server.cpp 是服务器端代码，client.cpp 是客户端代码。

要实现的功能是：客户端从服务器读取一个字符串并打印出来。

服务器端代码 server.cpp：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>int main(){//创建套接字int serv_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);//将套接字和IP、端口绑定struct sockaddr_in serv_addr;memset(&serv_addr, 0, sizeof(serv_addr));  //每个字节都用0填充serv_addr.sin_family = AF_INET;  //使用IPv4地址serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");  //具体的IP地址serv_addr.sin_port = htons(1234);  //端口bind(serv_sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr));//进入监听状态，等待用户发起请求listen(serv_sock, 20);//接收客户端请求struct sockaddr_in clnt_addr;socklen_t clnt_addr_size = sizeof(clnt_addr);int clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size);//向客户端发送数据char str[] = "http://c.biancheng.net/socket/";write(clnt_sock, str, sizeof(str));//关闭套接字close(clnt_sock);close(serv_sock);return 0;
}

客户端代码 client.cpp：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>int main(){//创建套接字int sock = socket(AF_INET, SOCK_STREAM, 0);//向服务器（特定的IP和端口）发起请求struct sockaddr_in serv_addr;memset(&serv_addr, 0, sizeof(serv_addr));  //每个字节都用0填充serv_addr.sin_family = AF_INET;  //使用IPv4地址serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");  //具体的IP地址serv_addr.sin_port = htons(1234);  //端口connect(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr));//读取服务器传回的数据char buffer[40];read(sock, buffer, sizeof(buffer)-1);printf("Message form server: %s\n", buffer);//关闭套接字close(sock);return 0;
}