1 /*
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #if 0
31 #ifndef lint
32 static const char copyright[] =
33 "@(#) Copyright (c) 1989, 1993\n\
34 The Regents of the University of California. All rights reserved.\n";
35 #endif /* not lint */
36
37 #ifndef lint
38 static char sccsid[] = "@(#)nohup.c 8.1 (Berkeley) 6/6/93";
39 #endif /* not lint */
40 #endif
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43
44 #include <sys/param.h>
45 #include <sys/stat.h>
46
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55
56 static void dofile(void);
57 static void usage(void);
58
59 #define FILENAME "nohup.out"
60 /*
61 * POSIX mandates that we exit with:
62 * 126 - If the utility was found, but failed to execute.
63 * 127 - If any other error occurred.
64 */
65 #define EXIT_NOEXEC 126
66 #define EXIT_NOTFOUND 127
67 #define EXIT_MISC 127
68
69 int
main(int argc,char * argv[])70 main(int argc, char *argv[])
71 {
72 int exit_status;
73
74 while (getopt(argc, argv, "") != -1)
75 usage();
76 argc -= optind;
77 argv += optind;
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 err(EXIT_MISC, "%s", argv[0]);
86
87 (void)signal(SIGHUP, SIG_IGN);
88
89 execvp(*argv, argv);
90 exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC;
91 err(exit_status, "%s", argv[0]);
92 }
93
94 static void
dofile(void)95 dofile(void)
96 {
97 int fd;
98 char path[MAXPATHLEN];
99 const char *p;
100
101 /*
102 * POSIX mandates if the standard output is a terminal, the standard
103 * output is appended to nohup.out in the working directory. Failing
104 * that, it will be appended to nohup.out in the directory obtained
105 * from the HOME environment variable. If file creation is required,
106 * the mode_t is set to S_IRUSR | S_IWUSR.
107 */
108 p = FILENAME;
109 fd = open(p, O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR);
110 if (fd != -1)
111 goto dupit;
112 if ((p = getenv("HOME")) != NULL && *p != '\0' &&
113 (size_t)snprintf(path, sizeof(path), "%s/%s", p, FILENAME) <
114 sizeof(path)) {
115 fd = open(p = path, O_RDWR | O_CREAT | O_APPEND,
116 S_IRUSR | S_IWUSR);
117 if (fd != -1)
118 goto dupit;
119 }
120 errx(EXIT_MISC, "can't open a nohup.out file");
121
122 dupit:
123 if (dup2(fd, STDOUT_FILENO) == -1)
124 err(EXIT_MISC, NULL);
125 (void)fprintf(stderr, "appending output to %s\n", p);
126 }
127
128 static void
usage(void)129 usage(void)
130 {
131 (void)fprintf(stderr, "usage: nohup [--] utility [arguments]\n");
132 exit(EXIT_MISC);
133 }
134