Daemon logging in Linux

Unix has had for a long while a special logging framework called syslog. Type in your shell

man 3 syslog

and you’ll get the help for the C interface to it.

Some examples

#include <stdio.h>
#include <unistd.h>
#include <syslog.h>

int main(void) {

 openlog("slog", LOG_PID|LOG_CONS, LOG_USER);
 syslog(LOG_INFO, "A different kind of Hello world ... ");
 closelog();

 return 0;
}