xephemdbd, xephemdbd.html and xephemdbd.pl, together with the xephem *.edb, gsc
and ppm.xe database files, form a complete package for operating an
astronomical database web service. The service is useful enough just from the
sample html form interface. But providing the data via the web access mechanism
reduces firewall issues and provides access from several interface options
without the need to invent and support dedicated tcp/ip services. The data 
become available to any form of web clients, such as java apps, perl scripts,
etc.

To install as a web service:

    1) build xephemdbd (see README and Makefile).

    2) edit xephemdbd.pl so the variable "dbdir" is an absolute path to the
       directory containing your collection of *.edb, ppm.xe and gsc files.
       This is expected to be the same directory as XEphem refers to as
       ShareDir/catalogs.
       
    3) make a fresh directory for xephemdbd and its friends off your cgi-bin
       root directory, for example /home/httpd/cgi-bin/xephemdbd. then
       copy xephemdbd, xephemdbd.pl and cgi-bin.pl there. Make sure
       permissions are such as to allow these files to be executed by
       whatever uid your web server runs as, and also for the server to
       create new files in the xephemdbd directory. Usually the easiest way
       is to do the work as root, then chown -R to the effective uid of
       the server, often `nobody'. A log of requests and other messages will
       accumulate in xephemdbd.log within this directory too.

    4) Edit xephemdbd.html so the "<FORM ACTION" path will find xephemdbd.pl.
       Then copy it to where you put html files, for example /home/httpd/html.

That should do it. Point your browser to

    http://<yoursite>/xephemdbd.html.
    
Fill in the form, press Submit. xephemdbd.pl should start xephemdbd running.
This might take a little time depending on your hardware and the number of *.edb
files. Having a lot of memory helps; figure about 100 bytes per object. Once
xephemdbd gets going, it will fork a child process to service each request which
then exits when complete. Eventually you will get back the results on your
browser. Subsequent requests will go faster. The sample xephemdbd.html form
provided is just an example to of how a client accesses the GET service. The
same service can be accessed from any web client, sich as xephem once the
Field Stars setup form is set up to point to your site.

Let me know how it goes,

Elwood Downey
ecdowney@ClearSkyInstitute.com

! For RCS Only -- Do Not Edit
! @(#) $RCSfile: INSTALL,v $ $Date: 1998/07/14 16:54:55 $ $Revision: 1.3 $ $Name:  $
