geomview is a program for the display and manipulation of OOGL objects. If you haven't already done so, you should familiarize yourself with its capabililities now. Consult the documents overview and oogltour in the doc directory, and the man page for geomview, both sections 1 and 5. The section 1 manual page describes the user interface of the program, while the section 5 manual page describes the command language through which external programs can communicate with geomview. It is this command language which this example will use.
This corresponds to 2 different ways to provide geomview with geometry for viewing. The first reads descriptions of objects from a file. geomview has a file browser from which users can choose files to examine. This is appropriate when the geometry is static. The second method is useful when you desire to view a changing geometry. This second method uses 2-way pipes to update the changing geometry from your application and to pass back information from geomview to your application. This communication uses the command language described in geomview(5). In this situation, your application is known as an external module for geomview.
This document will show how to create and run an external module, in this case one simply known as example. This and all the other files involved in this are to be found in the directory GEOM/src/bin/example.