... PHP 3 <= 3.0.18, PHP 4 >= 4.0.0) error_log -- send an error message somewhere . int error_log ( string message, int message_type [, string destination [, string extra_headers]]) . Sends an error message to the web server's error log, a TCP port or to a file. ... message is sent to PHP's system logger, using the Operating System's system logging mechanism or a file, depending on what the error_log configuration directive is set to. 1 . ... message is sent through the PHP debugging connection. ...