adding the bit of tomfoolery which looks at the raw byte code of functions

ex18.c

@@ -80,6 +80,13 @@ void test_sorting(int *numbers, int count, compare_cb cmp)
     printf("\n");
 
     free(sorted);
+
+    unsigned char *data = (unsigned char *)cmp;
+
+    for(i = 0; i < 25; i++) {
+        printf("%0x:", data[i]);
+    }
+    printf("\n");
 }