DOKK / manpages / debian 12 / b3sum / b3sum.1.en
B3SUM(1) User Commands B3SUM(1)

b3sum - compute and check BLAKE3 hash

b3sum [FLAGS] [OPTIONS] [FILE]...

Print or check BLAKE3 checksums.

With no FILE, or when FILE is -, read standard input.

Reads BLAKE3 sums from the [file]s and checks them
Prints help information
Uses the keyed mode. The secret key is read from standard input, and it must be exactly 32 raw bytes.
Disables memory mapping. Currently this also disables multithreading.
Omits filenames in the output
Skips printing OK for each successfully verified file. Must be used with --check.
Writes raw output bytes to stdout, rather than hex. --no-names is implied. In this case, only a single input is allowed.
Prints version information

Uses the key derivation mode, with the given context string. Cannot be used with --keyed.
The number of output bytes, prior to hex encoding (default 32)
The maximum number of threads to use. By default, this is the number of logical cores. If this flag is omitted, or if its value is 0, RAYON_NUM_THREADS is also respected.

<FILE>...
Files to hash, or checkfiles to check. When no file is given, or when - is given, read standard input.

November 2020 b3sum 0.3.7