vms.pm

source of perl for linux application,

    $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;
}


=item catpath (override)

Construct a complete filespec using VMS syntax

=cut

sub catpath {
    my($self,$dev,$dir,$file) = @_;
    
    # We look for a volume in $dev, then in $dir, but not both
    my ($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)) {
      $dir = "[$dir]" unless $dir =~ /[\[<\/]/;
      $dir = vmspath($dir);
    }
    "$dev$dir$file";
}

=item abs2rel (override)

Use VMS syntax when converting filespecs.

=cut

sub abs2rel {
    my $self = shift;
    return vmspath(File::Spec::Unix::abs2rel( $self, @_ ))
        if grep m{/}, @_;

    my($path,$base) = @_;
    $base = $self->_cwd() unless defined $base and length $base;

    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 ) ) ;
}


=item rel2abs (override)

Use VMS syntax when converting filespecs.

=cut

sub rel2abs {
    my $self = shift ;
    my ($path,$base ) = @_;
    return undef unless defined $path;
    if ($path =~ m/\//) {
	$path = ( -d $path || $path =~ m/\/\z/  # educated guessing about
		   ? vmspath($path)             # whether it's a directory
		   : vmsify($path) );
    }
    $base = vmspath($base) if defined $base && $base =~ m/\//;
    # 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 ) ;
        }

        # 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 = '' ;
        $sep = '.'
            if ( $base_directories =~ m{[^.\]>]\Z(?!\n)} &&
                 $path_directories =~ m{^[^.\[<]}s
            ) ;
        $base_directories = "$base_directories$sep$path_directories";
        $base_directories =~ s{\.?[\]>][\[<]\.?}{.};

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


=back

=head1 COPYRIGHT

Copyright (c) 2004 by the Perl 5 Porters.  All rights reserved.

This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=head1 SEE ALSO

See L<File::Spec> and L<File::Spec::Unix>.  This package overrides the
implementation of these methods, not the semantics.

An explanation of VMS file specs can be found at
L<"http://h71000.www7.hp.com/doc/731FINAL/4506/4506pro_014.html#apps_locating_naming_files">.

=cut

1;