#32665 [NEW]: Premature flushing of output buffer when register_shutdown function called

From: prathap at ee dot pdn dot ac dot lk Operating system: Gentoo Linux PHP version: 5.0.3 PHP Bug Type: Output Control Bug description: Premature flushing of output buffer when register_shutdown function called Description: ------------ Hello, I've posted a miniature version of my code here to explain my doubt. <CODE> <? phpinfo(); ob_start(); register_shutdown_function("hello"); echo ("HELLO"); die(); function hello() { $logfile = "logfile"; $error_string = ob_get_contents(); if(!$handle = fopen($logfile, "a")) { echo("Could not open logfile for writing!"); ob_end_flush(); exit; } if(fwrite($handle, $error_string) === FALSE) { echo("Could not write to logfile!"); ob_end_flush(); exit; } fclose($handle); ob_end_clean(); } ?> </CODE> This simply does not work the way it should. i.e ob_get_contents doen't return any string and the buffer just gets flushed by itself at termination. Though the PHP manual says it is not possible to retrieve the contents of any output buffers using ob_get_contents() with PHP < 4.0.6. But I am using PHP 5. x.x I posted this problem in the mailing list and I got this response from skrol29: I've tested your code on PHP 4.3.3 and I have the same behavior has yours. "Hello" is output at the end of the PhpInfo data, followed by a PHP notice : Notice: ob_end_clean(): failed to delete buffer. No buffer to delete. in ... And there is an empty "logfile" file created in the Apache directory insteaf of the script's directory. If you change in your script: *********** register_shutdown_function("hello"); echo ("HELLO <br>"); die(); *********** by *********** // register_shutdown_function("hello"); echo ("HELLO <br>"); hello() die(); *********** then it runs as expected and the "logfile" file is created in the script's directory. It seems that when calling the shutdown function, all the buffered output is immedialty sent to the client and the buffer mode is closed. You maybe have PHP bug here, or the manual is wrong about the possibility to retrieve the contents. But we can notice that this also happens at the end of a script when there is no shutdown function. ---- I am still not sure if this is a bug. But I would be very grateful if someone generously volunteers to see to this. Thank you and congrats on for the good work you have been carrying on all throughout. Prathap -- Edit bug report at http://bugs.php.net/?id=32665&edit=1 -- Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=32665&r=trysnapshot4 Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=32665&r=trysnapshot50 Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=32665&r=trysnapshot51 Fixed in CVS: http://bugs.php.net/fix.php?id=32665&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=32665&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=32665&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=32665&r=needscript Try newer version: http://bugs.php.net/fix.php?id=32665&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=32665&r=support Expected behavior: http://bugs.php.net/fix.php?id=32665&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=32665&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=32665&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=32665&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=32665&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=32665&r=dst IIS Stability: http://bugs.php.net/fix.php?id=32665&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=32665&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=32665&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=32665&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=32665&r=mysqlcfg