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
main(int argc,char * argv[])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
dofile(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
usage(void)139 usage(void)
140 {
141 (void)fprintf(stderr, "usage: nohup command\n");
142 exit(EXIT_MISC);
143 }
144