>perl -wMstrict -le
"my $scalar = 42;
 print qq{scalar before subroutine: $scalar};
 S();
 print qq{scalar after subroutine: $scalar};
 sub S {
   for $scalar (1 .. 3) {
     print qq{scalar in subroutine for-loop: $scalar};
     }
   }
"
scalar before subroutine: 42
scalar in subroutine for-loop: 1
scalar in subroutine for-loop: 2
scalar in subroutine for-loop: 3
scalar after subroutine: 42