1 /* $OpenBSD: pidfile.c,v 1.11 2015/06/03 02:24:36 millert 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 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 if (pidfile_path != NULL) { 59 free(pidfile_path); 60 pidfile_path = NULL; 61 } 62 63 /* _PATH_VARRUN includes trailing / */ 64 if (asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename) == -1) 65 return (-1); 66 67 if ((f = fopen(pidfile_path, "w")) == NULL) { 68 save_errno = errno; 69 free(pidfile_path); 70 pidfile_path = NULL; 71 errno = save_errno; 72 return (-1); 73 } 74 75 pid = getpid(); 76 if (fprintf(f, "%ld\n", (long)pid) <= 0 || fflush(f) != 0) { 77 save_errno = errno; 78 (void) fclose(f); 79 (void) unlink(pidfile_path); 80 free(pidfile_path); 81 pidfile_path = NULL; 82 errno = save_errno; 83 return (-1); 84 } 85 (void) fclose(f); 86 87 pidfile_pid = pid; 88 if (atexit(pidfile_cleanup) < 0) { 89 save_errno = errno; 90 (void) unlink(pidfile_path); 91 free(pidfile_path); 92 pidfile_path = NULL; 93 pidfile_pid = 0; 94 errno = save_errno; 95 return (-1); 96 } 97 98 return (0); 99 } 100 101 static void 102 pidfile_cleanup(void) 103 { 104 105 if (pidfile_path != NULL && pidfile_pid == getpid()) 106 (void) unlink(pidfile_path); 107 } 108