package File::Spec::VMS;

use strict;
use vars qw(@ISA $VERSION);
require File::Spec::Unix;

$VERSION = '3.30';
$VERSION = eval $VERSION;

@ISA = qw(File::Spec::Unix);

use File::Basename;
use VMS::Filespec;

# Need to look up the feature settings.  The preferred way is to use the
# VMS::Feature module, but that may not be available to dual life modules.

my $use_feature;
BEGIN {
    if (eval { local $SIG{__DIE__}; require VMS::Feature; }) {
        $use_feature = 1;
    }
}

# Need to look up the UNIX report mode.  This may become a dynamic mode
# in the future.
sub _unix_rpt {
    my $unix_rpt;
    if ($use_feature) {
        $unix_rpt = VMS::Feature::current("filename_unix_report");
    } else {
        my $env_unix_rpt = $ENV{'DECC$FILENAME_UNIX_REPORT'} || '';
        $unix_rpt = $env_unix_rpt =~ /^[ET1]/i; 
    }
    return $unix_rpt;
}

# Need to look up the EFS character set mode.  This may become a dynamic
# mode in the future.
sub _efs {
    my $efs;
    if ($use_feature) {
        $efs = VMS::Feature::current("efs_charset");
    } else {
        my $env_efs = $ENV{'DECC$EFS_CHARSET'} || '';
        $efs = $env_efs =~ /^[ET1]/i; 
    }
    return $efs;
}


sub canonpath {
    my($self,$path) = @_;

    return undef unless defined $path;

    my $efs = $self->_efs;

    if ($path =~ m|/|) { # Fake Unix
      my $pathify = $path =~ m|/\Z(?!\n)|;
      $path = $self->SUPER::canonpath($path);

      # Do not convert to VMS when EFS character sets are in use
      return $path if $efs;

      if ($pathify) { return vmspath($path); }
      else          { return vmsify($path);  }
    }
    else {

#FIXME - efs parsing has different rules.  Characters in a VMS filespec
#        are only delimiters if not preceded by '^';

	$path =~ tr/<>/[]/;			# < and >       ==> [ and ]
	$path =~ s/\]\[\./\.\]\[/g;		# ][.		==> .][
	$path =~ s/\[000000\.\]\[/\[/g;		# [000000.][	==> [
	$path =~ s/\[000000\./\[/g;		# [000000.	==> [
	$path =~ s/\.\]\[000000\]/\]/g;		# .][000000]	==> ]
	$path =~ s/\.\]\[/\./g;			# foo.][bar     ==> foo.bar
	1 while ($path =~ s/([\[\.])(-+)\.(-+)([\.\]])/$1$2$3$4/);
						# That loop does the following
						# with any amount of dashes:
						# .-.-.		==> .--.
						# [-.-.		==> [--.
						# .-.-]		==> .--]
						# [-.-]		==> [--]
	1 while ($path =~ s/([\[\.])[^\]\.]+\.-(-+)([\]\.])/$1$2$3/);
						# That loop does the following
						# with any amount (minimum 2)
						# of dashes:
						# .foo.--.	==> .-.
						# .foo.--]	==> .-]
						# [foo.--.	==> [-.
						# [foo.--]	==> [-]
						#
						# And then, the remaining cases
	$path =~ s/\[\.-/[-/;			# [.-		==> [-
	$path =~ s/\.[^\]\.]+\.-\./\./g;	# .foo.-.	==> .
	$path =~ s/\[[^\]\.]+\.-\./\[/g;	# [foo.-.	==> [
	$path =~ s/\.[^\]\.]+\.-\]/\]/g;	# .foo.-]	==> ]
	$path =~ s/\[[^\]\.]+\.-\]/\[000000\]/g;# [foo.-]       ==> [000000]
	$path =~ s/\[\]// unless $path eq '[]';	# []		==>
	return $path;
    }
}

sub catdir {
    my $self = shift;
    my $dir = pop;

    my $efs = $self->_efs;
    my $unix_rpt = $self->_unix_rpt;


    my @dirs = grep {defined() && length()} @_;
    if ($efs) {
        # Legacy mode removes blank entries.
        # But that breaks existing generic perl code that
        # uses a blank path at the beginning of the array
        # to indicate an absolute path.
        # So put it back if found.
        if (@_) {
            if ($_[0] eq '') {
                unshift @dirs, '';
            }
        }
    }

    my $rslt;
    if (@dirs) {
	my $path = (@dirs == 1 ? $dirs[0] : $self->catdir(@dirs));
	my ($spath,$sdir) = ($path,$dir);

        if ($efs) {
            # Extended character set in use, go into DWIM mode.

            # Now we need to identify what the directory is in
            # of the specification in order to merge them.
            my $path_unix = 0;
            $path_unix = 1 if ($path =~ m#/#);
            $path_unix = 1 if ($path =~ /^\.\.?$/);
            my $path_vms = 0;
            $path_vms = 1 if ($path =~ m#[\[<\]]#);
            $path_vms = 1 if ($path =~ /^--?$/);
            my $dir_unix = 0;
            $dir_unix = 1 if ($dir =~ m#/#);
            $dir_unix = 1 if ($dir =~ /^\.\.?$/);
            my $dir_vms = 0;
            $dir_vms = 1 if ($dir =~ m#[\[<\]]#);
            $dir_vms = 1 if ($dir =~ /^--?$/);

            my $unix_mode = 0;
            if (($path_unix != $dir_unix) && ($path_vms != $dir_vms)) {
                # Ambiguous, so if in $unix_rpt mode then assume UNIX.
                $unix_mode = 1 if $unix_rpt;
            } else {
                $unix_mode = 1 if (!$path_vms && !$dir_vms && $unix_rpt);
                $unix_mode = 1 if ($path_unix || $dir_unix);
            }

            if ($unix_mode) {

                # Fix up mixed syntax imput as good as possible - GIGO
                $path = unixify($path) if $path_vms;
                $dir = unixify($dir) if $dir_vms;

                $rslt = $path;
                # Append a path delimiter
                $rslt .= '/' unless ($rslt =~ m#/$#);

                $rslt .= $dir;
                return $self->SUPER::canonpath($rslt);
            } else {

                #with <> posible instead of [.
                # Normalize the brackets
                # Fixme - need to not switch when preceded by ^.
                $path =~ s/</\[/g;
                $path =~ s/>/\]/g;
                $dir =~ s/</\[/g;
                $dir =~ s/>/\]/g;

                # Fix up mixed syntax imput as good as possible - GIGO
                $path = vmsify($path) if $path_unix;
                $dir = vmsify($dir) if $dir_unix;

                #Possible path values: foo: [.foo] [foo] foo, and $(foo)
                #or starting with '-', or foo.dir
                #If path is foo, it needs to be converted to [.foo]

                # Fix up a bare path name.
                unless ($path_vms) {
                    $path =~ s/\.dir\Z(?!\n)//i;
                    if (($path ne '') && ($path !~ /^-/)) {
                        # Non blank and not prefixed with '-', add a dot
                        $path = '[.' . $path;
                    } else {
                        # Just start a directory.
                        $path = '[' . $path;
                    }
                } else {
                    $path =~ s/\]$//;
                }

                #Possible dir values: [.dir] dir and $(foo)

                # No punctuation may have a trailing .dir
                unless ($dir_vms) {
                    $dir =~ s/\.dir\Z(?!\n)//i;
                } else {

                    #strip off the brackets
                    $dir =~ s/^\[//;
                    $dir =~ s/\]$//;
                }

                #strip off the leading dot if present.
                $dir =~ s/^\.//;

                # Now put the specifications together.
                if ($dir ne '') {
                    # Add a separator unless this is an absolute path
                    $path .= '.' if ($path ne '[');
                    $rslt = $path . $dir . ']';
                } else {
                    $rslt = $path . ']';
                }
            }

	} else {
	    # Traditional ODS-2 mode.
	    $spath =~ s/\.dir\Z(?!\n)//i; $sdir =~ s/\.dir\Z(?!\n)//i; 

	    $sdir = $self->eliminate_macros($sdir)
		unless $sdir =~ /^[\w\-]+\Z(?!\n)/s;
	    $rslt = $self->fixpath($self->eliminate_macros($spath)."/$sdir",1);

	    # Special case for VMS absolute directory specs: these will have
	    # had device prepended during trip through Unix syntax in
	    # eliminate_macros(), since Unix syntax has no way to express
	    # "absolute from the top of this device's directory tree".
	    if ($spath =~ /^[\[<][^.\-]/s) { $rslt =~ s/^[^\[<]+//s; }
	} 
    } else {
	# Single directory, just make sure it is in directory format
	# Return an empty string on null input, and pass through macros.

	if    (not defined $dir or not length $dir) { $rslt = ''; }
	elsif ($dir =~ /^\$\([^\)]+\)\Z(?!\n)/s) { 
	    $rslt = $dir;
	} else {
            my $unix_mode = 0;

            if ($efs) {
                my $dir_unix = 0;
                $dir_unix = 1 if ($dir =~ m#/#);
                $dir_unix = 1 if ($dir =~ /^\.\.?$/);
                my $dir_vms = 0;
                $dir_vms = 1 if ($dir =~ m#[\[<\]]#);
                $dir_vms = 1 if ($dir =~ /^--?$/);

                if ($dir_vms == $dir_unix) {
                    # Ambiguous, so if in $unix_rpt mode then assume UNIX.
                    $unix_mode = 1 if $unix_rpt;
                } else {
                    $unix_mode = 1 if $dir_unix;
                }
            }

            if ($unix_mode) {
                return $dir;
            } else {
                # For VMS, force it to be in directory format
	 	$rslt = vmspath($dir);
	    }
	}
    }
    return $self->canonpath($rslt);
}

sub catfile {
    my $self = shift;
    my $tfile = pop();
    my $file = $self->canonpath($tfile);
    my @files = grep {defined() && length()} @_;

    my $efs = $self->_efs;
    my $unix_rpt = $self->_unix_rpt;

    # Assume VMS mode
    my $unix_mode = 0;
    my $file_unix = 0;
    my $file_vms = 0;
    if ($efs) {

        # Now we need to identify format the file is in
        # of the specification in order to merge them.
        $file_unix = 1 if ($tfile =~ m#/#);
        $file_unix = 1 if ($tfile =~ /^\.\.?$/);
        $file_vms = 1 if ($tfile =~ m#[\[<\]]#);
        $file_vms = 1 if ($tfile =~ /^--?$/);

        # We may know for sure what the format is.
        if (($file_unix != $file_vms)) {
            $unix_mode = 1 if ($file_unix && $unix_rpt);
        }
    }

    my $rslt;
    if (@files) {
	# concatenate the directories.
	my $path;
        if (@files == 1) {
           $path = $files[0];
        } else {
            if ($file_vms) {
                # We need to make sure this is in VMS mode to avoid doing
                # both a vmsify and unixfy on the same path, as that may
                # lose significant data.
                my $i = @files - 1;
                my $tdir = $files[$i];
                my $tdir_vms = 0;
                my $tdir_unix = 0;
                $tdir_vms = 1 if ($tdir =~ m#[\[<\]]#);
                $tdir_unix = 1 if ($tdir =~ m#/#);
                $tdir_unix = 1 if ($tdir =~ /^\.\.?$/);

                if (!$tdir_vms) {
                    if ($tdir_unix) { 
                        $tdir = vmspath($tdir);
                    } else {
                        $tdir =~ s/\.dir\Z(?!\n)//i;
                        $tdir = '[.' . $tdir . ']';
                    }
                    $files[$i] = $tdir;
                }
            }
            $path = $self->catdir(@files);
        }
	my $spath = $path;

        # Some thing building a VMS path in pieces may try to pass a
        # directory name in filename format, so normalize it.
	$spath =~ s/\.dir\Z(?!\n)//i;

        # if the spath ends with a directory delimiter and the file is bare,
        # then just concat them.
        # FIX-ME: In VMS format "[]<>:" are not delimiters if preceded by '^' 
        # Quite a bit of Perl does not know that yet.
	if ($spath =~ /^[^\)\]\/:>]+\)\Z(?!\n)/s && basename($file) eq $file) {
	    $rslt = "$spath$file";
	} else {
            if ($efs) {

                # Now we need to identify what the directory is in
                # of the specification in order to merge them.
                my $spath_unix = 0;
                $spath_unix = 1 if ($spath =~ m#/#);
                $spath_unix = 1 if ($spath =~ /^\.\.?$/);
                my $spath_vms = 0;
                $spath_vms = 1 if ($spath =~ m#[\[<\]]#);
                $spath_vms = 1 if ($spath =~ /^--?$/);

                # Assume VMS mode
                if (($spath_unix == $spath_vms) &&
                    ($file_unix == $file_vms)) {
                     # Ambigous, so if in $unix_rpt mode then assume UNIX.
                     $unix_mode = 1 if $unix_rpt;
                } else {
                     $unix_mode = 1
                         if (($spath_unix || $file_unix) && $unix_rpt);
                }

                if (!$unix_mode) {
                    if ($spath_vms) {
                        $spath = '[' . $spath . ']' if $spath =~ /^-/;
                        $rslt = vmspath($spath);
                    } else {
                        $rslt = '[.' . $spath . ']';
                    }
                    $file = vmsify($file) if ($file_unix);
                } else {
                    $spath = unixify($spath) if ($spath_vms);
                    $rslt = $spath;
                    $file = unixify($file) if ($file_vms);

                    # Unix merge may need a directory delimitor.
                    # A null path indicates root on Unix.
                    $rslt .= '/' unless ($rslt =~ m#/$#);
                }

                $rslt .= $file;
                $rslt =~ s/\]\[//;

	    } else {
		# Traditional VMS Perl mode expects that this is done.
		# Note for future maintainers:
		# This is left here for compatibility with perl scripts
		# that have come to expect this behavior, even though
		# usually the Perl scripts ported to VMS have to be
		# patched because of it changing Unix syntax file
		# to VMS format.

		$rslt = $self->eliminate_macros($spath);


	        $rslt = vmsify($rslt.((defined $rslt) &&
		    ($rslt ne '') ? '/' : '').unixify($file));
	    }
	}
    }
    else {
        # Only passed a single file?
        my $xfile = $file;

        # Traditional VMS perl expects this conversion.
        $xfile = vmsify($file) unless ($efs);

        $rslt = (defined($file) && length($file)) ? $xfile : '';
    }
    return $self->canonpath($rslt) unless $unix_rpt;

    # In Unix report mode, do not strip off redundent path information.
    return $rslt;
}


sub curdir {
    my $self = shift @_;
    return '.' if ($self->_unix_rpt);
    return '[]';
}

sub devnull {
    my $self = shift @_;
    return '/dev/null' if ($self->_unix_rpt);
    return "_NLA0:";
}

sub rootdir {
    my $self = shift @_;
    if ($self->_unix_rpt) {
       # Root may exist, try it first.
       my $try = '/';
       my ($dev1, $ino1) = stat('/');
       my ($dev2, $ino2) = stat('.');

       # Perl falls back to '.' if it can not determine '/'
       if (($dev1 != $dev2) || ($ino1 != $ino2)) {
           return $try;
       }
       # Fall back to UNIX format sys$disk.
       return '/sys$disk/';
    }
    return 'SYS$DISK:[000000]';
}

my $tmpdir;
sub tmpdir {
    my $self = shift @_;
    return $tmpdir if defined $tmpdir;
    if ($self->_unix_rpt) {
        $tmpdir = $self->_tmpdir('/tmp', '/sys$scratch', $ENV{TMPDIR});
        return $tmpdir;
    }

    $tmpdir = $self->_tmpdir( 'sys$scratch:', $ENV{TMPDIR} );
}

sub updir {
    my $self = shift @_;
    return '..' if ($self->_unix_rpt);
    return '[-]';
}

sub case_tolerant {
    return 1;
}

sub path {
    my (@dirs,$dir,$i);
    while ($dir = $ENV{'DCL$PATH;' . $i++}) { push(@dirs,$dir); }
    return @dirs;
}

sub file_name_is_absolute {
    my ($self,$file) = @_;
    # If it's a logical name, expand it.
    $file = $ENV{$file} while $file =~ /^[\w\$\-]+\Z(?!\n)/s && $ENV{$file};
    return scalar($file =~ m!^/!s             ||
		  $file =~ m![<\[][^.\-\]>]!  ||
		  $file =~ /:[^<\[]/);
}

sub splitpath {
    my($self,$path, $nofile) = @_;
    my($dev,$dir,$file)      = ('','','');
    my $efs = $self->_efs;
    my $vmsify_path = vmsify($path);
    if ($efs) {
        my $path_vms = 0;
        $path_vms = 1 if ($path =~ m#[\[<\]]#);
        $path_vms = 1 if ($path =~ /^--?$/);
        if (!$path_vms) {
            return $self->SUPER::splitpath($path, $nofile);
        }
        $vmsify_path = $path;
    }

    if ( $nofile ) {
        #vmsify('d1/d2/d3') returns '[.d1.d2]d3'
        #vmsify('/d1/d2/d3') returns 'd1:[d2]d3'
        if( $vmsify_path =~ /(.*)\](.+)/ ){
            $vmsify_path = $1.'.'.$2.']';
        }
        $vmsify_path =~ /(.+:)?(.*)/s;
        $dir = defined $2 ? $2 : ''; # dir can be '0'
        return ($1 || '',$dir,$file);
    }
    else {
        $vmsify_path =~ /(.+:)?([\[<].*[\]>])?(.*)/s;
        return ($1 || '',$2 || '',$3);
    }
}

sub splitdir {
    my($self,$dirspec) = @_;
    my @dirs = ();
    return @dirs if ( (!defined $dirspec) || ('' eq $dirspec) );

    my $efs = $self->_efs;

    my $dir_unix = 0;
    $dir_unix = 1 if ($dirspec =~ m#/#);
    $dir_unix = 1 if ($dirspec =~ /^\.\.?$/);

    # Unix filespecs in EFS mode handled by Unix routines.
    if ($efs && $dir_unix) {
        return $self->SUPER::splitdir($dirspec);
    }

    # FIX ME, only split for VMS delimiters not prefixed with '^'.

    $dirspec =~ tr/<>/[]/;			# < and >	==> [ and ]
    $dirspec =~ s/\]\[\./\.\]\[/g;		# ][.		==> .][
    $dirspec =~ s/\[000000\.\]\[/\[/g;		# [000000.][	==> [
    $dirspec =~ s/\[000000\./\[/g;		# [000000.	==> [
    $dirspec =~ s/\.\]\[000000\]/\]/g;		# .][000000]	==> ]
    $dirspec =~ s/\.\]\[/\./g;			# foo.][bar	==> foo.bar
    while ($dirspec =~ s/(^|[\[\<\.])\-(\-+)($|[\]\>\.])/$1-.$2$3/g) {}
						# That loop does the following
						# with any amount of dashes:
						# .--.		==> .-.-.
						# [--.		==> [-.-.
						# .--]		==> .-.-]
						# [--]		==> [-.-]
    $dirspec = "[$dirspec]" unless $dirspec =~ /[\[<]/; # make legal
    $dirspec =~ s/^(\[|<)\./$1/;
    @dirs = split /(?<!\^)\./, vmspath($dirspec);
    $dirs[0] =~ s/^[\[<]//s;  $dirs[-1] =~ s/[\]>]\Z(?!\n)//s;
    @dirs;
}


sub catpath {
    my($self,$dev,$dir,$file) = @_;
    
    my $efs = $self->_efs;
    my $unix_rpt = $self->_unix_rpt;

    my $unix_mode = 0;
    my $dir_unix = 0;
    $dir_unix = 1 if ($dir =~ m#/#);
    $dir_unix = 1 if ($dir =~ /^\.\.?$/);
    my $dir_vms = 0;
    $dir_vms = 1 if ($dir =~ m#[\[<\]]#);
    $dir_vms = 1 if ($dir =~ /^--?$/);

    if ($efs && (length($dev) == 0)) {
        if ($dir_unix == $dir_vms) {
            $unix_mode = $unix_rpt;
        } else {
            $unix_mode = $dir_unix;
        }
    } 

    # We look for a volume in $dev, then in $dir, but not both
    # but only if using VMS syntax.
    if (!$unix_mode) {
        $dir = vmspath($dir) if $dir_unix;
        my ($dir_volume, $dir_dir, $dir_file) = $self->splitpath($dir);
        $dev = $dir_volume unless length $dev;
        $dir = length $dir_file ? $self->catfile($dir_dir, $dir_file) :
                                  $dir_dir;
    }
    if ($dev =~ m|^/+([^/]+)|) { $dev = "$1:"; }
    else { $dev .= ':' unless $dev eq '' or $dev =~ /:\Z(?!\n)/; }
    if (length($dev) or length($dir)) {
      if ($efs) {
          if ($unix_mode) {
              $dir .= '/' unless ($dir =~ m#/$#);
          } else {
              $dir = vmspath($dir) if (($dir =~ m#/#) || ($dir =~ /^\.\.?$/));
              $dir = "[$dir]" unless $dir =~ /^[\[<]/;
          }
      } else {
          $dir = "[$dir]" unless $dir =~ /[\[<\/]/;
          $dir = vmspath($dir);
      }
    }
    "$dev$dir$file";
}

sub abs2rel {
    my $self = shift;
    my($path,$base) = @_;

    my $efs = $self->_efs;
    my $unix_rpt = $self->_unix_rpt;

    if (!$efs) {
        return vmspath(File::Spec::Unix::abs2rel( $self, @_ ))
            if grep m{/}, @_;
    }

    # We need to identify what the directory is in
    # of the specification in order to process them
    my $path_unix = 0;
    $path_unix = 1 if ($path =~ m#/#);
    $path_unix = 1 if ($path =~ /^\.\.?$/);
    my $path_vms = 0;
    $path_vms = 1 if ($path =~ m#[\[<\]]#);
    $path_vms = 1 if ($path =~ /^--?$/);

    my $unix_mode = 0;
    if ($path_vms == $path_unix) {
        $unix_mode = $unix_rpt;
    } else {
        $unix_mode = $path_unix;
    }

    my $base_unix = 0;
    my $base_vms = 0;

    if (defined $base) {
        $base_unix = 1 if ($base =~ m#/#);
        $base_unix = 1 if ($base =~ /^\.\.?$/);
        $base_vms = 1 if ($base =~ m#[\[<\]]#);
        $base_vms = 1 if ($base =~ /^--?$/);

        if ($path_vms == $path_unix) {
            if ($base_vms == $base_unix) {
                $unix_mode = $unix_rpt;
            } else {
                $unix_mode = $base_unix;
            }
        } else {
            $unix_mode = 0 if $base_vms;
        }
    }

    if ($efs) {
        if ($unix_mode) {
            # We are UNIX mode.
            $base = unixpath($base) if $base_vms;
            $base = unixify($path) if $path_vms;

            # Here VMS is different, and in order to do this right
            # we have to take the realpath for both the path and the base
            # so that we can remove the common components.

            if ($path =~ m#^/#) {
                if (defined $base) {

                    # For the shorterm, if the starting directories are
                    # common, remove them.
                    my $bq = qq($base);
                    $bq =~ s/\$/\\\$/;
                    $path =~ s/^$bq//i;
                }
                return $path;
            }

            return File::Spec::Unix::abs2rel( $self, $path, $base );

        } else {
            $base = vmspath($base) if $base_unix;
            $path = vmsify($path) if $path_unix;
        }
    }

    unless (defined $base and length $base) {
        $base = $self->_cwd();
        if ($efs) {
            $base_unix = 1 if ($base =~ m#/#);
            $base_unix = 1 if ($base =~ /^\.\.?$/);
            $base = vmspath($base) if $base_unix;
        }
    }

    for ($path, $base) { $_ = $self->canonpath($_) }

    # Are we even starting $path on the same (node::)device as $base?  Note that
    # logical paths or nodename differences may be on the "same device" 
    # but the comparison that ignores device differences so as to concatenate 
    # [---] up directory specs is not even a good idea in cases where there is 
    # a logical path difference between $path and $base nodename and/or device.
    # Hence we fall back to returning the absolute $path spec
    # if there is a case blind device (or node) difference of any sort
    # and we do not even try to call $parse() or consult %ENV for $trnlnm()
    # (this module needs to run on non VMS platforms after all).
    
    my ($path_volume, $path_directories, $path_file) = $self->splitpath($path);
    my ($base_volume, $base_directories, $base_file) = $self->splitpath($base);
    return $path unless lc($path_volume) eq lc($base_volume);

    for ($path, $base) { $_ = $self->rel2abs($_) }

    # Now, remove all leading components that are the same
    my @pathchunks = $self->splitdir( $path_directories );
    my $pathchunks = @pathchunks;
    unshift(@pathchunks,'000000') unless $pathchunks[0] eq '000000';
    my @basechunks = $self->splitdir( $base_directories );
    my $basechunks = @basechunks;
    unshift(@basechunks,'000000') unless $basechunks[0] eq '000000';

    while ( @pathchunks && 
            @basechunks && 
            lc( $pathchunks[0] ) eq lc( $basechunks[0] ) 
          ) {
        shift @pathchunks ;
        shift @basechunks ;
    }

    # @basechunks now contains the directories to climb out of,
    # @pathchunks now has the directories to descend in to.
    if ((@basechunks > 0) || ($basechunks != $pathchunks)) {
      $path_directories = join '.', ('-' x @basechunks, @pathchunks) ;
    }
    else {
      $path_directories = join '.', @pathchunks;
    }
    $path_directories = '['.$path_directories.']';
    return $self->canonpath( $self->catpath( '', $path_directories, $path_file ) ) ;
}


sub rel2abs {
    my $self = shift ;
    my ($path,$base ) = @_;
    return undef unless defined $path;

    my $efs = $self->_efs;
    my $unix_rpt = $self->_unix_rpt;

    # We need to identify what the directory is in
    # of the specification in order to process them
    my $path_unix = 0;
    $path_unix = 1 if ($path =~ m#/#);
    $path_unix = 1 if ($path =~ /^\.\.?$/);
    my $path_vms = 0;
    $path_vms = 1 if ($path =~ m#[\[<\]]#);
    $path_vms = 1 if ($path =~ /^--?$/);

    my $unix_mode = 0;
    if ($path_vms == $path_unix) {
        $unix_mode = $unix_rpt;
    } else {
        $unix_mode = $path_unix;
    }

    my $base_unix = 0;
    my $base_vms = 0;

    if (defined $base) {
        $base_unix = 1 if ($base =~ m#/#);
        $base_unix = 1 if ($base =~ /^\.\.?$/);
        $base_vms = 1 if ($base =~ m#[\[<\]]#);
        $base_vms = 1 if ($base =~ /^--?$/);

        # If we could not determine the path mode, see if we can find out
        # from the base.
        if ($path_vms == $path_unix) {
            if ($base_vms != $base_unix) {
                $unix_mode = $base_unix;
            }
        }
    }

    if (!$efs) {
        # Legacy behavior, convert to VMS syntax.
        $unix_mode = 0;
        if (defined $base) {
            $base = vmspath($base) if $base =~ m/\//;
        }

        if ($path =~ m/\//) {
	    $path = ( -d $path || $path =~ m/\/\z/  # educated guessing about
		       ? vmspath($path)             # whether it's a directory
		       : vmsify($path) );
        }
   }

    # Clean up and split up $path
    if ( ! $self->file_name_is_absolute( $path ) ) {
        # Figure out the effective $base and clean it up.
        if ( !defined( $base ) || $base eq '' ) {
            $base = $self->_cwd;
        }
        elsif ( ! $self->file_name_is_absolute( $base ) ) {
            $base = $self->rel2abs( $base ) ;
        }
        else {
            $base = $self->canonpath( $base ) ;
        }

        if ($efs) {
            # base may have changed, so need to look up format again.
            if ($unix_mode) {
                $base_vms = 1 if ($base =~ m#[\[<\]]#);
                $base_vms = 1 if ($base =~ /^--?$/);
                $base = unixpath($base) if $base_vms;
                $base .= '/' unless ($base =~ m#/$#);
            } else {
                $base_unix = 1 if ($base =~ m#/#);
                $base_unix = 1 if ($base =~ /^\.\.?$/);
                $base = vmspath($base) if $base_unix; 
            }
        }

        # Split up paths
        my ( $path_directories, $path_file ) =
            ($self->splitpath( $path ))[1,2] ;

        my ( $base_volume, $base_directories ) =
            $self->splitpath( $base ) ;

        $path_directories = '' if $path_directories eq '[]' ||
                                  $path_directories eq '<>';
        my $sep = '' ;

        if ($efs) {
            # Merge the paths assuming that the base is absolute.
            $base_directories = $self->catdir('',
                                              $base_directories,
                                              $path_directories);
        } else {
            # Legacy behavior assumes VMS only paths
            $sep = '.'
                if ( $base_directories =~ m{[^.\]>]\Z(?!\n)} &&
                     $path_directories =~ m{^[^.\[<]}s
                ) ;
            $base_directories = "$base_directories$sep$path_directories";
            $base_directories =~ s{\.?[\]>][\[<]\.?}{.};
        }

        $path_file = '' if ($path_file eq '.') && $unix_mode;

        $path = $self->catpath( $base_volume, $base_directories, $path_file );
   }

    return $self->canonpath( $path ) ;
}


# eliminate_macros() and fixpath() are MakeMaker-specific methods
# which are used inside catfile() and catdir().  MakeMaker has its own
# copies as of 6.06_03 which are the canonical ones.  We leave these
# here, in peace, so that File::Spec continues to work with MakeMakers
# prior to 6.06_03.
# 
# Please consider these two methods deprecated.  Do not patch them,
# patch the ones in ExtUtils::MM_VMS instead.
#
# Update:  MakeMaker 6.48 is still using these routines on VMS.
# so they need to be kept up to date with ExtUtils::MM_VMS.
#
# The traditional VMS mode using ODS-2 disks depends on these routines
# being here.  These routines should not be called in when the
# C<DECC$EFS_CHARSET> or C<DECC$FILENAME_REPORT_UNIX> modes are enabled.

sub eliminate_macros {
    my($self,$path) = @_;
    return '' unless (defined $path) && ($path ne '');
    $self = {} unless ref $self;

    if ($path =~ /\s/) {
      return join ' ', map { $self->eliminate_macros($_) } split /\s+/, $path;
    }

    my $npath = unixify($path);
    # sometimes unixify will return a string with an off-by-one trailing null
    $npath =~ s{\0$}{};

    my($complex) = 0;
    my($head,$macro,$tail);

    # perform m##g in scalar context so it acts as an iterator
    while ($npath =~ m#(.*?)\$\((\S+?)\)(.*)#gs) { 
        if (defined $self->{$2}) {
            ($head,$macro,$tail) = ($1,$2,$3);
            if (ref $self->{$macro}) {
                if (ref $self->{$macro} eq 'ARRAY') {
                    $macro = join ' ', @{$self->{$macro}};
                }
                else {
                    print "Note: can't expand macro \$($macro) containing ",ref($self->{$macro}),
                          "\n\t(using MMK-specific deferred substitutuon; MMS will break)\n";
                    $macro = "\cB$macro\cB";
                    $complex = 1;
                }
            }
            else { ($macro = unixify($self->{$macro})) =~ s#/\Z(?!\n)##; }
            $npath = "$head$macro$tail";
        }
    }
    if ($complex) { $npath =~ s#\cB(.*?)\cB#\${$1}#gs; }
    $npath;
}

# Deprecated.  See the note above for eliminate_macros().

# Catchall routine to clean up problem MM[SK]/Make macros.  Expands macros
# in any directory specification, in order to avoid juxtaposing two
# VMS-syntax directories when MM[SK] is run.  Also expands expressions which
# are all macro, so that we can tell how long the expansion is, and avoid
# overrunning DCL's command buffer when MM[KS] is running.

# fixpath() checks to see whether the result matches the name of a
# directory in the current default directory and returns a directory or
# file specification accordingly.  C<$is_dir> can be set to true to
# force fixpath() to consider the path to be a directory or false to force
# it to be a file.

sub fixpath {
    my($self,$path,$force_path) = @_;
    return '' unless $path;
    $self = bless {}, $self unless ref $self;
    my($fixedpath,$prefix,$name);

    if ($path =~ /\s/) {
      return join ' ',
             map { $self->fixpath($_,$force_path) }
	     split /\s+/, $path;
    }

    if ($path =~ m#^\$\([^\)]+\)\Z(?!\n)#s || $path =~ m#[/:>\]]#) { 
        if ($force_path or $path =~ /(?:DIR\)|\])\Z(?!\n)/) {
            $fixedpath = vmspath($self->eliminate_macros($path));
        }
        else {
            $fixedpath = vmsify($self->eliminate_macros($path));
        }
    }
    elsif ((($prefix,$name) = ($path =~ m#^\$\(([^\)]+)\)(.+)#s)) && $self->{$prefix}) {
        my($vmspre) = $self->eliminate_macros("\$($prefix)");
        # is it a dir or just a name?
        $vmspre = ($vmspre =~ m|/| or $prefix =~ /DIR\Z(?!\n)/) ? vmspath($vmspre) : '';
        $fixedpath = ($vmspre ? $vmspre : $self->{$prefix}) . $name;
        $fixedpath = vmspath($fixedpath) if $force_path;
    }
    else {
        $fixedpath = $path;
        $fixedpath = vmspath($fixedpath) if $force_path;
    }
    # No hints, so we try to guess
    if (!defined($force_path) and $fixedpath !~ /[:>(.\]]/) {
        $fixedpath = vmspath($fixedpath) if -d $fixedpath;
    }

    # Trim off root dirname if it's had other dirs inserted in front of it.
    $fixedpath =~ s/\.000000([\]>])/$1/;
    # Special case for VMS absolute directory specs: these will have had device
    # prepended during trip through Unix syntax in eliminate_macros(), since
    # Unix syntax has no way to express "absolute from the top of this device's
    # directory tree".
    if ($path =~ /^[\[>][^.\-]/) { $fixedpath =~ s/^[^\[<]+//; }
    $fixedpath;
}


1;
