% test.pl
    ca foo->bar

    $VAR1 = {
          'foo' => 'bar'
        };

##</code><code>##

    if ($in =~ /^(\w{2})\s+(\w+)->(\w+)$/) {
        my($command, $key, $value) = ($1, $2, $3);
        $aliases{$key} = $value;
    }