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# File::Spec::Unix

- NAME
- SYNOPSIS
- DESCRIPTION
- METHODS
- SEE ALSO

## 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 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 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 the catpath() entry elsewhere 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 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 the cwd() manpage is used. If $base is relative, 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() manpage.

  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() manpage.

  No checks against the filesystem are made on most systems. 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() manpage is used. If $base is relative, 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() manpage.

  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 systems. 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

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