www.git-scm.com/
|
||||
[2]: http://www.kernel.org/pub/software/scm/git/docs/user-manual.html
|
||||
[3]: http://eagain.net/articles/git-for-computer-scientists/
|
||||
[4]: https://pdos.csail.mit.edu/6.828/2018/tools.html
|
||||
[5]: https://6828.scripts.mit.edu/2018/handin.py/
|
||||
[6]: https://pdos.csail.mit.edu/6.828/2018/readings/pcasm-book.pdf
|
||||
[7]: http://www.delorie.com/djgpp/doc/brennan/brennan_att_inline_djgpp.html
|
||||
[8]: https://pdos.csail.mit.edu/6.828/2018/reference.html
|
||||
[9]: https://pdos.csail.mit.edu/6.828/2018/readings/i386/toc.htm
|
||||
[10]: http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html
|
||||
[11]: http://developer.amd.com/resources/developer-guides-manuals/
|
||||
[12]: http://www.qemu.org/
|
||||
[13]: http://www.gnu.org/software/gdb/
|
||||
[14]: http://web.archive.org/web/20040404164813/members.iweb.net.au/~pstorr/pcbook/book2/book2.htm
|
||||
[15]: https://pdos.csail.mit.edu/6.828/2018/readings/boot-cdrom.pdf
|
||||
[16]: https://pdos.csail.mit.edu/6.828/2018/labguide.html
|
||||
[17]: http://www.amazon.com/C-Programming-Language-2nd/dp/0131103628/sr=8-1/qid=1157812738/ref=pd_bbs_1/104-1502762-1803102?ie=UTF8&s=books
|
||||
[18]: http://library.mit.edu/F/AI9Y4SJ2L5ELEE2TAQUAAR44XV5RTTQHE47P9MKP5GQDLR9A8X-10422?func=item-global&doc_library=MIT01&doc_number=000355242&year=&volume=&sub_library=
|
||||
[19]: https://pdos.csail.mit.edu/6.828/2018/labs/lab1/pointers.c
|
||||
[20]: https://pdos.csail.mit.edu/6.828/2018/readings/pointers.pdf
|
||||
[21]: https://pdos.csail.mit.edu/6.828/2018/readings/elf.pdf
|
||||
[22]: http://en.wikipedia.org/wiki/Executable_and_Linkable_Format
|
||||
[23]: https://sourceware.org/gdb/current/onlinedocs/gdb/Memory.html
|
||||
[24]: http://web.cs.mun.ca/~michael/c/ascii-table.html
|
||||
[25]: http://www.webopedia.com/TERM/b/big_endian.html
|
||||
[26]: http://www.networksorcery.com/enp/ien/ien137.txt
|
||||
[27]: http://rrbrandt.dee.ufcg.edu.br/en/docs/ansi/
|
||||
@ -1,138 +0,0 @@
|
||||
translating----geekpi
|
||||
|
||||
Clinews – Read News And Latest Headlines From Commandline
|
||||
======
|
||||
|
||||
|
||||
|
||||
A while ago, we have written about a CLI news client named [**InstantNews**][1] that helps you to read news and latest headlines from commandline instantly. Today, I stumbled upon a similar utility named **Clinews** which serves the same purpose – reading news and latest headlines from popular websites, blogs from Terminal. You don’t need to install GUI applications or mobile apps. You can read what’s happening in the world right from your Terminal. It is free, open source utility written using **NodeJS**.
|
||||
|
||||
### Installing Clinews
|
||||
|
||||
Since Clinews is written using NodeJS, you can install it using NPM package manager. If you haven’t install NodeJS, install it as described in the following link.
|
||||
|
||||
Once node installed, run the following command to install Clinews:
|
||||
|
||||
```
|
||||
$ npm i -g clinews
|
||||
```
|
||||
|
||||
You can also install Clinews using **Yarn** :
|
||||
|
||||
```
|
||||
$ yarn global add clinews
|
||||
```
|
||||
|
||||
Yarn itself can installed using npm
|
||||
|
||||
```
|
||||
$ npm -i yarn
|
||||
```
|
||||
|
||||
### Configure News API
|
||||
|
||||
Clinews retrieves all news headlines from [**News API**][2]. News API is a simple and easy-to-use API that returns JSON metadata for the headlines currently published on a range of news sources and blogs. It currently provides live headlines from 70 popular sources, including Ars Technica, BBC, Blooberg, CNN, Daily Mail, Engadget, ESPN, Financial Times, Google News, hacker News, IGN, Mashable, National Geographic, Reddit r/all, Reuters, Speigel Online, Techcrunch, The Guardian, The Hindu, The Huffington Post, The Newyork Times, The Next Web, The Wall street Journal, USA today and [**more**][3].
|
||||
|
||||
First, you need an API key from News API. Go to [**https://newsapi.org/register**][4] URL and register a free account to get the API key.
|
||||
|
||||
Once you got the API key from News API site, edit your **.bashrc** file:
|
||||
|
||||
```
|
||||
$ vi ~/.bashrc
|
||||
|
||||
```
|
||||
|
||||
Add newsapi API key at the end like below:
|
||||
|
||||
```
|
||||
export IN_API_KEY="Paste-API-key-here"
|
||||
|
||||
```
|
||||
|
||||
Please note that you need to paste the key inside the double quotes. Save and close the file.
|
||||
|
||||
Run the following command to update the changes.
|
||||
|
||||
```
|
||||
$ source ~/.bashrc
|
||||
|
||||
```
|
||||
|
||||
Done. Now let us go ahead and fetch the latest headlines from new sources.
|
||||
|
||||
### Read News And Latest Headlines From Commandline
|
||||
|
||||
To read news and latest headlines from specific new source, for example **The Hindu** , run:
|
||||
|
||||
```
|
||||
$ news fetch the-hindu
|
||||
|
||||
```
|
||||
|
||||
Here, **“the-hindu”** is the new source id (fetch id).
|
||||
|
||||
The above command will fetch latest 10 headlines from The Hindu news portel and display them in the Terminal. Also, it displays a brief description of the news, the published date and time, and the actual link to the source.
|
||||
|
||||
**Sample output:**
|
||||
|
||||
|
||||
|
||||
To read a news in your browser, hold Ctrl key and click on the URL. It will open in your default web browser.
|
||||
|
||||
To view all the sources you can get news from, run:
|
||||
|
||||
```
|
||||
$ news sources
|
||||
|
||||
```
|
||||
|
||||
**Sample output:**
|
||||
|
||||
|
||||
|
||||
As you see in the above screenshot, Clinews lists all news sources including the name of the news source, fetch id, description of the site, website URL and the country where it is located. As of writing this guide, Clinews currently supports 70+ news sources.
|
||||
|
||||
Clinews can also able to search for news stories across all sources matching search criteria/term. Say for example, to list all news stories with titles containing the words **“Tamilnadu”** , use the following command:
|
||||
|
||||
```
|
||||
$ news search "Tamilnadu"
|
||||
```
|
||||
|
||||
This command will scrap all news sources for stories that match term **Tamilnadu**.
|
||||
|
||||
Clinews has some extra flags that helps you to
|
||||
|
||||
* limit the amount of news stories you want to see,
|
||||
* sort news stories (top, latest, popular),
|
||||
* display news stories category wise (E.g. business, entertainment, gaming, general, music, politics, science-and-nature, sport, technology)
|
||||
|
||||
|
||||
|
||||
For more details, see the help section:
|
||||
|
||||
```
|
||||
$ clinews -h
|
||||
```
|
||||
|
||||
And, that’s all for now. Hope this was useful. More good stuffs to come. Stay tuned!
|
||||
|
||||
Cheers!
|
||||
|
||||
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.ostechnix.com/clinews-read-news-and-latest-headlines-from-commandline/
|
||||
|
||||
作者：[SK][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.ostechnix.com/author/sk/
|
||||
[1]: https://www.ostechnix.com/get-news-instantly-commandline-linux/
|
||||
[2]: https://newsapi.org/
|
||||
[3]: https://newsapi.org/sources
|
||||
[4]: https://newsapi.org/register
|
||||
@ -1,3 +1,5 @@
|
||||
translating by ypingcn
|
||||
|
||||
Control your data with Syncthing: An open source synchronization tool
|
||||
======
|
||||
Decide how to store and share your personal information.
|
||||
|
||||
Some files were not shown because too many files have changed in this diff Show More
Loading…
Reference in New Issue
Block a user