Fasttrack to UFFI › Steve Jenson's blog

I performed a small experiment, trying to track down a bug in a Common Lisp package that I'm porting to OpenMCL. I realized that some of my steps for tracking this down would probably make for a super simple tutorial on using UFFI

First, make a quick C library

lib.c:


    #include <stdio.h>
    


    int teststuff(int i) {

    return i;

    }

Now compile it:


    $ gcc -g -c -dynamiclib -o lib.o lib.c

Now build a dynamic library:


    $ libtool -dynamic -o lib.so lib.o -lc

Use ASDF to install UFFI

Now create a simple Lisp program that calls your function

test-uffi.lisp:


    (asdf:operate 'asdf:load-op :uffi)

    (uffi:load-foreign-library #p"/Users/stevej/lib.so" :supporting-libraries '("c"))
    


    (uffi:def-function "teststuff" ((hello :int)) :returning :int)
    


    (teststuff 1)

Voila, your first UFFI program.