Bit::ShiftReg is a perl module that implements rotate left, rotate right, arithmetic shift left, and logical shift right operations with carry flag for all C integer types. The results depend on the number of bits with that the integer types unsigned char, unsigned short, unsigned int, and unsigned long have on your machine. The module automatically determines the number of bits of each integer type and adjusts its internal constants accordingly. WWW: http://search.cpan.org/dist/Bit-ShiftReg/