TCP通信实现（服务端与客户端）

TCP通信实现（服务器端)

案例

// TCP 通信的服务器端#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>int main() {// 1.创建socket(用于监听的套接字)int lfd = socket(AF_INET, SOCK_STREAM, 0);if(lfd == -1) {perror("socket");exit(-1);}// 2.绑定#include <netinet/in.h>
// struct sockaddr_in
// {
// sa_family_t sin_family; /* __SOCKADDR_COMMON(sin_) */
// in_port_t sin_port; /* Port number. */
// struct in_addr sin_addr; /* Internet address. */
// /* Pad to size of `struct sockaddr'. */
// unsigned char sin_zero[sizeof (struct sockaddr) - __SOCKADDR_COMMON_SIZE -
// sizeof (in_port_t) - sizeof (struct in_addr)];
// };
// struct in_addr
// {
// 	in_addr_t s_addr;
// };struct sockaddr_in saddr;saddr.sin_family = AF_INET;// inet_pton(AF_INET, "192.168.193.128", saddr.sin_addr.s_addr);saddr.sin_addr.s_addr = INADDR_ANY;  // 0.0.0.0 表示任意地址，计算机有多个网卡，每个网卡ip地址可能都不一样。只有服务端可以这样写saddr.sin_port = htons(9999);//将一个短整型数从主机字节序转换到网络字节序。int ret = bind(lfd, (struct sockaddr *)&saddr, sizeof(saddr));if(ret == -1) {perror("bind");exit(-1);}// 3.监听ret = listen(lfd, 8);if(ret == -1) {perror("listen");exit(-1);}// 4.接收客户端连接struct sockaddr_in clientaddr;int len = sizeof(clientaddr);//是一个阻塞的函数 int cfd = accept(lfd, (struct sockaddr *)&clientaddr, &len);if(cfd == -1) {perror("accept");exit(-1);}// 输出客户端的信息char clientIP[16];inet_ntop(AF_INET, &clientaddr.sin_addr.s_addr, clientIP, sizeof(clientIP));//网络字节序转主机字节序。ip地址转换unsigned short clientPort = ntohs(clientaddr.sin_port);//网络字节序转主机字节序，端口号转换printf("client ip is %s, port is %d\n", clientIP, clientPort);// 5.通信char recvBuf[1024] = {0};while(1) {// 获取客户端的数据int num = read(cfd, recvBuf, sizeof(recvBuf));if(num == -1) {perror("read");exit(-1);} else if(num > 0) {printf("recv client data : %s\n", recvBuf);} else if(num == 0) {// 表示客户端断开连接printf("clinet closed...");break;}char * data = "hello,i am server";// 给客户端发送数据write(cfd, data, strlen(data));}// 关闭文件描述符close(cfd);close(lfd);return 0;
}

TCP通信实现（客户端）

案例

// TCP通信的客户端#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>int main() {// 1.创建套接字int fd = socket(AF_INET, SOCK_STREAM, 0);if(fd == -1) {perror("socket");exit(-1);}// 2.连接服务器端struct sockaddr_in serveraddr;serveraddr.sin_family = AF_INET;inet_pton(AF_INET, "192.168.128.128", &serveraddr.sin_addr.s_addr);serveraddr.sin_port = htons(9999);int ret = connect(fd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));if(ret == -1) {perror("connect");exit(-1);}// 3. 通信char recvBuf[1024] = {0};while(1) {char * data = "hello,i am client";// 给客户端发送数据write(fd, data , strlen(data));sleep(1);int len = read(fd, recvBuf, sizeof(recvBuf));if(len == -1) {perror("read");exit(-1);} else if(len > 0) {printf("recv server data : %s\n", recvBuf);} else if(len == 0) {// 表示服务器端断开连接printf("server closed...");break;}}// 关闭连接close(fd);return 0;
}

daic@daic:~/Linux/linuxwebserver/part04networkProgramming/lesson32$ ./client 
recv server data : hello,i am server
recv server data : hello,i am server
recv server data : hello,i am server
recv server data : hello,i am server
recv server data : hello,i am server
recv server data : hello,i am server

daic@daic:~/Linux/linuxwebserver/part04networkProgramming/lesson32$ ./server 
client ip is 192.168.128.128, port is 54410
recv client data : hello,i am client
recv client data : hello,i am client
recv client data : hello,i am client
recv client data : hello,i am client
recv client data : hello,i am client
recv client data : hello,i am client
recv client data : hello,i am client
recv client data : hello,i am client
recv client data : hello,i am client