tar.c

gnu tar 源码包。 tar 软件是 Unix 系统下的一个打包软件

    case WILDCARDS_OPTION:
      args->wildcards = enable_wildcards;
      break;

    case WILDCARDS_MATCH_SLASH_OPTION:
      args->matching_flags &= ~ FNM_FILE_NAME;
      break;

    case NO_RECURSION_OPTION:
      recursion_option = 0;
      break;

    case NO_SAME_OWNER_OPTION:
      same_owner_option = -1;
      break;

    case NO_SAME_PERMISSIONS_OPTION:
      same_permissions_option = -1;
      break;

    case RECURSION_OPTION:
      recursion_option = FNM_LEADING_DIR;
      break;

    case SAME_OWNER_OPTION:
      same_owner_option = 1;
      break;

    case UNQUOTE_OPTION:
      unquote_option = true;
      break;

    case NO_UNQUOTE_OPTION:
      unquote_option = false;
      break;

    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':

#ifdef DEVICE_PREFIX
      {
	int device = key - '0';
	int density;
	static char buf[sizeof DEVICE_PREFIX + 10];
	char *cursor;

	if (arg[1])
	  argp_error (state, _("Malformed density argument: %s"), quote (arg));

	strcpy (buf, DEVICE_PREFIX);
	cursor = buf + strlen (buf);

#ifdef DENSITY_LETTER

	sprintf (cursor, "%d%c", device, arg[0]);

#else /* not DENSITY_LETTER */

	switch (arg[0])
	  {
	  case 'l':
	    device += LOW_DENSITY_NUM;
	    break;

	  case 'm':
	    device += MID_DENSITY_NUM;
	    break;

	  case 'h':
	    device += HIGH_DENSITY_NUM;
	    break;

	  default:
	    argp_error (state, _("Unknown density: `%c'"), arg[0]);
	  }
	sprintf (cursor, "%d", device);

#endif /* not DENSITY_LETTER */

	if (archive_names == allocated_archive_names)
	  archive_name_array = x2nrealloc (archive_name_array,
					   &allocated_archive_names,
					   sizeof (archive_name_array[0]));
	archive_name_array[archive_names++] = xstrdup (buf);
      }
      break;

#else /* not DEVICE_PREFIX */

      argp_error (state,
		  _("Options `-[0-7][lmh]' not supported by *this* tar"));

#endif /* not DEVICE_PREFIX */

    case '?':
      tar_help (state);
      close_stdout ();
      exit (0);

    case USAGE_OPTION:
      argp_state_help (state, state->out_stream, ARGP_HELP_USAGE);
      close_stdout ();
      exit (0);

    case VERSION_OPTION:
      version_etc (state->out_stream, "tar", PACKAGE_NAME, VERSION,
		   "John Gilmore", "Jay Fenlason", (char *) NULL);
      close_stdout ();
      exit (0);

    case HANG_OPTION:
      _argp_hang = atoi (arg ? arg : "3600");
      while (_argp_hang-- > 0)
	sleep (1);
      break;

    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}

static struct argp argp = {
  options,
  parse_opt,
  N_("[FILE]..."),
  doc,
  NULL,
  NULL,
  NULL
};

void
usage (int status)
{
  argp_help (&argp, stderr, ARGP_HELP_SEE, (char*) program_name);
  close_stdout ();
  exit (status);
}

/* Parse the options for tar.  */

static struct argp_option *
find_argp_option (struct argp_option *o, int letter)
{
  for (;
       !(o->name == NULL
	 && o->key == 0
	 && o->arg == 0
	 && o->flags == 0
	 && o->doc == NULL); o++)
    if (o->key == letter)
      return o;
  return NULL;
}

static void
decode_options (int argc, char **argv)
{
  int idx;
  struct tar_args args;

  /* Set some default option values.  */
  args.textual_date = NULL;
  args.wildcards = default_wildcards;
  args.matching_flags = 0;
  args.include_anchored = EXCLUDE_ANCHORED;
  args.o_option = false;
  args.pax_option = false;
  args.backup_suffix_string = getenv ("SIMPLE_BACKUP_SUFFIX");
  args.version_control_string = 0;
  args.input_files = false;
  args.compress_autodetect = false;
  
  subcommand_option = UNKNOWN_SUBCOMMAND;
  archive_format = DEFAULT_FORMAT;
  blocking_factor = DEFAULT_BLOCKING;
  record_size = DEFAULT_BLOCKING * BLOCKSIZE;
  excluded = new_exclude ();
  newer_mtime_option.tv_sec = TYPE_MINIMUM (time_t);
  newer_mtime_option.tv_nsec = -1;
  recursion_option = FNM_LEADING_DIR;
  unquote_option = true;
  tar_sparse_major = 1;
  tar_sparse_minor = 0;

  owner_option = -1;
  group_option = -1;

  check_device_option = true;
  
  /* Convert old-style tar call by exploding option element and rearranging
     options accordingly.  */

  if (argc > 1 && argv[1][0] != '-')
    {
      int new_argc;		/* argc value for rearranged arguments */
      char **new_argv;		/* argv value for rearranged arguments */
      char *const *in;		/* cursor into original argv */
      char **out;		/* cursor into rearranged argv */
      const char *letter;	/* cursor into old option letters */
      char buffer[3];		/* constructed option buffer */

      /* Initialize a constructed option.  */

      buffer[0] = '-';
      buffer[2] = '\0';

      /* Allocate a new argument array, and copy program name in it.  */

      new_argc = argc - 1 + strlen (argv[1]);
      new_argv = xmalloc ((new_argc + 1) * sizeof (char *));
      in = argv;
      out = new_argv;
      *out++ = *in++;

      /* Copy each old letter option as a separate option, and have the
	 corresponding argument moved next to it.  */

      for (letter = *in++; *letter; letter++)
	{
	  struct argp_option *opt;

	  buffer[1] = *letter;
	  *out++ = xstrdup (buffer);
	  opt = find_argp_option (options, *letter);
	  if (opt && opt->arg)
	    {
	      if (in < argv + argc)
		*out++ = *in++;
	      else
		USAGE_ERROR ((0, 0, _("Old option `%c' requires an argument."),
			      *letter));
	    }
	}

      /* Copy all remaining options.  */

      while (in < argv + argc)
	*out++ = *in++;
      *out = 0;

      /* Replace the old option list by the new one.  */

      argc = new_argc;
      argv = new_argv;
    }

  /* Parse all options and non-options as they appear.  */

  prepend_default_options (getenv ("TAR_OPTIONS"), &argc, &argv);

  if (argp_parse (&argp, argc, argv, ARGP_IN_ORDER|ARGP_NO_HELP,
		  &idx, &args))
    exit (TAREXIT_FAILURE);


  /* Special handling for 'o' option:

     GNU tar used to say "output old format".
     UNIX98 tar says don't chown files after extracting (we use
     "--no-same-owner" for this).

     The old GNU tar semantics is retained when used with --create
     option, otherwise UNIX98 semantics is assumed */

  if (args.o_option)
    {
      if (subcommand_option == CREATE_SUBCOMMAND)
	{
	  /* GNU Tar <= 1.13 compatibility */
	  set_archive_format ("v7");
	}
      else
	{
	  /* UNIX98 compatibility */
	  same_owner_option = -1;
	}
    }

  /* Handle operands after any "--" argument.  */
  for (; idx < argc; idx++)
    {
      name_add_name (argv[idx], MAKE_INCL_OPTIONS (&args));
      args.input_files = true;
    }

  /* Warn about implicit use of the wildcards in command line arguments.
     See TODO */
  warn_regex_usage = args.wildcards == default_wildcards;

  /* Derive option values and check option consistency.  */

  if (archive_format == DEFAULT_FORMAT)
    {
      if (args.pax_option)
	archive_format = POSIX_FORMAT;
      else
	archive_format = DEFAULT_ARCHIVE_FORMAT;
    }

  if ((volume_label_option && subcommand_option == CREATE_SUBCOMMAND)
      || incremental_option
      || multi_volume_option
      || sparse_option)
    assert_format (FORMAT_MASK (OLDGNU_FORMAT)
		   | FORMAT_MASK (GNU_FORMAT)
		   | FORMAT_MASK (POSIX_FORMAT));

  if (occurrence_option)
    {
      if (!args.input_files)
	USAGE_ERROR ((0, 0,
		      _("--occurrence is meaningless without a file list")));
      if (subcommand_option != DELETE_SUBCOMMAND
	  && subcommand_option != DIFF_SUBCOMMAND
	  && subcommand_option != EXTRACT_SUBCOMMAND
	  && subcommand_option != LIST_SUBCOMMAND)
	    USAGE_ERROR ((0, 0,
			  _("--occurrence cannot be used in the requested operation mode")));
    }

  if (seekable_archive && subcommand_option == DELETE_SUBCOMMAND)
    {
      /* The current code in delete.c is based on the assumption that
	 skip_member() reads all data from the archive. So, we should
	 make sure it won't use seeks. On the other hand, the same code
	 depends on the ability to backspace a record in the archive,
	 so setting seekable_archive to false is technically incorrect.
         However, it is tested only in skip_member(), so it's not a
	 problem. */
      seekable_archive = false;
    }

  if (archive_names == 0)
    {
      /* If no archive file name given, try TAPE from the environment, or
	 else, DEFAULT_ARCHIVE from the configuration process.  */

      archive_names = 1;
      archive_name_array[0] = getenv ("TAPE");
      if (! archive_name_array[0])
	archive_name_array[0] = DEFAULT_ARCHIVE;
    }

  /* Allow multiple archives only with `-M'.  */

  if (archive_names > 1 && !multi_volume_option)
    USAGE_ERROR ((0, 0,
		  _("Multiple archive files require `-M' option")));

  if (listed_incremental_option
      && NEWER_OPTION_INITIALIZED (newer_mtime_option))
    USAGE_ERROR ((0, 0,
		  _("Cannot combine --listed-incremental with --newer")));

  if (volume_label_option)
    {
      if (archive_format == GNU_FORMAT || archive_format == OLDGNU_FORMAT)
	{
	  size_t volume_label_max_len =
	    (sizeof current_header->header.name
	     - 1 /* for trailing '\0' */
	     - (multi_volume_option
		? (sizeof " Volume "
		   - 1 /* for null at end of " Volume " */
		   + INT_STRLEN_BOUND (int) /* for volume number */
		   - 1 /* for sign, as 0 <= volno */)
		: 0));
	  if (volume_label_max_len < strlen (volume_label_option))
	    USAGE_ERROR ((0, 0,
			  ngettext ("%s: Volume label is too long (limit is %lu byte)",
				    "%s: Volume label is too long (limit is %lu bytes)",
				    volume_label_max_len),
			  quotearg_colon (volume_label_option),
			  (unsigned long) volume_label_max_len));
	}
      /* else FIXME
	 Label length in PAX format is limited by the volume size. */
    }

  if (verify_option)
    {
      if (multi_volume_option)
	USAGE_ERROR ((0, 0, _("Cannot verify multi-volume archives")));
      if (use_compress_program_option)
	USAGE_ERROR ((0, 0, _("Cannot verify compressed archives")));
    }

  if (use_compress_program_option)
    {
      if (multi_volume_option)
	USAGE_ERROR ((0, 0, _("Cannot use multi-volume compressed archives")));
      if (subcommand_option == UPDATE_SUBCOMMAND
	  || subcommand_option == APPEND_SUBCOMMAND
	  || subcommand_option == DELETE_SUBCOMMAND)
	USAGE_ERROR ((0, 0, _("Cannot update compressed archives")));
      if (subcommand_option == CAT_SUBCOMMAND)
	USAGE_ERROR ((0, 0, _("Cannot concatenate compressed archives")));
    }

  /* It is no harm to use --pax-option on non-pax archives in archive
     reading mode. It may even be useful, since it allows to override
     file attributes from tar headers. Therefore I allow such usage.
     --gray */
  if (args.pax_option
      && archive_format != POSIX_FORMAT
      && (subcommand_option != EXTRACT_SUBCOMMAND
	  || subcommand_option != DIFF_SUBCOMMAND
	  || subcommand_option != LIST_SUBCOMMAND))
    USAGE_ERROR ((0, 0, _("--pax-option can be used only on POSIX archives")));

  /* If ready to unlink hierarchies, so we are for simpler files.  */
  if (recursive_unlink_option)
    old_files_option = UNLINK_FIRST_OLD_FILES;


  if (test_label_option)
    {
      /* --test-label is silent if the user has specified the label name to
	 compare against. */
      if (!args.input_files)
	verbose_option++;
    }
  else if (utc_option)
    verbose_option = 2;

  /* Forbid using -c with no input files whatsoever.  Check that `-f -',
     explicit or implied, is used correctly.  */

  switch (subcommand_option)
    {
    case CREATE_SUBCOMMAND:
      if (!args.input_files && !files_from_option)
	USAGE_ERROR ((0, 0,
		      _("Cowardly refusing to create an empty archive")));
      if (args.compress_autodetect && archive_names
	  && strcmp (archive_name_array[0], "-"))
	set_comression_program_by_suffix (archive_name_array[0],
					  use_compress_program_option);
      break;

    case EXTRACT_SUBCOMMAND:
    case LIST_SUBCOMMAND:
    case DIFF_SUBCOMMAND:
      for (archive_name_cursor = archive_name_array;
	   archive_name_cursor < archive_name_array + archive_names;
	   archive_name_cursor++)
	if (!strcmp (*archive_name_cursor, "-"))
	  request_stdin ("-f");
      break;

    case CAT_SUBCOMMAND:
    case UPDATE_SUBCOMMAND:
    case APPEND_SUBCOMMAND:
      for (archive_name_cursor = archive_name_array;
	   archive_name_cursor < archive_name_array + archive_names;
	   archive_name_cursor++)
	if (!strcmp (*archive_name_cursor, "-"))
	  USAGE_ERROR ((0, 0,
			_("Options `-Aru' are incompatible with `-f -'")))