Installing/Configuring
PHP Manual

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Network Configuration Options
Name Default Changeable Changelog
define_syslog_variables "0" PHP_INI_ALL Deprecated in PHP 5.3.0. This deprecated feature will certainly be removed in the future.
For further details and definitions of the PHP_INI_* modes, see the Where a configuration setting may be set.

Here's a short explanation of the configuration directives.

define_syslog_variables boolean

Whether or not to define the various syslog variables (e.g. $LOG_PID, $LOG_CRON, etc.). Turning it off is a good idea performance-wise. At runtime, you can define these variables by calling define_syslog_variables().


Installing/Configuring
PHP Manual