libdrizzleで繋いで閉じるだけ

exampleを参考にしつつ。

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include <libdrizzle/drizzle_client.h>

static void result_info(drizzle_result_st *result) {
  printf("Result:     row_count=%" PRId64 "\n"
         "            insert_id=%" PRId64 "\n"
         "        warning_count=%u\n"
         "         column_count=%u\n\n",
         drizzle_result_row_count(result),
         drizzle_result_insert_id(result),
         drizzle_result_warning_count(result),
         drizzle_result_column_count(result));
}

int main() {
  drizzle_st        drizzle;
  drizzle_con_st    con;
  drizzle_result_st result;
  drizzle_return_t  ret;

  if (NULL == drizzle_create(&drizzle)) {
    fprintf(stderr, "drizzle_create failed\n");
    exit(1);
  }

  drizzle_add_options(&drizzle, DRIZZLE_NON_BLOCKING);

  if (NULL == drizzle_con_add_tcp(&drizzle, &con, "192.168.200.150", 3306, "root", NULL, "mysql", DRIZZLE_CON_MYSQL)) {
    fprintf(stderr, "drizzle_con_add_tcp:%s\n", drizzle_error(&drizzle));
    exit(1);
  }

  while (1) {
    drizzle_query(&con, &result, "show tables", 11, &ret);

    if (DRIZZLE_RETURN_OK == ret) {
      break;
    }

    if (DRIZZLE_RETURN_IO_WAIT != ret) {
      fprintf(stderr, "drizzle_query:%s\n", drizzle_error(&drizzle));
      exit(1);
    }

    if (DRIZZLE_RETURN_OK != drizzle_con_wait(&drizzle)) {
      fprintf(stderr, "drizzle_con_wait:%s\n", drizzle_error(&drizzle));
      exit(1);
    }

    while (NULL == drizzle_con_ready(&drizzle)) {
      fprintf(stderr, "drizzle_con_ready:%s\n", drizzle_error(&drizzle));
      exit(1);
    }

    printf(".");
  }

  puts("");
  result_info(&result);

  drizzle_result_free(&result);
  drizzle_con_free(&con);
  drizzle_free(&drizzle);

  return 0;
}

生成系の関数でポインタの代わりにNULLを渡すとlibdrizzle側でアロケートしてくれるけど（xxx_freeで解放）、ノンブロッキングでdrizzle_queryが何度も呼ばれることを考えると、drizzle_result_stは呼び出し側でアロケートした方が良いのかも。