1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. 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 #if 0 33 #ifndef lint 34 static const char copyright[] = 35 "@(#) Copyright (c) 1989, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 static char sccsid[] = "@(#)nohup.c 8.1 (Berkeley) 6/6/93"; 41 #endif /* not lint */ 42 #endif 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include <sys/param.h> 47 #include <sys/stat.h> 48 49 #include <err.h> 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <signal.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 static void dofile(void); 59 static void usage(void); 60 61 #define FILENAME "nohup.out" 62 /* 63 * POSIX mandates that we exit with: 64 * 126 - If the utility was found, but failed to execute. 65 * 127 - If any other error occurred. 66 */ 67 #define EXIT_NOEXEC 126 68 #define EXIT_NOTFOUND 127 69 #define EXIT_MISC 127 70 71 int 72 main(int argc, char *argv[]) 73 { 74 int exit_status; 75 76 while (getopt(argc, argv, "") != -1) 77 usage(); 78 argc -= optind; 79 argv += optind; 80 if (argc < 1) 81 usage(); 82 83 if (isatty(STDOUT_FILENO)) 84 dofile(); 85 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) 86 /* may have just closed stderr */ 87 err(EXIT_MISC, "%s", argv[0]); 88 89 (void)signal(SIGHUP, SIG_IGN); 90 91 execvp(*argv, argv); 92 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC; 93 err(exit_status, "%s", argv[0]); 94 } 95 96 static void 97 dofile(void) 98 { 99 int fd; 100 char path[MAXPATHLEN]; 101 const char *p; 102 103 /* 104 * POSIX mandates if the standard output is a terminal, the standard 105 * output is appended to nohup.out in the working directory. Failing 106 * that, it will be appended to nohup.out in the directory obtained 107 * from the HOME environment variable. If file creation is required, 108 * the mode_t is set to S_IRUSR | S_IWUSR. 109 */ 110 p = FILENAME; 111 fd = open(p, O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR); 112 if (fd != -1) 113 goto dupit; 114 if ((p = getenv("HOME")) != NULL && *p != '\0' && 115 (size_t)snprintf(path, sizeof(path), "%s/%s", p, FILENAME) < 116 sizeof(path)) { 117 fd = open(p = path, O_RDWR | O_CREAT | O_APPEND, 118 S_IRUSR | S_IWUSR); 119 if (fd != -1) 120 goto dupit; 121 } 122 errx(EXIT_MISC, "can't open a nohup.out file"); 123 124 dupit: 125 if (dup2(fd, STDOUT_FILENO) == -1) 126 err(EXIT_MISC, NULL); 127 (void)fprintf(stderr, "appending output to %s\n", p); 128 } 129 130 static void 131 usage(void) 132 { 133 (void)fprintf(stderr, "usage: nohup [--] utility [arguments]\n"); 134 exit(EXIT_MISC); 135 } 136