openlog()和syslog()的用法

http://blog.chinaunix.net/u/22878/

openlog()：opens a connection to the system logger for a program

syslog()：generates a log message, which will be distributed  by  syslogd(8).

 

LOG_PID：Include PID with each message.

LOG_CONS：Write directly to system console if there is an error while sending to system logger.

LOG_ERR：error conditions

LOG_LOCAL0 through LOG_LOCAL7：reserved for local use

 

#include

int main()
{
 int test = 10;
 
 openlog("MySysLogTest", LOG_PID|LOG_CONS, LOG_LOCAL7);
 
 syslog(LOG_LOCAL7|LOG_ERR, "ERROR: just my test error msg syslog(test val=%d)\n", test);

 closelog();

 return 0;
}

 

这个小程序执行完后

/var/log/boot.log:Nov 16 11:18:08 localhost MySysLogTest[2804]: ERROR: just my test error msg syslog(test val=10)
/var/log/messages:Nov 16 11:18:08 localhost MySysLogTest[2804]: ERROR: just my test error msg syslog(test val=10)