273 lines
14 KiB
Plaintext
Generated
273 lines
14 KiB
Plaintext
Generated
<!DOCTYPE html>
|
||
<html>
|
||
<head>
|
||
<meta charset="utf-8">
|
||
<title>Go в примерах: Подкоманды командной строки (Command-Line Subcommands)</title>
|
||
<link rel=stylesheet href="site.css">
|
||
</head>
|
||
<script>
|
||
onkeydown = (e) => {
|
||
|
||
if (e.key == "ArrowLeft") {
|
||
window.location.href = 'command-line-flags';
|
||
}
|
||
|
||
|
||
if (e.key == "ArrowRight") {
|
||
window.location.href = 'environment-variables';
|
||
}
|
||
|
||
}
|
||
</script>
|
||
<body>
|
||
<div class="example" id="command-line-subcommands">
|
||
<h2><a href="./">Go в примерах</a>: Подкоманды командной строки (Command-Line Subcommands)</h2>
|
||
|
||
<table>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Некоторые инструменты командной строки, такие как <code>go</code>
|
||
или <code>git</code>, имеют много <em>подкоманд</em>, каждая со своим
|
||
собственным набором флагов. Например, <code>go build</code> и
|
||
<code>go get</code> - это две разные подкоманды инструмента <code>go</code>.
|
||
Пакет <code>flag</code> позволяет нам легко определять простые
|
||
подкоманды, которые имеют свои собственные флаги.</p>
|
||
|
||
</td>
|
||
<td class="code empty leading">
|
||
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
<a href="http://play.golang.org/p/sr1FH0P_2Te" target="_blank"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
|
||
<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="kn">import</span> <span class="p">(</span>
|
||
<span class="s">"flag"</span>
|
||
<span class="s">"fmt"</span>
|
||
<span class="s">"os"</span>
|
||
<span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Мы объявляем подкоманду, используя функцию <code>NewFlagSet</code>,
|
||
и приступаем к определению новых флагов, специфичных
|
||
для этой подкоманды.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">fooCmd</span> <span class="o">:=</span> <span class="nx">flag</span><span class="p">.</span><span class="nx">NewFlagSet</span><span class="p">(</span><span class="s">"foo"</span><span class="p">,</span> <span class="nx">flag</span><span class="p">.</span><span class="nx">ExitOnError</span><span class="p">)</span>
|
||
<span class="nx">fooEnable</span> <span class="o">:=</span> <span class="nx">fooCmd</span><span class="p">.</span><span class="nx">Bool</span><span class="p">(</span><span class="s">"enable"</span><span class="p">,</span> <span class="kc">false</span><span class="p">,</span> <span class="s">"enable"</span><span class="p">)</span>
|
||
<span class="nx">fooName</span> <span class="o">:=</span> <span class="nx">fooCmd</span><span class="p">.</span><span class="nx">String</span><span class="p">(</span><span class="s">"name"</span><span class="p">,</span> <span class="s">""</span><span class="p">,</span> <span class="s">"name"</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Для другой подкоманды мы можем определить другие
|
||
флаги.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="nx">barCmd</span> <span class="o">:=</span> <span class="nx">flag</span><span class="p">.</span><span class="nx">NewFlagSet</span><span class="p">(</span><span class="s">"bar"</span><span class="p">,</span> <span class="nx">flag</span><span class="p">.</span><span class="nx">ExitOnError</span><span class="p">)</span>
|
||
<span class="nx">barLevel</span> <span class="o">:=</span> <span class="nx">barCmd</span><span class="p">.</span><span class="nx">Int</span><span class="p">(</span><span class="s">"level"</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="s">"level"</span><span class="p">)</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Подкоманда ожидается в качестве первого аргумента
|
||
программы.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="nx">os</span><span class="p">.</span><span class="nx">Args</span><span class="p">)</span> <span class="p"><</span> <span class="mi">2</span> <span class="p">{</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"expected 'foo' or 'bar' subcommands"</span><span class="p">)</span>
|
||
<span class="nx">os</span><span class="p">.</span><span class="nx">Exit</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
|
||
<span class="p">}</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Проверяем, какая подкоманда вызвана.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre> <span class="k">switch</span> <span class="nx">os</span><span class="p">.</span><span class="nx">Args</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">{</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Для каждой подкоманды мы анализируем ее собственные
|
||
флаги и имеем доступ к аргументам.</p>
|
||
|
||
</td>
|
||
<td class="code">
|
||
|
||
<div class="highlight"><pre> <span class="k">case</span> <span class="s">"foo"</span><span class="p">:</span>
|
||
<span class="nx">fooCmd</span><span class="p">.</span><span class="nx">Parse</span><span class="p">(</span><span class="nx">os</span><span class="p">.</span><span class="nx">Args</span><span class="p">[</span><span class="mi">2</span><span class="p">:])</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"subcommand 'foo'"</span><span class="p">)</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" enable:"</span><span class="p">,</span> <span class="o">*</span><span class="nx">fooEnable</span><span class="p">)</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" name:"</span><span class="p">,</span> <span class="o">*</span><span class="nx">fooName</span><span class="p">)</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" tail:"</span><span class="p">,</span> <span class="nx">fooCmd</span><span class="p">.</span><span class="nx">Args</span><span class="p">())</span>
|
||
<span class="k">case</span> <span class="s">"bar"</span><span class="p">:</span>
|
||
<span class="nx">barCmd</span><span class="p">.</span><span class="nx">Parse</span><span class="p">(</span><span class="nx">os</span><span class="p">.</span><span class="nx">Args</span><span class="p">[</span><span class="mi">2</span><span class="p">:])</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"subcommand 'bar'"</span><span class="p">)</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" level:"</span><span class="p">,</span> <span class="o">*</span><span class="nx">barLevel</span><span class="p">)</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" tail:"</span><span class="p">,</span> <span class="nx">barCmd</span><span class="p">.</span><span class="nx">Args</span><span class="p">())</span>
|
||
<span class="k">default</span><span class="p">:</span>
|
||
<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"expected 'foo' or 'bar' subcommands"</span><span class="p">)</span>
|
||
<span class="nx">os</span><span class="p">.</span><span class="nx">Exit</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
|
||
<span class="p">}</span>
|
||
<span class="p">}</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
</table>
|
||
|
||
<table>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="gp">$</span> go build command-line-subcommands.go
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Первый вызов подкоманды foo.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="gp">$</span> ./command-line-subcommands foo -enable -name<span class="o">=</span>joe a1 a2
|
||
<span class="go">subcommand 'foo'</span>
|
||
<span class="go"> enable: true</span>
|
||
<span class="go"> name: joe</span>
|
||
<span class="go"> tail: [a1 a2]</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Теперь пробуем bar.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="gp">$</span> ./command-line-subcommands bar -level <span class="m">8</span> a1
|
||
<span class="go">subcommand 'bar'</span>
|
||
<span class="go"> level: 8</span>
|
||
<span class="go"> tail: [a1]</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Но bar не может принимать флаги определенные для foo.</p>
|
||
|
||
</td>
|
||
<td class="code leading">
|
||
|
||
<div class="highlight"><pre><span class="gp">$</span> ./command-line-subcommands bar -enable a1
|
||
<span class="go">flag provided but not defined: -enable</span>
|
||
<span class="go">Usage of bar:</span>
|
||
<span class="go"> -level int</span>
|
||
<span class="go"> level</span>
|
||
</pre></div>
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
<tr>
|
||
<td class="docs">
|
||
<p>Далее мы рассмотрим переменные окружения, еще один
|
||
распространенный способ параметризации программ.</p>
|
||
|
||
</td>
|
||
<td class="code empty">
|
||
|
||
|
||
</td>
|
||
</tr>
|
||
|
||
</table>
|
||
|
||
|
||
<p class="next">
|
||
Следующий пример: <a href="environment-variables">Переменные среды (Environment Variables)</a>.
|
||
</p>
|
||
|
||
<p class="footer">
|
||
by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/command-line-subcommands">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
|
||
<br/>
|
||
переведено Nick S. | <a href="https://github.com/badkaktus/gobyexample">исходники</a>
|
||
</p>
|
||
</div>
|
||
<script>
|
||
var codeLines = [];
|
||
codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A \"flag\"\u000A \"fmt\"\u000A \"os\"\u000A)\u000A');codeLines.push('func main() {\u000A');codeLines.push(' fooCmd := flag.NewFlagSet(\"foo\", flag.ExitOnError)\u000A fooEnable := fooCmd.Bool(\"enable\", false, \"enable\")\u000A fooName := fooCmd.String(\"name\", \"\", \"name\")\u000A');codeLines.push(' barCmd := flag.NewFlagSet(\"bar\", flag.ExitOnError)\u000A barLevel := barCmd.Int(\"level\", 0, \"level\")\u000A');codeLines.push(' if len(os.Args) \x3C 2 {\u000A fmt.Println(\"expected \'foo\' or \'bar\' subcommands\")\u000A os.Exit(1)\u000A }\u000A');codeLines.push(' switch os.Args[1] {\u000A');codeLines.push(' case \"foo\":\u000A fooCmd.Parse(os.Args[2:])\u000A fmt.Println(\"subcommand \'foo\'\")\u000A fmt.Println(\" enable:\", *fooEnable)\u000A fmt.Println(\" name:\", *fooName)\u000A fmt.Println(\" tail:\", fooCmd.Args())\u000A case \"bar\":\u000A barCmd.Parse(os.Args[2:])\u000A fmt.Println(\"subcommand \'bar\'\")\u000A fmt.Println(\" level:\", *barLevel)\u000A fmt.Println(\" tail:\", barCmd.Args())\u000A default:\u000A fmt.Println(\"expected \'foo\' or \'bar\' subcommands\")\u000A os.Exit(1)\u000A }\u000A}\u000A');codeLines.push('');codeLines.push('');codeLines.push('');codeLines.push('');codeLines.push('');
|
||
</script>
|
||
<script src="site.js" async></script>
|
||
</body>
|
||
</html>
|