1 /* $OpenBSD: nohup.c,v 1.12 2003/06/03 02:56:14 millert Exp $ */ 2 /* $NetBSD: nohup.c,v 1.6 1995/08/31 23:35:25 jtc Exp $ */ 3 4 /* 5 * Copyright (c) 1989 The Regents of the University of California. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 char copyright[] = 35 "@(#) Copyright (c) 1989 The Regents of the University of California.\n\ 36 All rights reserved.\n"; 37 #endif /* not lint */ 38 39 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)nohup.c 5.4 (Berkeley) 6/1/90"; 42 #endif 43 static char rcsid[] = "$OpenBSD: nohup.c,v 1.12 2003/06/03 02:56:14 millert Exp $"; 44 #endif /* not lint */ 45 46 #include <sys/param.h> 47 #include <sys/file.h> 48 #include <sys/stat.h> 49 #include <fcntl.h> 50 #include <unistd.h> 51 #include <signal.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <errno.h> 56 #include <err.h> 57 58 static void dofile(void); 59 __dead static void usage(void); 60 61 /* 62 * nohup shall exit with one of the following values: 63 * 126 - The utility was found but could not be invoked. 64 * 127 - An error occurred in the nohup utility, or the utility could 65 * not be found. 66 */ 67 #define EXIT_NOEXEC 126 68 #define EXIT_NOTFOUND 127 69 #define EXIT_MISC 127 70 71 /* 72 * If the standard output is a terminal, all output written to 73 * its standard output shall be appended to the end of the file 74 * nohup.out in the current directory. If nohup.out cannot be 75 * created or opened for appending, the output shall be appended 76 * to the end of the file nohup.out in the directory specified 77 * by the HOME environment variable. 78 * 79 * If a file is created, the file's permission bits shall be 80 * set to S_IRUSR | S_IWUSR. 81 */ 82 #define FILENAME "nohup.out" 83 84 int 85 main(int argc, char *argv[]) 86 { 87 int exit_status; 88 89 if (argc < 2) 90 usage(); 91 92 if (isatty(STDOUT_FILENO)) 93 dofile(); 94 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) { 95 /* may have just closed stderr */ 96 (void)fprintf(stdin, "nohup: %s\n", strerror(errno)); 97 exit(EXIT_MISC); 98 } 99 100 /* 101 * The nohup utility shall take the standard action for all signals 102 * except that SIGHUP shall be ignored. 103 */ 104 (void)signal(SIGHUP, SIG_IGN); 105 106 execvp(argv[1], &argv[1]); 107 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC; 108 err(exit_status, "%s", argv[1]); 109 } 110 111 static void 112 dofile(void) 113 { 114 int fd; 115 const char *p; 116 char path[MAXPATHLEN]; 117 118 p = FILENAME; 119 if ((fd = open(p, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0) 120 goto dupit; 121 if ((p = getenv("HOME")) != NULL && *p != '\0' && 122 (strlen(p) + strlen(FILENAME) + 1) < sizeof(path)) { 123 (void)strlcpy(path, p, sizeof(path)); 124 (void)strlcat(path, "/", sizeof(path)); 125 (void)strlcat(path, FILENAME, sizeof(path)); 126 if ((fd = open(p = path, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0) 127 goto dupit; 128 } 129 errx(EXIT_MISC, "can't open a nohup.out file"); 130 131 dupit: 132 (void)lseek(fd, (off_t)0, SEEK_END); 133 if (dup2(fd, STDOUT_FILENO) == -1) 134 err(EXIT_MISC, NULL); 135 (void)fprintf(stderr, "sending output to %s\n", p); 136 } 137 138 __dead static void 139 usage(void) 140 { 141 (void)fprintf(stderr, "usage: nohup command\n"); 142 exit(EXIT_MISC); 143 } 144