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/* $OpenBSD: nohup.c,v 1.14 2009/10/27 23:59:41 deraadt Exp $ */
/* $NetBSD: nohup.c,v 1.6 1995/08/31 23:35:25 jtc Exp $ */
/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <err.h>
static void dofile(void);
__dead static void usage(void);
/*
* nohup shall exit with one of the following values:
* 126 - The utility was found but could not be invoked.
* 127 - An error occurred in the nohup utility, or the utility could
* not be found.
*/
#define EXIT_NOEXEC 126
#define EXIT_NOTFOUND 127
#define EXIT_MISC 127
/*
* If the standard output is a terminal, all output written to
* its standard output shall be appended to the end of the file
* nohup.out in the current directory. If nohup.out cannot be
* created or opened for appending, the output shall be appended
* to the end of the file nohup.out in the directory specified
* by the HOME environment variable.
*
* If a file is created, the file's permission bits shall be
* set to S_IRUSR | S_IWUSR.
*/
#define FILENAME "nohup.out"
int
main(int argc, char *argv[])
{
int exit_status;
if (argc < 2)
usage();
if (isatty(STDOUT_FILENO))
dofile();
if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) {
/* may have just closed stderr */
(void)fprintf(stdin, "nohup: %s\n", strerror(errno));
exit(EXIT_MISC);
}
/*
* The nohup utility shall take the standard action for all signals
* except that SIGHUP shall be ignored.
*/
(void)signal(SIGHUP, SIG_IGN);
execvp(argv[1], &argv[1]);
exit_status = (errno == ENOENT) ? EXIT_NOTFOUND : EXIT_NOEXEC;
err(exit_status, "%s", argv[1]);
}
static void
dofile(void)
{
int fd;
const char *p;
char path[MAXPATHLEN];
p = FILENAME;
if ((fd = open(p, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0)
goto dupit;
if ((p = getenv("HOME")) != NULL && *p != '\0' &&
(strlen(p) + strlen(FILENAME) + 1) < sizeof(path)) {
(void)strlcpy(path, p, sizeof(path));
(void)strlcat(path, "/", sizeof(path));
(void)strlcat(path, FILENAME, sizeof(path));
if ((fd = open(p = path, O_RDWR|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR)) >= 0)
goto dupit;
}
errx(EXIT_MISC, "can't open a nohup.out file");
dupit:
(void)lseek(fd, (off_t)0, SEEK_END);
if (dup2(fd, STDOUT_FILENO) == -1)
err(EXIT_MISC, NULL);
(void)fprintf(stderr, "sending output to %s\n", p);
}
__dead static void
usage(void)
{
(void)fprintf(stderr, "usage: nohup utility [arg ...]\n");
exit(EXIT_MISC);
}
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