#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#define MAGIC 0xdeadbeef
#define FLAG_FILE "flag"
#define PORT 8888
void get_flag(int client_sock) {
    FILE *file = fopen(FLAG_FILE, "r");
    if (file == NULL) {
        perror("fopen");
        return;
    }
    char flag[128];
    if (fgets(flag, sizeof(flag), file) == NULL) {
        perror("fgets");
        fclose(file);
        return;
    }
    fclose(file);
    send(client_sock, flag, strlen(flag), 0);
    
    close(client_sock);
}
void handle_client(int client_sock) {
    char buffer[64];
    unsigned int magic;
    unsigned int size;
    printf("client_sock: %d\n", client_sock);
    
    if (recv(client_sock, &magic, sizeof(magic), 0) <= 0) {
        perror("recv");
        close(client_sock);
        return;
    }
    
    if (magic != MAGIC) {
        printf("Invalid magic number\n");
        close(client_sock);
        return;
    }
    
    if (recv(client_sock, &size, 4, 0) <= 0) {
        perror("recv");
        close(client_sock);
        return;
    }
    
    if (recv(client_sock, buffer, size, 0) <= 0) {
        perror("recv");
        close(client_sock);
        return;
    }
    
    printf("Received content: %s\n", buffer);
}
 * @description
 * 实现一个服务器程序，使用 TCP 协议监听指定的端口，并处理来自客户端的连接请求。
 * 服务器会打印出 "Server listening on port XXXX"，其中 XXXX 是端口号，然后进入死循环等待客户端的连接。
 * 当有新的客户端连接时，服务器会调用 handle_client 函数处理该连接。
 * 如果发生错误，则输出相应的错误信息并退出程序。
 *
 * @param {boolean} isClientConnected
 * 表示是否已经连接到了客户端，默认为 false。
 *
 * @returns {number}
 * 返回一个整数，表示服务器监听的端口号。
 */
int main() {
    int server_sock, client_sock;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len = sizeof(client_addr);
    
    server_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (server_sock < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }
    
    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)) < 0) {
        perror("bind");
        close(server_sock);
        exit(EXIT_FAILURE);
    }
    
    if (listen(server_sock, 5) < 0) {
        perror("listen");
        close(server_sock);
        exit(EXIT_FAILURE);
    }
    printf("Server listening on port %d\n", PORT);
    
    while ((client_sock = accept(server_sock, (struct sockaddr *)&client_addr, &client_addr_len)) >= 0) {
        handle_client(client_sock);
    }
    close(server_sock);
    return 0;
}