Cep

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <json.h>
#include <curl/curl.h>

struct request
{
   char *response;
   size_t size;
};

static size_t func(void *data, size_t size, size_t nmemb, void *userp)
{
   size_t size_p = size * nmemb;
   struct request *mem = (struct request *)userp;

   char *ptr = realloc(mem->response, mem->size + size_p + 1);
  if(!ptr)
  {
     fputs("Failed Memory\n", stdout);
     return EXIT_FAILURE;
  }

   mem->response = ptr;
   memcpy(&(mem->response[mem->size]), data, size_p);
   mem->size += size_p;
   mem->response[mem->size] = 0;

   return size_p;
}

void parse(char *buffer)
{
     struct json_object *jobj;
     struct json_object *j[10];
     jobj = json_tokener_parse(buffer);

     size_t i;
     static char *keys[] = {"cep", "logradouro", "complemento",
                       "bairro", "localidade", "uf",
                       "ibge", "gia", "ddd", "siafi"};


     for(i = 0; i < 10; i++)
        json_object_object_get_ex(jobj, keys[i], &j[i]);


     for(i=0; i < 10; i++)
     {
         if(json_object_get_string(j[i]) != NULL)
           printf("%s\n", json_object_get_string(j[i]));
         else
         {
           fputs("Failed Json\n", stdout);
           goto exit;
         }
      }
      exit:
       json_object_put(jobj);
}

int main(void)
{
    struct request s;
    s.response = malloc(1000);

    if(!s.response)
    {
      fputs("Failed Memory\n", stdout);
      return EXIT_FAILURE;
    }
    s.size = 0;

    fputs("Input your CEP: ", stdout);

    char cep[9];
    scanf("%9[^\n]s", cep);

    size_t i, j = 0;

    for(i = 0; cep[i]; i++)
      if(cep[i] >= '0' && cep[i] <= '9') j++;

    if(j == 8)
    {

       char url[50];

       snprintf(url, sizeof url, "http://viacep.com.br/ws/%s/json/", cep);

       CURL *curl = curl_easy_init();

       if(curl)
       {
           curl_easy_setopt(curl, CURLOPT_URL, url);
           curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, func);
           curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&s);
           curl_easy_perform(curl);
           parse(s.response);
           curl_easy_cleanup(curl);
        } else {
           fputs("Request Failed\n", stdout);
           return EXIT_FAILURE;
        }
     }  else  {
        fputs("Invalid Number\n", stdout);
    }

     free(s.response);

    return 0;
}