Note: help and version output are generated by a naïve script which tries a few variants of
<command> --help, <command> -h etc. to find the command's help and version info.
Sometimes it gets lucky, sometimes it doesn't; if the output below looks wrong, it probably is.
nsupdate -V (return code: 0)
nsupdate -h (return code: 1)
nsupdate: invalid argument -h
usage: nsupdate [-dD] [-L level] [-l][-g | -o | -y keyname:secret | -k keyfile] [-v] [-V] [-P] [-T] [filename]