167 lines
7.6 KiB
Plaintext
Generated

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Go by Example: Epoch</title>
<link rel=stylesheet href="site.css">
</head>
<script>
onkeydown = (e) => {
if (e.key == "ArrowLeft") {
window.location.href = 'time';
}
if (e.key == "ArrowRight") {
window.location.href = 'time-formatting-parsing';
}
}
</script>
<body>
<div class="example" id="epoch">
<h2><a href="./">Go by Example</a>: Epoch</h2>
<table>
<tr>
<td class="docs">
<p>A common requirement in programs is getting the number
of seconds, milliseconds, or nanoseconds since the
<a href="https://en.wikipedia.org/wiki/Unix_time">Unix epoch</a>.
Here&rsquo;s how to do it in Go.</p>
</td>
<td class="code empty leading">
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<a href="https://go.dev/play/p/lRmD1EWHHPz"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
<pre class="chroma"><code><span class="line"><span class="cl"><span class="kn">package</span> <span class="nx">main</span></span></span></code></pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><code><span class="line"><span class="cl"><span class="kn">import</span> <span class="p">(</span>
</span></span><span class="line"><span class="cl"> <span class="s">&#34;fmt&#34;</span>
</span></span><span class="line"><span class="cl"> <span class="s">&#34;time&#34;</span>
</span></span><span class="line"><span class="cl"><span class="p">)</span></span></span></code></pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><code><span class="line"><span class="cl"><span class="kd">func</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span></span></span></code></pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Use <code>time.Now</code> with <code>Unix</code>, <code>UnixMilli</code> or <code>UnixNano</code>
to get elapsed time since the Unix epoch in seconds,
milliseconds or nanoseconds, respectively.</p>
</td>
<td class="code leading">
<pre class="chroma"><code><span class="line"><span class="cl"> <span class="nx">now</span> <span class="o">:=</span> <span class="nx">time</span><span class="p">.</span><span class="nf">Now</span><span class="p">()</span>
</span></span><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">now</span><span class="p">)</span></span></span></code></pre>
</td>
</tr>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><code><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">now</span><span class="p">.</span><span class="nf">Unix</span><span class="p">())</span>
</span></span><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">now</span><span class="p">.</span><span class="nf">UnixMilli</span><span class="p">())</span>
</span></span><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">now</span><span class="p">.</span><span class="nf">UnixNano</span><span class="p">())</span></span></span></code></pre>
</td>
</tr>
<tr>
<td class="docs">
<p>You can also convert integer seconds or nanoseconds
since the epoch into the corresponding <code>time</code>.</p>
</td>
<td class="code">
<pre class="chroma"><code><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">time</span><span class="p">.</span><span class="nf">Unix</span><span class="p">(</span><span class="nx">now</span><span class="p">.</span><span class="nf">Unix</span><span class="p">(),</span> <span class="mi">0</span><span class="p">))</span>
</span></span><span class="line"><span class="cl"> <span class="nx">fmt</span><span class="p">.</span><span class="nf">Println</span><span class="p">(</span><span class="nx">time</span><span class="p">.</span><span class="nf">Unix</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="nx">now</span><span class="p">.</span><span class="nf">UnixNano</span><span class="p">()))</span>
</span></span><span class="line"><span class="cl"><span class="p">}</span></span></span></code></pre>
</td>
</tr>
</table>
<table>
<tr>
<td class="docs">
</td>
<td class="code leading">
<pre class="chroma"><code><span class="line"><span class="cl"><span class="gp">$</span> go run epoch.go
</span></span><span class="line"><span class="cl"><span class="go">2012-10-31 16:13:58.292387 +0000 UTC
</span></span></span><span class="line"><span class="cl"><span class="go">1351700038
</span></span></span><span class="line"><span class="cl"><span class="go">1351700038292
</span></span></span><span class="line"><span class="cl"><span class="go">1351700038292387000
</span></span></span><span class="line"><span class="cl"><span class="go">2012-10-31 16:13:58 +0000 UTC
</span></span></span><span class="line"><span class="cl"><span class="go">2012-10-31 16:13:58.292387 +0000 UTC</span></span></span></code></pre>
</td>
</tr>
<tr>
<td class="docs">
<p>Next we&rsquo;ll look at another time-related task: time
parsing and formatting.</p>
</td>
<td class="code empty">
</td>
</tr>
</table>
<p class="next">
Next example: <a href="time-formatting-parsing">Time Formatting / Parsing</a>.
</p>
<p class="footer">
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>
</p>
</div>
<script>
var codeLines = [];
codeLines.push('');codeLines.push('package main\u000A');codeLines.push('import (\u000A \"fmt\"\u000A \"time\"\u000A)\u000A');codeLines.push('func main() {\u000A');codeLines.push(' now :\u003D time.Now()\u000A fmt.Println(now)\u000A');codeLines.push(' fmt.Println(now.Unix())\u000A fmt.Println(now.UnixMilli())\u000A fmt.Println(now.UnixNano())\u000A');codeLines.push(' fmt.Println(time.Unix(now.Unix(), 0))\u000A fmt.Println(time.Unix(0, now.UnixNano()))\u000A}\u000A');codeLines.push('');codeLines.push('');
</script>
<script src="site.js" async></script>
</body>
</html>