file::spec::unix(3)

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 ) ;

catdir()

Concatenate two or more directory names to form a com
plete 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 direc
tory. "." 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->split

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

path( $path, $no_file );

Splits a path in to volume, directory, and filename por
tions. 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 direc
tory and file are catenated. 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 desti
nation 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(3)