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<h1 class="refname">flush</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">flush</span> — <span class="dc-title">Flush the output buffer</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.flush-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type"><span class="type void">void</span></span> <span class="methodname"><strong>flush</strong></span>
( <span class="methodparam">void</span>
)</div>
<p class="para rdfs-comment">
Flushes the write buffers of PHP and whatever backend PHP is using (CGI,
a web server, etc). This attempts to push current output all the way to
the browser with a few caveats.
</p>
<p class="para">
<span class="function"><strong>flush()</strong></span> may not be able to override the buffering scheme
of your web server and it has no effect on any client-side buffering in the
browser. It also doesn't affect PHP's userspace output buffering mechanism.
This means you will have to call both <span class="function"><a href="function.ob-flush.html" class="function">ob_flush()</a></span> and
<span class="function"><strong>flush()</strong></span> to flush the ob output buffers if you are using
those.
</p>
<p class="para">
Several servers, especially on Win32, will still buffer the output from
your script until it terminates before transmitting the results to the
browser.
</p>
<p class="para">
Server modules for Apache like mod_gzip may do buffering of their own that
will cause <span class="function"><strong>flush()</strong></span> to not result in data being sent
immediately to the client.
</p>
<p class="para">
Even the browser may buffer its input before displaying it. Netscape, for
example, buffers text until it receives an end-of-line or the beginning of
a tag, and it won't render tables until the </table> tag of the
outermost table is seen.
</p>
<p class="para">
Some versions of Microsoft Internet Explorer will only start to display
the page after they have received 256 bytes of output, so you may need to
send extra whitespace before flushing to get those browsers to display the
page.
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.flush-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
No value is returned.
</p>
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