b2sum --version (return code: 0)
b2sum (GNU coreutils) 8.26 Copyright (C) 2016 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by Padraig Brady and Samuel Neves.
b2sum --help (return code: 0)
Usage: b2sum [OPTION]... [FILE]... Print or check BLAKE2 (512-bit) checksums. With no FILE, or when FILE is -, read standard input. -b, --binary read in binary mode -c, --check read BLAKE2 sums from the FILEs and check them -l, --length digest length in bits; must not exceed the maximum for the blake2 algorithm and must be a multiple of 8 --tag create a BSD-style checksum -t, --text read in text mode (default) The following five options are useful only when verifying checksums: --ignore-missing don't fail or report status for missing files --quiet don't print OK for each successfully verified file --status don't output anything, status code shows success --strict exit non-zero for improperly formatted checksum lines -w, --warn warn about improperly formatted checksum lines --help display this help and exit --version output version information and exit The sums are computed as described in RFC 7693. When checking, the input should be a former output of this program. The default mode is to print a line with checksum, a space, a character indicating input mode ('*' for binary, ' ' for text or where binary is insignificant), and name for each FILE. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> Full documentation at: <http://www.gnu.org/software/coreutils/b2sum> or available locally via: info '(coreutils) b2sum invocation'