NAME

CRC64 - Calculate the cyclic redundancy check.

SYNOPSIS

   use SWISS::CRC64;
   
   $crc = SWISS::CRC64::crc64("IHATEMATH");
   #returns the string "E3DCADD69B01ADD1"
   ($crc_low, $crc_high) = SWISS::CRC64::crc64("IHATEMATH");
   #returns two 32-bit unsigned integers, 3822890454 and 2600578513

DESCRIPTION

SWISS-PROT + TREMBL use a 64-bit Cyclic Redundancy Check for the amino acid sequences.

The algorithm to compute the CRC is described in the ISO 3309 standard. The generator polynomial is x64 + x4 + x3 + x + 1. Reference: W. H. Press, S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, "Numerical recipes in C", 2nd ed., Cambridge University Press. Pages 896ff.

Functions

crc64 string

Calculate the CRC64 (cyclic redundancy checksum) for string.

In array context, returns two integers equal to the higher and lower 32 bits of the CRC64. In scalar context, returns a 16-character string containing the CRC64 in hexadecimal format.