Here is an example of openlog, syslog, and closelog:
This example sets the logmask so that debug and informational messages
get discarded without ever reaching Syslog. So the second syslog
in the example does nothing.
#include <syslog.h>
setlogmask (LOG_UPTO (LOG_NOTICE));
openlog ("exampleprog", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
syslog (LOG_NOTICE, "Program started by User %d", getuid ());
syslog (LOG_INFO, "A tree falls in a forest");
closelog ();