xephemdbd, xephemdbd.html, start-xephemdbd.pl and xephemdbd.pl (with
cgi-lib.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 start-xephemdbd.pl so the variable "dbdir" is an absolute path to
       the directory containing your collection of *.edb, ppm.xe and gsc
       catalogs. This is expected to be the same directory as XEphem refers to
       as ShareDir/catalogs.
       
    3) make a fresh directory named xephemdbd off your cgi-bin root
       directory, for example /home/httpd/cgi-bin/xephemdbd. then copy
       xephemdbd, start-xephemdbd.pl, 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 so the server can
       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'. The files xephemdbd.log and xephemdbd.trace 
       will accumulate information over time; take a look at them occasionally
       and clean out as desired.

    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, such 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: 2003/12/05 06:27:38 $ $Revision: 1.4 $ $Name:  $
