Path::Class::Dir - Objects representing directories
version 0.37
use Path::Class; # Exports dir() by default
my $dir = dir('foo', 'bar'); # Path::Class::Dir object
my $dir = Path::Class::Dir->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 methods:
my $handle = $dir->open;
while (my $file = $handle->read) {
$file = $dir->file($file); # Turn into Path::Class::File object
...
}
# Iterate with Path::Class methods:
while (my $file = $dir->next) {
# $file is a Path::Class::File or Path::Class::Dir object
...
}
The Path::Class::Dir class contains functionality for manipulating
directory names in a cross-platform way.
- $dir = Path::Class::Dir->new( , , ... )
-
- $dir = dir( , , ... )
-
Creates a new
Path::Class::Dir 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->new() (or
dir() ) refers to the current directory (File::Spec->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 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, the Path::Class::File manpage objects always
return false, and
Path::Class::Dir 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( , , ..., )
-
Returns a the Path::Class::File manpage object representing an entry in
$dir
or one of its subdirectories. Internally, this just calls <
Path::Class::File- new( @_ ) >>.
- $subdir = $dir->subdir( , , ... )
-
Returns a new
Path::Class::Dir 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 the Path::Class::File manpage and/or
Path::Class::Dir
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 object representing $dir as an
absolute path. An optional argument, given as either a string or a
Path::Class::Dir 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 object representing $dir as a
relative path. An optional argument, given as either a string or a
Path::Class::Dir 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 object, a
the Path::Class::File manpage 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 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 .
Any generated objects (subdirectories, files, parents, etc.) will also
retain this type.
- $foreign = Path::Class::Dir->new_foreign($type, @args)
-
Returns a
Path::Class::Dir 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 .
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- 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 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->open and returns the result as an
the IO::Dir manpage object. If the opening fails, undef is returned and
$! is set.
- $dir->mkpath($verbose, $mode)
-
Passes all arguments, including
$dir , to File::Path::mkpath()
>> and returns the result (a list of all directories created).
- $dir->rmtree($verbose, $cautious)
-
Passes all arguments, including
$dir , to File::Path::rmtree()
>> 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 's remove() method.
- $dir->tempfile(...)
-
An interface to the File::Temp manpage'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 or
the Path::Class::File manpage 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 the File::Find manpage module does,
and of course File::Find will work fine on the Path::Class manpage objects,
but the advantage of the recurse() method is that it will also feed
your callback routine Path::Class 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 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() (more easily
available as $item->PRUNE ), no children of analyzed
item will be analyzed (mostly as if you set $File::Find::prune=1 ). Of course
pruning is available only in preorder , in postorder return value
has no effect.
- $st = $file->stat()
-
Invokes
File::stat::stat() on this directory and returns a
File::stat 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.
Ken Williams, kwilliams@cpan.org
the Path::Class manpage, the Path::Class::File manpage, the File::Spec manpage
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