PHP: ob_implicit_flush

Description

void ob_implicit_flush ( [int flag] )

ob_implicit_flush() will turn implicit flushing on or off (if no flag is given, it defaults to on). Implicit flushing will result in a flush operation after every output call, so that explicit calls to flush() will no longer be needed.

Turning implicit flushing on will disable output buffering, the output buffers current output will be sent as if ob_end_flush() had been called.

User Contributed Notes
ob_implicit_flush

mhumphrey at _spammenot_designvision dot com
18-Aug-2003 04:41


From experimenting, it looks like using sessions with session.use_trans_sid=1 will force your output to be buffered regardless of this setting.



My guess is that this is so PHP can hunt for URLs in your output to automatically add the Session ID to them.  It must wait until script output is complete before it starts that replacement, rather than doing it "on the fly".



When i comment out my session_start() line, i get continuous output to the browser.  Put it back in, and i only see the page when it's completely loaded.  Change session.use_trans_sid = 0 and i get continuous output again.

calimero at Creatixnet dot com
07-Jul-2003 02:00


######### BEWARE ##########



There is a bug (or at least an unexpected feature of ob_implicit_flush) that has been already discussed on the PHP bugtracker :



http://bugs.php.net/bug.php?id=23877

http://bugs.php.net/bug.php?id=16676



Code like this WILL NOT work :



<?

// This will not work as expected on Linux.

ob_implicit_flush (1);

for($i=0;$i<10;$i++) {

   echo "grrrrrrrrrr\n";

   sleep(1);

}

?>



This feature happens on Linux versions of PHP, in all versions of php4 prior to 4.3.3 (don't know yet for the next ones) but also in php5 beta1. ob_implicit_flush has NO EFFECT on command-line (console, CLI) scripts, no flushing at all will be made, all output will be sent at the end of the script.



There is a workaround using ob_end_flush() and ob_flush, here it is :



<?

// This works !

ob_end_flush();

for($i=0;$i<10;$i++) {

  echo "yeah :-))))\n";

  @ob_flush();

  sleep(1);

}

?>



hope this will help. It would have helped me...