/* mknod -- make special files
   Copyright (C) 1990, 1991, 1995 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 <djm@ai.mit.edu>  */

#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>

#include "system.h"
#include "modechange.h"
#include "version.h"
#include "error.h"
#include "xstrtol.h"

/* 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}
};

static void
usage (int status)
{
  if (status != 0)
    fprintf (stderr, "Try `%s --help' for more information.\n",
	     program_name);
  else
    {
      printf ("Usage: %s [OPTION]... NAME TYPE [MAJOR MINOR]\n", program_name);
      printf ("\
Create the special file NAME of the given TYPE.\n\
\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);
}

void
main (int argc, char **argv)
{
  unsigned short newmode;
  struct mode_change *change;
  char *symbolic_mode;
  int optc;
  int i_major, i_minor;
  long int tmp_major, tmp_minor;
  char *s;

  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 ("mknod - %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);
	}

      s = argv[optind + 2];
      if (xstrtol (s, NULL, 0, &tmp_major, NULL) != LONGINT_OK)
	error (1, 0, "invalid major device number `%s'", s);

      s = argv[optind + 3];
      if (xstrtol (s, NULL, 0, &tmp_minor, NULL) != LONGINT_OK)
	error (1, 0, "invalid minor device number `%s'", s);

      i_major = (int) tmp_major;
      i_minor = (int) tmp_minor;

      if (mknod (argv[optind], newmode | S_IFBLK, makedev (i_major, i_minor)))
	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);
	}

      s = argv[optind + 2];
      if (xstrtol (s, NULL, 0, &tmp_major, NULL) != LONGINT_OK)
	error (1, 0, "invalid major device number `%s'", s);

      s = argv[optind + 3];
      if (xstrtol (s, NULL, 0, &tmp_minor, NULL) != LONGINT_OK)
	error (1, 0, "invalid minor device number `%s'", s);

      i_major = (int) tmp_major;
      i_minor = (int) tmp_minor;

      if (mknod (argv[optind], newmode | S_IFCHR, makedev (i_major, i_minor)))
	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);
}