The behaviour of these functions is affected by settings in php.ini.
For further details and definition of the PHP_INI_* constants see ini_set().
Here is a short explanation of the configuration directives.
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().
The constants below are always available as part of the PHP core.
Table 2. openlog() Options
| Constant | Description |
|---|---|
| LOG_CONS | if there is an error while sending data to the system logger, write directly to the system console |
| LOG_NDELAY | open the connection to the logger immediately |
| LOG_ODELAY | (default) delay opening the connection until the first message is logged |
| LOG_PERROR | print log message also to standard error |
| LOG_PID | include PID with each message |
Table 3. syslog() Priorities (in descending order)
| 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 |