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Manpage of File::Spec::Unix

File::Spec::Unix

Section: Perl Programmers Reference Guide (3perl)
Updated: 2005-03-28
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NAME

File::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 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


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 ``file_name_is_absolute'' in File::Spec::MacOS). 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 (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 directory 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 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 most systems. On MacOS, the filesystem may be consulted (see ``file_name_is_absolute'' in File::Spec::MacOS). 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 most systems. On MacOS, the filesystem may be consulted (see ``file_name_is_absolute'' in File::Spec::MacOS). 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


 

Index

NAME
SYNOPSIS
DESCRIPTION
METHODS
SEE ALSO

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Time: 16:13:56 GMT, April 19, 2024