网络编程-tcp连接：服务器与客户端

使用服务器和客户端的代码，实现服务器和客户端的互相聊天功能
实现两台电脑之间互相聊天

方案一：

服务器代码（server.c）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <arpa/inet.h>
#include <sys/socket.h>#define PORT 8888
#define BUF_SIZE 1024// 客户端连接的套接字，供线程间共享
int client_sock = -1;// 线程函数：接收客户端消息并打印
void* recv_msg(void* arg) {char buf[BUF_SIZE];while (1) {// 读取客户端消息int len = read(client_sock, buf, sizeof(buf));if (len <= 0) {printf("客户端断开连接或接收失败\n");close(client_sock);pthread_exit(NULL); }buf[len] = '\0'; printf("客户端：%s\n", buf);}
}int main() {// 1. 创建监听套接字int server_sock = socket(AF_INET, SOCK_STREAM, 0);if (server_sock == -1) {perror("socket");return 1;}// 2. 绑定端口struct sockaddr_in server_addr;server_addr.sin_family = AF_INET;server_addr.sin_addr.s_addr = INADDR_ANY;server_addr.sin_port = htons(PORT);if (bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {perror("bind");close(server_sock);return 1;}// 3. 监听连接if (listen(server_sock, 5) == -1) {perror("listen");close(server_sock);return 1;}printf("服务器启动，等待客户端连接...\n");// 4. 接受客户端连接struct sockaddr_in client_addr;socklen_t client_addr_len = sizeof(client_addr);client_sock = accept(server_sock, (struct sockaddr*)&client_addr, &client_addr_len);if (client_sock == -1) {perror("accept");close(server_sock);return 1;}printf("客户端 %s:%d 已连接\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));// 5. 创建线程：专门处理接收客户端消息pthread_t recv_thread;if (pthread_create(&recv_thread, NULL, recv_msg, NULL) != 0) {perror("pthread_create");close(client_sock);close(server_sock);return 1;}// 分离线程，避免主线程调用 pthread_joinpthread_detach(recv_thread);// 6. 主线程：发送消息给客户端（从键盘输入）char buf[BUF_SIZE];while (1) {// 从键盘读取输入fgets(buf, sizeof(buf), stdin);// 去掉换行符（fgets 会把换行也读进来）buf[strcspn(buf, "\n")] = '\0'; // 发送给客户端write(client_sock, buf, strlen(buf)); }// 7. 关闭套接字（实际因 while(1) 很少走到这，可在信号或退出逻辑里处理）close(client_sock);close(server_sock);return 0;
}

客户端代码（client.c）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <arpa/inet.h>
#include <sys/socket.h>#define SERVER_IP "127.0.0.1"  
#define PORT 8888             
#define BUF_SIZE 1024// 与服务器通信的套接字，供线程间共享
int sock = -1;// 线程函数：接收服务器消息并打印
void* recv_msg(void* arg) {char buf[BUF_SIZE];while (1) {// 读取服务器消息int len = read(sock, buf, sizeof(buf));if (len <= 0) {printf("服务器断开连接或接收失败\n");close(sock);pthread_exit(NULL); }buf[len] = '\0'; printf("服务器：%s\n", buf);}
}int main() {// 1. 创建套接字sock = socket(AF_INET, SOCK_STREAM, 0);if (sock == -1) {perror("socket");return 1;}// 2. 连接服务器struct sockaddr_in server_addr;server_addr.sin_family = AF_INET;server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);server_addr.sin_port = htons(PORT);if (connect(sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {perror("connect");close(sock);return 1;}printf("已连接服务器 %s:%d\n", SERVER_IP, PORT);// 3. 创建线程：专门处理接收服务器消息pthread_t recv_thread;if (pthread_create(&recv_thread, NULL, recv_msg, NULL) != 0) {perror("pthread_create");close(sock);return 1;}// 分离线程pthread_detach(recv_thread);// 4. 主线程：发送消息给服务器（从键盘输入）char buf[BUF_SIZE];while (1) {// 从键盘读取输入fgets(buf, sizeof(buf), stdin);// 去掉换行符buf[strcspn(buf, "\n")] = '\0'; // 发送给服务器write(sock, buf, strlen(buf)); }// 5. 关闭套接字（实际很少走到，可在退出逻辑处理）close(sock);return 0;
}

方案二：

chat_client.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <pthread.h>#define PORT 8888
#define BUFFER_SIZE 1024
#define SERVER_IP "127.0.0.1"int client_socket;
pthread_t send_thread, recv_thread;// 接收消息线程函数
void* receive_messages(void* arg) {char buffer[BUFFER_SIZE];while (1) {memset(buffer, 0, BUFFER_SIZE);int bytes_received = recv(client_socket, buffer, BUFFER_SIZE, 0);if (bytes_received <= 0) {printf("服务器断开连接\n");close(client_socket);exit(EXIT_SUCCESS);}printf("服务器: %s\n", buffer);}return NULL;
}// 发送消息线程函数
void* send_messages(void* arg) {char buffer[BUFFER_SIZE];while (1) {memset(buffer, 0, BUFFER_SIZE);fgets(buffer, BUFFER_SIZE, stdin);// 去除换行符size_t len = strlen(buffer);if (len > 0 && buffer[len-1] == '\n') {buffer[len-1] = '\0';}// 发送消息if (send(client_socket, buffer, strlen(buffer), 0) == -1) {perror("发送消息失败");close(client_socket);exit(EXIT_FAILURE);}// 输入"exit"退出聊天if (strcmp(buffer, "exit") == 0) {printf("退出聊天\n");close(client_socket);exit(EXIT_SUCCESS);}}return NULL;
}int main() {struct sockaddr_in server_addr;// 创建套接字client_socket = socket(AF_INET, SOCK_STREAM, 0);if (client_socket == -1) {perror("创建套接字失败");exit(EXIT_FAILURE);}// 准备服务器地址memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);server_addr.sin_port = htons(PORT);// 连接服务器if (connect(client_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {perror("连接服务器失败");exit(EXIT_FAILURE);}printf("已连接到服务器\n");printf("开始聊天，输入'exit'退出\n");// 创建发送和接收线程if (pthread_create(&send_thread, NULL, send_messages, NULL) != 0) {perror("创建发送线程失败");exit(EXIT_FAILURE);}if (pthread_create(&recv_thread, NULL, receive_messages, NULL) != 0) {perror("创建接收线程失败");exit(EXIT_FAILURE);}// 等待线程结束pthread_join(send_thread, NULL);pthread_join(recv_thread, NULL);// 关闭套接字close(client_socket);return 0;
}

chat_server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <pthread.h>#define PORT 8888
#define BUFFER_SIZE 1024int client_socket;
pthread_t send_thread, recv_thread;// 接收消息线程函数
void* receive_messages(void* arg) {char buffer[BUFFER_SIZE];while (1) {memset(buffer, 0, BUFFER_SIZE);int bytes_received = recv(client_socket, buffer, BUFFER_SIZE, 0);if (bytes_received <= 0) {printf("客户端断开连接\n");close(client_socket);exit(EXIT_SUCCESS);}printf("客户端: %s\n", buffer);}return NULL;
}// 发送消息线程函数
void* send_messages(void* arg) {char buffer[BUFFER_SIZE];while (1) {memset(buffer, 0, BUFFER_SIZE);fgets(buffer, BUFFER_SIZE, stdin);// 去除换行符size_t len = strlen(buffer);if (len > 0 && buffer[len-1] == '\n') {buffer[len-1] = '\0';}// 发送消息if (send(client_socket, buffer, strlen(buffer), 0) == -1) {perror("发送消息失败");close(client_socket);exit(EXIT_FAILURE);}// 输入"exit"退出聊天if (strcmp(buffer, "exit") == 0) {printf("退出聊天\n");close(client_socket);exit(EXIT_SUCCESS);}}return NULL;
}int main() {int server_socket;struct sockaddr_in server_addr, client_addr;socklen_t client_addr_len = sizeof(client_addr);// 创建套接字server_socket = socket(AF_INET, SOCK_STREAM, 0);if (server_socket == -1) {perror("创建套接字失败");exit(EXIT_FAILURE);}// 设置套接字选项int opt = 1;if (setsockopt(server_socket, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {perror("设置套接字选项失败");exit(EXIT_FAILURE);}// 准备服务器地址memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_addr.s_addr = INADDR_ANY;server_addr.sin_port = htons(PORT);// 绑定套接字if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {perror("绑定套接字失败");exit(EXIT_FAILURE);}// 监听连接if (listen(server_socket, 1) == -1) {perror("监听失败");exit(EXIT_FAILURE);}printf("服务器已启动，等待客户端连接...\n");// 接受客户端连接client_socket = accept(server_socket, (struct sockaddr*)&client_addr, &client_addr_len);if (client_socket == -1) {perror("接受连接失败");exit(EXIT_FAILURE);}printf("客户端已连接\n");printf("开始聊天，输入'exit'退出\n");// 创建发送和接收线程if (pthread_create(&send_thread, NULL, send_messages, NULL) != 0) {perror("创建发送线程失败");exit(EXIT_FAILURE);}if (pthread_create(&recv_thread, NULL, receive_messages, NULL) != 0) {perror("创建接收线程失败");exit(EXIT_FAILURE);}// 等待线程结束pthread_join(send_thread, NULL);pthread_join(recv_thread, NULL);// 关闭套接字close(client_socket);close(server_socket);return 0;
}