1 /* 2 * Copyright (c) 1989, 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 * @(#) Copyright (c) 1989, 1993 The Regents of the University of California. All rights reserved. 30 * @(#)nohup.c 8.1 (Berkeley) 6/6/93 31 * $FreeBSD: src/usr.bin/nohup/nohup.c,v 1.4.2.2 2001/08/02 01:45:45 obrien Exp $ 32 * $DragonFly: src/usr.bin/nohup/nohup.c,v 1.5 2004/12/22 00:12:30 liamfoy Exp $ 33 */ 34 35 #include <sys/param.h> 36 #include <sys/stat.h> 37 38 #include <err.h> 39 #include <errno.h> 40 #include <fcntl.h> 41 #include <signal.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <unistd.h> 45 46 static void dofile(void); 47 static void usage(void); 48 49 #define FILENAME "nohup.out" 50 /* 51 * POSIX mandates that we exit with: 52 * 126 - If the utility was found, but failed to execute. 53 * 127 - If any other error occurred. 54 */ 55 #define EXIT_NOEXEC 126 56 #define EXIT_NOTFOUND 127 57 #define EXIT_MISC 127 58 59 int 60 main(int argc, char **argv) 61 { 62 int exit_status; 63 64 while (getopt(argc, argv, "") != -1) 65 usage(); 66 argc -= optind; 67 argv += optind; 68 if (argc < 1) 69 usage(); 70 71 if (isatty(STDOUT_FILENO)) 72 dofile(); 73 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) 74 /* may have just closed stderr */ 75 err(EXIT_MISC, "%s", argv[0]); 76 77 signal(SIGHUP, SIG_IGN); 78 79 execvp(*argv, argv); 80 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC; 81 err(exit_status, "%s", argv[0]); 82 } 83 84 static void 85 dofile(void) 86 { 87 int fd; 88 char path[MAXPATHLEN]; 89 const char *p; 90 91 /* 92 * POSIX mandates if the standard output is a terminal, the standard 93 * output is appended to nohup.out in the working directory. Failing 94 * that, it will be appended to nohup.out in the directory obtained 95 * from the HOME environment variable. If file creation is required, 96 * the mode_t is set to S_IRUSR | S_IWUSR. 97 */ 98 p = FILENAME; 99 fd = open(p, O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR); 100 if (fd != -1) 101 goto dupit; 102 if ((p = getenv("HOME")) != NULL && *p != '\0' && 103 (size_t)snprintf(path, sizeof(path), "%s/%s", p, FILENAME) < 104 sizeof(path)) { 105 fd = open(p = path, O_RDWR | O_CREAT | O_APPEND, 106 S_IRUSR | S_IWUSR); 107 if (fd != -1) 108 goto dupit; 109 } 110 errx(EXIT_MISC, "can't open a nohup.out file"); 111 112 dupit: 113 if (dup2(fd, STDOUT_FILENO) == -1) 114 err(EXIT_MISC, "dup2 failed"); 115 fprintf(stderr, "appending output to %s\n", p); 116 } 117 118 static void 119 usage(void) 120 { 121 fprintf(stderr, "usage: nohup [--] command [arguments]\n"); 122 exit(EXIT_MISC); 123 } 124