C:\>perl -E "use warnings;$a = chr(0); $a x= 2**31;
substr( $a, 0, 2**16 ) =~ tr[\0][\1];
substr( $a, 2**16, 2**16 ) =~ tr[\0][\1];"
substr outside of string at -e line 1.
Use of uninitialized value in transliteration (tr///) at -e line 1.