简单的Socket示例

命令行参数：
Server.exe
PortNumber，例如Server 8000

Client.exe IPAddress PortNumber，例如Client 127.0.0.1 8000
然后在客户端的命令行输入字符串并回车，客户端将会把消息发送到服务器。服务器再把消息传回客户端。

服务器端，Server.cpp：

#include <winsock2.h>
#include <stdio.h>
#include <windows.h>
#pragma comment(lib,"ws2_32.lib")

int main(int argc, char* argv[])
{
//判断是否输入了端口号
if(argc!=2)
{
printf("Usage: %s PortNumber\n",argv[0]);
exit(-1);
}
//把端口号转化成整数
short port;
if((port = atoi(argv[1]))==0)
{
printf("端口号有误！");
exit(-1);
}
WSADATA wsa;
//初始化套接字DLL
if(WSAStartup(MAKEWORD(2,2),&wsa)!=0)
{
printf("套接字初始化失败!");
exit(-1);
}
//创建套接字
SOCKET serverSocket;

if((serverSocket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==INVALID_SOCKET)
{
printf("创建套接字失败！");
exit(-1);
}
struct sockaddr_in serverAddress;

memset(&serverAddress,0,sizeof(sockaddr_in));
serverAddress.sin_family=AF_INET;
serverAddress.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
serverAddress.sin_port = htons(port);
//绑定

if(bind(serverSocket,(sockaddr*)&serverAddress,sizeof(serverAddress))==SOCKET_ERROR)
{
printf("套接字绑定到端口失败！端口: %d\n",port);
exit(-1);
}
//进入侦听状态
if(listen(serverSocket,SOMAXCONN)==SOCKET_ERROR)
{
printf("侦听失败！");
exit(-1);
}
printf("Server %d is listening......\n",port);
SOCKET clientSocket;//用来和客户端通信的套接字
struct sockaddr_in clientAddress;//用来和客户端通信的套接字地址

memset(&clientAddress,0,sizeof(clientAddress));
int addrlen = sizeof(clientAddress);

//接受连接

if((clientSocket=accept(serverSocket,(sockaddr*)&clientAddress,&addrlen))==INVALID_SOCKET)
{
printf("接受客户端连接失败！");
exit(-1);
}
printf("Accept connection from
%s\n",inet_ntoa(clientAddress.sin_addr));
char buf[4096];
while(1)
{
//接收数据
int bytes;

if((bytes=recv(clientSocket,buf,sizeof(buf),0))==SOCKET_ERROR)
{
printf("接收数据失败!\n");
exit(-1);
}
buf[bytes]='\0';
printf("Message from %s:
%s\n",inet_ntoa(clientAddress.sin_addr),buf);
if(send(clientSocket,buf,bytes,0)==SOCKET_ERROR)
{
printf("发送数据失败！");
exit(-1);
}
}
//清理套接字占用的资源
WSACleanup();
return 0;
}

客户端，Cilent.cpp：

#include
<winsock2.h>
#include <stdio.h>
#include <windows.h>
#pragma comment(lib,"ws2_32.lib")
int main(int argc, char* argv[])
{
//判断是否输入了IP地址和端口号
if(argc!=3)
{
printf("Usage: %s IPAddress PortNumber\n",argv[0]);
exit(-1);
}
//把字符串的IP地址转化为u_long
unsigned long ip;
if((ip=inet_addr(argv[1]))==INADDR_NONE)
{
printf("不合法的IP地址：%s",argv[1]);
exit(-1);
}
//把端口号转化成整数
short port;
if((port = atoi(argv[2]))==0)
{
printf("端口号有误！");
exit(-1);
}
printf("Connecting to
%s:%d......\n",inet_ntoa(*(in_addr*)&ip),port);
WSADATA wsa;
//初始化套接字DLL
if(WSAStartup(MAKEWORD(2,2),&wsa)!=0)
{
printf("套接字初始化失败!");
exit(-1);
}
//创建套接字
SOCKET sock;

if((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==INVALID_SOCKET)
{
printf("创建套接字失败！");
exit(
944d
-1);
}
struct sockaddr_in serverAddress;

memset(&serverAddress,0,sizeof(sockaddr_in));
serverAddress.sin_family=AF_INET;
serverAddress.sin_addr.S_un.S_addr = ip;
serverAddress.sin_port = htons(port);
//建立和服务器的连接

if(connect(sock,(sockaddr*)&serverAddress,sizeof(serverAddress))==SOCKET_ERROR)
{
printf("建立连接失败！");
exit(-1);
}
char buf[4096];
while(1)
{
printf(">");
//从控制台读取一行数据
gets(buf);
//发送给服务器
if(send(sock,buf,strlen(buf),0)==SOCKET_ERROR)
{
printf("发送数据失败！");
exit(-1);
}
int bytes;
if((bytes=recv(sock,buf,sizeof(buf),0))==SOCKET_ERROR)
{
printf("接收数据失败!\n");
exit(-1);
}
buf[bytes]='\0';
printf("Message from %s:
%s\n",inet_ntoa(serverAddress.sin_addr),buf);
}
//清理套接字占用的资源
WSACleanup();
return 0;
}