#include <syslog.h>#include <stdio.h>#include <unistd.h>int main(){    int logmask;    openlog("logmask", LOG_PID|LOG_CONS, LOG_USER);    syslog(LOG_INFO,"informative message, pid = %d", getpid());    syslog(LOG_DEBUG,"debug message, should appear");    logmask = setlogmask(LOG_UPTO(LOG_NOTICE));    syslog(LOG_DEBUG,"debug message, should not appear");    exit(0);}