PHP: ob_end_flush

Description

bool ob_end_flush ( void )

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 function returns TRUE when it successfully discarded one buffer and FALSE otherwise. 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).

Замечание: This function is similar to ob_get_flush(), except that ob_get_flush() returns the buffer as a string.

The following example shows an easy way to flush and end all output buffers:

Пример 1. ob_end_flush() example

<?php while (@ob_end_flush()); ?>

Замечание: If the function fails it generates an E_NOTICE.
The boolean return value was added in PHP 4.2.0.

ob_end_flush

skippy at zuavra dot net
01-Jul-2005 02:10


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.

jhannus at 128kb dot com
05-Jun-2004 09:18


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();

}



?>

kriek at jonkriek dot com
29-Mar-2003 09:22


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().

brett at realestate-school dot com
26-Sep-2002 01:01


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.