/usr/bin/udunits2: invalid option -- '-'
Usage:
    udunits2 -h
    udunits2 [-A|-L|-U] [-r] [-H <have>] [-W <want>] [<XML_file>]

where:
    -A          Use ASCII encoding (default).
    -L          Use ISO-8859-1 (ISO Latin-1) encoding.
    -U          Use UTF-8 encoding.
    -h          Help.  Print this message.
    -r          Reveal any problems in the database.
    -H <have>   Use <have> unit for conversion. Default is reply to prompt.
    -W <want>   Use <want> unit for conversion. Empty string requests
                definition of <have> unit. Default is reply to prompt.
    <XML_file>  XML database file. Default is "/usr/share/udunits/udunits2.xml".