About

This "hello world" exercise is a modified version of the embed example from the ecl repository.

The exercise demonstrates:

1. writing an ECL program (lprog) which uses FFI to access a constant defined in a C header file
2. compiling lprog using ecl
3. writing a C program (cprog) which calls function provided by lprog
4. compiling a C program (cprog) which links lprog

Following along at home

1. clone the ecl repository
2. install ecl from your distribution's package manager (YMMV; I can confirm that this example works on Debian 11.5 using ECL 20.4.24) or from source
3. run make from this repository's root
4. you should now have and executable which can be run using: ./ecl-hello-r-lisp

Credits, Resources, etc.

• https://common-lisp.net/project/ecl/main.html
• https://gitlab.com/embeddable-common-lisp/ecl/tree/develop/examples/embed
• https://stackoverflow.com/questions/47562440/how-can-i-return-a-string-from-a-call-to-ffic-inline-in-ecl