(PHP 4, PHP 5, PHP 7)
ob_end_flush — Flush (send) the output buffer and turn off output buffering
This function will send the contents of the topmost output buffer (if any) and turn this output buffer off. If you want to further process the buffer's contents you have to call ob_get_contents() before ob_end_flush() as the buffer contents are discarded after ob_end_flush() is called.
The output buffer must be started by ob_start() with PHP_OUTPUT_HANDLER_FLUSHABLE and PHP_OUTPUT_HANDLER_REMOVABLE flags. Otherwise ob_end_flush() will not work.
Note: This function is similar to ob_get_flush(), except that ob_get_flush() returns the buffer as a string.
Returns TRUE on success or FALSE on failure. Reasons for failure are first that you called the
function without an active buffer or that for some reason a buffer could
not be deleted (possible for special buffer).
If the function fails it generates an E_NOTICE.
Example #1 ob_end_flush() example
The following example shows an easy way to flush and end all output buffers:
<?php
while (@ob_end_flush());
?>
A note on the above example...
with PHP 4 >= 4.2.0, PHP 5 you can use a combination of ob_get_level() and ob_end_flush() to avoid using the @ (error suppresion) which should probably be a little faaster.
<?php
while (ob_get_level() > 0) {
ob_end_flush();
}
?>
best way to compress a css code:
<?php
header('Content-type: text/css');
ob_start("compress");
function compress($buffer) {
// remove comments
$buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);
// remove tabs, spaces, newlines, etc.
$buffer = str_replace(array("\r\n", "\r", "\n", "\t", ' ', ' ', ' '), '', $buffer);
return $buffer;
}
include('./template/main.css');
include('./template/classes.css');
<?php
ob_end_flush();
?>
Include in <head>:
<link rel="stylesheet" type="text/css" href="/design.php" media="all" />
If you enable zlib.output_compression then level count will be increased by 1 and then this code:
<?php while (ob_get_level()) { ob_end_clean(); } ?>
will just freeze your script.
Wanted to speed things up and put some processing after the page has been delivered to the client. That drove me almost insane, but finally, I found a solution (php 5.2.5):
<?php
ob_start(); // outer buffer
ob_start(); // inner buffer to catch URL rewrites and other post processing
session_start(); // registers URL rewriter with inner buffer!
echo '...';
// log performance data to log files *after* delivering the page!
register_shutdown_function(array($benchmarkclass,'log_perf_data'));
// now flush output output to client
ob_end_flush();
// need to calculate content length *after* URL rewrite!
header("Content-length: ".ob_get_length());
ob_end_flush();
// now we close the session and do some arbitrary clean-up tasks
// registered using register_shutdown_function()
session_write_close();
?>
It appears that ob_end_flush() is very important if you are looping. For instance if you are using a mass mailer that uses the output buffer for creating HTML content. Use ob_end_flush() to avoid server errors.
Apart from being mostly redundant, ob_end_flush() can be downright damaging in some weird cases.
Actual example: a particular page on an Intranet website which would appear blank on Internet Explorer 6 when ob_start('ob_gzhandler') was called in the beginning and ob_end_flush() at the end.
We couldn't figure out what made that page special no matter what we tried. The ob_ functions were placed in scripts which were include()'d by all pages just the same, but only that page did this.
Even stranger, the problem only appeared on direct browser/server connections. Whenever the connection passed through a proxy the problem dissapeared. I'm guessing some kind of HTTP encoding headers mumbo-jumbo.
Solution: unless you really need it in particular cases, remove the ob_end_flush() call and rely on the builtin, automatic buffer flush.
It appears that you can call ob_end_flush() regardless of whether or not output buffering was ever started using ob_start(). This can prove useful because it saves you from having to create conditional statements based on whether a particular function or include file has started output buffering. You can simply call the ob_end_flush() anyway and if there's output in the buffer, it will be sent, otherwise your script will just keep on keepin' on.
Remember that chromium browser (and maybe other webkit-based browsers) have some issues with ob_end_flush.
http://code.google.com/p/chromium/issues/detail?id=31410
You may use
header("Content-Type: text/plain");
to solve those issues if you do not need html.
ob_end_flush() isn't needed in MOST cases because it is called automatically at the end of script execution by PHP itself when output buffering is turned on either in the php.ini or by calling ob_start().
