基于TCP的服务器与客户端的搭建

#include <sys/types.h>#include <sys/socket.h>#include <stdio.h>#include <unistd.h>#include <string.h>#include <arpa/inet.h>#define PORT  9999int main(){//1、创建socketint listen_socket = socket(AF_INET, SOCK_STREAM, 0);if (listen_socket == -1){perror ("socket");return -1;}// 2、命名套接字，绑定本地的ip地址和端口#if 0struct sockaddr_in{short int sin_family;  /* Internet地址族 */unsigned short int sin_port;  /* 端口号 */struct in_addr sin_addr;   /* IP地址 */unsigned char sin_zero[8];  /* 填0 */}；struct in_addr{unsigned long s_addr;}#endifstruct sockaddr_in addr;memset(&addr, 0, sizeof(addr));addr.sin_family  = AF_INET;     // 设置地址族addr.sin_port    = htons(PORT); // 设置本地端口addr.sin_addr.s_addr = htonl(INADDR_ANY);   // 使用本地的任意IP地址int  ret = bind(listen_socket,  (struct sockaddr *)&addr, sizeof(addr));if (ret == -1){perror ("bind");return -1;}// 3、监听本地套接字ret = listen(listen_socket, 5);if (ret == -1){perror ("listen");return -1;}printf ("等待客户端连接.......\n");// 4、接收连接// 监听套接字不能用来与客户端进行通信，它的职责是监听客户端的连接// accpet 处理客户端的连接，如果成功接收，会返回一个新的套接字，用来与客户端进行通信// accept的第三个参数 是一个传入传出参数struct sockaddr_in client_addr; // 用来保存客户端的ip和端口信息int len = sizeof(client_addr);int client_socket = accept(listen_socket,   (struct sockaddr *)&client_addr,  &len);if (client_socket == -1){perror ("accept");}printf ("成功接收一个客户端: %s\n", inet_ntoa(client_addr.sin_addr));char buf[1024];while (1){int ret = read (client_socket, buf, 1023);buf[ret] = '\0';printf ("%s\n", buf);write (client_socket, buf, ret);}return 0;}

#include <sys/types.h>#include <sys/socket.h>#include <stdio.h>#include <unistd.h>#include <string.h>#include <arpa/inet.h>#define PORT  9999int main(){int listen_socket = socket(AF_INET, SOCK_STREAM, 0);if(listen_socket == -1){perror("socket");return -1;}struct sockaddr_in addr;memset(&addr, 0, sizeof(addr));addr.sin_family = AF_INET;addr.sin_port   = htons(PORT);addr.sin_addr.s_addr = htonl(INADDR_ANY);int ret = connect(listen_socket, (struct sockaddr *)&addr, sizeof(addr));if(ret == -1){perror("connect");return 0;}printf("连接上服务器\n");char buf[1024];memset(buf, 0, sizeof(buf));while (1){fgets(buf, sizeof(buf), stdin);int ret = write (listen_socket, buf, 1023);buf[ret] = '\0';//printf ("%s\n", buf);read (listen_socket, buf, ret);}return 0;}

小结：

服务器

1. 创建一个socket，用函数socket()
2. 绑定IP地址、端口等信息到socket上，用函数bind()
3.设置允许的最大连接数，用函数listen()
4.接收客户端上来的连接，用函数accept()
5.收发数据，用函数send()和recv()，或者read()和write()
6.关闭网络连接

客户端

1.创建一个socket，用函数socket()
2.设置要连接的对方的IP地址和端口等属性
3.连接服务器，用函数connect()
4.收发数据，用函数send()和recv()，或者
 read()和write()
5.关闭网络连接