UDP不像TCP,无需在连接状态下交换数据,因此基于UDP的服务器端和客户端无需建立连接过程。也就是说,无需调用listen()函数和accept()函数。UDP中只有创建套接字的过程和数据交换的过程。
运行结果:
源代码:
服务器端:
#include <stdio.h>
#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib") //加载ws2_32.dll
const int BUFSIZE = 100;
int main()
{
WSADATA wsaData;
WSAStartup(MAKEWORD(2, 2), &wsaData);
//创建套接字
SOCKET servSock = socket(AF_INET, SOCK_DGRAM, 0);
//绑定套接字
sockaddr_in servAddr;
//每个字节都用0填充
memset(&servAddr, 0, sizeof(servAddr));
//使用IPv4地址
servAddr.sin_family = AF_INET;
//自动获取IP地址
servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
//端口
servAddr.sin_port = htons(1234);
bind(servSock, (sockaddr *)&servSock, sizeof(servSock));
//接收客户端请求
//客户端地址信息
sockaddr clntAddr;
int nSize = sizeof(sockaddr);
//缓冲区
char buffer[BUFSIZE] = {0};
while(true)
{
int strLen = recvfrom(servSock, buffer, BUFSIZE, 0, &clntAddr, &nSize);
sendto(servSock, buffer, strLen, 0, &clntAddr, nSize);
}
closesocket(servSock);
WSACleanup();
return 0;
}
客户端:
#include <stdio.h>
#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib") //加载ws2_32.dll
const int BUFSIZE = 100;
int main()
{
//初始化DLL
WSADATA wsaData;
WSAStartup(MAKEWORD(2,2), &wsaData);
//创建套接字
SOCKET servSock = socket(AF_INET, SOCK_DGRAM, 0);
//服务器地址信息
sockaddr_in servAddr;
//每个字节都用0填充
memset(&servAddr, 0, sizeof(servAddr));
servAddr.sin_family = AF_INET;
servAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
servAddr.sin_port = htons(1234);
char buffer[BUFSIZE] = {0};
sockaddr fromAddr;
int nSize = sizeof(sockaddr);
//不断获取用户输入并发送给服务器,然后接收服务器数据
while(true)
{
printf("Input a string: ");
gets(buffer);
sendto(servSock, buffer, strlen(buffer), 0, (sockaddr *)&servAddr, sizeof(servAddr));
int strLen = recvfrom(servSock, buffer, BUFSIZE, 0, &fromAddr, &nSize);
printf("Message form server: %s\n", buffer);
memset(buffer, 0, sizeof(buffer));
}
closesocket(servSock);
system("pause");
return 0;
}