### 19.3 Low Level X Interface

A sample program for drawing things on X windows from lisp is included in the file gcl/lsp/littleXlsp.lsp

That routine invokes the corresponding C routines in XLIB. So in order to use it you must ‘faslink’ in the X routines. Directions are given at the beginning of the lisp file, for either building them into the image or using faslink.

This program is also a good tutorial on invoking C from lisp.

See also defentry and faslink.