error_log | PHP 3.0
bool error_log(string message, int message_type[, string destination][, string extra_headers]) |
Sends an error message somewhere.

error_reporting | PHP 3.0
int error_reporting(int new_error_level=null) |
Returns the current error_reporting level, and, if an argument was passed, changes to the new level.

restore_error_handler | PHP 4.0.1
void restore_error_handler(void) |
Restores the previously defined error handler function.

set_error_handler | PHP 4.0.1
string set_error_handler(string error_handler) |
Sets a user-defined error handler function; returns the previously defined error handler, or false on error.

trigger_error | PHP 4.0.1
void trigger_error(string messsage[, int error_type]) |
Generates a user-level error/warning/notice message.