File::Spec::Unix(3pm)					 Perl Programmers Reference Guide				     File::Spec::Unix(3pm)

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 over-
       ride 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 ) ;

       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 directory from the following list or "" if none 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 in to volume, directory, and filename portions. On systems with no concept of volume, returns undef 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 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 cate-
	 nated.  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 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 "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 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 "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.

SEE ALSO

       File::Spec

perl v5.8.0							    2002-06-01						     File::Spec::Unix(3pm)