1 /* $OpenBSD: pidfile.c,v 1.5 2002/05/26 09:29:02 deraadt 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) 41 static const char rcsid[] = "$OpenBSD: pidfile.c,v 1.5 2002/05/26 09:29:02 deraadt 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 52 static char *pidfile_path; 53 static pid_t pidfile_pid; 54 55 static void pidfile_cleanup(void); 56 57 extern char *__progname; 58 59 int 60 pidfile(const char *basename) 61 { 62 FILE *f; 63 int save_errno; 64 pid_t pid; 65 66 if (basename == NULL) 67 basename = __progname; 68 69 if (pidfile_path != NULL) { 70 free(pidfile_path); 71 pidfile_path = NULL; 72 } 73 74 /* _PATH_VARRUN includes trailing / */ 75 (void) asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename); 76 if (pidfile_path == NULL) 77 return (-1); 78 79 if ((f = fopen(pidfile_path, "w")) == NULL) { 80 save_errno = errno; 81 free(pidfile_path); 82 pidfile_path = NULL; 83 errno = save_errno; 84 return (-1); 85 } 86 87 pid = getpid(); 88 if (fprintf(f, "%ld\n", (long)pid) <= 0 || fclose(f) != 0) { 89 save_errno = errno; 90 (void) unlink(pidfile_path); 91 free(pidfile_path); 92 pidfile_path = NULL; 93 errno = save_errno; 94 return (-1); 95 } 96 97 pidfile_pid = pid; 98 if (atexit(pidfile_cleanup) < 0) { 99 save_errno = errno; 100 (void) unlink(pidfile_path); 101 free(pidfile_path); 102 pidfile_path = NULL; 103 pidfile_pid = 0; 104 errno = save_errno; 105 return (-1); 106 } 107 108 return (0); 109 } 110 111 static void 112 pidfile_cleanup(void) 113 { 114 115 if (pidfile_path != NULL && pidfile_pid == getpid()) 116 (void) unlink(pidfile_path); 117 } 118