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<title>Outputs a file</title>
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<div class="refnamediv">
<h1 class="refname">readfile</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">readfile</span> — <span class="dc-title">Outputs a file</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.readfile-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>readfile</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$filename</code></span>
[, <span class="methodparam"><span class="type">bool</span> <code class="parameter">$use_include_path</code><span class="initializer"> = false</span></span>
[, <span class="methodparam"><span class="type">resource</span> <code class="parameter">$context</code></span>
]] )</div>
<p class="para rdfs-comment">
Reads a file and writes it to the output buffer.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.readfile-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">filename</code></em></span>
<dd>
<p class="para">
The filename being read.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">use_include_path</code></em></span>
<dd>
<p class="para">
You can use the optional second parameter and set it to <strong><code>TRUE</code></strong>, if
you want to search for the file in the <a href="ini.core.html#ini.include-path" class="link">include_path</a>, too.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">context</code></em></span>
<dd>
<p class="para">
A context stream <span class="type"><a href="language.types.resource.html" class="type resource">resource</a></span>.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.readfile-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns the number of bytes read from the file. If an error
occurs, <strong><code>FALSE</code></strong> is returned and unless the function was called as
@ <span class="function"><strong>readfile()</strong></span>, an error message is printed.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.readfile-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-2422">
<p><strong>Example #1 Forcing a download using <span class="function"><strong>readfile()</strong></span></strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$file </span><span style="color: #007700">= </span><span style="color: #DD0000">'monkey.gif'</span><span style="color: #007700">;<br /><br />if (</span><span style="color: #0000BB">file_exists</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-Description: File Transfer'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-Type: application/octet-stream'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-Disposition: attachment; filename='</span><span style="color: #007700">.</span><span style="color: #0000BB">basename</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">));<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-Transfer-Encoding: binary'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Expires: 0'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Cache-Control: must-revalidate'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Pragma: public'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-Length: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">filesize</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">));<br /> </span><span style="color: #0000BB">ob_clean</span><span style="color: #007700">();<br /> </span><span style="color: #0000BB">flush</span><span style="color: #007700">();<br /> </span><span style="color: #0000BB">readfile</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">);<br /> exit;<br />}<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="mediaobject">
<div class="imageobject">
<img src="images/e88cefb5c3fca5060e2490b9763c4433-readfile.png" alt="Open / Save dialogue" width="319" height="245" />
</div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-function.readfile-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
<span class="function"><strong>readfile()</strong></span> will not present any memory issues,
even when sending large files, on its own. If you encounter an
out of memory error ensure that output buffering is off with
<span class="function"><a href="function.ob-get-level.html" class="function">ob_get_level()</a></span>.
</p>
</p></blockquote>
<div class="tip"><strong class="tip">Tip</strong><p class="simpara">A URL can be used as a
filename with this function if the <a href="filesystem.configuration.html#ini.allow-url-fopen" class="link">fopen wrappers</a> have been enabled.
See <span class="function"><a href="function.fopen.html" class="function">fopen()</a></span> for more details on how to specify the
filename. See the <a href="wrappers.html" class="xref">Supported Protocols and Wrappers</a> for links to information
about what abilities the various wrappers have, notes on their usage,
and information on any predefined variables they may
provide.</p></div>
<blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">Context support was added
with PHP 5.0.0. For a description of <em>contexts</em>, refer to
<a href="book.stream.html" class="xref">Streams</a>.</span></p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-function.readfile-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.fpassthru.html" class="function" rel="rdfs-seeAlso">fpassthru()</a> - Output all remaining data on a file pointer</span></li>
<li class="member"> <span class="function"><a href="function.file.html" class="function" rel="rdfs-seeAlso">file()</a> - Reads entire file into an array</span></li>
<li class="member"> <span class="function"><a href="function.fopen.html" class="function" rel="rdfs-seeAlso">fopen()</a> - Opens file or URL</span></li>
<li class="member"> <span class="function"><a href="function.include.html" class="function" rel="rdfs-seeAlso">include</a> - include</span></li>
<li class="member"> <span class="function"><a href="function.require.html" class="function" rel="rdfs-seeAlso">require</a> - require</span></li>
<li class="member"> <span class="function"><a href="function.virtual.html" class="function" rel="rdfs-seeAlso">virtual()</a> - Perform an Apache sub-request</span></li>
<li class="member"> <span class="function"><a href="function.file-get-contents.html" class="function" rel="rdfs-seeAlso">file_get_contents()</a> - Reads entire file into a string</span></li>
<li class="member"><a href="wrappers.html" class="xref">Supported Protocols and Wrappers</a></li>
</ul>
</p>
</div>
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