[#325 state:resolved] Added IO::String, Path::Class and Sub::Install …

…to extlib.

extlib/Path/Class.pm

@@ -0,0 +1,177 @@
+package Path::Class;
+
+$VERSION = '0.21';
+@ISA = qw(Exporter);
+@EXPORT    = qw(file dir);
+@EXPORT_OK = qw(file dir foreign_file foreign_dir);
+
+use strict;
+use Exporter;
+use Path::Class::File;
+use Path::Class::Dir;
+
+sub file { Path::Class::File->new(@_) }
+sub dir  { Path::Class::Dir ->new(@_) }
+sub foreign_file { Path::Class::File->new_foreign(@_) }
+sub foreign_dir  { Path::Class::Dir ->new_foreign(@_) }
+
+
+1;
+__END__
+
+=head1 NAME
+
+Path::Class - Cross-platform path specification manipulation
+
+=head1 SYNOPSIS
+
+  use Path::Class;
+  
+  my $dir  = dir('foo', 'bar');       # Path::Class::Dir object
+  my $file = file('bob', 'file.txt'); # Path::Class::File object
+  
+  # Stringifies to 'foo/bar' on Unix, 'foo\bar' on Windows, etc.
+  print "dir: $dir\n";
+  
+  # Stringifies to 'bob/file.txt' on Unix, 'bob\file.txt' on Windows
+  print "file: $file\n";
+  
+  my $subdir  = $dir->subdir('baz');  # foo/bar/baz
+  my $parent  = $subdir->parent;      # foo/bar
+  my $parent2 = $parent->parent;      # foo
+  
+  my $dir2 = $file->dir;              # bob
+
+  # Work with foreign paths
+  use Path::Class qw(foreign_file foreign_dir);
+  my $file = foreign_file('Mac', ':foo:file.txt');
+  print $file->dir;                   # :foo:
+  print $file->as_foreign('Win32');   # foo\file.txt
+  
+  # Interact with the underlying filesystem:
+  
+  # $dir_handle is an IO::Dir object
+  my $dir_handle = $dir->open or die "Can't read $dir: $!";
+  
+  # $file_handle is an IO::File object
+  my $file_handle = $file->open($mode) or die "Can't read $file: $!";
+
+=head1 DESCRIPTION
+
+C<Path::Class> is a module for manipulation of file and directory
+specifications (strings describing their locations, like
+C<'/home/ken/foo.txt'> or C<'C:\Windows\Foo.txt'>) in a cross-platform
+manner.  It supports pretty much every platform Perl runs on,
+including Unix, Windows, Mac, VMS, Epoc, Cygwin, OS/2, and NetWare.
+
+The well-known module C<File::Spec> also provides this service, but
+it's sort of awkward to use well, so people sometimes avoid it, or use
+it in a way that won't actually work properly on platforms
+significantly different than the ones they've tested their code on.
+
+In fact, C<Path::Class> uses C<File::Spec> internally, wrapping all
+the unsightly details so you can concentrate on your application code.
+Whereas C<File::Spec> provides functions for some common path
+manipulations, C<Path::Class> provides an object-oriented model of the
+world of path specifications and their underlying semantics.
+C<File::Spec> doesn't create any objects, and its classes represent
+the different ways in which paths must be manipulated on various
+platforms (not a very intuitive concept).  C<Path::Class> creates
+objects representing files and directories, and provides methods that
+relate them to each other.  For instance, the following C<File::Spec>
+code:
+
+ my $absolute = File::Spec->file_name_is_absolute(
+                  File::Spec->catfile( @dirs, $file )
+                );
+
+can be written using C<Path::Class> as
+
+ my $absolute = Path::Class::File->new( @dirs, $file )->is_absolute;
+
+or even as 
+
+ my $absolute = file( @dirs, $file )->is_absolute;
+
+Similar readability improvements should happen all over the place when
+using C<Path::Class>.
+
+Using C<Path::Class> can help solve real problems in your code too -
+for instance, how many people actually take the "volume" (like C<C:>
+on Windows) into account when writing C<File::Spec>-using code?  I
+thought not.  But if you use C<Path::Class>, your file and directory objects
+will know what volumes they refer to and do the right thing.
+
+The guts of the C<Path::Class> code live in the C<Path::Class::File>
+and C<Path::Class::Dir> modules, so please see those
+modules' documentation for more details about how to use them.
+
+=head2 EXPORT
+
+The following functions are exported by default.
+
+=over 4
+
+=item file
+
+A synonym for C<< Path::Class::File->new >>.
+
+=item dir
+
+A synonym for C<< Path::Class::Dir->new >>.
+
+=back
+
+If you would like to prevent their export, you may explicitly pass an
+empty list to perl's C<use>, i.e. C<use Path::Class ()>.
+
+The following are exported only on demand.
+
+=over 4
+
+=item foreign_file
+
+A synonym for C<< Path::Class::File->new_foreign >>.
+
+=item foreign_dir
+
+A synonym for C<< Path::Class::Dir->new_foreign >>.
+
+=back
+
+=head1 Notes on Cross-Platform Compatibility
+
+Although it is much easier to write cross-platform-friendly code with
+this module than with C<File::Spec>, there are still some issues to be
+aware of.
+
+=over 4
+
+=item *
+
+Some platforms, notably VMS and some older versions of DOS (I think),
+all filenames must have an extension.  Thus if you create a file
+called F<foo/bar> and then ask for a list of files in the directory
+F<foo>, you may find a file called F<bar.> instead of the F<bar> you
+were expecting.  Thus it might be a good idea to use an extension in
+the first place.
+
+=back
+
+=head1 AUTHOR
+
+Ken Williams, KWILLIAMS@cpan.org
+
+=head1 COPYRIGHT
+
+Copyright (c) Ken Williams.  All rights reserved.
+
+This library is free software; you can redistribute it and/or
+modify it under the same terms as Perl itself.
+
+
+=head1 SEE ALSO
+
+Path::Class::Dir, Path::Class::File, File::Spec
+
+=cut