1 /* $OpenBSD: pidfile.c,v 1.14 2019/06/28 14:20:40 schwarze 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 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/types.h>
34 #include <errno.h>
35 #include <paths.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <unistd.h>
39 #include <util.h>
40
41 static char *pidfile_path;
42 static pid_t pidfile_pid;
43
44 static void pidfile_cleanup(void);
45
46 extern char *__progname;
47
48 int
pidfile(const char * basename)49 pidfile(const char *basename)
50 {
51 int save_errno;
52 pid_t pid;
53 FILE *f;
54
55 if (basename == NULL)
56 basename = __progname;
57
58 free(pidfile_path);
59 pidfile_path = NULL;
60
61 /* _PATH_VARRUN includes trailing / */
62 if (asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename) == -1)
63 return (-1);
64
65 if ((f = fopen(pidfile_path, "w")) == NULL) {
66 save_errno = errno;
67 free(pidfile_path);
68 pidfile_path = NULL;
69 errno = save_errno;
70 return (-1);
71 }
72
73 pid = getpid();
74 if (fprintf(f, "%ld\n", (long)pid) <= 0 || fflush(f) != 0) {
75 save_errno = errno;
76 (void) fclose(f);
77 (void) unlink(pidfile_path);
78 free(pidfile_path);
79 pidfile_path = NULL;
80 errno = save_errno;
81 return (-1);
82 }
83 (void) fclose(f);
84
85 pidfile_pid = pid;
86 if (atexit(pidfile_cleanup) != 0) {
87 save_errno = errno;
88 (void) unlink(pidfile_path);
89 free(pidfile_path);
90 pidfile_path = NULL;
91 pidfile_pid = 0;
92 errno = save_errno;
93 return (-1);
94 }
95
96 return (0);
97 }
98
99 static void
pidfile_cleanup(void)100 pidfile_cleanup(void)
101 {
102
103 if (pidfile_path != NULL && pidfile_pid == getpid())
104 (void) unlink(pidfile_path);
105 }
106