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<title>Gets a specific external variable by name and optionally filters it</title>
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<h1 class="refname">filter_input</h1>
<p class="verinfo">(PHP 5 >= 5.2.0)</p><p class="refpurpose"><span class="refname">filter_input</span> — <span class="dc-title">Gets a specific external variable by name and optionally filters it</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.filter-input-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <span class="methodname"><strong>filter_input</strong></span>
( <span class="methodparam"><span class="type">int</span> <code class="parameter">$type</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$variable_name</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$filter</code><span class="initializer"> = FILTER_DEFAULT</span></span>
[, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$options</code></span>
]] )</div>
</div>
<div class="refsect1 parameters" id="refsect1-function.filter-input-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">type</code></em></span>
<dd>
<p class="para">
One of <strong><code>INPUT_GET</code></strong>, <strong><code>INPUT_POST</code></strong>,
<strong><code>INPUT_COOKIE</code></strong>, <strong><code>INPUT_SERVER</code></strong>, or
<strong><code>INPUT_ENV</code></strong>.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">variable_name</code></em></span>
<dd>
<p class="para">
Name of a variable to get.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">filter</code></em></span>
<dd>
<p class="para">
The ID of the filter to apply. The <a href="filter.filters.html" class="xref">Types of filters</a>
manual page lists the available filters.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">options</code></em></span>
<dd>
<p class="para">
Associative array of options or bitwise disjunction of flags. If filter
accepts options, flags can be provided in "flags" field of array.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.filter-input-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Value of the requested variable on success, <strong><code>FALSE</code></strong> if the filter fails,
or <strong><code>NULL</code></strong> if the <em><code class="parameter">variable_name</code></em> variable is not set.
If the flag <strong><code>FILTER_NULL_ON_FAILURE</code></strong> is used, it
returns <strong><code>FALSE</code></strong> if the variable is not set and <strong><code>NULL</code></strong> if the filter fails.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.filter-input-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-5091">
<p><strong>Example #1 A <span class="function"><strong>filter_input()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$search_html </span><span style="color: #007700">= </span><span style="color: #0000BB">filter_input</span><span style="color: #007700">(</span><span style="color: #0000BB">INPUT_GET</span><span style="color: #007700">, </span><span style="color: #DD0000">'search'</span><span style="color: #007700">, </span><span style="color: #0000BB">FILTER_SANITIZE_SPECIAL_CHARS</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$search_url </span><span style="color: #007700">= </span><span style="color: #0000BB">filter_input</span><span style="color: #007700">(</span><span style="color: #0000BB">INPUT_GET</span><span style="color: #007700">, </span><span style="color: #DD0000">'search'</span><span style="color: #007700">, </span><span style="color: #0000BB">FILTER_SANITIZE_ENCODED</span><span style="color: #007700">);<br />echo </span><span style="color: #DD0000">"You have searched for </span><span style="color: #0000BB">$search_html</span><span style="color: #DD0000">.\n"</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"<a href='?search=</span><span style="color: #0000BB">$search_url</span><span style="color: #DD0000">'>Search again.</a>"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above example will output
something similar to:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
You have searched for Me &#38; son.
<a href='?search=Me%20%26%20son'>Search again.</a>
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.filter-input-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.filter-var.html" class="function" rel="rdfs-seeAlso">filter_var()</a> - Filters a variable with a specified filter</span></li>
<li class="member"> <span class="function"><a href="function.filter-input-array.html" class="function" rel="rdfs-seeAlso">filter_input_array()</a> - Gets external variables and optionally filters them</span></li>
<li class="member"> <span class="function"><a href="function.filter-var-array.html" class="function" rel="rdfs-seeAlso">filter_var_array()</a> - Gets multiple variables and optionally filters them</span></li>
<li class="member"><a href="filter.filters.html" class="xref">Types of filters</a></li>
</ul>
</p>
</div>
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