http://search.cpan.org/dist/perl-5.6.1/pod/perlfaq7.pod#How_can_I_tell_if_a_variable_is_tainted? 
    sub is_tainted {
        return ! eval { join('',@_), kill 0; 1; };
    }

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In reply to Re^2: detect taint mode in Perl 5.6.1 by Anonymous Monk
in thread detect taint mode in Perl 5.6.1 by young_apprentice

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