1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char rcsid[] = "$OpenBSD: daemon.c,v 1.5 2003/07/15 17:32:41 deraadt Exp $"; 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include <fcntl.h> 35 #include <paths.h> 36 #include <unistd.h> 37 #include <stdlib.h> 38 39 int 40 daemon(int nochdir, int noclose) 41 { 42 int fd; 43 44 switch (fork()) { 45 case -1: 46 return (-1); 47 case 0: 48 break; 49 default: 50 _exit(0); 51 } 52 53 if (setsid() == -1) 54 return (-1); 55 56 if (!nochdir) 57 (void)chdir("/"); 58 59 if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 60 (void)dup2(fd, STDIN_FILENO); 61 (void)dup2(fd, STDOUT_FILENO); 62 (void)dup2(fd, STDERR_FILENO); 63 if (fd > 2) 64 (void)close (fd); 65 } 66 return (0); 67 } 68