1 /* $OpenBSD: daemon.c,v 1.7 2010/07/27 22:29:09 marco Exp $ */ 2 /*- 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <fcntl.h> 32 #include <paths.h> 33 #include <unistd.h> 34 #include <stdlib.h> 35 36 int 37 daemon(int nochdir, int noclose) 38 { 39 int fd; 40 41 switch (fork()) { 42 case -1: 43 return (-1); 44 case 0: 45 break; 46 default: 47 _exit(0); 48 } 49 50 if (setsid() == -1) 51 return (-1); 52 53 if (!nochdir) 54 (void)chdir("/"); 55 56 if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 57 (void)dup2(fd, STDIN_FILENO); 58 (void)dup2(fd, STDOUT_FILENO); 59 (void)dup2(fd, STDERR_FILENO); 60 if (fd > 2) 61 (void)close(fd); 62 } 63 return (0); 64 } 65
