link:The Racke tForeign-Function Interface
+ +// mylib1.c
+#include <stdio.h>
+#include <stdlib.h>
+
+
+// Square an integer
+int isquare (int i){
+ return i * i;
+}
+command 中执行:
+ +gcc --shared -o mylib1.so mylib1.c
+mylib.rkt
+ +#lang racket
+
+(require ffi/unsafe
+ffi/unsafe/define)
+
+(define-ffi-definer mylib-define (ffi-lib "mylib1"))
+(mylib-define isquare (_fun _int -> _int))
+
+(isquare 5)
+mylib1.rkt
+ +#lang racket
+(require ffi/unsafe)
+
+(define mylib (ffi-lib "mylib1.so"))
+
+
+(define isquare
+(get-ffi-obj "isquare"
+ mylib
+ (_fun _int -> _int)))
+
+(isquare 1000)
+