https://groups.google.com/d/topic/nodejs/-vxpQpLOebk/discussion

learn.js

var utility = ffi.Library('utility', {
 'tesJson': ['void', ['string']]
});
var obj = {'1': 'one', '2': 'two'};
utility.tesJson(JSON.stringify(obj));

utility.c

void tesJson(char *text) {
  json_t *root;
  size_t i;
  json_error_t error;

  root = json_loads(text, 0, &error);

  for(i = 0; i < json_array_size(root); i++) {
    json_t *data;

    data = json_array_get(root, i);

    printf("%s\n", json_string_value(data));
  }
}