xref: /openbsd/lib/libc/gen/daemon.c (revision b7041c07)
1*b7041c07Sderaadt /*	$OpenBSD: daemon.c,v 1.8 2021/10/24 21:24:20 deraadt Exp $ */
2df930be7Sderaadt /*-
3df930be7Sderaadt  * Copyright (c) 1990, 1993
4df930be7Sderaadt  *	The Regents of the University of California.  All rights reserved.
5df930be7Sderaadt  *
6df930be7Sderaadt  * Redistribution and use in source and binary forms, with or without
7df930be7Sderaadt  * modification, are permitted provided that the following conditions
8df930be7Sderaadt  * are met:
9df930be7Sderaadt  * 1. Redistributions of source code must retain the above copyright
10df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer.
11df930be7Sderaadt  * 2. Redistributions in binary form must reproduce the above copyright
12df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer in the
13df930be7Sderaadt  *    documentation and/or other materials provided with the distribution.
146580fee3Smillert  * 3. Neither the name of the University nor the names of its contributors
15df930be7Sderaadt  *    may be used to endorse or promote products derived from this software
16df930be7Sderaadt  *    without specific prior written permission.
17df930be7Sderaadt  *
18df930be7Sderaadt  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19df930be7Sderaadt  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20df930be7Sderaadt  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21df930be7Sderaadt  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22df930be7Sderaadt  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23df930be7Sderaadt  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24df930be7Sderaadt  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25df930be7Sderaadt  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26df930be7Sderaadt  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27df930be7Sderaadt  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28df930be7Sderaadt  * SUCH DAMAGE.
29df930be7Sderaadt  */
30df930be7Sderaadt 
31df930be7Sderaadt #include <fcntl.h>
32df930be7Sderaadt #include <paths.h>
33df930be7Sderaadt #include <unistd.h>
3472e8150aSderaadt #include <stdlib.h>
35df930be7Sderaadt 
36df930be7Sderaadt int
daemon(int nochdir,int noclose)37f723aa39Sderaadt daemon(int nochdir, int noclose)
38df930be7Sderaadt {
39df930be7Sderaadt 	int fd;
40df930be7Sderaadt 
41df930be7Sderaadt 	switch (fork()) {
42df930be7Sderaadt 	case -1:
43df930be7Sderaadt 		return (-1);
44df930be7Sderaadt 	case 0:
45df930be7Sderaadt 		break;
46df930be7Sderaadt 	default:
47df930be7Sderaadt 		_exit(0);
48df930be7Sderaadt 	}
49df930be7Sderaadt 
50df930be7Sderaadt 	if (setsid() == -1)
51df930be7Sderaadt 		return (-1);
52df930be7Sderaadt 
53df930be7Sderaadt 	if (!nochdir)
54df930be7Sderaadt 		(void)chdir("/");
55df930be7Sderaadt 
56*b7041c07Sderaadt 	if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR)) != -1) {
57df930be7Sderaadt 		(void)dup2(fd, STDIN_FILENO);
58df930be7Sderaadt 		(void)dup2(fd, STDOUT_FILENO);
59df930be7Sderaadt 		(void)dup2(fd, STDERR_FILENO);
60df930be7Sderaadt 		if (fd > 2)
61df930be7Sderaadt 			(void)close(fd);
62df930be7Sderaadt 	}
63df930be7Sderaadt 	return (0);
64df930be7Sderaadt }
65