Q:

Perl 64 bit hex function

I would like to read in 64 bit hexadecimal numbers and do math with them using Perl.
I tried the following, but it doesn't seem to work. 
> perl -e 'use integer; printf("%x\n", hex("0xffffffffffff")<<2)'
Integer overflow in hexadecimal number at -e line 1.
fffffffc

A:

Works fine on my 64-bit system.
Try use bignum instead of use integer.

