This function discards the contents of the topmost output buffer and turns off this output buffering. If you want to further process the buffer's contents you have to call ob_get_contents before ob_end_clean as the buffer contents are discarded when ob_end_clean is called.
The output buffer must be started by ob_start with PHP_OUTPUT_HANDLER_CLEANABLE and PHP_OUTPUT_HANDLER_REMOVABLE flags. Otherwise ob_end_clean will not work.
This function has no parameters.
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).
Exceptions and Errors
If the function fails it generates an E_NOTICE.