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 1.4 2004/10/29 15:10:55 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 <string.h> 49 #include <unistd.h> 50 51 static void dofile(void); 52 static void usage(void); 53 54 #define FILENAME "nohup.out" 55 /* 56 * POSIX mandates that we exit with: 57 * 126 - If the utility was found, but failed to execute. 58 * 127 - If any other error occurred. 59 */ 60 #define EXIT_NOEXEC 126 61 #define EXIT_NOTFOUND 127 62 #define EXIT_MISC 127 63 64 int 65 main(int argc, char **argv) 66 { 67 int exit_status; 68 69 while (getopt(argc, argv, "") != -1) 70 usage(); 71 argc -= optind; 72 argv += optind; 73 if (argc < 1) 74 usage(); 75 76 if (isatty(STDOUT_FILENO)) 77 dofile(); 78 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) 79 /* may have just closed stderr */ 80 err(EXIT_MISC, "%s", argv[0]); 81 82 signal(SIGHUP, SIG_IGN); 83 84 execvp(*argv, argv); 85 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC; 86 err(exit_status, "%s", argv[0]); 87 } 88 89 static void 90 dofile(void) 91 { 92 int fd; 93 char path[MAXPATHLEN]; 94 const char *p; 95 96 /* 97 * POSIX mandates if the standard output is a terminal, the standard 98 * output is appended to nohup.out in the working directory. Failing 99 * that, it will be appended to nohup.out in the directory obtained 100 * from the HOME environment variable. If file creation is required, 101 * the mode_t is set to S_IRUSR | S_IWUSR. 102 */ 103 p = FILENAME; 104 fd = open(p, O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR); 105 if (fd != -1) 106 goto dupit; 107 if ((p = getenv("HOME")) != NULL && *p != '\0' && 108 (size_t)snprintf(path, sizeof(path), "%s/%s", p, FILENAME) < 109 sizeof(path)) { 110 fd = open(p = path, O_RDWR | O_CREAT | O_APPEND, 111 S_IRUSR | S_IWUSR); 112 if (fd != -1) 113 goto dupit; 114 } 115 errx(EXIT_MISC, "can't open a nohup.out file"); 116 117 dupit: 118 if (dup2(fd, STDOUT_FILENO) == -1) 119 err(EXIT_MISC, NULL); 120 fprintf(stderr, "appending output to %s\n", p); 121 } 122 123 static void 124 usage(void) 125 { 126 fprintf(stderr, "usage: nohup [--] command [arguments]\n"); 127 exit(EXIT_MISC); 128 } 129