G2++ Tutorial - G2++(3C++)

G2++ Tutorial - G2++(3C++)

G2++ is an upward-compatible extension to G2, a system developed by Jim Weythman and used widely within AT&T Bell Laboratories. G2 consists of a language, a C library, and a collection of tools for defining and manipulating complex, hierarchically-structured messages used for interprocess communication. G2 messages can also be used as records for long-term data storage in files, which is also a kind of interprocess communication. We will tend to use the more general term ``record,'' rather than ``message,'' in this tutorial.

The language is used to describe the structure of records and the types of data they can contain.
The C library contains I/O routines that can be called by C client programs in order to send, receive, and examine G2 records.
The tools are used for `batch processing' streams of G2 records.

The simplest way to characterize the extensions to G2 described in this paper (beginning in the section, ``Introduction to G2++'', would be to say that G2++ does for C++ what G2 does for C.

If you are already familiar with G2, you should now skip to the section, ``Introduction to G2++'', and begin reading about G2++. If you are completely unfamiliar with G2, or if you would like to learn more about the history, rationale, and current implementation of G2, keep reading. You can also read two short papers by Jim Weythman, both included as appendices to this tutorial for your convenience: ``G2 Data Language Reference'' and ``Guidelines for Using G2''.