      radec [-hh | -hms]

      read a series of coordinate pairs and convert between decimal and
      sexigesimal representations.  If the option -hh is given, the input
      is expected to be decimal degrees and the output will be sexigesimal
      (hours minutes seconds).  If the option -hms is given, the input is
      expected to be sexigesimal and the output will be decimal degree.
      Whitespace must be used for all separators.