Perl has a very handy construction
  {
    local $var = 2;
    ...
  }
This construction is *approximately* equivalent to
  {
    my $oldvar = $var;
    $var = 2;
    ...
    $var = $oldvar;
  }

##</code><code>##

D:\>perl -lwe "$var='qq';{local $var=2;print $var;}print $var"
2
qq

##</code><code>##

D:\>perl -lwe "my $var='qq';{local $var=2;print $var;}print $var"
Can't localize lexical variable $var at -e line 1.