BGE_MBX_TX_HOST_PROD0_LO is write-only, avoid reading it.
[dragonfly/vkernel-mp.git] / lib / libutil / pidfile.c
blob81259deb855f203113285491104c36c22574440a
1 /* $NetBSD: pidfile.c,v 1.6 2001/10/20 09:20:28 taca Exp $ */
2 /* $DragonFly: src/lib/libutil/pidfile.c,v 1.2 2005/03/04 05:31:11 cpressey Exp $ */
4 /*-
5 * Copyright (c) 1999 The NetBSD Foundation, Inc.
6 * All rights reserved.
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Jason R. Thorpe and Matthias Scheler.
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.
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.
40 #include <sys/param.h>
42 #include <paths.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
48 #include "libutil.h"
50 static int pidfile_atexit_done;
51 static pid_t pidfile_pid;
52 static char *pidfile_basename;
53 static char *pidfile_path;
55 static void pidfile_cleanup(void);
57 int
58 pidfile(const char *basename)
60 FILE *f;
63 * Register handler which will remove the pidfile later.
65 if (!pidfile_atexit_done) {
66 if (atexit(pidfile_cleanup) < 0)
67 return -1;
68 pidfile_atexit_done = 1;
71 if (basename == NULL)
72 basename = getprogname();
75 * If pidfile has already been created for the supplied basename
76 * we don't need to create a pidfile again.
78 if (pidfile_path != NULL) {
79 if (strcmp(pidfile_basename, basename) == 0)
80 return 0;
82 * Remove existing pidfile if it was created by this process.
84 pidfile_cleanup();
86 free(pidfile_path);
87 pidfile_path = NULL;
88 free(pidfile_basename);
89 pidfile_basename = NULL;
92 pidfile_pid = getpid();
94 pidfile_basename = strdup(basename);
95 if (pidfile_basename == NULL)
96 return -1;
98 /* _PATH_VARRUN includes trailing / */
99 asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename);
100 if (pidfile_path == NULL) {
101 free(pidfile_basename);
102 pidfile_basename = NULL;
103 return -1;
106 if ((f = fopen(pidfile_path, "w")) == NULL) {
107 free(pidfile_path);
108 pidfile_path = NULL;
109 free(pidfile_basename);
110 pidfile_basename = NULL;
111 return -1;
114 fprintf(f, "%d\n", pidfile_pid);
115 fclose(f);
116 return 0;
119 static void
120 pidfile_cleanup(void)
122 /* Only remove the pidfile if it was created by this process. */
123 if ((pidfile_path != NULL) && (pidfile_pid == getpid()))
124 unlink(pidfile_path);