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.
priority
priority
is a combination of the facility and
the level. Possible values are:
Table 1. 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 |
message
The message to send, except that the two characters %m will be replaced by the error message string (strerror) corresponding to the present value of errno.
On Windows NT, the syslog service is emulated using the Event Log.
Note: Use of LOG_LOCAL0 through LOG_LOCAL7 for the
facility
parameter of openlog() is not available in Windows.