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<h1 class="refname">escapeshellcmd</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">escapeshellcmd</span> — <span class="dc-title">Escape shell metacharacters</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.escapeshellcmd-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>escapeshellcmd</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$command</code></span>
)</div>
<p class="para rdfs-comment">
<span class="function"><strong>escapeshellcmd()</strong></span> escapes any characters in a
string that might be used to trick a shell command into executing
arbitrary commands. This function should be used to make sure
that any data coming from user input is escaped before this data
is passed to the <span class="function"><a href="function.exec.html" class="function">exec()</a></span> or
<span class="function"><a href="function.system.html" class="function">system()</a></span> functions, or to the <a href="language.operators.execution.html" class="link">backtick
operator</a>.
</p>
<p class="para">
Following characters are preceded by a backslash:
<em>#&;`|*?~<>^()[]{}$\</em>, <em>\x0A</em>
and <em>\xFF</em>. <em>'</em> and <em>"</em>
are escaped only if they are not paired. In Windows, all these characters
plus <em>%</em> are replaced by a space instead.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.escapeshellcmd-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">command</code></em></span>
<dd>
<p class="para">
The command that will be escaped.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.escapeshellcmd-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
The escaped string.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.escapeshellcmd-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-3675">
<p><strong>Example #1 <span class="function"><strong>escapeshellcmd()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// We allow arbitrary number of arguments intentionally here.<br /></span><span style="color: #0000BB">$command </span><span style="color: #007700">= </span><span style="color: #DD0000">'./configure '</span><span style="color: #007700">.</span><span style="color: #0000BB">$_POST</span><span style="color: #007700">[</span><span style="color: #DD0000">'configure_options'</span><span style="color: #007700">];<br /><br /></span><span style="color: #0000BB">$escaped_command </span><span style="color: #007700">= </span><span style="color: #0000BB">escapeshellcmd</span><span style="color: #007700">(</span><span style="color: #0000BB">$command</span><span style="color: #007700">);<br /> <br /></span><span style="color: #0000BB">system</span><span style="color: #007700">(</span><span style="color: #0000BB">$escaped_command</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.escapeshellcmd-notes">
<div class="warning"><strong class="warning">Warning</strong>
<p class="para">
<span class="function"><strong>escapeshellcmd()</strong></span> should be used on the whole
command string, and it still allows the attacker to pass
arbitrary number of arguments. For escaping a single argument
<span class="function"><a href="function.escapeshellarg.html" class="function">escapeshellarg()</a></span> should be used instead.
</p>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-function.escapeshellcmd-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.escapeshellarg.html" class="function" rel="rdfs-seeAlso">escapeshellarg()</a> - Escape a string to be used as a shell argument</span></li>
<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.popen.html" class="function" rel="rdfs-seeAlso">popen()</a> - Opens process file pointer</span></li>
<li class="member"> <span class="function"><a href="function.system.html" class="function" rel="rdfs-seeAlso">system()</a> - Execute an external program and display the output</span></li>
<li class="member"><a href="language.operators.execution.html" class="link">backtick operator</a></li>
</ul>
</p>
</div>
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