175 lines
4.9 KiB
Plaintext
Generated
175 lines
4.9 KiB
Plaintext
Generated
<!DOCTYPE html>
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<html>
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<head>
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<meta charset="utf-8">
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<title>Go by Example: Exit</title>
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<link rel=stylesheet href="site.css">
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</head>
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<script>
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onkeydown = (e) => {
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if (e.key == "ArrowLeft") {
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window.location.href = 'signals';
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}
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}
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</script>
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<body>
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<div class="example" id="exit">
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<h2><a href="./">Go by Example</a>: Exit</h2>
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<table>
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<tr>
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<td class="docs">
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<p>Use <code>os.Exit</code> to immediately exit with a given
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status.</p>
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</td>
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<td class="code empty leading">
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<a href="http://play.golang.org/p/b9aYzlENkb__R"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
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<pre class="chroma"><span class="kn">package</span> <span class="nx">main</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<pre class="chroma"><span class="kn">import</span> <span class="p">(</span>
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<span class="s">"fmt"</span>
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<span class="s">"os"</span>
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<span class="p">)</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<pre class="chroma"><span class="kd">func</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p><code>defer</code>s will <em>not</em> be run when using <code>os.Exit</code>, so
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this <code>fmt.Println</code> will never be called.</p>
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</td>
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<td class="code leading">
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<pre class="chroma">
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<span class="k">defer</span> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="s">"!"</span><span class="p">)</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Exit with status 3.</p>
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</td>
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<td class="code leading">
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<pre class="chroma">
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<span class="nx">os</span><span class="p">.</span><span class="nf">Exit</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span>
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<span class="p">}</span>
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</pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Note that unlike e.g. C, Go does not use an integer
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return value from <code>main</code> to indicate exit status. If
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you’d like to exit with a non-zero status you should
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use <code>os.Exit</code>.</p>
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</td>
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<td class="code empty">
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</td>
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</tr>
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</table>
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<table>
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<tr>
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<td class="docs">
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<p>If you run <code>exit.go</code> using <code>go run</code>, the exit
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will be picked up by <code>go</code> and printed.</p>
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</td>
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<td class="code leading">
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<pre class="chroma">
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<span class="gp">$</span> go run exit.go
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<span class="go">exit status 3</span></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>By building and executing a binary you can see
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the status in the terminal.</p>
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</td>
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<td class="code leading">
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<pre class="chroma">
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<span class="gp">$</span> go build exit.go
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<span class="gp">$</span> ./exit
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<span class="gp">$</span> echo $?
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<span class="go">3</span></pre>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Note that the <code>!</code> from our program never got printed.</p>
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</td>
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<td class="code empty">
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</td>
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</tr>
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</table>
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<p class="footer">
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by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> and <a href="https://eli.thegreenplace.net">Eli Bendersky</a> | <a href="https://github.com/mmcgrana/gobyexample">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
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</p>
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</div>
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<script>
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var codeLines = [];
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codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A \"fmt\"\u000A \"os\"\u000A)\u000A');codeLines.push('func main() {\u000A');codeLines.push(' defer fmt.Println(\"!\")\u000A');codeLines.push(' os.Exit(3)\u000A}\u000A');codeLines.push('');codeLines.push('');codeLines.push('');codeLines.push('');
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