complete -c b2sum -s l -l length -d 'digest length in bits; must not exceed the max for the blake2 algorithm and must be a multiple of 8' -r
complete -c b2sum -s c -l check -d 'read checksums from the FILEs and check them'
complete -c b2sum -s h -l help -d 'Print help'
complete -c b2sum -s V -l version -d 'Print version'