Provided by: wml_2.0.12ds1-10build2_amd64 
NAME
abs2rel - convert an absolute path to a relative path
rel2abs - convert a relative path to an absolute path
realpath - convert a logical path to a physical path (resolve symlinks)
splitpath - split a path in to volume, directory and filename components
joinpath - join volume, directory, and filename components to form a path
splitdirs - split directory specification in to component names
joindirs - join component names in to a directory specification
setfstype - set the file system type
SYNOPSIS
use File::PathConvert qw(realpath abs2rel rel2abs setfstype splitpath
joinpath splitdirs joindirs $resolved);
$relpath = abs2rel($abspath);
$abspath = abs2rel($abspath, $base);
$abspath = rel2abs($relpath);
$abspath = rel2abs($relpath, $base);
$path = realpath($logpath) || die "resolution stopped at $resolved";
( $volume, $directory, $filename )= splitpath( $path ) ;
( $volume, $directory, $filename )= splitpath( $path, 'nofile' ) ;
$path= joinpath( $volume, $directory, $filename ) ;
@directories= splitdirs( $directory ) ;
$directory= joindirs( @directories ) ;
DESCRIPTION
File::PathConvert provides functions to convert between absolute and relative paths, and
from logical paths to physical paths on a variety of filesystems, including the URL
'filesystem'.
Paths are decomposed internally in to volume, directory, and, sometimes filename portions
as appropriate to the operation and filesystem, then recombined. This preserves the
volume and filename portions so that they may be returned, and prevents them from
interfering with the path conversions.
Here are some examples of path decomposition. A '****' in a column indicates the column
is not used in "abs2rel" and "rel2abs" functions for that filesystem type.
FS VOLUME Directory filename
======= ======================= =============== =============
URL http: /a/b/ c?query
http://fubar.com /a/b/ c?query
//p.d.q.com /a/b/c/ ?query
VMS Server::Volume: [a.b] c
Server"access spec":: [a.b] c
Volume: [a.b] c
Win32 A: \a\b\c ****
\\server\Volume \a\b\c ****
\\server\Volume \a/b/c ****
Unix **** \a\b\c ****
MacOS Volume:: a:b:c ****
Many more examples abound in the test.pl included with this module.
Only the VMS and URL filesystems indicate if the last name in a path is a directory or
file. For other filesystems, all non-volume names are assumed to be directory names. For
URLs, the last name in a path is assumed to be a filename unless it ends in '/', '/.', or
'/..'.
Other assumptions are made as well, especially MacOS and VMS. THESE MAY CHANGE BASED ON
PROGRAMMER FEEDBACK!
The conversion routines "abs2rel", "rel2abs", and "realpath" are the main focus of this
package. "splitpath" and "joinpath" are provided to allow volume oriented filesystems
(almost anything non-unixian, actually) to be accomodated. "splitdirs" and "joindirs"
provide directory path grammar parsing and encoding, which is especially useful for VMS.
setfstype
This is called automatically on module load to set the filesystem type according to
$^O. The user can call this later set the filesystem type manually. If the name is
not recognized, unix defaults are used. Names matching /^URL$/i, /^VMS$/i,
/^MacOS$/i, or /^(ms)?(win|dos)/32|nt)?$/i yield the appropriate (hopefully)
filesystem settings. These strings may be generalized in the future.
Examples:
File::PathConvert::setfstype( 'url' ) ;
File::PathConvert::setfstype( 'Win32' ) ;
File::PathConvert::setfstype( 'HAL9000' ) ; # Results in Unix default
abs2rel
"abs2rel" converts an absolute path name to a relative path: converting /1/2/3/a/b/c
relative to /1/2/3 returns a/b/c
$relpath= abs2rel( $abspath ) ;
$relpath= abs2rel( $abspath, $base ) ;
If $abspath is already relative, it is returned unchanged. Otherwise the relative
path from $base to $abspath is returned. If $base is undefined the current directory
is used.
The volume and filename portions of $base are ignored if present. If $abspath and
$base are on different volumes, the volume from $abspath is used.
No filesystem calls are made except for getting the current working directory if $base
is undefined, so symbolic links are not checked for or resolved, and no check is done
for existence.
Examples
# Unix
'a/b/c' == abs2rel( 'a/b/c', $anything )
'a/b/c' == abs2rel( '/1/2/3/a/b/c', '/1/2/3' )
# DOS
'a\\b/c' == abs2rel( 'a\\b/c', $anything )
'a\\b/c' == abs2rel( '/1\\2/3/a\\b/c', '/1/2/3' )
# URL
'http:a/b/c' == abs2rel( 'http:a/b/c', $anything )
'http:a/b/c' == abs2rel( 'http:/1/2/3/a/b/c',
'ftp://t.org/1/2/3/?z' )
'http:a/b/c?q' == abs2rel( 'http:/1/2/3/a/b/c/?q',
'ftp://t.org/1/2/3?z' )
'http://s.com/a/b/c?q' == abs2rel( 'http://s.com/1/2/3/a/b/c?q',
'ftp://t.org/1/2/3/?z')
rel2abs
"rel2abs" makes converts a relative path name to an absolute path: converting a/b/c
relative to /1/2/3 returns /1/2/3/a/b/c.
$abspath= rel2abs( $relpath ) ;
$abspath= rel2abs( $relpath, $base ) ;
If $relpath is already absolute, it is returned unchanged. Otherwise $relpath is
taken to be relative to $base and the resulting absolute path is returned. If $base
is not supplied, the current working directory is used.
The volume portion of $relpath is ignored. The filename portion of $base is also
ignored. The volume from $base is returned if present. The filename portion of
$abspath is returned if present.
No filesystem calls are made except for getting the current working directory if $base
is undefined, so symbolic links are not checked for or resolved, and no check is done
for existence.
"rel2abs" will not return a path of the form "./file".
Examples
# Unix
'/a/b/c' == rel2abs( '/a/b/c', $anything )
'/1/2/3/a/b/c' == rel2abs( 'a/b/c', '/1/2/3' )
# DOS
'\\a\\b/c' == rel2abs( '\\a\\b/c', $anything )
'/1\\2/3\\a\\b/c' == rel2abs( 'a\\b/c', '/1\\2/3' )
'C:/1\\2/3\\a\\b/c' == rel2abs( 'D:a\\b/c', 'C:/1\\2/3' )
'\\\\s\\v/1\\2/3\\a\\b/c' == rel2abs( 'D:a\\b/c', '\\\\s\\v/1\\2/3' )
# URL
'http:/a/b/c?q' == rel2abs( 'http:/a/b/c?q', $anything )
'ftp://t.org/1/2/3/a/b/c?q'== rel2abs( 'http:a/b/c?q',
'ftp://t.org/1/2/3?z' )
realpath
"realpath" makes a canonicalized absolute pathname and resolves all symbolic links,
extra ``/'' characters, and references to /./ and /../ in the path. "realpath"
resolves both absolute and relative paths. It returns the resolved name on success,
otherwise it returns undef and sets the valiable $File::PathConvert::resolved to the
pathname that caused the problem.
All but the last component of the path must exist.
This implementation is based on 4.4BSD realpath(3). It is not tested under other
operating systems at this time.
If '/sys' is a symbolic link to '/usr/src/sys':
chdir('/usr');
'/usr/src/sys/kern' == realpath('../sys/kern');
'/usr/src/sys/kern' == realpath('/sys/kern');
splitpath
To be written...
joinpath
To be written...
Note that "joinpath( splitpath( $path ) )" usually yields path. URLs with directory
components ending in '/.' or '/..' will be fixed up to end in '/./' and '/../'.
splitdirs
To be written...
joindirs
BUGS
"realpath" is not fully multiplatform.
LIMITATIONS
• In URLs, paths not ending in '/' are split such that the last name in the path is a
filename. This is not intuitive: many people use such URLs for directories, and most
servers send a redirect. This may cause programmers using this package to code in
bugs, it may be more pragmatic to always assume all names are directory names. (Note
that the query portion is always part of the filename).
• If the relative and base paths are on different volumes, no error is returned. A
silent, hopefully reasonable assumption is made.
• No detection of unix style paths is done when other filesystems are selected, like
File::Basename does.
AUTHORS
Barrie Slaymaker <rbs@telerama.com> Shigio Yamaguchi <shigio@wafu.netgate.net>