File::Spec::Unix(Perl Programmers Reference GuFile::Spec::Unix(3)NAMEFile::Spec::Unix - methods used by File::Spec
SYNOPSIS
require File::Spec::Unix; # Done automatically by File::Spec
DESCRIPTION
Methods for manipulating file specifications.
METHODS
canonpath
No physical check on the filesystem, but a logical
cleanup of a path. On UNIX eliminated 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:
$ENV{TMPDIR}
/tmp
updir
Returns a string representation of the parent directory.
".." on UNIX.
no_upwards
Given a list of file names, strip out those that refer
to a parent directory. (Does not strip symlinks, only
'.', '..', and equivalents.)
case_tolerant
Returns a true or false value indicating, respectively,
that alphabetic is not or is significant when comparing
file specifications.
file_name_is_absolute
Takes as argument a path and returns true if it is an
absolute path.
This does not consult the local filesystem on Unix,
Win32, or OS/2. It does sometimes on MacOS (see the
file_name_is_absolute entry in the File::Spec::MacOS
manpage). It does consult the working environment for
VMS (see the file_name_is_absolute entry in the
File::Spec::VMS manpage).
path
Takes no argument, returns the environment variable PATH
as an array.
join
join is the same as catfile.
splitpath
($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 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 the catpath() entry else
where in this document to get back a path equivalent to
(usually identical to) the original path.
splitdir
The opposite of the catdir() entry elsewhere in this
document.
@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 (e.g. MacOS).
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 need
be. 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 the cwd() entry
elsewhere in this document is used. If $base is rela
tive, then it is converted to absolute form using the
rel2abs() entry elsewhere in this document. This means
that it is taken to be relative to the cwd() entry else
where in this document.
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 the rel2abs() entry elsewhere in this document.
This means that it is taken to be relative to the cwd()
entry elsewhere in this document.
No checks against the filesystem are made on most sys
tems. On MacOS, the filesystem may be consulted (see
the file_name_is_absolute entry in the File::Spec::MacOS
manpage). 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 the cwd() entry
elsewhere in this document is used. If $base is rela
tive, then it is converted to absolute form using the
rel2abs() entry elsewhere in this document. This means
that it is taken to be relative to the cwd() entry else
where in this document.
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 the canonpath() entry elsewhere in this document.
No checks against the filesystem are made on most sys
tems. On MacOS, the filesystem may be consulted (see
the file_name_is_absolute entry in the File::Spec::MacOS
manpage). On VMS, there is interaction with the working
environment, as logicals and macros are expanded.
Based on code written by Shigio Yamaguchi.
SEE ALSO
the File::Spec manpage
2001-03-03 perl v5.6.1 File::Spec::Unix(3)
