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 #endif 40 #include <sys/cdefs.h> 41 #include <sys/param.h> 42 #include <sys/stat.h> 43 44 #include <err.h> 45 #include <errno.h> 46 #include <fcntl.h> 47 #include <signal.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 53 static void dofile(void); 54 static void usage(void) __dead2; 55 56 #define FILENAME "nohup.out" 57 /* 58 * POSIX mandates that we exit with: 59 * 126 - If the utility was found, but failed to execute. 60 * 127 - If any other error occurred. 61 */ 62 #define EXIT_NOEXEC 126 63 #define EXIT_NOTFOUND 127 64 #define EXIT_MISC 127 65 66 int 67 main(int argc, char *argv[]) 68 { 69 int exit_status; 70 71 while (getopt(argc, argv, "") != -1) 72 usage(); 73 argc -= optind; 74 argv += optind; 75 if (argc < 1) 76 usage(); 77 78 if (isatty(STDOUT_FILENO)) 79 dofile(); 80 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) 81 /* may have just closed stderr */ 82 err(EXIT_MISC, "%s", argv[0]); 83 84 (void)signal(SIGHUP, SIG_IGN); 85 86 execvp(*argv, argv); 87 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC; 88 err(exit_status, "%s", argv[0]); 89 } 90 91 static void 92 dofile(void) 93 { 94 int fd; 95 char path[MAXPATHLEN]; 96 const char *p; 97 98 /* 99 * POSIX mandates if the standard output is a terminal, the standard 100 * output is appended to nohup.out in the working directory. Failing 101 * that, it will be appended to nohup.out in the directory obtained 102 * from the HOME environment variable. If file creation is required, 103 * the mode_t is set to S_IRUSR | S_IWUSR. 104 */ 105 p = FILENAME; 106 fd = open(p, O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR); 107 if (fd != -1) 108 goto dupit; 109 if ((p = getenv("HOME")) != NULL && *p != '\0' && 110 (size_t)snprintf(path, sizeof(path), "%s/%s", p, FILENAME) < 111 sizeof(path)) { 112 fd = open(p = path, O_RDWR | O_CREAT | O_APPEND, 113 S_IRUSR | S_IWUSR); 114 if (fd != -1) 115 goto dupit; 116 } 117 errx(EXIT_MISC, "can't open a nohup.out file"); 118 119 dupit: 120 if (dup2(fd, STDOUT_FILENO) == -1) 121 err(EXIT_MISC, NULL); 122 (void)fprintf(stderr, "appending output to %s\n", p); 123 } 124 125 static void 126 usage(void) 127 { 128 (void)fprintf(stderr, "usage: nohup [--] utility [arguments]\n"); 129 exit(EXIT_MISC); 130 } 131