The "sha3sum" command:

Compute an SHA3 checksum of all files named on the command-line. If a file is named "-" then take its content from standard input.

To be clear: The official NIST FIPS-202 implementation of SHA3 with the added 01 padding is used, not the original Keccak submission.

Options:

--224

Compute a SHA3-224 hash

--256

Compute a SHA3-256 hash (the default)

--384

Compute a SHA3-384 hash

--512

Compute a SHA3-512 hash

--size N

An N-bit hash. N must be a multiple of 32 between 128 and 512.

-h|--dereference

If FILE is a symbolic link, compute the hash on the object pointed to, not on the link itself.

See also: md5sum, sha1sum