6.5 b2sum: Print or check BLAKE2 digests

b2sum computes a 512-bit checksum for each specified file.

If a file is specified as ‘-’ or if no files are given b2sum computes the checksum for the standard input. b2sum can also determine whether a file and checksum are consistent. Synopsis:

b2sum [option]… [file]…

b2sum uses the ‘Untagged output format’ for each specified file, as described at cksum output modes.

The program accepts cksum common options. Also see Common options.

In addition b2sum supports the following options.


Change (shorten) the default digest length. This is specified in bits and thus must be a multiple of 8. This option is ignored when --check is specified, as the length is automatically determined when checking.