windows下socket开发udp程序

以下代码均在VC6.0上调试通过。

服务器端代码：

//UDP server
//listen port 9102
//receive string and display it

//Visual C++ 6.0

#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib,"ws2_32.lib")

#define BUFLEN 1024

int main(void)
{
	SOCKET soc;
	SOCKADDR_IN addr;
	char buf[BUFLEN];
	int len;

    WSADATA wsa;
	WSAStartup(MAKEWORD(1,1),&wsa);	//initial Ws2_32.dll by a process

	memset(&addr, 0, sizeof(addr));

	if((soc = socket(AF_INET,SOCK_DGRAM,0)) <= 0)
	{
		printf("Create socket fail!\n");
		return -1;
	}

	
	addr.sin_family = AF_INET;
	addr.sin_port = htons(9102);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);

	if(bind(soc,(struct sockaddr *)&addr,sizeof(struct sockaddr))!=0)
	{
		printf("Bind fail!\n");
		return -1;
	}


	len = sizeof(addr);
	printf("start listen...\n");
	while(1) {
		recvfrom(soc, buf, BUFLEN, 0,(struct sockaddr*)&addr, &len);
		printf("%s\n",buf);
	}
	
	WSACleanup();                     //关闭
	return 0;
}

客户端代码：

//UDP client
//client send string to server

//Visual C++ 6.0

#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib,"ws2_32.lib")

#define BUFLEN 1024

int main(void)
{
	SOCKET soc;
	SOCKADDR_IN addr;
	unsigned char buf[BUFLEN];

    WSADATA wsa;
	WSAStartup(MAKEWORD(2,2),&wsa);	//initial Ws2_32.dll by a process

	memset(&addr, 0, sizeof(addr));


	if((soc = socket(AF_INET,SOCK_DGRAM,0)) <= 0)
	{
		printf("Create socket fail!\n");
		return -1;
	}
	
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = inet_addr("127.0.0.1");
	addr.sin_port = htons(9102);
	bind(soc,(struct sockaddr *)&addr,sizeof(addr));

	
	while(1) {
		scanf("%s", buf);
		sendto(soc, buf, strlen(buf)+1, 0, (struct sockaddr *)&addr, sizeof(addr));
	}

	WSACleanup();	//clean up Ws2_32.dll
	return 0;
}