4.6.5 接收数据

　　在向服务器发送问候语之后，客户端调用RecvLine()函数接收服务器的应答。RecvLine()函数的实现与服务器相似，不同的是没有对recv()函数调用失败作立即处理，而是返回FALSE。如果RecvLine()函数返回FALSE，则先调用ShowErrorMsg()函数显示错误信息，然后客户端退出。

RecvLine()函数程序清单如下。

/*

 *      读取一行数据

 */

BOOL        RecvLine(SOCKET s, char* buf)

{

         BOOL        retVal = TRUE;                                                //返回值

         BOOL        bLineEnd = FALSE;                                       //行结束

         int              nReadLen = 0;                                                //读入字节数

         int              nDataLen = 0;                                                 //数据长度

         while (!bLineEnd && bConning)                                             //与客户端连接 没有换行

         {

                   nReadLen = recv(s, buf + nDataLen, 1, 0);        //每次接收一个字节

                   //错误处理

                   if (SOCKET_ERROR == nReadLen)

                   {

                            retVal= FALSE;                                                //读数据失败

                            break;                                                               //跳出循环

                   }

                  

                   if (0 == nReadLen)                                                  //客户端关闭

                   {

                            retVal = FALSE;                                               //读数据失败

                            break ;                                                              //跳出循环

                   }

                  

                   //读入数据

                   if ('/n' == *(buf + nDataLen))       //换行符

                   {

                            bLineEnd = TRUE;             //接收数据结束

                   }else{

                            nDataLen += nReadLen;  //增加数据长度

                   }

         }

        

         return retVal;

}