names.c

gnu tar 源码包。 tar 软件是 Unix 系统下的一个打包软件

	{
	  chdir_do (cursor->change_dir);
	  namelist = 0;
	  nametail = &namelist;
	  return true;
	}

      cursor = namelist_match (file_name, length);
      if (cursor)
	{
	  if (!(ISSLASH (file_name[cursor->length]) && recursion_option)
	      || cursor->found_count == 0)
	    cursor->found_count++; /* remember it matched */
	  if (starting_file_option)
	    {
	      free (namelist);
	      namelist = 0;
	      nametail = &namelist;
	    }
	  chdir_do (cursor->change_dir);

	  /* We got a match.  */
	  return ISFOUND (cursor);
	}

      /* Filename from archive not found in namelist.  If we have the whole
	 namelist here, just return 0.  Otherwise, read the next name in and
	 compare it.  If this was the last name, namelist->found_count will
	 remain on.  If not, we loop to compare the newly read name.  */

      if (same_order_option && namelist->found_count)
	{
	  name_gather ();	/* read one more */
	  if (namelist->found_count)
	    return false;
	}
      else
	return false;
    }
}

/* Returns true if all names from the namelist were processed.
   P is the stat_info of the most recently processed entry.
   The decision is postponed until the next entry is read if:

   1) P ended with a slash (i.e. it was a directory)
   2) P matches any entry from the namelist *and* represents a subdirectory
   or a file lying under this entry (in the terms of directory structure).

   This is necessary to handle contents of directories. */
bool
all_names_found (struct tar_stat_info *p)
{
  struct name const *cursor;
  size_t len;

  if (test_label_option)
    return true;
  if (!p->file_name || occurrence_option == 0 || p->had_trailing_slash)
    return false;
  len = strlen (p->file_name);
  for (cursor = namelist; cursor; cursor = cursor->next)
    {
      if ((cursor->name[0] && !WASFOUND (cursor))
	  || (len >= cursor->length && ISSLASH (p->file_name[cursor->length])))
	return false;
    }
  return true;
}

static inline int
is_pattern (const char *string)
{
  return strchr (string, '*') || strchr (string, '[') || strchr (string, '?');
}

static void
regex_usage_warning (const char *name)
{
  static int warned_once = 0;

  if (warn_regex_usage && is_pattern (name))
    {
      warned_once = 1;
      WARN ((0, 0,
	     /* TRANSLATORS: The following three msgids form a single sentence.
	      */
	     _("Pattern matching characters used in file names. Please,")));
      WARN ((0, 0,
	     _("use --wildcards to enable pattern matching, or --no-wildcards to")));
      WARN ((0, 0,
	     _("suppress this warning.")));
    }
}

/* Print the names of things in the namelist that were not matched.  */
void
names_notfound (void)
{
  struct name const *cursor;

  for (cursor = namelist; cursor; cursor = cursor->next)
    if (!WASFOUND (cursor) && cursor->name[0])
      {
	regex_usage_warning (cursor->name);
	if (cursor->found_count == 0)
	  ERROR ((0, 0, _("%s: Not found in archive"),
		  quotearg_colon (cursor->name)));
	else
	  ERROR ((0, 0, _("%s: Required occurrence not found in archive"),
		  quotearg_colon (cursor->name)));  
      }

  /* Don't bother freeing the name list; we're about to exit.  */
  namelist = 0;
  nametail = &namelist;

  if (same_order_option)
    {
      const char *name;

      while ((name = name_next (1)) != NULL)
	{
	  regex_usage_warning (name);
	  ERROR ((0, 0, _("%s: Not found in archive"),
		  quotearg_colon (name)));
	}
    }
}

/* Sorting name lists.  */

/* Sort linked LIST of names, of given LENGTH, using COMPARE to order
   names.  Return the sorted list.  Apart from the type `struct name'
   and the definition of SUCCESSOR, this is a generic list-sorting
   function, but it's too painful to make it both generic and portable
   in C.  */

static struct name *
merge_sort (struct name *list, int length,
	    int (*compare) (struct name const*, struct name const*))
{
  struct name *first_list;
  struct name *second_list;
  int first_length;
  int second_length;
  struct name *result;
  struct name **merge_point;
  struct name *cursor;
  int counter;

# define SUCCESSOR(name) ((name)->next)

  if (length == 1)
    return list;

  if (length == 2)
    {
      if ((*compare) (list, SUCCESSOR (list)) > 0)
	{
	  result = SUCCESSOR (list);
	  SUCCESSOR (result) = list;
	  SUCCESSOR (list) = 0;
	  return result;
	}
      return list;
    }

  first_list = list;
  first_length = (length + 1) / 2;
  second_length = length / 2;
  for (cursor = list, counter = first_length - 1;
       counter;
       cursor = SUCCESSOR (cursor), counter--)
    continue;
  second_list = SUCCESSOR (cursor);
  SUCCESSOR (cursor) = 0;

  first_list = merge_sort (first_list, first_length, compare);
  second_list = merge_sort (second_list, second_length, compare);

  merge_point = &result;
  while (first_list && second_list)
    if ((*compare) (first_list, second_list) < 0)
      {
	cursor = SUCCESSOR (first_list);
	*merge_point = first_list;
	merge_point = &SUCCESSOR (first_list);
	first_list = cursor;
      }
    else
      {
	cursor = SUCCESSOR (second_list);
	*merge_point = second_list;
	merge_point = &SUCCESSOR (second_list);
	second_list = cursor;
      }
  if (first_list)
    *merge_point = first_list;
  else
    *merge_point = second_list;

  return result;

#undef SUCCESSOR
}

/* A comparison function for sorting names.  Put found names last;
   break ties by string comparison.  */

static int
compare_names (struct name const *n1, struct name const *n2)
{
  int found_diff = WASFOUND(n2) - WASFOUND(n1);
  return found_diff ? found_diff : strcmp (n1->name, n2->name);
}

/* Add all the dirs under NAME, which names a directory, to the namelist.
   If any of the files is a directory, recurse on the subdirectory.
   DEVICE is the device not to leave, if the -l option is specified.  */

static void
add_hierarchy_to_namelist (struct name *name, dev_t device)
{
  char *file_name = name->name;
  const char *buffer = get_directory_contents (file_name, device);

  if (! buffer)
    name->dir_contents = "\0\0\0\0";
  else
    {
      size_t name_length = name->length;
      size_t allocated_length = (name_length >= NAME_FIELD_SIZE
				 ? name_length + NAME_FIELD_SIZE
				 : NAME_FIELD_SIZE);
      char *namebuf = xmalloc (allocated_length + 1);
				/* FIXME: + 2 above?  */
      const char *string;
      size_t string_length;
      int change_dir = name->change_dir;

      name->dir_contents = buffer;
      strcpy (namebuf, file_name);
      if (! ISSLASH (namebuf[name_length - 1]))
	{
	  namebuf[name_length++] = '/';
	  namebuf[name_length] = '\0';
	}

      for (string = buffer; *string; string += string_length + 1)
	{
	  string_length = strlen (string);
	  if (*string == 'D')
	    {
	      struct name *np;

	      if (allocated_length <= name_length + string_length)
		{
		  do
		    {
		      allocated_length *= 2;
		      if (! allocated_length)
			xalloc_die ();
		    }
		  while (allocated_length <= name_length + string_length);

		  namebuf = xrealloc (namebuf, allocated_length + 1);
		}
	      strcpy (namebuf + name_length, string + 1);
	      np = addname (namebuf, change_dir);
	      add_hierarchy_to_namelist (np, device);
	    }
	}

      free (namebuf);
    }
}

/* Collect all the names from argv[] (or whatever), expand them into a
   directory tree, and sort them.  This gets only subdirectories, not
   all files.  */

void
collect_and_sort_names (void)
{
  struct name *name;
  struct name *next_name;
  int num_names;
  struct stat statbuf;

  name_gather ();

  if (listed_incremental_option)
    read_directory_file ();

  if (!namelist)
    addname (".", 0);

  for (name = namelist; name; name = next_name)
    {
      next_name = name->next;
      if (name->found_count || name->dir_contents)
	continue;
      if (name->matching_flags & EXCLUDE_WILDCARDS)
	/* NOTE: EXCLUDE_ANCHORED is not relevant here */
	/* FIXME: just skip regexps for now */
	continue;
      chdir_do (name->change_dir);
      if (name->name[0] == 0)
	continue;

      if (deref_stat (dereference_option, name->name, &statbuf) != 0)
	{
	  stat_diag (name->name);
	  continue;
	}
      if (S_ISDIR (statbuf.st_mode))
	{
	  name->found_count++;
	  add_hierarchy_to_namelist (name, statbuf.st_dev);
	}
    }

  num_names = 0;
  for (name = namelist; name; name = name->next)
    num_names++;
  namelist = merge_sort (namelist, num_names, compare_names);

  for (name = namelist; name; name = name->next)
    name->found_count = 0;

  if (listed_incremental_option)
    {
      for (name = namelist; name && name->name[0] == 0; name++)
	;
      if (name)
	name->dir_contents = append_incremental_renames (name->dir_contents);
    }
}

/* This is like name_match, except that
    1. It returns a pointer to the name it matched, and doesn't set FOUND
    in structure. The caller will have to do that if it wants to.
    2. If the namelist is empty, it returns null, unlike name_match, which
    returns TRUE. */
struct name *
name_scan (const char *file_name)
{
  size_t length = strlen (file_name);

  while (1)
    {
      struct name *cursor = namelist_match (file_name, length);
      if (cursor)
	return cursor;

      /* Filename from archive not found in namelist.  If we have the whole
	 namelist here, just return 0.  Otherwise, read the next name in and
	 compare it.  If this was the last name, namelist->found_count will
	 remain on.  If not, we loop to compare the newly read name.  */

      if (same_order_option && namelist && namelist->found_count)
	{
	  name_gather ();	/* read one more */
	  if (namelist->found_count)
	    return 0;
	}
      else
	return 0;
    }
}

/* This returns a name from the namelist which doesn't have ->found
   set.  It sets ->found before returning, so successive calls will
   find and return all the non-found names in the namelist.  */
struct name *gnu_list_name;

char *
name_from_list (void)
{
  if (!gnu_list_name)
    gnu_list_name = namelist;
  while (gnu_list_name
	 && (gnu_list_name->found_count || gnu_list_name->name[0] == 0))
    gnu_list_name = gnu_list_name->next;
  if (gnu_list_name)
    {
      gnu_list_name->found_count++;
      chdir_do (gnu_list_name->change_dir);
      return gnu_list_name->name;
    }
  return 0;
}

void
blank_name_list (void)
{
  struct name *name;

  gnu_list_name = 0;
  for (name = namelist; name; name = name->next)
    name->found_count = 0;
}

/* Yield a newly allocated file name consisting of FILE_NAME concatenated to
   NAME, with an intervening slash if FILE_NAME does not already end in one. */
char *
new_name (const char *file_name, const char *name)
{
  size_t file_name_len = strlen (file_name);
  size_t namesize = strlen (name) + 1;
  int slash = file_name_len && ! ISSLASH (file_name[file_name_len - 1]);
  char *buffer = xmalloc (file_name_len + slash + namesize);
  memcpy (buffer, file_name, file_name_len);
  buffer[file_name_len] = '/';
  memcpy (buffer + file_name_len + slash, name, namesize);
  return buffer;
}

/* Return nonzero if file NAME is excluded.  */
bool
excluded_name (char const *name)
{
  return excluded_file_name (excluded, name + FILE_SYSTEM_PREFIX_LEN (name));
}

/* Names to avoid dumping.  */
static Hash_table *avoided_name_table;

/* Remember to not archive NAME.  */
void
add_avoided_name (char const *name)
{
  hash_string_insert (&avoided_name_table, name);
}

/* Should NAME be avoided when archiving?  */
bool
is_avoided_name (char const *name)
{
  return hash_string_lookup (avoided_name_table, name);
}


static Hash_table *individual_file_table;

static void
register_individual_file (char const *name)
{
  struct stat st;

  if (deref_stat (dereference_option, name, &st) != 0)
    return; /* Will be complained about later */
  if (S_ISDIR (st.st_mode))
    return;

  hash_string_insert (&individual_file_table, name);
}

bool
is_individual_file (char const *name)
{
  return hash_string_lookup (individual_file_table, name);
}



/* Return the size of the prefix of FILE_NAME that is removed after
   stripping NUM leading file name components.  NUM must be
   positive.  */

size_t
stripped_prefix_len (char const *file_name, size_t num)
{
  char const *p = file_name + FILE_SYSTEM_PREFIX_LEN (file_name);
  while (ISSLASH (*p))
    p++;
  while (*p)
    {
      bool slash = ISSLASH (*p);
      p++;
      if (slash)
	{
	  if (--num == 0)
	    return p - file_name;
	  while (ISSLASH (*p))
	    p++;
	}
    }
  return -1;
}

/* Return nonzero if NAME contains ".." as a file name component.  */
bool
contains_dot_dot (char const *name)
{
  char const *p = name + FILE_SYSTEM_PREFIX_LEN (name);

  for (;; p++)
    {
      if (p[0] == '.' && p[1] == '.' && (ISSLASH (p[2]) || !p[2]))
	return 1;

      while (! ISSLASH (*p))
	{
	  if (! *p++)
	    return 0;
	}
    }
}