#!/usr/bin/perl -w
  use strict;
  use Scalar::Util qw/ tainted /;
  use Inline C => 'void starttaint() { PL_tainting = 1; }';

  my $line = <>;
  print "line tainted: ", tainted($line), "\n";
  print "\$0 tainted: ", tainted($0), "\n";
  starttaint();
  $line = <>;
  print "line tainted: ", tainted($line), "\n";
  print "\$0 tainted: ", tainted($0), "\n";