173 lines
4.9 KiB
Plaintext

<!DOCTYPE html>
<html>
<head>
<meta http-eqiv="content-type" content="text/html;charset=utf-8">
<title>Go by Example: Exit</title>
<link rel=stylesheet href="site.css">
</head>
<script type="text/javascript">
if (window.location.host == "gobyexample.com") {
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'UA-34996217-1']);
_gaq.push(['_trackPageview']);
(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
}
</script>
<body>
<div class="example" id="exit">
<h2><a href="./">Go by Example</a>: Exit</h2>
<table>
<tr>
<td class="docs">
<p>Use <code>os.Exit</code> to immediately exit with a given
status.</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/CDiAh9SXRM"><img title="Run code" src="play.png" class="run" /></a>
<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="s">&quot;fmt&quot;</span>
<span class="kn">import</span> <span class="s">&quot;os&quot;</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><code>defer</code>s will <em>not</em> be run when using <code>os.Exit</code>, so
this <code>fmt.Println</code> will never be called.</p>
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="k">defer</span> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">&quot;!&quot;</span><span class="p">)</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Exit with status 3.</p>
</td>
<td class="code leading">
<div class="highlight"><pre> <span class="nx">os</span><span class="p">.</span><span class="nx">Exit</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span>
<span class="p">}</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Note that unlike e.g. C, Go does not use an integer
return value from <code>main</code> to indicate exit status. If
you&rsquo;d like to exit with a non-zero status you should
use <code>os.Exit</code>.</p>
</td>
<td class="code empty">
</td>
</tr>
</table>
<table>
<tr>
<td class="docs">
<p>If you run <code>exit.go</code> using <code>go run</code>, the exit
will be picked up by <code>go</code> and printed.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="gp">$</span> go run exit.go
<span class="go">exit status 3</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>By building and executing a binary you can see
the status in the terminal.</p>
</td>
<td class="code leading">
<div class="highlight"><pre><span class="gp">$</span> go build exit.go
<span class="gp">$</span> ./exit
<span class="gp">$</span> <span class="nb">echo</span> <span class="nv">$?</span>
<span class="go">3</span>
</pre></div>
</td>
</tr>
<tr>
<td class="docs">
<p>Note that the <code>!</code> from our program never got printed.</p>
</td>
<td class="code empty">
</td>
</tr>
</table>
<p class="footer">
<a href="https://twitter.com/gobyexample">@gobyexample</a> | <a href="mailto:mmcgrana@gmail.com">feedback</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/exit">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
</p>
</div>
</body>
</html>