Hi Luca,

You should consider the fact that 'grep' creates a temporary data structure and that Perl's garbage collection probably won't release it back to the OS (from my experience).

Please consider a simpler way to do what you ask without consuming exessive memory -

foreach (keys %$a){
        !/le/ and $c->{$_} = $a->{$_};
}
[download]

Note that you can use the same loop for adding more restrictions or perform more actions if you need, which may save you run-time in some cases.

Enjoy,
Mickey