tina@lugosi:~$ perl -Mstrict -wle'
sub handler {
  my $x = 23;
  sub inner {
       print "inner before: $x";
      $x = $x + 42;
      print "inner: $x";
  }
}
inner();
'
Variable "$x" will not stay shared at -e line 5.
Use of uninitialized value in concatenation (.) or string at -e line 5.
inner before: 
Use of uninitialized value in addition (+) at -e line 5.
inner: 42