luff/new-rusty-book
1
0
Fork 0
mirror of https://github.com/sunface/new-rusty-book.git synced 2025-06-23 12:38:56 +00:00
Code Issues Packages Projects Releases Wiki Activity
Files
57d7f88195054c8473e582518d48a48074bbe1a3
new-rusty-book/os/command.html
sunface 07ee9c1713 deploy
2024-03-19 10:09:18 +08:00

414 lines
25 KiB
HTML
Raw Blame History

<!DOCTYPE HTML>
<html lang="zh-CN" class="sidebar-visible no-js light">
<head>
<!-- Book generated using mdBook -->
<meta charset="UTF-8">
<title>调用系统命令 - Rusty Book(锈书)</title>
<!-- Custom HTML head -->
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<meta name="description" content="">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="theme-color" content="#ffffff" />
<link rel="icon" href="../favicon.svg">
<link rel="shortcut icon" href="../favicon.png">
<link rel="stylesheet" href="../css/variables.css">
<link rel="stylesheet" href="../css/general.css">
<link rel="stylesheet" href="../css/chrome.css">
<link rel="stylesheet" href="../css/print.css" media="print">
<!-- Fonts -->
<link rel="stylesheet" href="../FontAwesome/css/font-awesome.css">
<link rel="stylesheet" href="../fonts/fonts.css">
<!-- Highlight.js Stylesheets -->
<link rel="stylesheet" href="../highlight.css">
<link rel="stylesheet" href="../tomorrow-night.css">
<link rel="stylesheet" href="../ayu-highlight.css">
<!-- Custom theme stylesheets -->
<link rel="stylesheet" href="../theme/style1.css">
</head>
<body>
<!-- Provide site root to javascript -->
<script type="text/javascript">
var path_to_root = "../";
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
</script>
<!-- Work around some values being stored in localStorage wrapped in quotes -->
<script type="text/javascript">
try {
var theme = localStorage.getItem('mdbook-theme');
var sidebar = localStorage.getItem('mdbook-sidebar');
if (theme.startsWith('"') && theme.endsWith('"')) {
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
}
if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
}
} catch (e) { }
</script>
<!-- Set the theme before any content is loaded, prevents flash -->
<script type="text/javascript">
var theme;
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
if (theme === null || theme === undefined) { theme = default_theme; }
var html = document.querySelector('html');
html.classList.remove('no-js')
html.classList.remove('light')
html.classList.add(theme);
html.classList.add('js');
</script>
<!-- Hide / unhide sidebar before it is displayed -->
<script type="text/javascript">
var html = document.querySelector('html');
var sidebar = 'hidden';
if (document.body.clientWidth >= 1080) {
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
sidebar = sidebar || 'visible';
}
html.classList.remove('sidebar-visible');
html.classList.add("sidebar-" + sidebar);
</script>
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
<div class="sidebar-scrollbox">
<ol class="chapter"><li class="chapter-item expanded affix "><a href="../about.html">Rusty Book</a></li><li class="chapter-item expanded affix "><li class="part-title">Awesome</li><li class="spacer"></li><li class="chapter-item expanded "><a href="../awesome-daily-dev.html">日常开发常用库</a></li><li class="chapter-item expanded "><a href="../awesome-superstar.html">Rust 明星项目</a></li><li class="chapter-item expanded "><a href="../awesome-empowering-js.html">使用 Rust 增强 JS</a></li><li class="chapter-item expanded "><a href="../awesome-games.html">Rust开发的游戏</a></li><li class="chapter-item expanded "><a href="../awesome-gamedev.html">游戏引擎</a></li><li class="chapter-item expanded affix "><li class="part-title">Awesome + Cookbook</li><li class="spacer"></li><li class="chapter-item expanded "><a href="../algos/awesome.html">实用算法</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><div>数据结构</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../algos/datastructures/bitfield.html">位字段</a></li></ol></li><li class="chapter-item "><a href="../algos/randomness.html">生成随机值</a></li><li class="chapter-item "><a href="../algos/sorting.html">Vec 排序</a></li><li class="chapter-item "><div>压缩算法</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../algos/compression/tar.html">使用.tar包</a></li></ol></li><li class="chapter-item "><div>密码学</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../algos/cryptography/hashing.html">哈希</a></li><li class="chapter-item "><a href="../algos/cryptography/encryption.html">加密</a></li></ol></li><li class="chapter-item "><div>数学计算</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../algos/math/linear-algebra.html">线性代数</a></li><li class="chapter-item "><a href="../algos/math/trigonometry.html">三角函数</a></li><li class="chapter-item "><a href="../algos/math/complex.html">复数</a></li><li class="chapter-item "><a href="../algos/math/statistics.html">统计学</a></li><li class="chapter-item "><a href="../algos/math/misc.html">杂项</a></li></ol></li></ol></li><li class="chapter-item expanded "><a href="../cmd/awesome.html">命令行</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../cmd/parsing.html">参数解析</a></li><li class="chapter-item "><a href="../cmd/ansi.html">终端输出格式化</a></li></ol></li><li class="chapter-item expanded "><a href="../os/awesome.html">操作系统</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../os/processor.html">处理器</a></li><li class="chapter-item expanded "><a href="../os/command.html" class="active">调用系统命令</a></li></ol></li><li class="chapter-item expanded "><div>并发和并行</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../cocurrency/threads.html">多线程</a></li><li class="chapter-item "><a href="../cocurrency/parallel.html">使用rayon并行处理数据</a></li></ol></li><li class="chapter-item expanded "><div>数据库</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../database/sqlite.html">SQLite</a></li><li class="chapter-item "><a href="../database/postgres.html">Postgres</a></li></ol></li><li class="chapter-item expanded "><div>日期和时间</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../datetime/duration.html">时间计算和转换</a></li><li class="chapter-item "><a href="../datetime/parsing.html">解析和显示</a></li></ol></li><li class="chapter-item expanded "><div>开发者工具</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../devtools/log.html">日志</a></li><li class="chapter-item "><a href="../devtools/config-log.html">配置日志</a></li><li class="chapter-item "><a href="../devtools/version.html">版本号</a></li><li class="chapter-item "><a href="../devtools/build-tools.html">构建时工具</a></li></ol></li><li class="chapter-item expanded "><div>编解码</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../encoding/strings.html">字符编码</a></li><li class="chapter-item "><a href="../encoding/csv.html">CSV</a></li><li class="chapter-item "><a href="../encoding/structured.html">结构化数据</a></li></ol></li><li class="chapter-item expanded "><div>错误处理</div></li><li class="chapter-item expanded "><div>文件操作</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../files/read-write.html">文件读写</a></li><li class="chapter-item "><a href="../files/dir.html">目录访问</a></li></ol></li><li class="chapter-item expanded "><div>内存管理</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../memory/global-vars.html">全局变量</a></li></ol></li><li class="chapter-item expanded "><div>网络协议</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../protocols/tcpip.html">TCP/IP</a></li></ol></li><li class="chapter-item expanded "><div>文本处理</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../text/regex.html">正则表达式</a></li><li class="chapter-item "><a href="../text/string.html">字符串解析</a></li></ol></li><li class="chapter-item expanded "><div>Web编程</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../web/scraping.html">提取网络链接( 爬虫 )</a></li></ol></li></ol>
</div>
<div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
</nav>
<div id="page-wrapper" class="page-wrapper">
<div class="page">
<div id="menu-bar-hover-placeholder"></div>
<div id="menu-bar" class="menu-bar sticky bordered">
<div class="left-buttons">
<button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
<i class="fa fa-bars"></i>
</button>
<button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
<i class="fa fa-paint-brush"></i>
</button>
<ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
<li role="none"><button role="menuitem" class="theme" id="light">Light (default)</button></li>
<li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
<li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
<li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
<li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
</ul>
<button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
<i class="fa fa-search"></i>
</button>
</div>
<h1 class="menu-title">Rusty Book(锈书)</h1>
<div class="right-buttons">
<a href="../print.html" title="Print this book" aria-label="Print this book">
<i id="print-button" class="fa fa-print"></i>
</a>
<a href="https://github.com/studyrs/rusty-book" title="Git repository" aria-label="Git repository">
<i id="git-repository-button" class="fa fa-github"></i>
</a>
<a href="https://github.com/studyrs/rusty-book/edit/main/src/os/command.md" title="Suggest an edit" aria-label="Suggest an edit">
<i id="git-edit-button" class="fa fa-edit"></i>
</a>
</div>
</div>
<div id="search-wrapper" class="hidden">
<form id="searchbar-outer" class="searchbar-outer">
<input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
</form>
<div id="searchresults-outer" class="searchresults-outer hidden">
<div id="searchresults-header" class="searchresults-header"></div>
<ul id="searchresults">
</ul>
</div>
</div>
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
<script type="text/javascript">
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
});
</script>
<div id="content" class="content">
<!-- Page table of contents -->
<div class="sidetoc"><nav class="pagetoc"></nav></div>
<main>
<h1 id="调用系统命令"><a class="header" href="#调用系统命令">调用系统命令</a></h1>
<h3 id="调用一个外部命令并处理输出内容"><a class="header" href="#调用一个外部命令并处理输出内容">调用一个外部命令并处理输出内容</a></h3>
<p>下面的代码将调用操作系统中的 <code>git log --oneline</code> 命令，然后使用 <a href="https://docs.rs/regex/*/regex/struct.Regex.html">regex</a> 对它输出到 <code>stdout</code> 上的调用结果进行解析，以获取哈希值和最后 5 条提交信息( commit )。</p>
<pre><pre class="playground"><code class="language-rust editable edition2021"><span class="boring">use error_chain::error_chain;
</span>
use std::process::Command;
use regex::Regex;
<span class="boring">error_chain!{
</span><span class="boring"> foreign_links {
</span><span class="boring"> Io(std::io::Error);
</span><span class="boring"> Regex(regex::Error);
</span><span class="boring"> Utf8(std::string::FromUtf8Error);
</span><span class="boring"> }
</span><span class="boring">}
</span>
#[derive(PartialEq, Default, Clone, Debug)]
struct Commit {
hash: String,
message: String,
}
fn main() -&gt; Result&lt;()&gt; {
let output = Command::new(&quot;git&quot;).arg(&quot;log&quot;).arg(&quot;--oneline&quot;).output()?;
if !output.status.success() {
error_chain::bail!(&quot;Command executed with failing error code&quot;);
}
let pattern = Regex::new(r&quot;(?x)
([0-9a-fA-F]+) # commit hash
(.*) # The commit message&quot;)?;
String::from_utf8(output.stdout)?
.lines()
.filter_map(|line| pattern.captures(line))
.map(|cap| {
Commit {
hash: cap[1].to_string(),
message: cap[2].trim().to_string(),
}
})
.take(5)
.for_each(|x| println!(&quot;{:?}&quot;, x));
Ok(())
}</code></pre></pre>
<h3 id="调用-python-解释器运行代码并检查返回的错误码"><a class="header" href="#调用-python-解释器运行代码并检查返回的错误码">调用 python 解释器运行代码并检查返回的错误码</a></h3>
<pre><pre class="playground"><code class="language-rust editable edition2021"><span class="boring">use error_chain::error_chain;
</span>
use std::collections::HashSet;
use std::io::Write;
use std::process::{Command, Stdio};
<span class="boring">error_chain!{
</span><span class="boring"> errors { CmdError }
</span><span class="boring"> foreign_links {
</span><span class="boring"> Io(std::io::Error);
</span><span class="boring"> Utf8(std::string::FromUtf8Error);
</span><span class="boring"> }
</span><span class="boring">}
</span>
fn main() -&gt; Result&lt;()&gt; {
let mut child = Command::new(&quot;python&quot;).stdin(Stdio::piped())
.stderr(Stdio::piped())
.stdout(Stdio::piped())
.spawn()?;
child.stdin
.as_mut()
.ok_or(&quot;Child process stdin has not been captured!&quot;)?
.write_all(b&quot;import this; copyright(); credits(); exit()&quot;)?;
let output = child.wait_with_output()?;
if output.status.success() {
let raw_output = String::from_utf8(output.stdout)?;
let words = raw_output.split_whitespace()
.map(|s| s.to_lowercase())
.collect::&lt;HashSet&lt;_&gt;&gt;();
println!(&quot;Found {} unique words:&quot;, words.len());
println!(&quot;{:#?}&quot;, words);
Ok(())
} else {
let err = String::from_utf8(output.stderr)?;
error_chain::bail!(&quot;External command failed:\n {}&quot;, err)
}
}</code></pre></pre>
<h3 id="通过管道来运行外部命令"><a class="header" href="#通过管道来运行外部命令">通过管道来运行外部命令</a></h3>
<p>下面的例子将显示当前目录中大小排名前十的文件和子目录，效果等效于命令 <code>du -ah . | sort -hr | head -n 10</code>。</p>
<p><a href="https://doc.rust-lang.org/std/process/struct.Command.html"><code>Command</code></a> 命令代表一个进程，其中父进程通过 <a href="https://doc.rust-lang.org/std/process/struct.Stdio.html">Stdio::piped</a> 来捕获子进程的输出。</p>
<pre><pre class="playground"><code class="language-rust editable edition2021"><span class="boring">use error_chain::error_chain;
</span>
use std::process::{Command, Stdio};
<span class="boring">error_chain! {
</span><span class="boring"> foreign_links {
</span><span class="boring"> Io(std::io::Error);
</span><span class="boring"> Utf8(std::string::FromUtf8Error);
</span><span class="boring"> }
</span><span class="boring">}
</span>
fn main() -&gt; Result&lt;()&gt; {
let directory = std::env::current_dir()?;
let mut du_output_child = Command::new(&quot;du&quot;)
.arg(&quot;-ah&quot;)
.arg(&amp;directory)
.stdout(Stdio::piped())
.spawn()?;
if let Some(du_output) = du_output_child.stdout.take() {
let mut sort_output_child = Command::new(&quot;sort&quot;)
.arg(&quot;-hr&quot;)
.stdin(du_output)
.stdout(Stdio::piped())
.spawn()?;
du_output_child.wait()?;
if let Some(sort_output) = sort_output_child.stdout.take() {
let head_output_child = Command::new(&quot;head&quot;)
.args(&amp;[&quot;-n&quot;, &quot;10&quot;])
.stdin(sort_output)
.stdout(Stdio::piped())
.spawn()?;
let head_stdout = head_output_child.wait_with_output()?;
sort_output_child.wait()?;
println!(
&quot;Top 10 biggest files and directories in '{}':\n{}&quot;,
directory.display(),
String::from_utf8(head_stdout.stdout).unwrap()
);
}
}
Ok(())
}</code></pre></pre>
<h3 id="将子进程的-stdout-和-stderr-重定向到同一个文件"><a class="header" href="#将子进程的-stdout-和-stderr-重定向到同一个文件">将子进程的 stdout 和 stderr 重定向到同一个文件</a></h3>
<p>下面的例子将生成一个子进程，然后将它的标准输出和标准错误输出都输出到同一个文件中。最终的效果跟 Unix 命令 <code>ls . oops &gt;out.txt 2&gt;&amp;1</code> 相同。</p>
<p><a href="https://doc.rust-lang.org/std/fs/struct.File.html#method.try_clone">File::try_clone</a> 会克隆一份文件句柄的引用，然后保证这两个句柄在写的时候会使用相同的游标位置。</p>
<pre><pre class="playground"><code class="language-rust editable edition2021">use std::fs::File;
use std::io::Error;
use std::process::{Command, Stdio};
fn main() -&gt; Result&lt;(), Error&gt; {
let outputs = File::create(&quot;out.txt&quot;)?;
let errors = outputs.try_clone()?;
Command::new(&quot;ls&quot;)
.args(&amp;[&quot;.&quot;, &quot;oops&quot;])
.stdout(Stdio::from(outputs))
.stderr(Stdio::from(errors))
.spawn()?
.wait_with_output()?;
Ok(())
}</code></pre></pre>
<h3 id="持续处理子进程的输出"><a class="header" href="#持续处理子进程的输出">持续处理子进程的输出</a></h3>
<p>下面的代码会创建一个管道，然后当 <code>BufReader</code> 更新时，就持续从 <code>stdout</code> 中读取数据。最终效果等同于 Unix 命令 <code>journalctl | grep usb</code>。</p>
<pre><pre class="playground"><code class="language-rust editable edition2021">use std::process::{Command, Stdio};
use std::io::{BufRead, BufReader, Error, ErrorKind};
fn main() -&gt; Result&lt;(), Error&gt; {
let stdout = Command::new(&quot;journalctl&quot;)
.stdout(Stdio::piped())
.spawn()?
.stdout
.ok_or_else(|| Error::new(ErrorKind::Other,&quot;Could not capture standard output.&quot;))?;
let reader = BufReader::new(stdout);
reader
.lines()
.filter_map(|line| line.ok())
.filter(|line| line.find(&quot;usb&quot;).is_some())
.for_each(|line| println!(&quot;{}&quot;, line));
Ok(())
}</code></pre></pre>
<h3 id="读取环境变量"><a class="header" href="#读取环境变量">读取环境变量</a></h3>
<p>使用 <a href="https://doc.rust-lang.org/std/env/fn.var.html">std::env::var</a> 可以读取系统中的环境变量。</p>
<pre><pre class="playground"><code class="language-rust editable edition2021">use std::env;
use std::fs;
use std::io::Error;
fn main() -&gt; Result&lt;(), Error&gt; {
// 读取环境变量 `CONFIG` 的值并写入到 `config_path` 中。
// 若 `CONFIG` 环境变量没有设置，则使用一个默认的值 &quot;/etc/myapp/config&quot;
let config_path = env::var(&quot;CONFIG&quot;)
.unwrap_or(&quot;/etc/myapp/config&quot;.to_string());
let config: String = fs::read_to_string(config_path)?;
println!(&quot;Config: {}&quot;, config);
Ok(())
}</code></pre></pre>
<div id="giscus-container"></div>
</main>
<nav class="nav-wrapper" aria-label="Page navigation">
<!-- Mobile navigation buttons -->
<a rel="prev" href="../os/processor.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a rel="next" href="../cocurrency/threads.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
<div style="clear: both"></div>
</nav>
</div>
</div>
<nav class="nav-wide-wrapper" aria-label="Page navigation">
<a rel="prev" href="../os/processor.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a rel="next" href="../cocurrency/threads.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
</nav>
</div>
<script type="text/javascript">
window.playground_copyable = true;
</script>
<script src="../ace.js" type="text/javascript" charset="utf-8"></script>
<script src="../editor.js" type="text/javascript" charset="utf-8"></script>
<script src="../mode-rust.js" type="text/javascript" charset="utf-8"></script>
<script src="../theme-dawn.js" type="text/javascript" charset="utf-8"></script>
<script src="../theme-tomorrow_night.js" type="text/javascript" charset="utf-8"></script>
<script src="../elasticlunr.min.js" type="text/javascript" charset="utf-8"></script>
<script src="../mark.min.js" type="text/javascript" charset="utf-8"></script>
<script src="../searcher.js" type="text/javascript" charset="utf-8"></script>
<script src="../clipboard.min.js" type="text/javascript" charset="utf-8"></script>
<script src="../highlight.js" type="text/javascript" charset="utf-8"></script>
<script src="../book.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript" charset="utf-8">
var pagePath = "os/command.md"
</script>
<!-- Custom JS scripts -->
<script type="text/javascript" src="../assets/custom1.js"></script>
<script type="text/javascript" src="../assets/bigPicture.js"></script>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink