xref: /netbsd-src/lib/libutil/pidfile.c (revision 27578b9aac214cc7796ead81dcc5427e79d5f2a0)
1 /*	$NetBSD: pidfile.c,v 1.4 2001/02/19 22:43:42 cgd Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 __RCSID("$NetBSD: pidfile.c,v 1.4 2001/02/19 22:43:42 cgd Exp $");
42 #endif
43 
44 #include <sys/param.h>
45 #include <paths.h>
46 #include <stdlib.h>
47 #include <stdio.h>
48 #include <unistd.h>
49 #include <util.h>
50 
51 static char *pidfile_path;
52 
53 static void pidfile_cleanup(void);
54 
55 void
56 pidfile(const char *basename)
57 {
58 	FILE *f;
59 
60 	if (pidfile_path != NULL)
61 		return;
62 
63 	if (basename == NULL)
64 		basename = getprogname();
65 
66 	/* _PATH_VARRUN includes trailing / */
67 	(void) asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename);
68 	if (pidfile_path == NULL)
69 		return;
70 
71 	if ((f = fopen(pidfile_path, "w")) == NULL)
72 		return;
73 
74 	(void) fprintf(f, "%d\n", getpid());
75 	(void) fclose(f);
76 
77 	(void) atexit(pidfile_cleanup);
78 }
79 
80 static void
81 pidfile_cleanup(void)
82 {
83 
84 	if (pidfile_path != NULL)
85 		(void) unlink(pidfile_path);
86 }
87