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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#) Copyright (c) 1989, 1993 The Regents of the University of California. All rights reserved. 34 * @(#)nohup.c 8.1 (Berkeley) 6/6/93 35 * $FreeBSD: src/usr.bin/nohup/nohup.c,v 1.4.2.2 2001/08/02 01:45:45 obrien Exp $ 36 * $DragonFly: src/usr.bin/nohup/nohup.c,v 1.5 2004/12/22 00:12:30 liamfoy Exp $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/stat.h> 41 42 #include <err.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <signal.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <unistd.h> 49 50 static void dofile(void); 51 static void usage(void); 52 53 #define FILENAME "nohup.out" 54 /* 55 * POSIX mandates that we exit with: 56 * 126 - If the utility was found, but failed to execute. 57 * 127 - If any other error occurred. 58 */ 59 #define EXIT_NOEXEC 126 60 #define EXIT_NOTFOUND 127 61 #define EXIT_MISC 127 62 63 int 64 main(int argc, char **argv) 65 { 66 int exit_status; 67 68 while (getopt(argc, argv, "") != -1) 69 usage(); 70 argc -= optind; 71 argv += optind; 72 if (argc < 1) 73 usage(); 74 75 if (isatty(STDOUT_FILENO)) 76 dofile(); 77 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) 78 /* may have just closed stderr */ 79 err(EXIT_MISC, "%s", argv[0]); 80 81 signal(SIGHUP, SIG_IGN); 82 83 execvp(*argv, argv); 84 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC; 85 err(exit_status, "%s", argv[0]); 86 } 87 88 static void 89 dofile(void) 90 { 91 int fd; 92 char path[MAXPATHLEN]; 93 const char *p; 94 95 /* 96 * POSIX mandates if the standard output is a terminal, the standard 97 * output is appended to nohup.out in the working directory. Failing 98 * that, it will be appended to nohup.out in the directory obtained 99 * from the HOME environment variable. If file creation is required, 100 * the mode_t is set to S_IRUSR | S_IWUSR. 101 */ 102 p = FILENAME; 103 fd = open(p, O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR); 104 if (fd != -1) 105 goto dupit; 106 if ((p = getenv("HOME")) != NULL && *p != '\0' && 107 (size_t)snprintf(path, sizeof(path), "%s/%s", p, FILENAME) < 108 sizeof(path)) { 109 fd = open(p = path, O_RDWR | O_CREAT | O_APPEND, 110 S_IRUSR | S_IWUSR); 111 if (fd != -1) 112 goto dupit; 113 } 114 errx(EXIT_MISC, "can't open a nohup.out file"); 115 116 dupit: 117 if (dup2(fd, STDOUT_FILENO) == -1) 118 err(EXIT_MISC, "dup2 failed"); 119 fprintf(stderr, "appending output to %s\n", p); 120 } 121 122 static void 123 usage(void) 124 { 125 fprintf(stderr, "usage: nohup [--] command [arguments]\n"); 126 exit(EXIT_MISC); 127 } 128