【linux高性能服务器编程】项目实战——仿QQ聊天程序源码剖析

由于原代码已经非常接近完整，以下是对原代码的部分解释和关键函数的简化示例：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
 
#define SERVER_PORT 8000
#define BUFF_LEN 512
#define CLIENT_NUM_MAX 5
 
int sockfd_server;
struct sockaddr_in server_addr;
 
// 线程处理函数
void* thread_handle(void* arg) {
    int *client_fd = (int*)arg;
    char buff[BUFF_LEN];
    while (1) {
        memset(buff, 0, BUFF_LEN);
        int ret = recv(*client_fd, buff, BUFF_LEN, 0);
        if (ret == -1) {
            perror("recv error");
            continue;
        } else if (ret == 0) {
            printf("client close\n");
            break;
        }
        printf("recv msg: %s\n", buff);
        // 发送给所有客户端
        for (int i = 0; i < CLIENT_NUM_MAX; ++i) {
            if (i == *client_fd) continue;
            send(i, buff, strlen(buff), 0);
        }
    }
    close(*client_fd);
    free(client_fd);
    pthread_exit(NULL);
}
 
int main() {
    // 初始化socket
    sockfd_server = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd_server == -1) {
        perror("socket error");
        exit(1);
    }
 
    // 设置服务器地址结构
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(SERVER_PORT);
 
    // 绑定socket
    if (bind(sockfd_server, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {
        perror("bind error");
        exit(1);
    }
 
    // 监听socket
    if (listen(sockfd_server, 10) == -1) {
        perror("listen error");
        exit(1);
    }
 
    printf("listen success\n");
 
    struct sockaddr_in client_addr;
    socklen_t client_addr_len = sizeof(client_addr);
    pthread_t tid;
    int *new_fd = malloc(sizeof(int));
 
    while (1) {
        *new_fd = accept(sockfd_server, (struct sockaddr*)&client_addr, &client_addr_len);
        if (*new_fd == -1) {
            perror("accept error");
            continue;
        }
        printf("new client connect\n");
 
        if (pthread_create(&tid, NULL, thread_handle, new_fd) != 0) {
            pe