/* cmd.c - command to cmp an operating system */
/*
 *  VasEBoot  --  GRand Unified Bootloader
 *  Copyright (C) 2003,2005,2006,2007,2009  Free Software Foundation, Inc.
 *
 *  VasEBoot 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  VasEBoot 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 VasEBoot.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <VasEBoot/dl.h>
#include <VasEBoot/misc.h>
#include <VasEBoot/file.h>
#include <VasEBoot/mm.h>
#include <VasEBoot/command.h>
#include <VasEBoot/i18n.h>

VasEBoot_MOD_LICENSE ("GPLv3+");

#define BUFFER_SIZE 512

static VasEBoot_err_t
VasEBoot_cmd_cmp (VasEBoot_command_t cmd __attribute__ ((unused)),
	      int argc, char **args)
{
  VasEBoot_ssize_t rd1, rd2;
  VasEBoot_off_t pos;
  VasEBoot_file_t file1 = 0;
  VasEBoot_file_t file2 = 0;
  char *buf1 = 0;
  char *buf2 = 0;

  if (argc != 2)
    return VasEBoot_error (VasEBoot_ERR_BAD_ARGUMENT, N_("two arguments expected"));

  VasEBoot_printf_ (N_("Compare file `%s' with `%s':\n"), args[0],
		args[1]);

  file1 = VasEBoot_file_open (args[0]);
  file2 = VasEBoot_file_open (args[1]);
  if (! file1 || ! file2)
    goto cleanup;

  if (VasEBoot_file_size (file1) != VasEBoot_file_size (file2))
    VasEBoot_printf_ (N_("Files differ in size: %llu [%s], %llu [%s]\n"),
		  (unsigned long long) VasEBoot_file_size (file1), args[0],
		  (unsigned long long) VasEBoot_file_size (file2), args[1]);
  else
    {
      pos = 0;

      buf1 = VasEBoot_malloc (BUFFER_SIZE);
      buf2 = VasEBoot_malloc (BUFFER_SIZE);

      if (! buf1 || ! buf2)
        goto cleanup;

      do
	{
	  int i;

	  rd1 = VasEBoot_file_read (file1, buf1, BUFFER_SIZE);
	  rd2 = VasEBoot_file_read (file2, buf2, BUFFER_SIZE);

	  if (rd1 != rd2)
	    goto cleanup;

	  for (i = 0; i < rd2; i++)
	    {
	      if (buf1[i] != buf2[i])
		{
		  VasEBoot_printf_ (N_("Files differ at the offset %llu: 0x%x [%s], 0x%x [%s]\n"),
				(unsigned long long) (i + pos), buf1[i],
				args[0], buf2[i], args[1]);
		  goto cleanup;
		}
	    }
	  pos += BUFFER_SIZE;

	}
      while (rd2);

      /* TRANSLATORS: it's always exactly 2 files.  */
      VasEBoot_printf_ (N_("The files are identical.\n"));
    }

cleanup:

  VasEBoot_free (buf1);
  VasEBoot_free (buf2);
  if (file1)
    VasEBoot_file_close (file1);
  if (file2)
    VasEBoot_file_close (file2);

  return VasEBoot_errno;
}

static VasEBoot_command_t cmd;

VasEBoot_MOD_INIT(cmp)
{
  cmd = VasEBoot_register_command ("cmp", VasEBoot_cmd_cmp,
			       N_("FILE1 FILE2"), N_("Compare two files."));
}

VasEBoot_MOD_FINI(cmp)
{
  VasEBoot_unregister_command (cmd);
}