ls.c

Linux.Programming.by example 的源代码绝对经典

	case 2:		/* Second label character */
	  if (*p)
	    {
	      label[1] = *(p++);
	      state = 3;
	    }
	  else
	    state = -1;	/* Error */
	  break;

	case 3:		/* Equal sign after indicator label */
	  state = -1;	/* Assume failure... */
	  if (*(p++) == '=')/* It *should* be... */
	    {
	      for (ind_no = 0; indicator_name[ind_no] != NULL; ++ind_no)
		{
		  if (STREQ (label, indicator_name[ind_no]))
		    {
		      color_indicator[ind_no].string = buf;
		      state = ((color_indicator[ind_no].len =
				get_funky_string (&buf, &p, 0)) < 0 ? -1 : 1);
		      break;
		    }
		}
	      if (state == -1)
		error (0, 0, _("unrecognized prefix: %s"), quotearg (label));
	    }
	 break;

	case 4:		/* Equal sign after *.ext */
	  if (*(p++) == '=')
	    {
	      ext->seq.string = buf;
	      state = (ext->seq.len =
		       get_funky_string (&buf, &p, 0)) < 0 ? -1 : 1;
	    }
	  else
	    state = -1;
	  break;
	}
    }

  if (state < 0)
    {
      struct color_ext_type *e;
      struct color_ext_type *e2;

      error (0, 0,
	     _("unparsable value for LS_COLORS environment variable"));
      free (color_buf);
      for (e = color_ext_list; e != NULL; /* empty */)
	{
	  e2 = e;
	  e = e->next;
	  free (e2);
	}
      print_with_color = 0;
    }

  if (color_indicator[C_LINK].len == 6
      && !strncmp (color_indicator[C_LINK].string, "target", 6))
    color_symlink_as_referent = 1;
}

/* Request that the directory named NAME have its contents listed later.
   If REALNAME is nonzero, it will be used instead of NAME when the
   directory name is printed.  This allows symbolic links to directories
   to be treated as regular directories but still be listed under their
   real names.  NAME == NULL is used to insert a marker entry for the
   directory named in REALNAME.
   If F is non-NULL, we use its dev/ino information to save
   a call to stat -- when doing a recursive (-R) traversal.  */

static void
queue_directory (const char *name, const char *realname)
{
  struct pending *new;

  new = XMALLOC (struct pending, 1);
  new->realname = realname ? xstrdup (realname) : NULL;
  new->name = name ? xstrdup (name) : NULL;
  new->next = pending_dirs;
  pending_dirs = new;
}

/* Read directory `name', and list the files in it.
   If `realname' is nonzero, print its name instead of `name';
   this is used for symbolic links to directories. */

static void
print_dir (const char *name, const char *realname)
{
  register DIR *dirp;
  register struct dirent *next;
  register uintmax_t total_blocks = 0;
  static int first = 1;

  errno = 0;
  dirp = opendir (name);
  if (!dirp)
    {
      error (0, errno, "%s", quotearg_colon (name));
      exit_status = 1;
      return;
    }

  if (LOOP_DETECT)
    {
      struct stat dir_stat;
      int fd = dirfd (dirp);

      /* If dirfd failed, endure the overhead of using stat.  */
      if ((0 <= fd
	   ? fstat (fd, &dir_stat)
	   : stat (name, &dir_stat)) < 0)
	{
	  error (0, errno, _("cannot determine device and inode of %s"),
		 quotearg_colon (name));
	  exit_status = 1;
	  return;
	}

      /* If we've already visited this dev/inode pair, warn that
	 we've found a loop, and do not process this directory.  */
      if (visit_dir (dir_stat.st_dev, dir_stat.st_ino))
	{
	  error (0, 0, _("not listing already-listed directory: %s"),
		 quotearg_colon (name));
	  return;
	}

      DEV_INO_PUSH (dir_stat.st_dev, dir_stat.st_ino);
    }

  /* Read the directory entries, and insert the subfiles into the `files'
     table.  */

  clear_files ();

  while (1)
    {
      /* Set errno to zero so we can distinguish between a readdir failure
	 and when readdir simply finds that there are no more entries.  */
      errno = 0;
      if ((next = readdir (dirp)) == NULL)
	{
	  if (errno)
	    {
	      /* Save/restore errno across closedir call.  */
	      int e = errno;
	      closedir (dirp);
	      errno = e;

	      /* Arrange to give a diagnostic after exiting this loop.  */
	      dirp = NULL;
	    }
	  break;
	}

      if (file_interesting (next))
	{
	  enum filetype type = unknown;

#if HAVE_STRUCT_DIRENT_D_TYPE
	  if (next->d_type == DT_BLK
	      || next->d_type == DT_CHR
	      || next->d_type == DT_DIR
	      || next->d_type == DT_FIFO
	      || next->d_type == DT_LNK
	      || next->d_type == DT_REG
	      || next->d_type == DT_SOCK)
	    type = next->d_type;
#endif
	  total_blocks += gobble_file (next->d_name, type, 0, name);
	}
    }

  if (dirp == NULL || CLOSEDIR (dirp))
    {
      error (0, errno, _("reading directory %s"), quotearg_colon (name));
      exit_status = 1;
      /* Don't return; print whatever we got. */
    }

  /* Sort the directory contents.  */
  sort_files ();

  /* If any member files are subdirectories, perhaps they should have their
     contents listed rather than being mentioned here as files.  */

  if (recursive)
    extract_dirs_from_files (name, 1);

  if (recursive || print_dir_name)
    {
      if (!first)
	DIRED_PUTCHAR ('\n');
      first = 0;
      DIRED_INDENT ();
      PUSH_CURRENT_DIRED_POS (&subdired_obstack);
      dired_pos += quote_name (stdout, realname ? realname : name,
			       dirname_quoting_options, NULL);
      PUSH_CURRENT_DIRED_POS (&subdired_obstack);
      DIRED_FPUTS_LITERAL (":\n", stdout);
    }

  if (format == long_format || print_block_size)
    {
      const char *p;
      char buf[LONGEST_HUMAN_READABLE + 1];

      DIRED_INDENT ();
      p = _("total");
      DIRED_FPUTS (p, stdout, strlen (p));
      DIRED_PUTCHAR (' ');
      p = human_readable (total_blocks, buf, human_output_opts,
			  ST_NBLOCKSIZE, output_block_size);
      DIRED_FPUTS (p, stdout, strlen (p));
      DIRED_PUTCHAR ('\n');
    }

  if (files_index)
    print_current_files ();
}

/* Add `pattern' to the list of patterns for which files that match are
   not listed.  */

static void
add_ignore_pattern (const char *pattern)
{
  register struct ignore_pattern *ignore;

  ignore = XMALLOC (struct ignore_pattern, 1);
  ignore->pattern = pattern;
  /* Add it to the head of the linked list. */
  ignore->next = ignore_patterns;
  ignore_patterns = ignore;
}

/* Return nonzero if the file in `next' should be listed. */

static int
file_interesting (const struct dirent *next)
{
  register struct ignore_pattern *ignore;

  for (ignore = ignore_patterns; ignore; ignore = ignore->next)
    if (fnmatch (ignore->pattern, next->d_name, FNM_PERIOD) == 0)
      return 0;

  if (really_all_files
      || next->d_name[0] != '.'
      || (all_files
	  && next->d_name[1] != '\0'
	  && (next->d_name[1] != '.' || next->d_name[2] != '\0')))
    return 1;

  return 0;
}

/* Enter and remove entries in the table `files'.  */

/* Empty the table of files. */

static void
clear_files (void)
{
  register int i;

  for (i = 0; i < files_index; i++)
    {
      free (files[i].name);
      if (files[i].linkname)
	free (files[i].linkname);
    }

  files_index = 0;
  block_size_size = 4;
}

/* Add a file to the current table of files.
   Verify that the file exists, and print an error message if it does not.
   Return the number of blocks that the file occupies.  */

static uintmax_t
gobble_file (const char *name, enum filetype type, int explicit_arg,
	     const char *dirname)
{
  register uintmax_t blocks;
  register char *path;

  if (files_index == nfiles)
    {
      nfiles *= 2;
      files = XREALLOC (files, struct fileinfo, nfiles);
    }

  files[files_index].linkname = 0;
  files[files_index].linkmode = 0;
  files[files_index].linkok = 0;

  if (explicit_arg
      || format_needs_stat
      || (format_needs_type
	  && (type == unknown

	      /* FIXME: remove this disjunct.
		 I don't think we care about symlinks here, but for now
		 this won't make a big performance difference.  */
	      || type == symbolic_link

	      /* --indicator-style=classify (aka -F)
		 requires that we stat each regular file
		 to see if it's executable.  */
	      || (type == normal && (indicator_style == classify
				     /* This is so that --color ends up
					highlighting files with the executable
					bit set even when options like -F are
					not specified.  */
				     || print_with_color)))))

    {
      /* `path' is the absolute pathname of this file. */
      int err;

      if (name[0] == '/' || dirname[0] == 0)
	path = (char *) name;
      else
	{
	  path = (char *) alloca (strlen (name) + strlen (dirname) + 2);
	  attach (path, dirname, name);
	}

      switch (dereference)
	{
	case DEREF_ALWAYS:
	  err = stat (path, &files[files_index].stat);
	  break;

	case DEREF_COMMAND_LINE_ARGUMENTS:
	case DEREF_COMMAND_LINE_SYMLINK_TO_DIR:
	  if (explicit_arg)
	    {
	      int need_lstat;
	      err = stat (path, &files[files_index].stat);

	      if (dereference == DEREF_COMMAND_LINE_ARGUMENTS)
		break;

	      need_lstat = (err < 0
			    ? errno == ENOENT
			    : ! S_ISDIR (files[files_index].stat.st_mode));
	      if (!need_lstat)
		break;

	      /* stat failed because of ENOENT, maybe indicating a dangling
		 symlink.  Or stat succeeded, PATH does not refer to a
		 directory, and --dereference-command-line-symlink-to-dir is
		 in effect.  Fall through so that we call lstat instead.  */
	    }

	default: /* DEREF_NEVER */
	  err = lstat (path, &files[files_index].stat);
	  break;
	}

      if (err < 0)
	{
	  error (0, errno, "%s", quotearg_colon (path));
	  exit_status = 1;
	  return 0;
	}

#if HAVE_ACL
      if (format == long_format)
	{
	  int n = file_has_acl (path, &files[files_index].stat);
	  files[files_index].have_acl = (0 < n);
	  if (n < 0)
	    error (0, errno, "%s", quotearg_colon (path));
	}
#endif

      if (S_ISLNK (files[files_index].stat.st_mode)
	  && (format == long_format || check_symlink_color))
	{
	  char *linkpath;
	  struct stat linkstats;

	  get_link_name (path, &files[files_index]);
	  linkpath = make_link_path (path, files[files_index].linkname);

	  /* Avoid following symbolic links when possible, ie, when
	     they won't be traced and when no indicator is needed. */
	  if (linkpath
	      && (indicator_style != none || check_symlink_color)
	      && stat (linkpath, &linkstats) == 0)
	    {
	      files[files_index].linkok = 1;

	      /* Symbolic links to directories that are mentioned on the
	         command line are automatically traced if not being
	         listed as files.  */
	      if (!explicit_arg || format == long_format
		  || !S_ISDIR (linkstats.st_mode))
		{
		  /* Get the linked-to file's mode for the filetype indicator
		     in long listings.  */
		  files[files_index].linkmode = linkstats.st_mode;
		  files[files_index].linkok = 1;
		}
	    }
	  if (linkpath)
	    free (linkpath);
	}

      if (S_ISLNK (files[files_index].stat.st_mode))
	files[files_index].filetype = symbolic_link;
      else if (S_ISDIR (files[files_index].stat.st_mode))
	{
	  if (explicit_arg && !immediate_dirs)
	    files[files_index].filetype = arg_directory;
	  else
	    files[files_index].filetype = directory;
	}
      else
	files[files_index].filetype = normal;

      blocks = ST_NBLOCKS (files[files_index].stat);
      {
	char buf[LONGEST_HUMAN_READABLE + 1];
	int len = strlen (human_readable (blocks, buf, human_output_opts,
					  ST_NBLOCKSIZE, output_block_size));
	if (block_size_size < len)
	  block_size_size = len < 7 ? len : 7;
      }
    }
  else
    {
      files[files_index].filetype = type;
#if HAVE_STRUCT_DIRENT_D_TYPE
      files[files_index].stat.st_mode = DTTOIF (type);
#endif
      blocks = 0;
    }

  files[files_index].name = xstrdup (name);
  files_index++;

  return blocks;
}

#ifdef S_ISLNK

/* Put the name of the file that `filename' is a symbolic link to
   into the `linkname' field of `f'. */

static void
get_link_name (const char *filename, struct fileinfo *f)
{
  f->linkname = xreadlink (filename);
  if (f->linkname == NULL)
    {
      error (0, errno, _("cannot read symbolic link %s"),
	     quotearg_colon (filename));
      exit_status = 1;
    }
}

/* If `linkname' is a relative path and `path' contains one or more
   leading directories, return `linkname' with those directories
   prepended; otherwise, return a copy of `linkname'.
   If `linkname' is zero, return zero. */

static char *
make_link_path (const char *path, const char *linkname)
{
  char *linkbuf;
  size_t bufsiz;

  if (linkname == 0)
    return 0;

  if (*linkname == '/')
    return xstrdup (linkname);

  /* The link is to a relative path.  Prepend any leading path
     in `path' to the link name. */
  linkbuf = strrchr (path, '/');
  if (linkbuf == 0)
    return xstrdup (linkname);

  bufsiz = linkbuf - path + 1;
  linkbuf = xmalloc (bufsiz + strlen (linkname) + 1);
  strncpy (linkbuf, path, bufsiz);
  strcpy (linkbuf + bufsiz, linkname);
  return linkbuf;
}
#endif

/* Return nonzero if base_name (NAME) ends in `.' or `..'
   This is so we don't try to recurse on `././././. ...' */

static int
basename_is_dot_or_dotdot (const char *n