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<title>Gets the value of an environment variable</title>
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<h1 class="refname">getenv</h1>
<p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">getenv</span> — <span class="dc-title">Gets the value of an environment variable</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.getenv-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>getenv</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$varname</code></span>
[, <span class="methodparam"><span class="type">bool</span> <code class="parameter">$local_only</code><span class="initializer"> = <strong><code>FALSE</code></strong></span></span>
] )</div>
<div class="methodsynopsis dc-description">
<span class="type">array</span> <span class="methodname"><strong>getenv</strong></span>
( <span class="methodparam">void</span>
)</div>
<p class="para rdfs-comment">
Gets the value of an environment variable.
</p>
<p class="para">
You can see a list of all the environmental variables by using
<span class="function"><a href="function.phpinfo.html" class="function">phpinfo()</a></span>. Many of these variables are listed within
<a href="http://www.faqs.org/rfcs/rfc3875" class="link external">» RFC 3875</a>, specifically
section 4.1, "Request Meta-Variables".
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.getenv-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">varname</code></dt>
<dd>
<p class="para">
The variable name.
</p>
</dd>
<dt>
<code class="parameter">local_only</code></dt>
<dd>
<p class="para">
Set to true to only return local environment variables (set by the operating system or putenv).
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.getenv-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns the value of the environment variable
<code class="parameter">varname</code>, or <strong><code>FALSE</code></strong> if the environment
variable <code class="parameter">varname</code> does not exist.
If <code class="parameter">varname</code> is omitted, all environment variables are
returned as associative <span class="type"><a href="language.types.array.html" class="type array">array</a></span>.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.getenv-changelog">
<h3 class="title">Changelog</h3>
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>7.1.0</td>
<td>
The <code class="parameter">varname</code> can now be omitted to retrieve an
associative <span class="type"><a href="language.types.array.html" class="type array">array</a></span> of all environment variables.
</td>
</tr>
<tr>
<td>5.5.38, 5.6.24, 7.0.9</td>
<td>
The <code class="parameter">local_only</code> parameter has been added.
</td>
</tr>
</tbody>
</table>
</div>
<div class="refsect1 notes" id="refsect1-function.getenv-notes">
<h3 class="title">Notes</h3>
<div class="warning"><strong class="warning">Warning</strong>
<p class="para">
If PHP is running in a SAPI such as Fast CGI, this function will
always return the value of an environment variable set by the SAPI,
even if <span class="function"><a href="function.putenv.html" class="function">putenv()</a></span> has been used to set a local
environment variable of the same name. Use the <code class="parameter">local_only</code>
parameter to return the value of locally-set environment variables.
</p>
</div>
</div>
<div class="refsect1 examples" id="refsect1-function.getenv-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-539">
<p><strong>Example #1 <span class="function"><strong>getenv()</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">// Example use of getenv()<br /></span><span style="color: #0000BB">$ip </span><span style="color: #007700">= </span><span style="color: #0000BB">getenv</span><span style="color: #007700">(</span><span style="color: #DD0000">'REMOTE_ADDR'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Or simply use a Superglobal ($_SERVER or $_ENV)<br /></span><span style="color: #0000BB">$ip </span><span style="color: #007700">= </span><span style="color: #0000BB">$_SERVER</span><span style="color: #007700">[</span><span style="color: #DD0000">'REMOTE_ADDR'</span><span style="color: #007700">];<br /><br /></span><span style="color: #FF8000">// Safely get the value of an environment variable, ignoring whether <br />// or not it was set by a SAPI or has been changed with putenv<br /></span><span style="color: #0000BB">$ip </span><span style="color: #007700">= </span><span style="color: #0000BB">getenv</span><span style="color: #007700">(</span><span style="color: #DD0000">'REMOTE_ADDR'</span><span style="color: #007700">, </span><span style="color: #0000BB">true</span><span style="color: #007700">) ?: </span><span style="color: #0000BB">getenv</span><span style="color: #007700">(</span><span style="color: #DD0000">'REMOTE_ADDR'</span><span style="color: #007700">)<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.getenv-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="function"><a href="function.putenv.html" class="function" rel="rdfs-seeAlso">putenv()</a> - Sets the value of an environment variable</span></li>
<li class="member"><span class="function"><a href="function.apache-getenv.html" class="function" rel="rdfs-seeAlso">apache_getenv()</a> - Get an Apache subprocess_env variable</span></li>
<li class="member"><a href="language.variables.superglobals.html" class="link">Superglobals</a></li>
</ul>
</p>
</div>
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