1/* $NetBSD: nohup.c,v 1.14 2009/04/12 23:38:17 lukem Exp $ */ 2 3/* 4 * Copyright (c) 1989 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33#ifndef lint 34__COPYRIGHT("@(#) Copyright (c) 1989\ 35 The Regents of the University of California. All rights reserved."); 36#endif /* not lint */ 37 38#ifndef lint 39#if 0 40static char sccsid[] = "@(#)nohup.c 5.4 (Berkeley) 6/1/90"; 41#endif 42__RCSID("$NetBSD: nohup.c,v 1.14 2009/04/12 23:38:17 lukem Exp $"); 43#endif /* not lint */ 44 45#include <sys/param.h> 46#include <sys/file.h> 47#include <sys/stat.h> 48#include <fcntl.h> 49#include <unistd.h> 50#include <signal.h> 51#include <stdio.h> 52#include <stdlib.h> 53#include <string.h> 54#include <errno.h> 55 56static void dofile(void); 57__dead static void usage(void); 58 59/* nohup shall exit with one of the following values: 60 126 - The utility was found but could not be invoked. 61 127 - An error occurred in the nohup utility, or the utility could 62 not be found. */ 63#define EXIT_NOEXEC 126 64#define EXIT_NOTFOUND 127 65#define EXIT_MISC 127 66 67int 68main(int argc, char **argv) 69{ 70 int exit_status; 71 72 while (getopt(argc, argv, "") != -1) { 73 usage(); 74 } 75 argc -= optind; 76 argv += optind; 77 78 if (argc < 1) 79 usage(); 80 81 if (isatty(STDOUT_FILENO)) 82 dofile(); 83 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) { 84 /* may have just closed stderr */ 85 (void)fprintf(stdin, "nohup: %s\n", strerror(errno)); 86 exit(EXIT_MISC); 87 } 88 89 /* The nohup utility shall take the standard action for all signals 90 except that SIGHUP shall be ignored. */ 91 (void)signal(SIGHUP, SIG_IGN); 92 93 execvp(argv[0], &argv[0]); 94 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC; 95 (void)fprintf(stderr, "nohup: %s: %s\n", argv[0], strerror(errno)); 96 exit(exit_status); 97} 98 99static void 100dofile(void) 101{ 102 int fd; 103 char path[MAXPATHLEN]; 104 const char *p; 105 106 /* If the standard output is a terminal, all output written to 107 its standard output shall be appended to the end of the file 108 nohup.out in the current directory. If nohup.out cannot be 109 created or opened for appending, the output shall be appended 110 to the end of the file nohup.out in the directory specified 111 by the HOME environment variable. 112 113 If a file is created, the file's permission bits shall be 114 set to S_IRUSR | S_IWUSR. */ 115#define FILENAME "nohup.out" 116 p = FILENAME; 117 if ((fd = open(p, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0) 118 goto dupit; 119 if ((p = getenv("HOME")) != NULL) { 120 (void)strlcpy(path, p, sizeof(path)); 121 (void)strlcat(path, "/", sizeof(path)); 122 (void)strlcat(path, FILENAME, sizeof(path)); 123 if ((fd = open(p = path, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0) 124 goto dupit; 125 } 126 (void)fprintf(stderr, "nohup: can't open a nohup.out file.\n"); 127 exit(EXIT_MISC); 128 129dupit: (void)lseek(fd, 0L, SEEK_END); 130 if (dup2(fd, STDOUT_FILENO) == -1) { 131 (void)fprintf(stderr, "nohup: %s\n", strerror(errno)); 132 exit(EXIT_MISC); 133 } 134 (void)fprintf(stderr, "sending output to %s\n", p); 135} 136 137static void 138usage(void) 139{ 140 (void)fprintf(stderr, "usage: nohup utility [argument ...]\n"); 141 exit(EXIT_MISC); 142} 143