>perl -wMstrict -le
"our $RtnVal;
 our $SomeOtherGlobal;
 ;;
 my $coderef = sub {
   $RtnVal = $_[0];
   if ($RtnVal eq 'Ok') { $SomeOtherGlobal = 'Foo'; }
   };
 ;;
 for my $arg (qw(Ok NotOk)) {
   $RtnVal = $coderef->($arg);
   print qq{RtnVal '$RtnVal'};
   }
 ;;
 for my $arg (qw(Ok NotOk)) {
   $coderef->($arg);
   print qq{RtnVal '$RtnVal'};
   }
"
RtnVal 'Foo'
RtnVal ''
RtnVal 'Ok'
RtnVal 'NotOk'