# phpman > perldoc > Path::Class::Dir

## NAME
    [Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown) - Objects representing directories

## VERSION
    version 0.37

## SYNOPSIS
      use [Path::Class](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass/markdown);  # Exports dir() by default

      my $dir = dir('foo', 'bar');       # [Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown) object
      my $dir = [Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)->new('foo', 'bar');  # Same thing

      # Stringifies to 'foo/bar' on Unix, 'foo\bar' on Windows, etc.
      print "dir: $dir\n";

      if ($dir->is_absolute) { ... }
      if ($dir->is_relative) { ... }

      my $v = $dir->volume; # Could be 'C:' on Windows, empty string
                            # on Unix, 'Macintosh HD:' on Mac OS

      $dir->cleanup; # Perform logical cleanup of pathname
      $dir->resolve; # Perform physical cleanup of pathname

      my $file = $dir->file('file.txt'); # A file in this directory
      my $subdir = $dir->subdir('george'); # A subdirectory
      my $parent = $dir->parent; # The parent directory, 'foo'

      my $abs = $dir->absolute; # Transform to absolute path
      my $rel = $abs->relative; # Transform to relative path
      my $rel = $abs->relative('/foo'); # Relative to /foo

      print $dir->as_foreign('Mac');   # :foo:bar:
      print $dir->as_foreign('Win32'); #  foo\bar

      # Iterate with [IO::Dir](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ADir/markdown) methods:
      my $handle = $dir->open;
      while (my $file = $handle->read) {
        $file = $dir->file($file);  # Turn into [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown) object
        ...
      }

      # Iterate with [Path::Class](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass/markdown) methods:
      while (my $file = $dir->next) {
        # $file is a [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown) or [Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown) object
        ...
      }

## DESCRIPTION
    The "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" class contains functionality for manipulating directory names in a
    cross-platform way.

## METHODS
    $dir = [Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)->new( <dir1>, <dir2>, ... )
    $dir = dir( <dir1>, <dir2>, ... )
        Creates a new "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object and returns it. The arguments specify names of
        directories which will be joined to create a single directory object. A volume may also be
        specified as the first argument, or as part of the first argument. You can use
        platform-neutral syntax:

          my $dir = dir( 'foo', 'bar', 'baz' );

        or platform-native syntax:

          my $dir = dir( 'foo/bar/baz' );

        or a mixture of the two:

          my $dir = dir( 'foo/bar', 'baz' );

        All three of the above examples create relative paths. To create an absolute path, either
        use the platform native syntax for doing so:

          my $dir = dir( '/var/tmp' );

        or use an empty string as the first argument:

          my $dir = dir( '', 'var', 'tmp' );

        If the second form seems awkward, that's somewhat intentional - paths like "/var/tmp" or
        "\Windows" aren't cross-platform concepts in the first place (many non-Unix platforms don't
        have a notion of a "root directory"), so they probably shouldn't appear in your code if
        you're trying to be cross-platform. The first form is perfectly natural, because paths like
        this may come from config files, user input, or whatever.

        As a special case, since it doesn't otherwise mean anything useful and it's convenient to
        define this way, "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)->new()" (or "dir()") refers to the current directory
        ("[File::Spec](https://www.chedong.com/phpMan.php/perldoc/File%3A%3ASpec/markdown)->curdir"). To get the current directory as an absolute path, do
        "dir()->absolute".

        Finally, as another special case "dir(undef)" will return undef, since that's usually an
        accident on the part of the caller, and returning the root directory would be a nasty
        surprise just asking for trouble a few lines later.

    $dir->stringify
        This method is called internally when a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object is used in a string
        context, so the following are equivalent:

          $string = $dir->stringify;
          $string = "$dir";

    $dir->volume
        Returns the volume (e.g. "C:" on Windows, "Macintosh HD:" on Mac OS, etc.) of the directory
        object, if any. Otherwise, returns the empty string.

    $dir->basename
        Returns the last directory name of the path as a string.

    $dir->is_dir
        Returns a boolean value indicating whether this object represents a directory. Not
        surprisingly, [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown) objects always return false, and "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" objects
        always return true.

    $dir->is_absolute
        Returns true or false depending on whether the directory refers to an absolute path
        specifier (like "/usr/local" or "\Windows").

    $dir->is_relative
        Returns true or false depending on whether the directory refers to a relative path specifier
        (like "lib/foo" or "./dir").

    $dir->cleanup
        Performs a logical cleanup of the file path. For instance:

          my $dir = dir('/foo//baz/./foo')->cleanup;
          # $dir now represents '/foo/baz/foo';

    $dir->resolve
        Performs a physical cleanup of the file path. For instance:

          my $dir = dir('/foo//baz/../foo')->resolve;
          # $dir now represents '/foo/foo', assuming no symlinks

        This actually consults the filesystem to verify the validity of the path.

    $file = $dir->file( <dir1>, <dir2>, ..., <file> )
        Returns a [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown) object representing an entry in $dir or one of its
        subdirectories. Internally, this just calls "[Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown)->new( @_ )".

    $subdir = $dir->subdir( <dir1>, <dir2>, ... )
        Returns a new "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object representing a subdirectory of $dir.

    $parent = $dir->parent
        Returns the parent directory of $dir. Note that this is the *logical* parent, not
        necessarily the physical parent. It really means we just chop off entries from the end of
        the directory list until we cain't chop no more. If the directory is relative, we start
        using the relative forms of parent directories.

        The following code demonstrates the behavior on absolute and relative directories:

          $dir = dir('/foo/bar');
          for (1..6) {
            print "Absolute: $dir\n";
            $dir = $dir->parent;
          }

          $dir = dir('foo/bar');
          for (1..6) {
            print "Relative: $dir\n";
            $dir = $dir->parent;
          }

          ########### Output on Unix ################
          Absolute: /foo/bar
          Absolute: /foo
          Absolute: /
          Absolute: /
          Absolute: /
          Absolute: /
          Relative: foo/bar
          Relative: foo
          Relative: .
          Relative: ..
          Relative: ../..
          Relative: ../../..

    @list = $dir->children
        Returns a list of [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown) and/or "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" objects listed in this
        directory, or in scalar context the number of such objects. Obviously, it is necessary for
        $dir to exist and be readable in order to find its children.

        Note that the children are returned as subdirectories of $dir, i.e. the children of foo will
        be foo/bar and foo/baz, not bar and baz.

        Ordinarily "children()" will not include the *self* and *parent* entries "." and ".." (or
        their equivalents on non-Unix systems), because that's like I'm-my-own-grandpa business. If
        you do want all directory entries including these special ones, pass a true value for the
        "all" parameter:

          @c = $dir->children(); # Just the children
          @c = $dir->children(all => 1); # All entries

        In addition, there's a "no_hidden" parameter that will exclude all normally "hidden" entries
        - on Unix this means excluding all entries that begin with a dot ("."):

          @c = $dir->children(no_hidden => 1); # Just normally-visible entries

    $abs = $dir->absolute
        Returns a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object representing $dir as an absolute path. An optional
        argument, given as either a string or a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object, specifies the directory
        to use as the base of relativity - otherwise the current working directory will be used.

    $rel = $dir->relative
        Returns a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object representing $dir as a relative path. An optional
        argument, given as either a string or a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object, specifies the directory
        to use as the base of relativity - otherwise the current working directory will be used.

    $boolean = $dir->subsumes($other)
        Returns true if this directory spec subsumes the other spec, and false otherwise. Think of
        "subsumes" as "contains", but we only look at the *specs*, not whether $dir actually
        contains $other on the filesystem.

        The $other argument may be a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object, a [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown) object, or a
        string. In the latter case, we assume it's a directory.

          # Examples:
          dir('foo/bar' )->subsumes(dir('foo/bar/baz'))  # True
          dir('/foo/bar')->subsumes(dir('/foo/bar/baz')) # True
          dir('foo/..')->subsumes(dir('foo/../bar))      # True
          dir('foo/bar' )->subsumes(dir('bar/baz'))      # False
          dir('/foo/bar')->subsumes(dir('foo/bar'))      # False
          dir('foo/..')->subsumes(dir('bar'))            # False! Use C<contains> to resolve ".."

    $boolean = $dir->contains($other)
        Returns true if this directory actually contains $other on the filesystem. $other doesn't
        have to be a direct child of $dir, it just has to be subsumed after both paths have been
        resolved.

    $foreign = $dir->as_foreign($type)
        Returns a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object representing $dir as it would be specified on a system
        of type $type. Known types include "Unix", "Win32", "Mac", "VMS", and "OS2", i.e. anything
        for which there is a subclass of "[File::Spec](https://www.chedong.com/phpMan.php/perldoc/File%3A%3ASpec/markdown)".

        Any generated objects (subdirectories, files, parents, etc.) will also retain this type.

    $foreign = [Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)->new_foreign($type, @args)
        Returns a "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" object representing $dir as it would be specified on a system
        of type $type. Known types include "Unix", "Win32", "Mac", "VMS", and "OS2", i.e. anything
        for which there is a subclass of "[File::Spec](https://www.chedong.com/phpMan.php/perldoc/File%3A%3ASpec/markdown)".

        The arguments in @args are the same as they would be specified in "new()".

    @list = $dir->dir_list([OFFSET, [LENGTH]])
        Returns the list of strings internally representing this directory structure. Each
        successive member of the list is understood to be an entry in its predecessor's directory
        list. By contract, "[Path::Class](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass/markdown)->new( $dir->dir_list )" should be equivalent to $dir.

        The semantics of this method are similar to Perl's "splice" or "substr" functions; they
        return "LENGTH" elements starting at "OFFSET". If "LENGTH" is omitted, returns all the
        elements starting at "OFFSET" up to the end of the list. If "LENGTH" is negative, returns
        the elements from "OFFSET" onward except for "-LENGTH" elements at the end. If "OFFSET" is
        negative, it counts backward "OFFSET" elements from the end of the list. If "OFFSET" and
        "LENGTH" are both omitted, the entire list is returned.

        In a scalar context, "dir_list()" with no arguments returns the number of entries in the
        directory list; "dir_list(OFFSET)" returns the single element at that offset;
        "dir_list(OFFSET, LENGTH)" returns the final element that would have been returned in a list
        context.

    $dir->components
        Identical to "dir_list()". It exists because there's an analogous method "dir_list()" in the
        "[Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown)" class that also returns the basename string, so this method lets someone
        call "components()" without caring whether the object is a file or a directory.

    $fh = $dir->open()
        Passes $dir to "[IO::Dir](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ADir/markdown)->open" and returns the result as an [IO::Dir](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ADir/markdown) object. If the opening
        fails, "undef" is returned and $! is set.

    $dir->mkpath($verbose, $mode)
        Passes all arguments, including $dir, to "[File::Path::mkpath](https://www.chedong.com/phpMan.php/perldoc/File%3A%3APath%3A%3Amkpath/markdown)()" and returns the result (a
        list of all directories created).

    $dir->rmtree($verbose, $cautious)
        Passes all arguments, including $dir, to "[File::Path::rmtree](https://www.chedong.com/phpMan.php/perldoc/File%3A%3APath%3A%3Armtree/markdown)()" and returns the result (the
        number of files successfully deleted).

    $dir->remove()
        Removes the directory, which must be empty. Returns a boolean value indicating whether or
        not the directory was successfully removed. This method is mainly provided for consistency
        with "[Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown)"'s "remove()" method.

    $dir->tempfile(...)
        An interface to [File::Temp](https://www.chedong.com/phpMan.php/perldoc/File%3A%3ATemp/markdown)'s "tempfile()" function. Just like that function, if you call
        this in a scalar context, the return value is the filehandle and the file is "unlink"ed as
        soon as possible (which is immediately on Unix-like platforms). If called in a list context,
        the return values are the filehandle and the filename.

        The given directory is passed as the "DIR" parameter.

        Here's an example of pretty good usage which doesn't allow race conditions, won't leave
        yucky tempfiles around on your filesystem, etc.:

          my $fh = $dir->tempfile;
          print $fh "Here's some data...\n";
          seek($fh, 0, 0);
          while (<$fh>) { do something... }

        Or in combination with a "fork":

          my $fh = $dir->tempfile;
          print $fh "Here's some more data...\n";
          seek($fh, 0, 0);
          if ($pid=fork()) {
            wait;
          } else {
            something($_) while <$fh>;
          }

    $dir_or_file = $dir->next()
        A convenient way to iterate through directory contents. The first time "next()" is called,
        it will "open()" the directory and read the first item from it, returning the result as a
        "[Path::Class::Dir](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3ADir/markdown)" or [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown) object (depending, of course, on its actual type).
        Each subsequent call to "next()" will simply iterate over the directory's contents, until
        there are no more items in the directory, and then the undefined value is returned. For
        example, to iterate over all the regular files in a directory:

          while (my $file = $dir->next) {
            next unless -f $file;
            my $fh = $file->open('r') or die "Can't read $file: $!";
            ...
          }

        If an error occurs when opening the directory (for instance, it doesn't exist or isn't
        readable), "next()" will throw an exception with the value of $!.

    $dir->traverse( sub { ... }, @args )
        Calls the given callback for the root, passing it a continuation function which, when
        called, will call this recursively on each of its children. The callback function should be
        of the form:

          sub {
            my ($child, $cont, @args) = @_;
            # ...
          }

        For instance, to calculate the number of files in a directory, you can do this:

          my $nfiles = $dir->traverse(sub {
            my ($child, $cont) = @_;
            return sum($cont->(), ($child->is_dir ? 0 : 1));
          });

        or to calculate the maximum depth of a directory:

          my $depth = $dir->traverse(sub {
            my ($child, $cont, $depth) = @_;
            return max($cont->($depth + 1), $depth);
          }, 0);

        You can also choose not to call the callback in certain situations:

          $dir->traverse(sub {
            my ($child, $cont) = @_;
            return if -l $child; # don't follow symlinks
            # do something with $child
            return $cont->();
          });

    $dir->traverse_if( sub { ... }, sub { ... }, @args )
        traverse with additional "should I visit this child" callback. Particularly useful in case
        examined tree contains inaccessible directories.

        Canonical example:

          $dir->traverse_if(
            sub {
               my ($child, $cont) = @_;
               # do something with $child
               return $cont->();
            },
            sub {
               my ($child) = @_;
               # Process only readable items
               return -r $child;
            });

        Second callback gets single parameter: child. Only children for which it returns true will
        be processed by the first callback.

        Remaining parameters are interpreted as in traverse, in particular "traverse_if(callback,
        sub { 1 }, @args" is equivalent to "traverse(callback, @args)".

    $dir->recurse( callback => sub {...} )
        Iterates through this directory and all of its children, and all of its children's children,
        etc., calling the "callback" subroutine for each entry. This is a lot like what the
        [File::Find](https://www.chedong.com/phpMan.php/perldoc/File%3A%3AFind/markdown) module does, and of course "[File::Find](https://www.chedong.com/phpMan.php/perldoc/File%3A%3AFind/markdown)" will work fine on [Path::Class](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass/markdown) objects,
        but the advantage of the "recurse()" method is that it will also feed your callback routine
        "[Path::Class](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass/markdown)" objects rather than just pathname strings.

        The "recurse()" method requires a "callback" parameter specifying the subroutine to invoke
        for each entry. It will be passed the "[Path::Class](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass/markdown)" object as its first argument.

        "recurse()" also accepts two boolean parameters, "depthfirst" and "preorder" that control
        the order of recursion. The default is a preorder, breadth-first search, i.e. "depthfirst =>
        0, preorder => 1". At the time of this writing, all combinations of these two parameters are
        supported *except* "depthfirst => 0, preorder => 0".

        "callback" is normally not required to return any value. If it returns special constant
        "[Path::Class::Entity::PRUNE](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AEntity%3A%3APRUNE/markdown)()" (more easily available as "$item->PRUNE"), no children of
        analyzed item will be analyzed (mostly as if you set "$[File::Find::prune](https://www.chedong.com/phpMan.php/perldoc/File%3A%3AFind%3A%3Aprune/markdown)=1"). Of course
        pruning is available only in "preorder", in postorder return value has no effect.

    $st = $file->stat()
        Invokes "[File::stat::stat](https://www.chedong.com/phpMan.php/perldoc/File%3A%3Astat%3A%3Astat/markdown)()" on this directory and returns a "[File::stat](https://www.chedong.com/phpMan.php/perldoc/File%3A%3Astat/markdown)" object
        representing the result.

    $st = $file->lstat()
        Same as "stat()", but if $file is a symbolic link, "lstat()" stats the link instead of the
        directory the link points to.

    $class = $file->file_class()
        Returns the class which should be used to create file objects.

        Generally overridden whenever this class is subclassed.

## AUTHOR
    Ken Williams, <kwilliams@cpan.org>

## SEE ALSO
    [Path::Class](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass/markdown), [Path::Class::File](https://www.chedong.com/phpMan.php/perldoc/Path%3A%3AClass%3A%3AFile/markdown), [File::Spec](https://www.chedong.com/phpMan.php/perldoc/File%3A%3ASpec/markdown)