xref: /netbsd-src/lib/libc/gen/daemon.c (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: daemon.c,v 1.8 2000/01/22 22:19:09 mycroft Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)daemon.c	8.1 (Berkeley) 6/4/93";
40 #else
41 __RCSID("$NetBSD: daemon.c,v 1.8 2000/01/22 22:19:09 mycroft Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include "namespace.h"
46 #include <fcntl.h>
47 #include <paths.h>
48 #include <stdlib.h>
49 #include <unistd.h>
50 
51 #ifdef __weak_alias
52 __weak_alias(daemon,_daemon)
53 #endif
54 
55 int
56 daemon(nochdir, noclose)
57 	int nochdir, noclose;
58 {
59 	int fd;
60 
61 	switch (fork()) {
62 	case -1:
63 		return (-1);
64 	case 0:
65 		break;
66 	default:
67 		_exit(0);
68 	}
69 
70 	if (setsid() == -1)
71 		return (-1);
72 
73 	if (!nochdir)
74 		(void)chdir("/");
75 
76 	if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
77 		(void)dup2(fd, STDIN_FILENO);
78 		(void)dup2(fd, STDOUT_FILENO);
79 		(void)dup2(fd, STDERR_FILENO);
80 		if (fd > STDERR_FILENO)
81 			(void)close(fd);
82 	}
83 	return (0);
84 }
85