From LQWiki

cksum prints CRC checksum and byte counts of each file.

cksum can be used to check if files are transfered without error (or not corrupted during storage).

cksum * > cksum.list

generates checksums' file. After transfer (or after a long storage) you can check if files are the same:

cksum * cksum.list-2

diff cksum.list cksum.list-2

cksum also can be used for fast searching for duplicates. After issuing

cksum *

identical files have same checksums.

Conversely, files with same chcecksums and same sizes almost always are identical. This can be checked further with diff.

See also

• md5sum