Web Standards Programmer's Reference: HTML, CSS, JavaScript®, Perl, Python®, and PHP

F.11. Error Handling

Function	Returns	Description
error_log(string message [, int message_type [, string destination [, string extra_headers]]])	bool	Sends an error message somewhere.
debug_print_backtrace(void) */	void	Prints a backtrace.
debug_backtrace(void)	array	Returns backtrace as array.
restore_error_handler(void)	void	Restores the previously defined error handler function.
set_exception_handler(string exception_handler)	string	Sets a user-defined exception handler function. Returns the previously defined exception handler, or false on error.
restore_exception_handler(void)	void	Restores the previously defined exception handler function.
trigger_error(string messsage [, int error_type])	void	Generates a user-level error/warning/notice message.
set_error_handler(string error_handler)	string	Sets a user-defined error handler function. Returns the previously defined error handler, or false on error.
leak(int num_bytes=3)	void	Causes an intentional memory leak, for testing/debugging purposes.