1/*
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 * Portions copyright (c) 2007 Apple Inc.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#if 0
32#ifndef lint
33static const char copyright[] =
34"@(#) Copyright (c) 1989, 1993\n\
35	The Regents of the University of California.  All rights reserved.\n";
36#endif /* not lint */
37
38#ifndef lint
39static char sccsid[] = "@(#)nohup.c	8.1 (Berkeley) 6/6/93";
40#endif /* not lint */
41#endif
42#include <sys/cdefs.h>
43#ifndef __APPLE__
44__FBSDID("$FreeBSD: src/usr.bin/nohup/nohup.c,v 1.10 2003/05/03 19:44:46 obrien Exp $");
45#endif
46
47#include <sys/param.h>
48#include <sys/stat.h>
49
50#include <err.h>
51#include <errno.h>
52#include <fcntl.h>
53#include <signal.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <unistd.h>
58
59#ifdef __APPLE__
60#include <TargetConditionals.h>
61#include <vproc.h>
62#include <vproc_priv.h>
63#endif
64
65static void dofile(void);
66static void usage(void);
67
68#define	FILENAME	"nohup.out"
69/*
70 * POSIX mandates that we exit with:
71 * 126 - If the utility was found, but failed to execute.
72 * 127 - If any other error occurred.
73 */
74#define	EXIT_NOEXEC	126
75#define	EXIT_NOTFOUND	127
76#define	EXIT_MISC	127
77
78int
79main(int argc, char *argv[])
80{
81	int exit_status;
82
83	while (getopt(argc, argv, "") != -1)
84		usage();
85	argc -= optind;
86	argv += optind;
87	if (argc < 1)
88		usage();
89
90	if (isatty(STDOUT_FILENO))
91		dofile();
92	if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1)
93		/* may have just closed stderr */
94		err(EXIT_MISC, "%s", argv[0]);
95
96	(void)signal(SIGHUP, SIG_IGN);
97
98#if defined(__APPLE__) && !TARGET_OS_EMBEDDED
99	if (_vprocmgr_detach_from_console(0) != NULL)
100		err(EXIT_MISC, "can't detach from console");
101#endif
102	execvp(*argv, argv);
103	exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC;
104	err(exit_status, "%s", argv[0]);
105}
106
107static void
108dofile(void)
109{
110	int fd;
111	char path[MAXPATHLEN];
112	const char *p;
113
114	/*
115	 * POSIX mandates if the standard output is a terminal, the standard
116	 * output is appended to nohup.out in the working directory.  Failing
117	 * that, it will be appended to nohup.out in the directory obtained
118	 * from the HOME environment variable.  If file creation is required,
119	 * the mode_t is set to S_IRUSR | S_IWUSR.
120	 */
121	p = FILENAME;
122	fd = open(p, O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR);
123	if (fd != -1)
124		goto dupit;
125	if ((p = getenv("HOME")) != NULL && *p != '\0' &&
126	    (size_t)snprintf(path, sizeof(path), "%s/%s", p, FILENAME) <
127	    sizeof(path)) {
128		fd = open(p = path, O_RDWR | O_CREAT | O_APPEND,
129		    S_IRUSR | S_IWUSR);
130		if (fd != -1)
131			goto dupit;
132	}
133	errx(EXIT_MISC, "can't open a nohup.out file");
134
135dupit:
136#ifdef __APPLE__
137	(void)lseek(fd, 0L, SEEK_END);
138#endif
139	if (dup2(fd, STDOUT_FILENO) == -1)
140		err(EXIT_MISC, NULL);
141	(void)fprintf(stderr, "appending output to %s\n", p);
142}
143
144static void
145usage(void)
146{
147	(void)fprintf(stderr, "usage: nohup [--] utility [arguments]\n");
148	exit(EXIT_MISC);
149}
150