Usage: /usr/bin/sum [OPTION]... [FILE]...
Print or check BSD (16-bit) checksums.
Legacy interface to the cksum(1) utility.

With no FILE, or when FILE is -, read standard input.
  -r
         use BSD sum algorithm (the default), use 1K blocks
  -s, --sysv
         use System V sum algorithm, use 512 bytes blocks
      --help
         display this help and exit
      --version
         output version information and exit

Report bugs to: <bug-coreutils@gnu.org>.
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Full documentation <https://www.gnu.org/software/coreutils/sum>
or available locally via: info '(coreutils) sum invocation'