cksum — Compute a CRC Checksum

The cksum command calculates a CRC checksum and file size. It is useful for simple integrity checks, especially when comparing whether two files are exactly the same.

Basic use

cksum filename.txt

The output includes the checksum, byte count and file name.

cksum file1.txt file2.txt

For download verification, prefer stronger checksums such as SHA-256 when available.