//args是sql语句传回的参数，message是返回出错信息使用这些都是规定好的。
my_bool http_post_init(UDF_INIT *initid, UDF_ARGS *args, char *message);
//主函数体
longlong http_post(UDF_INIT *initid, UDF_ARGS *args, char *is_null,char *error);
//析构函数体
void http_post_deinit(UDF_INIT *initid);
//args是sql语句传回的参数，message是返回出错信息,使用这些都是规定好的。
//初始化函数体 my_bool http_post_init(UDF_INIT *initid, UDF_ARGS *args, char *message);
//主函数体 longlong http_post(UDF_INIT *initid, UDF_ARGS *args, char *is_null,char *error);
//析构函数体 void http_post_deinit(UDF_INIT *initid);

my_bool http_post_init(UDF_INIT *initid, UDF_ARGS *args, char *message)     {       if (args->arg_count != 2)       {         strcpy(message,"Wrong arguments to http_post; ");         return 1;       }  。

  。

      if(args->arg_count == 2 && args->args[1]!=NULL)       {             int flexibleLength = strlen(args->args[1]);  。

        if(flexibleLength > 160000)         {             int allocLength = 200 + flexibleLength;             if (!(initid->ptr=(char*) malloc(allocLength) ) )             {                     strcpy(message,"Couldn't allocate memory in http_post_init");                     return 1;             }             return 0;         }         else         {             initid->ptr=NULL;         }  。

      }        return 0;  。

    } 。

longlong http_post( UDF_INIT *initid, UDF_ARGS *args,                 char *is_null __attribute__((unused)),                 char *error __attribute__((unused))) {     char* sendBuffer=NULL;     CURL *curl;     CURLM *multi_handle;     int still_running;     int times=0;//try times if select false         int TRY_TIMES=25;     struct timeval timeout;//set a suitable timeout to play around with     timeout.tv_sec = 0;     timeout.tv_usec = 100000;  。

  。

    char sendArray[160000] = "\0";//can not move this into the if     if(initid->ptr == NULL)     {         //char sendArray[160000] = "\0";//error         sendBuffer=sendArray;     }     else     {         sendBuffer = initid->ptr;         TRY_TIMES=100;     }  。

    strcpy(sendBuffer,args->args[1]);     curl = curl_easy_init();     multi_handle = curl_multi_init();     if(curl && multi_handle)     {         /* what URL that receives this POST */         curl_easy_setopt(curl, CURLOPT_URL,args->args[0]);         curl_easy_setopt(curl, CURLOPT_HTTPPOST, 1);         curl_easy_setopt(curl,CURLOPT_POSTFIELDS,sendBuffer);         curl_multi_add_handle(multi_handle, curl);         while(CURLM_CALL_MULTI_PERFORM == curl_multi_perform(multi_handle,\ &still_running));         while(still_running && times< TRY_TIMES)          {               int rc;      //select() return code               int maxfd;               fd_set fdread;               fd_set fdwrite;               fd_set fdexcep;               FD_ZERO(&fdread);               FD_ZERO(&fdwrite);               FD_ZERO(&fdexcep);   //get file descriptors from the transfers              curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep,\ &maxfd);              rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);              switch(rc)             {                 case -1://select error                       break;                 case 0:                 default:        // timeout                      while(CURLM_CALL_MULTI_PERFORM !== curl_multi_perform(multi_handle, &still_running));                      break;              }                 times++;          }//end while        curl_multi_remove_handle(multi_handle,curl);        curl_multi_cleanup(multi_handle);//always cleanup        curl_easy_cleanup(curl);        if(times>=TRY_TIMES)        {             return 1;        }         return 0;   }//end if   return 1; } 。

void http_post_deinit(UDF_INIT *initid)
{
     if (initid!=NULL && initid->ptr!=NULL)
        {
            free(initid->ptr);
            initid->ptr = NULL;
        }
}

gcc -wall -I/usr/local/webserver/mysql/include/mysql/ -shared http_post.c -o http_post.so -fPIC
//使用mysql提供的头文件生成动态链接库
cp -f http_post.so /usr/local/webserver/mysql/lib/mysql/plugin/http_post.so
//将生成的.so文件放入mysql的plugin文件夹下
//进入mysql对动态链接库中的函数进行安装
cd /usr/local/webserver/mysql/bin/mysql
./mysql
//在mysql命令行下输入如下命令：
mysql> DROP FUNCTION IF EXISTS http_post;
//其目的是如果系统内安装了同名函数先进性drop。
mysql> CREATE FUNCTION http_post RETURNS INTEGER SONAME ‘http_post.so';
//生成http_post函数，并指明调用来源是http_post.so。
//最后调用函数，其目的是向指定ip和端口发送post数据。调用前先打开指定ip主机上的网络调试助手，并监听3888端。
mysql> select http_post(‘testpost.com/index.php','sfasfa');