sub validate_int { my $str = shift; state $max = int(eval $Config{nv_overflows_integers_at} or die); croak "not an integer" unless defined $str && $str=~/\A[0-9]+\z/; $str =~ s/\A0+(?=[1-9])//; croak "integer too big" if length $str > length $max || sprintf("%0*s", length $max, $str) gt $max; return 0+$str; }