hh:mm:ss dd:mm:ss yyyy [rest of line]
Where the fields are RA, Declination, and Epoch respectively. All three must be specified in the input data. If no epoch is specified on the command line, the present time is assumed.
Unless the radial option is specified, the output is in three fields, the angular distance, the right ascension distance and the declination distance (all in decimal degrees). The ra distance is converted to angular distance unless the nocos option is specified. When radial mode is specified only the angular distance is printed.
Any fields in the input following the first three (ra ,dec, epoch) will be copied to the output.
Instead of specifying a single object, the nearest options specifies a file containing a list of ras, decs, epochs. For each object on the input line, it searches for the nearest object and prints out the angular distance in the manner above. It also concatenates the rest of the line from the nearest obect and prints it out.