pidfile.c revision 1.9
1/* $OpenBSD: pidfile.c,v 1.9 2013/10/01 16:47:42 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/param.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 41static char *pidfile_path; 42static pid_t pidfile_pid; 43 44static void pidfile_cleanup(void); 45 46extern char *__progname; 47 48int 49pidfile(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 (void) asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename); 65 if (pidfile_path == NULL) 66 return (-1); 67 68 if ((f = fopen(pidfile_path, "w")) == NULL) { 69 save_errno = errno; 70 free(pidfile_path); 71 pidfile_path = NULL; 72 errno = save_errno; 73 return (-1); 74 } 75 76 pid = getpid(); 77 if (fprintf(f, "%ld\n", (long)pid) <= 0 || fflush(f) != 0) { 78 save_errno = errno; 79 (void) fclose(f); 80 (void) unlink(pidfile_path); 81 free(pidfile_path); 82 pidfile_path = NULL; 83 errno = save_errno; 84 return (-1); 85 } 86 (void) fclose(f); 87 88 pidfile_pid = pid; 89 if (atexit(pidfile_cleanup) < 0) { 90 save_errno = errno; 91 (void) unlink(pidfile_path); 92 free(pidfile_path); 93 pidfile_path = NULL; 94 pidfile_pid = 0; 95 errno = save_errno; 96 return (-1); 97 } 98 99 return (0); 100} 101 102static void 103pidfile_cleanup(void) 104{ 105 106 if (pidfile_path != NULL && pidfile_pid == getpid()) 107 (void) unlink(pidfile_path); 108} 109