#!/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";

##</code><code>##

  SV* taintvar() {
    PL_tainted = 1;
    return newSVpvn("", 0);
  }
  ...
  # perl code
  starttaint();
  my $tv = taintvar();
  sub taintme {
    wantarray ? map($_ .= $tv, @_) : $_[0] . $tv
  }