When invoked, output handlers are passed the contents of the buffer and a bitmask indicating the status of output buffering.
bufferphasePHP_OUTPUT_HANDLER_*
constants
.
Calling any of the following functions from within an output handler will result in a fatal error: ob_clean(), ob_end_clean(), ob_end_flush(), ob_flush(), ob_get_clean(), ob_get_flush(), ob_start().
Bilginize: If the
PHP_OUTPUT_HANDLER_DISABLEDof a handler is set, the handler will not be invoked by calling ob_end_clean(), ob_end_flush(), ob_get_clean(), ob_get_flush(), ob_clean(), ob_flush() or during PHP's shutdown process. Prior to PHP 8.4.0, this flag had no effect when calling ob_clean() or ob_flush().
Bilginize: The working directory of the script can change inside the shutdown function under some web servers, e.g. Apache or the built-in web server.