The GHS Programming Interface (PI) consists of a procedure library to which the user can link his own programs. This allows you unlimited freedom in developing your own extensions to GHS.
A command called "CUSTOM" is the gateway through which user-written commands are integrated with the GHS environment. Thus one or more special commands can be added to the system to do things which are presently outside its scope, or to change the way in which things are presently done.
The Programming Interface consists of a library linkable to programs written in specific programming languages. It includes over 50 procedures covering access to the geometry data and various calculations.