du.c

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/* Print N_BLOCKS followed by STRING on a line.  NBLOCKS is the number of
   ST_NBLOCKSIZE-byte blocks; convert it to OUTPUT_BLOCK_SIZE units before
   printing.  If OUTPUT_BLOCK_SIZE is negative, use a human readable
   notation instead.  */

static void
print_size (uintmax_t n_blocks, const char *string)
{
  char buf[LONGEST_HUMAN_READABLE + 1];
  printf ("%s\t%s\n",
	  human_readable_inexact (n_blocks, buf, ST_NBLOCKSIZE,
				  output_block_size, human_ceiling),
	  string);
  fflush (stdout);
}

/* Restore the previous working directory or exit.
   If CWD is null, simply call `chdir ("..")'.  Otherwise,
   use CWD and free it.  CURR_DIR_NAME is the name of the current directory
   and is used solely in failure diagnostics.  */

static void
pop_dir (struct saved_cwd *cwd, const char *curr_dir_name)
{
  if (cwd)
    {
      if (restore_cwd (cwd, "..", curr_dir_name))
	exit (1);
      free_cwd (cwd);
    }
  else if (chdir ("..") < 0)
    {
      error (1, errno, _("cannot change to `..' from directory %s"),
	     quote (curr_dir_name));
    }
}

/* Print (if appropriate) the size (in units determined by `output_block_size')
   of file or directory ENT. Return the size of ENT in units of 512-byte
   blocks.  TOP is one for external calls, zero for recursive calls.
   LAST_DEV is the device that the parent directory of ENT is on.
   DEPTH is the number of levels (in hierarchy) down from a command
   line argument.  Don't print if DEPTH > max_depth.
   An important invariant is that when this function returns, the current
   working directory is the same as when it was called.  */

static uintmax_t
count_entry (const char *ent, int top, dev_t last_dev, int depth)
{
  uintmax_t size;
  struct stat stat_buf;

  if (((top && opt_dereference_arguments)
       ? stat (ent, &stat_buf)
       : (*xstat) (ent, &stat_buf)) < 0)
    {
      error (0, errno, "%s", quote (path->text));
      exit_status = 1;
      return 0;
    }

  if (!opt_count_all
      && stat_buf.st_nlink > 1
      && hash_ins (stat_buf.st_ino, stat_buf.st_dev))
    return 0;			/* Have counted this already.  */

  size = ST_NBLOCKS (stat_buf);
  tot_size += size;

  if (S_ISDIR (stat_buf.st_mode))
    {
      unsigned pathlen;
      dev_t dir_dev;
      char *name_space;
      char *namep;
      struct saved_cwd *cwd;
      struct saved_cwd cwd_buf;
      struct stat e_buf;

      dir_dev = stat_buf.st_dev;

      /* Return `0' here, not SIZE, since the SIZE bytes
	 would reside in the new filesystem.  */
      if (opt_one_file_system && !top && last_dev != dir_dev)
	return 0;		/* Don't enter a new file system.  */

#ifndef S_ISLNK
# define S_ISLNK(s) 0
#endif
      /* If we're traversing more than one level, or if we're
	 dereferencing symlinks and we're about to chdir through a
	 symlink, remember the current directory so we can return to
	 it later.  In other cases, chdir ("..") works fine.
	 Treat `.' and `..' like multi-level paths, since `chdir ("..")'
	 wont't restore the current working directory after a `chdir'
	 to one of those.  */
      if (strchr (ent, '/')
	  || DOT_OR_DOTDOT (ent)
	  || (xstat == stat
	      && lstat (ent, &e_buf) == 0
	      && S_ISLNK (e_buf.st_mode)))
	{
	  if (save_cwd (&cwd_buf))
	    exit (1);
	  cwd = &cwd_buf;
	}
      else
	cwd = NULL;

      if (chdir (ent) < 0)
	{
	  error (0, errno, _("cannot change to directory %s"),
		 quote (path->text));
	  if (cwd)
	    free_cwd (cwd);
	  exit_status = 1;
	  /* Do return SIZE, here, since even though we can't chdir into ENT,
	     we *can* count the blocks used by its directory entry.  */
	  return opt_separate_dirs ? 0 : size;
	}

      name_space = savedir (".");
      if (name_space == NULL)
	{
	  error (0, errno, "%s", quote (path->text));
	  pop_dir (cwd, path->text);
	  exit_status = 1;
	  /* Do count the SIZE bytes.  */
	  return opt_separate_dirs ? 0 : size;
	}

      /* Remember the current path.  */

      str_concatc (path, "/");
      pathlen = path->length;

      for (namep = name_space; *namep; namep += strlen (namep) + 1)
	{
	  if (!excluded_filename (exclude, namep))
	    {
	      str_concatc (path, namep);
	      size += count_entry (namep, 0, dir_dev, depth + 1);
	      str_trunc (path, pathlen);
	    }
	}

      free (name_space);
      pop_dir (cwd, path->text);

      str_trunc (path, pathlen - 1); /* Remove the "/" we added.  */
      if (depth <= max_depth || top)
	print_size (size, path->length > 0 ? path->text : "/");
      return opt_separate_dirs ? 0 : size;
    }
  else if ((opt_all && depth <= max_depth) || top)
    {
      /* FIXME: make this an option.  */
      int print_only_dir_size = 0;
      if (!print_only_dir_size)
	print_size (size, path->length > 0 ? path->text : "/");
    }

  return size;
}

/* Recursively print the sizes of the directories (and, if selected, files)
   named in FILES, the last entry of which is NULL.  */

static void
du_files (char **files)
{
  int i;			/* Index in FILES. */

  for (i = 0; files[i]; i++)
    {
      char *arg;
      int s;

      arg = files[i];

      /* Delete final slash in the argument, unless the slash is alone.  */
      s = strlen (arg) - 1;
      if (s != 0)
	{
	  if (arg[s] == '/')
	    arg[s] = 0;

	  str_copyc (path, arg);
	}
      else if (arg[0] == '/')
	str_trunc (path, 0);	/* Null path for root directory.  */
      else
	str_copyc (path, arg);

      if (!print_totals)
	hash_clear (htab);

      count_entry (arg, 1, 0, 0);
    }

  if (print_totals)
    print_size (tot_size, _("total"));
}

int
main (int argc, char **argv)
{
  int c;
  char *cwd_only[2];
  int max_depth_specified = 0;

  /* If nonzero, display only a total for each argument. */
  int opt_summarize_only = 0;

  cwd_only[0] = ".";
  cwd_only[1] = NULL;

  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  exclude = new_exclude ();
  xstat = lstat;

  human_block_size (getenv ("DU_BLOCK_SIZE"), 0, &output_block_size);

  while ((c = getopt_long (argc, argv, "abchHklmsxB:DLSX:", long_options, NULL))
	 != -1)
    {
      long int tmp_long;
      switch (c)
	{
	case 0:			/* Long option. */
	  break;

	case 'a':
	  opt_all = 1;
	  break;

	case 'b':
	  output_block_size = 1;
	  break;

	case 'c':
	  print_totals = 1;
	  break;

	case 'h':
	  output_block_size = -1024;
	  break;

	case 'H':
	  output_block_size = -1000;
	  break;

	case 'k':
	  output_block_size = 1024;
	  break;

	case MAX_DEPTH_OPTION:		/* --max-depth=N */
	  if (xstrtol (optarg, NULL, 0, &tmp_long, NULL) != LONGINT_OK
	      || tmp_long < 0 || tmp_long > INT_MAX)
	    error (1, 0, _("invalid maximum depth %s"), quote (optarg));

	  max_depth_specified = 1;
	  max_depth = (int) tmp_long;
 	  break;

	case 'm': /* obsolescent */
	  output_block_size = 1024 * 1024;
	  break;

	case 'l':
	  opt_count_all = 1;
	  break;

	case 's':
	  opt_summarize_only = 1;
	  break;

	case 'x':
	  opt_one_file_system = 1;
	  break;

	case 'B':
	  human_block_size (optarg, 1, &output_block_size);
	  break;

	case 'D':
	  opt_dereference_arguments = 1;
	  break;

	case 'L':
	  xstat = stat;
	  break;

	case 'S':
	  opt_separate_dirs = 1;
	  break;

	case 'X':
	  if (add_exclude_file (add_exclude, exclude, optarg,
				EXCLUDE_WILDCARDS, '\n'))
	    error (1, errno, "%s", quote (optarg));
	  break;

	case EXCLUDE_OPTION:
	  add_exclude (exclude, optarg, EXCLUDE_WILDCARDS);
	  break;

	case_GETOPT_HELP_CHAR;

	case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);

	default:
	  usage (1);
	}
    }

  if (opt_all && opt_summarize_only)
    {
      error (0, 0, _("cannot both summarize and show all entries"));
      usage (1);
    }

  if (opt_summarize_only && max_depth_specified && max_depth == 0)
    {
      error (0, 0,
	     _("warning: summarizing is the same as using --max-depth=0"));
    }

  if (opt_summarize_only && max_depth_specified && max_depth != 0)
    {
      error (0, 0,
	     _("warning: summarizing conflicts with --max-depth=%d"),
	       max_depth);
      usage (1);
    }

  if (opt_summarize_only)
    max_depth = 0;

  /* Initialize the hash structure for inode numbers.  */
  hash_init ();

  str_init (&path, INITIAL_PATH_SIZE);

  du_files (optind == argc ? cwd_only : argv + optind);

  exit (exit_status);
}