This is the command line interface used in Xselect. It has some useful features for listing the available commands and the parameters and their current defaults. It also has scripting and alias facilities. It has some magic characters, which are captured in the parser, and so they must be surrounded by `` "'s to get past XPI.
The command lines in XPI are parsed in two layers, first by the GTBUF routine, and then by GTCOM. Since GTBUF gets the command line first, all its special characters get processed first. So some knowledge of these is necessary.
Some of the features of GTBUF and duplicated by GTCOM, such as the recall feature, and GTCOM adds some new features, like the alias. In the case of recall, the GTCOM version (without the tell-tale %'s) is more advanced.
The discussion of GTBUF that follows comes with small changes from the XSPECT manual.