bin/notty/notty.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  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
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/bin/notty/notty.c,v 1.2 2008/06/24 21:13:26 thomas Exp $
  35  */
  36 /*
  37  * NOTTY.C - program to disconnect a program from the tty and close
  38  *           stdin, stdout, and stderr (-012 to specify which descriptors
  39  *           to leave open).
  40  *
  41  * NOTTY [-012] <command>
  42  */
  43
  44 #include <sys/types.h>
  45 #include <sys/ioctl.h>
  46 #include <sys/time.h>
  47 #include <sys/wait.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <stdarg.h>
  52 #include <fcntl.h>
  53 #include <signal.h>
  54 #include <unistd.h>
  55
  56 static void usage(void);
  57
  58 int
  59 main(int ac, char **av)
  60 {
  61         const char *opts = "";
  62         int ttyfd;
  63         int fd;
  64
  65         if (ac == 1)
  66                 usage();
  67
  68         if (av[1]) {
  69                 if (av[1][0] == '-') {
  70                         opts = av[1];
  71                         ++av;
  72                 }
  73         }
  74
  75
  76         ttyfd = open("/dev/null", O_RDWR);
  77
  78         if (strchr(opts, '0') == NULL && ttyfd != 0)
  79                 dup2(ttyfd, 0);
  80         if (strchr(opts, '1') == NULL && ttyfd != 1)
  81                 dup2(ttyfd, 1);
  82         if (strchr(opts, '2') == NULL && ttyfd != 2)
  83                 dup2(ttyfd, 2);
  84
  85         if (ttyfd > 2)
  86                 close(ttyfd);
  87
  88         fd = open("/dev/tty", O_RDWR);
  89         if (fd >= 0) {
  90                 ioctl(fd, TIOCNOTTY, 0);
  91                 close(fd);
  92         }
  93
  94         if (fork() == 0) {
  95                 setsid();
  96                 exit(execvp(av[1], av + 1));
  97         }
  98         exit(0);
  99 }
 100
 101 static void
 102 usage(void)
 103 {
 104         fprintf(stderr, "notty [-012] command args ...\n");
 105         exit(1);
 106 }
 107