00_socket_demo

1.服务器端的代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>#define PORT 8080
#define BUFFER_SIZE 1024int main() {int server_fd, new_socket, valread;struct sockaddr_in address;int opt = 1;int addrlen = sizeof(address);char buffer[BUFFER_SIZE] = {0};char *hello = "Hello from server";// 创建socketif ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {perror("socket failed");exit(EXIT_FAILURE);}// 设置socket选项if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {perror("setsockopt failed");exit(EXIT_FAILURE);}address.sin_family = AF_INET;address.sin_addr.s_addr = INADDR_ANY;address.sin_port = htons(PORT);// 绑定地址和端口if (bind(server_fd, (struct sockaddr *)&address, sizeof(address))<0) {perror("bind failed");exit(EXIT_FAILURE);}// 监听连接if (listen(server_fd, 3) < 0) {perror("listen failed");exit(EXIT_FAILURE);}// 接受连接并处理请求if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen))<0) {perror("accept failed");exit(EXIT_FAILURE);}// 读取客户端发来的消息valread = read(new_socket, buffer, BUFFER_SIZE);printf("%s\n",buffer);// 向客户端发送消息send(new_socket , hello , strlen(hello) , 0);printf("Hello message sent\n");return 0;
}

创建了一个简单的服务器，监听8080端口，并接受客户端的连接。一旦建立连接，服务器将读取客户端发送的消息，并向客户端发送消息。

gcc ./server.c -o server

./server

2.客户端的代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>#define MAX_BUFFER_SIZE 1024int main() {int sock;struct sockaddr_in server_addr;char buffer[MAX_BUFFER_SIZE];// 创建套接字sock = socket(AF_INET, SOCK_STREAM, 0);if (sock == -1) {perror("socket");exit(EXIT_FAILURE);}// 设置服务器地址信息server_addr.sin_family = AF_INET;server_addr.sin_port = htons(8080);  // 服务器端口server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");  // 服务器IP地址// 连接服务器if (connect(sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {perror("connect");exit(EXIT_FAILURE);}// 发送数据到服务器char *message = "Hello, server!";if (send(sock, message, strlen(message), 0) == -1) {perror("send");exit(EXIT_FAILURE);}// 接收服务器的响应memset(buffer, 0, sizeof(buffer));if (recv(sock, buffer, sizeof(buffer) - 1, 0) == -1) {perror("recv");exit(EXIT_FAILURE);}printf("Server response: %s\n", buffer);// 关闭套接字close(sock);return 0;
}

创建了一个套接字，然后设置服务器的地址信息，包括服务器的IP地址和端口号。接下来，我们使用connect函数来连接服务器。如果连接成功，我们就可以使用send函数向服务器发送数据，使用recv函数接收服务器的响应。最后，我们关闭套接字。

gcc ./client.c -o client

./client