Documentation in File::Spec (was Re: minor File::Spec

                questions)
Message-Id: <20010822170904.A76069@linguist.thayer.dartmouth.edu>

p4raw-id: //depot/perl@11728

1 files changed, 212 insertions, 14 deletions

diff --git a/lib/File/Spec.pm b/lib/File/Spec.pm
index 35707cc780..19475c0321 100644
--- a/lib/File/Spec.pm
+++ b/lib/File/Spec.pm
@@ -16,6 +16,7 @@ require "File/Spec/$module.pm";
 @ISA = ("File::Spec::$module");
 
 1;
+
 __END__
 
 =head1 NAME
@@ -70,24 +71,221 @@ but rather as class methods:
 For simple uses, L<File::Spec::Functions> provides convenient functional
 forms of these methods.
 
-For a list of available methods, please consult L<File::Spec::Unix>,
-which contains the entire set, and which is inherited by the modules for
-other platforms. For further information, please see L<File::Spec::Mac>,
-L<File::Spec::OS2>, L<File::Spec::Win32>, or L<File::Spec::VMS>.
+=head1 METHODS
+
+=over 2
+
+=item canonpath
+
+No physical check on the filesystem, but a logical cleanup of a
+path.
+
+    $cpath = File::Spec->canonpath( $path ) ;
+
+=item catdir
+
+Concatenate two or more directory names to form a complete path ending
+with a directory. But remove the trailing slash from the resulting
+string, because it doesn't look good, isn't necessary and confuses
+OS2. Of course, if this is the root directory, don't cut off the
+trailing slash :-)
+
+    $path = File::Spec->catdir( @directories );
+
+=item catfile
+
+Concatenate one or more directory names and a filename to form a
+complete path ending with a filename
+
+    $path = File::Spec->catfile( @directories, $filename );
+
+=item curdir
+
+Returns a string representation of the current directory.
+
+    $curdir = File::Spec->curdir();
+
+=item devnull
+
+Returns a string representation of the null device.
+
+    $devnull = File::Spec->devnull();
+
+=item rootdir
+
+Returns a string representation of the root directory.
+
+    $rootdir = File::Spec->rootdir();
+
+=item tmpdir
+
+Returns a string representation of the first writable directory from a
+list of possible temporary directories.  Returns "" if no writable
+temporary directories are found.  The list of directories checked
+depends on the platform; e.g. File::Spec::Unix checks $ENV{TMPDIR} and
+/tmp.
+
+    $tmpdir = File::Spec->tmpdir();
+
+=item updir
+
+Returns a string representation of the parent directory.
+
+    $updir = File::Spec->updir();
+
+=item no_upwards
+
+Given a list of file names, strip out those that refer to a parent
+directory. (Does not strip symlinks, only '.', '..', and equivalents.)
+
+    @paths = File::Spec->no_upwards( @paths );
+
+=item case_tolerant
+
+Returns a true or false value indicating, respectively, that alphabetic
+is not or is significant when comparing file specifications.
+
+    $is_case_tolerant = File::Spec->case_tolerant();
+
+=item file_name_is_absolute
+
+Takes as argument a path and returns true if it is an absolute path.
+
+    $is_absolute = File::Spec->file_name_is_absolute( $path );
+
+This does not consult the local filesystem on Unix, Win32, or OS/2.  It
+does sometimes on MacOS (see L<File::Spec::MacOS/file_name_is_absolute>).
+It does consult the working environment for VMS (see
+L<File::Spec::VMS/file_name_is_absolute>).
+
+=item path
+
+Takes no argument, returns the environment variable PATH as an array.
+
+    @PATH = File::Spec->path();
+
+=item join
+
+join is the same as catfile.
+
+=item splitpath
+
+Splits a path in to volume, directory, and filename portions. On systems
+with no concept of volume, returns undef for volume. 
+
+    ($volume,$directories,$file) = File::Spec->splitpath( $path );
+    ($volume,$directories,$file) = File::Spec->splitpath( $path, $no_file );
+
+For systems with no syntax differentiating filenames from directories, 
+assumes that the last file is a path unless $no_file is true or a 
+trailing separator or /. or /.. is present. On Unix this means that $no_file
+true makes this return ( '', $path, '' ).
+
+The directory portion may or may not be returned with a trailing '/'.
+
+The results can be passed to L</catpath()> to get back a path equivalent to
+(usually identical to) the original path.
+
+=item splitdir
+
+The opposite of L</catdir()>.
+
+    @dirs = File::Spec->splitdir( $directories );
+
+$directories must be only the directory portion of the path on systems 
+that have the concept of a volume or that have path syntax that differentiates
+files from directories.
+
+Unlike just splitting the directories on the separator, empty
+directory names (C<''>) can be returned, because these are significant
+on some OSs (e.g. MacOS).
+
+=item catpath
+
+Takes volume, directory and file portions and returns an entire path. Under
+Unix, $volume is ignored, and directory and file are catenated.  A '/' is
+inserted if need be.  On other OSs, $volume is significant.
+
+    $full_path = File::Spec->catpath( $volume, $directory, $file );
+
+=item abs2rel
+
+Takes a destination path and an optional base path returns a relative path
+from the base path to the destination path:
+
+    $rel_path = File::Spec->abs2rel( $path ) ;
+    $rel_path = File::Spec->abs2rel( $path, $base ) ;
+
+If $base is not present or '', then L<cwd()> is used. If $base is relative, 
+then it is converted to absolute form using L</rel2abs()>. This means that it
+is taken to be relative to L<cwd()>.
+
+On systems with the concept of a volume, this assumes that both paths 
+are on the $destination volume, and ignores the $base volume. 
+
+On systems that have a grammar that indicates filenames, this ignores the 
+$base filename as well. Otherwise all path components are assumed to be
+directories.
+
+If $path is relative, it is converted to absolute form using L</rel2abs()>.
+This means that it is taken to be relative to L<cwd()>.
+
+No checks against the filesystem are made on most systems.  On MacOS,
+the filesystem may be consulted (see
+L<File::Spec::MacOS/file_name_is_absolute>).  On VMS, there is
+interaction with the working environment, as logicals and
+macros are expanded.
+
+Based on code written by Shigio Yamaguchi.
+
+=item rel2abs
+
+Converts a relative path to an absolute path. 
+
+    $abs_path = File::Spec->rel2abs( $path ) ;
+    $abs_path = File::Spec->rel2abs( $path, $base ) ;
+
+If $base is not present or '', then L<cwd()> is used. If $base is relative, 
+then it is converted to absolute form using L</rel2abs()>. This means that it
+is taken to be relative to L<cwd()>.
+
+On systems with the concept of a volume, this assumes that both paths 
+are on the $base volume, and ignores the $path volume. 
+
+On systems that have a grammar that indicates filenames, this ignores the 
+$base filename as well. Otherwise all path components are assumed to be
+directories.
+
+If $path is absolute, it is cleaned up and returned using L</canonpath()>.
+
+No checks against the filesystem are made on most systems.  On MacOS,
+the filesystem may be consulted (see
+L<File::Spec::MacOS/file_name_is_absolute>).  On VMS, there is
+interaction with the working environment, as logicals and
+macros are expanded.
+
+Based on code written by Shigio Yamaguchi.
+
+=back
+
+For further information, please see L<File::Spec::Unix>,
+L<File::Spec::Mac>, L<File::Spec::OS2>, L<File::Spec::Win32>, or
+L<File::Spec::VMS>.
 
 =head1 SEE ALSO
 
-File::Spec::Unix, File::Spec::Mac, File::Spec::OS2, File::Spec::Win32,
-File::Spec::VMS, File::Spec::Functions, ExtUtils::MakeMaker
+L<File::Spec::Unix>, L<File::Spec::Mac>, L<File::Spec::OS2>,
+L<File::Spec::Win32>, L<File::Spec::VMS>, L<File::Spec::Functions>,
+L<ExtUtils::MakeMaker>
 
 =head1 AUTHORS
 
-Kenneth Albanowski <F<kjahds@kjahds.com>>, Andy Dougherty
-<F<doughera@lafcol.lafayette.edu>>, Andreas KE<ouml>nig
-<F<A.Koenig@franz.ww.TU-Berlin.DE>>, Tim Bunce <F<Tim.Bunce@ig.co.uk>>. VMS
-support by Charles Bailey <F<bailey@newman.upenn.edu>>.  OS/2 support by
-Ilya Zakharevich <F<ilya@math.ohio-state.edu>>. Mac support by Paul Schinder
-<F<schinder@pobox.com>>.  abs2rel() and rel2abs() written by
-Shigio Yamaguchi <F<shigio@tamacom.com>>, modified by Barrie Slaymaker
-<F<barries@slaysys.com>>.  splitpath(), splitdir(), catpath() and catdir()
+Kenneth Albanowski <kjahds@kjahds.com>, Andy Dougherty
+<doughera@lafcol.lafayette.edu>, Andreas KE<ouml>nig
+<A.Koenig@franz.ww.TU-Berlin.DE>, Tim Bunce <Tim.Bunce@ig.co.uk. VMS
+support by Charles Bailey <bailey@newman.upenn.edu>.  OS/2 support by
+Ilya Zakharevich <ilya@math.ohio-state.edu>. Mac support by Paul Schinder
+<schinder@pobox.com>.  abs2rel() and rel2abs() written by
+Shigio Yamaguchi <shigio@tamacom.com>, modified by Barrie Slaymaker
+<barries@slaysys.com>.  splitpath(), splitdir(), catpath() and catdir()
 by Barrie Slaymaker.