pidfile.c revision 1.1 
1/*	$OpenBSD: pidfile.c,v 1.1 2001/09/28 20:16:42 jakob Exp $	*/
2/*	$NetBSD: pidfile.c,v 1.4 2001/02/19 22:43:42 cgd Exp $	*/
3
4/*-
5 * Copyright (c) 1999 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Jason R. Thorpe.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *        This product includes software developed by the NetBSD
22 *        Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 *    contributors may be used to endorse or promote products derived
25 *    from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40#if defined(LIBC_SCCS) && !defined(lint)
41static const char rcsid[] = "$OpenBSD: pidfile.c,v 1.1 2001/09/28 20:16:42 jakob Exp $";
42#endif /* LIBC_SCCS and not lint */
43
44#include <sys/param.h>
45#include <errno.h>
46#include <paths.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <unistd.h>
50#include <util.h>
51
52static char *pidfile_path;
53
54static void pidfile_cleanup(void);
55
56extern char *__progname;
57
58int
59pidfile(const char *basename)
60{
61	FILE *f;
62	int save_errno;
63
64	if (basename == NULL)
65		basename = __progname;
66
67	if (pidfile_path != NULL) {
68		free(pidfile_path);
69		pidfile_path = NULL;
70	}
71
72	/* _PATH_VARRUN includes trailing / */
73	(void) asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename);
74	if (pidfile_path == NULL)
75		return (-1);
76
77	if ((f = fopen(pidfile_path, "w")) == NULL) {
78		save_errno = errno;
79		free(pidfile_path);
80		pidfile_path = NULL;
81		errno = save_errno;
82		return (-1);
83	}
84
85	if (fprintf(f, "%d\n", getpid()) <= 0 || fclose(f) != 0) {
86		save_errno = errno;
87		(void) unlink(pidfile_path);
88		free(pidfile_path);
89		pidfile_path = NULL;
90		errno = save_errno;
91		return (-1);
92	}
93
94	(void) atexit(pidfile_cleanup);
95
96	return (0);
97}
98
99static void
100pidfile_cleanup(void)
101{
102
103	if (pidfile_path != NULL)
104		(void) unlink(pidfile_path);
105}
106