Advanced Programming in the UNIX® Environment

ptg10805159

476 Daemon Processes Chapter 13

}

switch (signo) {

case SIGHUP:

syslog(LOG_INFO, "Re-reading configuration file");

reread();

break;

case SIGTERM:

syslog(LOG_INFO, "got SIGTERM; exiting");

exit(0);

default:

syslog(LOG_INFO, "unexpected signal %d\n", signo);

}

}

return(0);

}

int

main(int argc, char *argv[])

{

int err;

pthread_t tid;

char *cmd;

struct sigaction sa;

if ((cmd = strrchr(argv[0], ’/’)) == NULL)

cmd = argv[0];

else

cmd++;

/*

*Become a daemon.

*/

daemonize(cmd);

/*

*Make sure only one copy of the daemon is running.

*/

if (already_running()) {

syslog(LOG_ERR, "daemon already running");

exit(1);

}

/*

*Restore SIGHUP default and block all signals.

*/

sa.sa_handler = SIG_DFL;

sigemptyset(&sa.sa_mask);

sa.sa_flags = 0;

if (sigaction(SIGHUP, &sa, NULL) < 0)

err_quit("%s: can’t restore SIGHUP default");