Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages

RedHat 9 (Linux i386) - man page for file::spec (redhat section 3pm)

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

NAME
       File::Spec - portably perform operations on file names

SYNOPSIS
	       use File::Spec;

	       $x=File::Spec->catfile('a', 'b', 'c');

       which returns 'a/b/c' under Unix. Or:

	       use File::Spec::Functions;

	       $x = catfile('a', 'b', 'c');

DESCRIPTION
       This module is designed to support operations commonly performed on file specifications
       (usually called "file names", but not to be confused with the contents of a file, or
       Perl's file handles), such as concatenating several directory and file names into a single
       path, or determining whether a path is rooted. It is based on code directly taken from
       MakeMaker 5.17, code written by Andreas Koenig, Andy Dougherty, Charles Bailey, Ilya
       Zakharevich, Paul Schinder, and others.

       Since these functions are different for most operating systems, each set of OS specific
       routines is available in a separate module, including:

	       File::Spec::Unix
	       File::Spec::Mac
	       File::Spec::OS2
	       File::Spec::Win32
	       File::Spec::VMS

       The module appropriate for the current OS is automatically loaded by File::Spec. Since
       some modules (like VMS) make use of facilities available only under that OS, it may not be
       possible to load all modules under all operating systems.

       Since File::Spec is object oriented, subroutines should not be called directly, as in:

	       File::Spec::catfile('a','b');

       but rather as class methods:

	       File::Spec->catfile('a','b');

       For simple uses, File::Spec::Functions provides convenient functional forms of these meth-
       ods.

METHODS
       canonpath
	 No physical check on the filesystem, but a logical cleanup of a path.

	     $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 :-)

	     $path = File::Spec->catdir( @directories );

       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 );

       curdir
	 Returns a string representation of the current directory.

	     $curdir = File::Spec->curdir();

       devnull
	 Returns a string representation of the null device.

	     $devnull = File::Spec->devnull();

       rootdir
	 Returns a string representation of the root directory.

	     $rootdir = File::Spec->rootdir();

       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();

       updir
	 Returns a string representation of the parent directory.

	     $updir = File::Spec->updir();

       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 );

       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();

       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, 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.

	     @PATH = File::Spec->path();

       join
	 join is the same as catfile.

       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 "catpath()" to get back a path equivalent to (usually iden-
	 tical 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.

       catpath()
	 Takes volume, directory and file portions and returns an entire path. Under Unix, $vol-
	 ume 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 );

       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 con-
	 verted 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 $desti-
	 nation 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 work-
	 ing 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 con-
	 verted 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 work-
	 ing environment, as logicals and macros are expanded.

	 Based on code written by Shigio Yamaguchi.

       For further information, please see File::Spec::Unix, File::Spec::Mac, File::Spec::OS2,
       File::Spec::Win32, or File::Spec::VMS.

SEE ALSO
       File::Spec::Unix, File::Spec::Mac, File::Spec::OS2, File::Spec::Win32, File::Spec::VMS,
       File::Spec::Functions, ExtUtils::MakeMaker

AUTHORS
       Kenneth Albanowski <kjahds@kjahds.com>, Andy Dougherty <doughera@lafayette.edu>, Andreas
       Koenig <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>, and Thomas
       Wegner <wegner_thomas@yahoo.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.

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


All times are GMT -4. The time now is 03:35 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
UNIX.COM Login
Username:
Password:  
Show Password