use strict;

use CGI;
my $query = CGI->new();

#######################################################################################
#######################################################################################

my $referrer = $ENV{HTTP_REFERER};
my $goto = $referrer;

if ($referrer =~ m|/en/|g) {
$goto =~ s|/en/|/ws/|g;
}
elsif ($referrer =~ m|/ws/|g) {
$goto =~ s|/ws/|/en/|g;
}
else {
die("Can't understand what to translate to.");
}

print $query->redirect($goto);

#!/usr/bin/perl

use strict;
use CGI qw/:redirect/;

my $redir = sub {
my $rev = { en => 'ws', ws => 'en' };
my $ref;
($ref = $ENV{HTTP_REFERER}) =~ s,/(ws|en)/,/$rev->{$1}/,;
return $ref;
};

print redirect(&$redir);