PC-Online 1996 May/PCOnline_05_1996.bin/linux/source/a/bin/fileutil.12/fileutil/fileutils-3.12/src/mknod.c

C/C++ Source or Header | 1994-10-07 | 5.0 KB | 205 lines

/* mknod -- make special files
   Copyright (C) 1990, 1991 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* Usage: mknod [-m mode] [--mode=mode] path {bcu} major minor
        make a block or character device node
          mknod [-m mode] [--mode=mode] path p
        make a FIFO (named pipe)

   Options:
   -m, --mode=mode    Set the mode of created nodes to MODE, which is
            symbolic as in chmod and uses the umask as a point of
            departure.

   David MacKenzie <[e-mail]>  */

#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>
#include "system.h"
#include "modechange.h"
#include "version.h"

void error ();

static void usage ();

/* The name this program was run with. */
char *program_name;

/* If non-zero, display usage information and exit.  */
static int show_help;

/* If non-zero, print the version on standard output and exit.  */
static int show_version;

static struct option const longopts[] =
{
  {"mode", required_argument, NULL, 'm'},
  {"help", no_argument, &show_help, 1},
  {"version", no_argument, &show_version, 1},
  {NULL, 0, NULL, 0}
};

void
main (argc, argv)
     int argc;
     char **argv;
{
  unsigned short newmode;
  struct mode_change *change;
  char *symbolic_mode;
  int optc;

  program_name = argv[0];
  symbolic_mode = NULL;

  while ((optc = getopt_long (argc, argv, "m:", longopts, (int *) 0)) != EOF)
    {
      switch (optc)
    {
    case 0:
      break;
    case 'm':
      symbolic_mode = optarg;
      break;
    default:
      usage (1);
    }
    }

  if (show_version)
    {
      printf ("%s\n", version_string);
      exit (0);
    }

  if (show_help)
    usage (0);

  newmode = 0666 & ~umask (0);
  if (symbolic_mode)
    {
      change = mode_compile (symbolic_mode, 0);
      if (change == MODE_INVALID)
    error (1, 0, "invalid mode");
      else if (change == MODE_MEMORY_EXHAUSTED)
    error (1, 0, "virtual memory exhausted");
      newmode = mode_adjust (newmode, change);
    }

  if (argc - optind != 2 && argc - optind != 4)
    {
      const char *msg;
      if (argc - optind < 2)
    msg = "too few arguments";
      else if (argc - optind > 4)
    msg = "too many arguments";
      else
    msg = "wrong number of arguments";
      error (0, 0, msg);
      usage (1);
    }

  /* Only check the first character, to allow mnemonic usage like
     `mknod /dev/rst0 character 18 0'. */

  switch (argv[optind + 1][0])
    {
    case 'b':            /* `block' or `buffered' */
#ifndef S_IFBLK
      error (4, 0, "block special files not supported");
#else
      if (argc - optind != 4)
    {
      error (0, 0, "\
when creating block special files, major and minor device\n\
numbers must be specified");
      usage (1);
    }
      if (mknod (argv[optind], newmode | S_IFBLK,
         makedev (atoi (argv[optind + 2]), atoi (argv[optind + 3]))))
    error (1, errno, "%s", argv[optind]);
#endif
      break;

    case 'c':            /* `character' */
    case 'u':            /* `unbuffered' */
#ifndef S_IFCHR
      error (4, 0, "character special files not supported");
#else
      if (argc - optind != 4)
    {
      error (0, 0, "\
when creating character special files, major and minor device\n\
numbers must be specified");
      usage (1);
    }
      if (mknod (argv[optind], newmode | S_IFCHR,
         makedev (atoi (argv[optind + 2]), atoi (argv[optind + 3]))))
    error (1, errno, "%s", argv[optind]);
#endif
      break;

    case 'p':            /* `pipe' */
#ifndef S_ISFIFO
      error (4, 0, "fifo files not supported");
#else
      if (argc - optind != 2)
    {
      error (0, 0, "\
major and minor device numbers may not be specified for fifo files");
      usage (1);
    }
      if (mkfifo (argv[optind], newmode))
    error (1, errno, "%s", argv[optind]);
#endif
      break;

    default:
      usage (1);
    }

  exit (0);
}

static void
usage (status)
     int status;
{
  if (status != 0)
    fprintf (stderr, "Try `%s --help' for more information.\n",
         program_name);
  else
    {
      printf ("Usage: %s [OPTION]... PATH TYPE [MAJOR MINOR]\n", program_name);
      printf ("\
\n\
  -m, --mode=MODE   set permission mode (as in chmod), not 0666 - umask\n\
      --help        display this help and exit\n\
      --version     output version information and exit\n\
\n\
MAJOR MINOR are forbidden for TYPE p, mandatory otherwise.  TYPE may be:\n\
\n\
  b      create a block (buffered) special file\n\
  c, u   create a character (unbuffered) special file   \n\
  p      create a FIFO\n");
    }
  exit (status);
}