Multiple catalogue servers

simpleserver.cgi can access only a single catalogue. Often you may want to write a server which can access each of several catalogues. In this case your configuration file must contain an entry for each catalogue, not each server. An additional parameter, whose value identifies the catalogue, is added to the query. The server parses this parameter to identify the catalogue required. You can decide the syntax and values of this parameter, though the configuration file and server must agree.

For example, suppose that you are writing a server which will provide access to the SAO, PPM and Hipparcos astrometric catalogues. You might invent a parameter called `catalogue' whose value identifies the catalogue. Your configuration file would then have three entries like:

serv_type:  catalog
long_name:  SAO (Smithsonian Astrophysical Observatory) catalog
short_name: sao@roe
url:        http://www.roe.ac.uk/~acd/cgi-bin/ast.cgi?catalogue=sao&ra=%ra&dec=...
symbol:     mag square 3

serv_type:  catalog
long_name:  PPM (Positions and Proper Motions) catalogue
short_name: ppm@roe
url:        http://www.roe.ac.uk/~acd/cgi-bin/ast.cgi?catalogue=ppm&ra=%ra&dec=...
symbol:     mag square 3

serv_type:  catalog
long_name:  Hipparcos catalogue
short_name: sao@roe
url:        http://www.roe.ac.uk/~acd/cgi-bin/ast.cgi?catalogue=hipparcos&ra=%ra&dec=...
symbol:     mag square 3

The server would be written to parse the value of catalogue and then search the catalogue indicated.