Path::Class::Dir - Objects representing directories |
Path::Class::Dir - Objects representing directories
version 0.35
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.
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.
Path::Class::Dir
object is
used in a string context, so the following are equivalent:
$string = $dir->stringify; $string = "$dir";
C:
on Windows, Macintosh HD:
on Mac OS,
etc.) of the directory object, if any. Otherwise, returns the empty
string.
Path::Class::Dir
objects always return true.
/usr/local
or \Windows
).
lib/foo
or ./dir
).
my $dir = dir('/foo//baz/./foo')->cleanup; # $dir now represents '/foo/baz/foo';
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.
$dir
or one of its subdirectories. Internally, this just calls <
Path::Class::File-
new( @_ ) >>.
Path::Class::Dir
object representing a subdirectory
of $dir
.
$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: ../../..
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
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.
Path::Class::Dir
object representing $dir
as a
relative path. An optional argument, given as either a string or a
Path::Class::Dir
object, specifies the directory to use as the base
of relativity - otherwise the current working directory will be used.
subsumes($other)
$dir
actually contains $other
on the
filesystem.
The $other
argument may be a Path::Class::Dir
object, a
the Path::Class::File manpage object, or a string. In the latter case, we
assume it's a directory.
# Examples: dir('foo/bar' )->subsumes(dir('foo/bar/baz')) # True dir('/foo/bar')->subsumes(dir('/foo/bar/baz')) # True dir('foo/bar' )->subsumes(dir('bar/baz')) # False dir('/foo/bar')->subsumes(dir('foo/bar')) # False
contains($other)
$other
on the
filesystem. $other
doesn't have to be a direct child of $dir
,
it just has to be subsumed.
as_foreign($type)
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.
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()
.
<
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_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.
open()
$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
, to
File::Path::mkpath()
>> and returns the result (a list of all directories created).
$dir
, to
File::Path::rmtree()
>> and returns the result (the number of files successfully deleted).
remove()
Path::Class::File
's remove()
method.
tempfile(...)
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>; }
next()
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 $!
.
sub { my ($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->(); });
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)
.
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.
stat()
File::stat::stat()
on this directory and returns a
File::stat
object representing the result.
lstat()
stat()
, but if $file
is a symbolic link, lstat()
stats the link instead of the directory the link points to.
file_class()
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
Path::Class::Dir - Objects representing directories |