1 /* $NetBSD: nohup.c,v 1.15 2011/09/06 18:24:15 joerg Exp $ */
2
3 /*
4 * Copyright (c) 1989 The Regents of the University of California.
5 * 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 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1989\
35 The Regents of the University of California. All rights reserved.");
36 #endif /* not lint */
37
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)nohup.c 5.4 (Berkeley) 6/1/90";
41 #endif
42 __RCSID("$NetBSD: nohup.c,v 1.15 2011/09/06 18:24:15 joerg Exp $");
43 #endif /* not lint */
44
45 #include <sys/param.h>
46 #include <sys/file.h>
47 #include <sys/stat.h>
48 #include <fcntl.h>
49 #include <unistd.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <errno.h>
55
56 static void dofile(void);
57 __dead static void usage(void);
58
59 /* nohup shall exit with one of the following values:
60 126 - The utility was found but could not be invoked.
61 127 - An error occurred in the nohup utility, or the utility could
62 not be found. */
63 #define EXIT_NOEXEC 126
64 #define EXIT_NOTFOUND 127
65 #define EXIT_MISC 127
66
67 int
main(int argc,char ** argv)68 main(int argc, char **argv)
69 {
70 int exit_status;
71
72 while (getopt(argc, argv, "") != -1) {
73 usage();
74 }
75 argc -= optind;
76 argv += optind;
77
78 if (argc < 1)
79 usage();
80
81 if (isatty(STDOUT_FILENO))
82 dofile();
83 if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) {
84 /* may have just closed stderr */
85 (void)fprintf(stdin, "nohup: %s\n", strerror(errno));
86 exit(EXIT_MISC);
87 }
88
89 /* The nohup utility shall take the standard action for all signals
90 except that SIGHUP shall be ignored. */
91 (void)signal(SIGHUP, SIG_IGN);
92
93 execvp(argv[0], &argv[0]);
94 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC;
95 (void)fprintf(stderr, "nohup: %s: %s\n", argv[0], strerror(errno));
96 exit(exit_status);
97 }
98
99 static void
dofile(void)100 dofile(void)
101 {
102 int fd;
103 char path[MAXPATHLEN];
104 const char *p;
105
106 /* If the standard output is a terminal, all output written to
107 its standard output shall be appended to the end of the file
108 nohup.out in the current directory. If nohup.out cannot be
109 created or opened for appending, the output shall be appended
110 to the end of the file nohup.out in the directory specified
111 by the HOME environment variable.
112
113 If a file is created, the file's permission bits shall be
114 set to S_IRUSR | S_IWUSR. */
115 #define FILENAME "nohup.out"
116 p = FILENAME;
117 if ((fd = open(p, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0)
118 goto dupit;
119 if ((p = getenv("HOME")) != NULL) {
120 (void)strlcpy(path, p, sizeof(path));
121 (void)strlcat(path, "/", sizeof(path));
122 (void)strlcat(path, FILENAME, sizeof(path));
123 if ((fd = open(p = path, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0)
124 goto dupit;
125 }
126 (void)fprintf(stderr, "nohup: can't open a nohup.out file.\n");
127 exit(EXIT_MISC);
128
129 dupit: (void)lseek(fd, 0L, SEEK_END);
130 if (dup2(fd, STDOUT_FILENO) == -1) {
131 (void)fprintf(stderr, "nohup: %s\n", strerror(errno));
132 exit(EXIT_MISC);
133 }
134 (void)fprintf(stderr, "sending output to %s\n", p);
135 }
136
137 static void
usage(void)138 usage(void)
139 {
140 (void)fprintf(stderr, "usage: nohup utility [argument ...]\n");
141 exit(EXIT_MISC);
142 }
143