It computes crc32s, and what of it?
crc32 - a 32-bit cyclic rendundancy check calculator
<files...> open files as inputs
-h display this text
-s <n> start cycle with n (default: 0xFFFFFFFF)
-p <n> use n as the crc divisor (default: 0x04C11DB7)
-e use big endian calculations
-b output as binary
-x NOT the output
-r reverse output's bits
numbers <n> may be in hexadecimal or octal using proper prefixes