Perl script to build the Ferret environment XML

#!/usr/bin/perl
# Build Ferret environment XML stub
#
my @EnvVars = qw(FER_DIR FER_DESCR FER_DATA FER_GRIDS FER_PALETTE
                 FER_GO PLOTFONTS FER_EXTERNAL_FUNCTIONS DODS_CONF);

        print '    ',"\n";
        foreach my $var (@EnvVars){
            $ENV{$var} = ". " . $ENV{$var} if $var !~ /PLOTFONT/;
            if ($var =~ /FER_GO|FER_PALETTE/){
                $ENV{$var} = "scripts jnls jnls/insitu jnls/section " . $ENV{$var};
                $ENV{$var} = $LasConfig{custom_name} . " " . $ENV{$var}
                    if $LasConfig{custom_name};
            } elsif ($var =~ /FER_DATA/){
                $ENV{$var} = "./data " . $ENV{$var};
            } elsif ($var =~ /FER_DESCR/){
                $ENV{$var} = "des " . $ENV{$var};
            } elsif ($var =~ /DODS_CONF/){
                $ENV{$var} = "dods/.dodsrc";
            }

            my @values = split(' ',$ENV{$var});

            # Trim so ". " and "." match
            foreach my $value (@values) {
               $value = trim($value);
            }

            #Extract unique entries, see perl FAQ
            undef %saw;
            @saw{@values} = ();
            @out = sort keys %saw;  # remove sort if undesired

            print '        ',"\n";
            print '            ',$var,'',"\n";
            foreach my $value (@out) {
               $value = trim($value);
               print '             ',$value,'',"\n";
            }
            print '        ',"\n";
        }
        print '    ',"\n";
        print '',"\n";

sub trim($)
{
        my $string = shift;
        $string =~ s/^\s+//;
        $string =~ s/\s+$//;
        return $string;
}