syslog Generate a system log message &reftitle.description; boolsyslog intpriority stringmessage syslog generates a log message that will be distributed by the system logger. For information on setting up a user defined log handler, see the syslog.conf 5 Unix manual page. More information on the syslog facilities and option can be found in the man pages for syslog 3 on Unix machines. &reftitle.parameters; priority priority is a combination of the facility and the level. Possible values are: Constant Description LOG_EMERG system is unusable LOG_ALERT action must be taken immediately LOG_CRIT critical conditions LOG_ERR error conditions LOG_WARNING warning conditions LOG_NOTICE normal, but significant, condition LOG_INFO informational message LOG_DEBUG debug-level message message The message to send. &reftitle.returnvalues; &return.success; &reftitle.examples; ]]> &reftitle.notes; On Windows, the syslog service is emulated using the Event Log. Use of LOG_LOCAL0 through LOG_LOCAL7 for the facility parameter of openlog is not available in Windows. &reftitle.seealso; openlog closelog syslog.filter INI setting (starting with PHP 7.3)