Start development on 386BSD 0.1

[unix-history] / .ref-386BSD-0.0 / usr / src / usr.bin / nohup / nohup.c

/*
* 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. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. 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.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)nohup.c     5.4 (Berkeley) 6/1/90";
#endif /* not lint */

#include <sys/param.h>
#include <sys/signal.h>
#include <sys/file.h>
#include <unistd.h>
#include <stdio.h>

extern int errno;

main(argc, argv)
       int argc;
       char **argv;
{
       char *strerror();

       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(1);
       }

       (void)signal(SIGHUP, SIG_IGN);
       (void)signal(SIGQUIT, SIG_IGN);

       execvp(argv[1], &argv[1]);
       (void)fprintf(stderr,
           "nohup: %s: %s\n", argv[1], strerror(errno));
       exit(1);
}

dofile()
{
       int fd;
       char *p, path[MAXPATHLEN];
       off_t lseek();
       char *getenv(), *strcpy(), *strcat(), *strerror();

#define FILENAME        "nohup.out"
       p = FILENAME;
       if ((fd = open(p, O_RDWR|O_CREAT, 0600)) >= 0)
               goto dupit;
       if (p = getenv("HOME")) {
               (void)strcpy(path, p);
               (void)strcat(path, "/");
               (void)strcat(path, FILENAME);
               if ((fd = open(p = path, O_RDWR|O_CREAT, 0600)) >= 0)
                       goto dupit;
       }
       (void)fprintf(stderr, "nohup: can't open a nohup.out file.\n");
       exit(1);

dupit:  (void)lseek(fd, 0L, SEEK_END);
       if (dup2(fd, STDOUT_FILENO) == -1) {
               (void)fprintf(stderr, "nohup: %s\n", strerror(errno));
               exit(1);
       }
       (void)fprintf(stderr, "sending output to %s\n", p);
}

usage()
{
       (void)fprintf(stderr, "usage: nohup command\n");
       exit(1);
}