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<h1 class="refname">shell_exec</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">shell_exec</span> — <span class="dc-title">Execute command via shell and return the complete output as a string</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.shell-exec-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>shell_exec</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$cmd</code></span>
)</div>
<p class="para rdfs-comment">
This function is identical to the <a href="language.operators.execution.html" class="link">backtick operator</a>.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.shell-exec-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">cmd</code></em></span>
<dd>
<p class="para">
The command that will be executed.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.shell-exec-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
The output from the executed command or <strong><code>NULL</code></strong> if an error occurred or the
command produces no output.
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
This function can return <strong><code>NULL</code></strong> both when an error occurs or the program
produces no output. It is not possible to detect execution failures using
this function. <span class="function"><a href="function.exec.html" class="function">exec()</a></span> should be used when access to the
program exit code is required.
</p>
</p></blockquote>
</div>
<div class="refsect1 examples" id="refsect1-function.shell-exec-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-3678">
<p><strong>Example #1 A <span class="function"><strong>shell_exec()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$output </span><span style="color: #007700">= </span><span style="color: #0000BB">shell_exec</span><span style="color: #007700">(</span><span style="color: #DD0000">'ls -lart'</span><span style="color: #007700">);<br />echo </span><span style="color: #DD0000">"<pre></span><span style="color: #0000BB">$output</span><span style="color: #DD0000"></pre>"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-function.shell-exec-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
This function is disabled when PHP is running in <a href="features.safe-mode.html" class="link">safe mode</a>.
</p>
</p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-function.shell-exec-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.exec.html" class="function" rel="rdfs-seeAlso">exec()</a> - Execute an external program</span></li>
<li class="member"> <span class="function"><a href="function.escapeshellcmd.html" class="function" rel="rdfs-seeAlso">escapeshellcmd()</a> - Escape shell metacharacters</span></li>
</ul>
</p>
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