usr/klibc/daemon.c

/*
 * daemon.c - "daemonize" a process
 */

#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

int daemon(int nochdir, int noclose)
{
	int nullfd;
	pid_t f;

	if (!nochdir) {
		if (chdir("/"))
			return -1;
	}

	if (!noclose) {
		if ((nullfd = open("/dev/null", O_RDWR)) < 0 ||
		    dup2(nullfd, 0) < 0 ||
		    dup2(nullfd, 1) < 0 ||
		    dup2(nullfd, 2) < 0)
			return -1;
		close(nullfd);
	}

	f = fork();
	if (f < 0)
		return -1;
	else if (f > 0)
		_exit(0);

	return setsid();
}