Error Handling and Logging
- debug_backtrace - Generates a backtrace
- debug_print_backtrace - Prints a backtrace
- error_clear_last - Clear the most recent error
- error_get_last - Get the last occurred error
- error_log - Send an error message to the defined error handling routines
- error_reporting - Sets which PHP errors are reported
- restore_error_handler - Restores the previous error handler function
- restore_exception_handler - Restores the previously defined exception handler function
- set_error_handler - Sets a user-defined error handler function
- set_exception_handler - Sets a user-defined exception handler function
- trigger_error - Generates a user-level error/warning/notice message
- user_error - Alias of <function>trigger_error</function>