


File::Spec::Unix(Perl Programmers Reference GFile::Spec::Unix(3p)


NAME
       File::Spec::Unix - File::Spec for Unix, base for other
       File::Spec modules

SYNOPSIS
        require File::Spec::Unix; # Done automatically by File::Spec

DESCRIPTION
       Methods for manipulating file specifications.  Other
       File::Spec modules, such as File::Spec::Mac, inherit from
       File::Spec::Unix and override specific methods.

METHODS
       canonpath()
         No physical check on the filesystem, but a logical
         cleanup of a path. On UNIX eliminates successive slashes
         and successive "/.".

             $cpath = File::Spec->canonpath( $path ) ;

         Note that this does *not* collapse x/../y sections into
         y.  This is by design.  If /foo on your system is a
         symlink to /bar/baz, then /foo/../quux is actually
         /bar/quux, not /quux as a naive ../-removal would give
         you.  If you want to do this kind of processing, you
         probably want "Cwd"'s "realpath()" function to actually
         traverse the filesystem cleaning up paths like this.

       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 :-)

       catfile
         Concatenate one or more directory names and a filename
         to form a complete path ending with a filename

       curdir
         Returns a string representation of the current
         directory.  "." on UNIX.

       devnull
         Returns a string representation of the null device.
         "/dev/null" on UNIX.

       rootdir
         Returns a string representation of the root directory.
         "/" on UNIX.

       tmpdir
         Returns a string representation of the first writable



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         directory from the following list or the current
         directory if none from the list are writable:

             $ENV{TMPDIR}
             /tmp

         Since perl 5.8.0, if running under taint mode, and if
         $ENV{TMPDIR} is tainted, it is not used.

       updir
         Returns a string representation of the parent directory.
         ".." on UNIX.

       no_upwards
         Given a list of file names, strip out those that refer
         to a parent directory. (Does not strip symlinks, only
         '.', '..', and equivalents.)

       case_tolerant
         Returns a true or false value indicating, respectively,
         that alphabetic is not or is significant when comparing
         file specifications.

       file_name_is_absolute
         Takes as argument a path and returns true if it is an
         absolute path.

         This does not consult the local filesystem on Unix,
         Win32, OS/2 or Mac OS (Classic).  It does consult the
         working environment for VMS (see "file_name_is_absolute"
         in File::Spec::VMS).

       path
         Takes no argument, returns the environment variable PATH
         as an array.

       join
         join is the same as catfile.

       splitpath
             ($volume,$directories,$file) = File::Spec->splitpath( $path );
             ($volume,$directories,$file) = File::Spec->splitpath( $path, $no_file );

         Splits a path into volume, directory, and filename
         portions. On systems with no concept of volume, returns
         '' for volume.

         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



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         trailing '/'.

         The results can be passed to "catpath()" to get back a
         path equivalent to (usually identical to) the original
         path.

       splitdir
         The opposite of "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 ('') can be returned, because
         these are significant on some OSs.

         On Unix,

             File::Spec->splitdir( "/a/b//c/" );

         Yields:

             ( '', 'a', 'b', '', 'c', '' )

       catpath()
         Takes volume, directory and file portions and returns an
         entire path. Under Unix, $volume is ignored, and
         directory and file are concatenated.  A '/' is inserted
         if needed (though if the directory portion doesn't start
         with '/' it is not added).  On other OSs, $volume is
         significant.

       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 cwd() is used. If
         $base is relative, then it is converted to absolute form
         using "rel2abs()". This means that it is taken to be
         relative to cwd().

         On systems that have a grammar that indicates filenames,
         this ignores the $base filename. Otherwise all path
         components are assumed to be directories.

         If $path is relative, it is converted to absolute form



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         using "rel2abs()".  This means that it is taken to be
         relative to cwd().

         No checks against the filesystem are made.  On VMS,
         there is interaction with the working environment, as
         logicals and macros are expanded.

         Based on code written by Shigio Yamaguchi.

       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 cwd() is used. If
         $base is relative, then it is converted to absolute form
         using "rel2abs()". This means that it is taken to be
         relative to cwd().

         On systems that have a grammar that indicates filenames,
         this ignores the $base filename. Otherwise all path
         components are assumed to be directories.

         If $path is absolute, it is cleaned up and returned
         using "canonpath()".

         No checks against the filesystem are made.  On VMS,
         there is interaction with the working environment, as
         logicals and macros are expanded.

         Based on code written by Shigio Yamaguchi.

COPYRIGHT
       Copyright (c) 2004 by the Perl 5 Porters.  All rights
       reserved.

       This program is free software; you can redistribute it
       and/or modify it under the same terms as Perl itself.

SEE ALSO
       File::Spec















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