c语言tcp员工管理系统的登陆界面服务端的代码

下面是一个简单的C语言TCP员工管理系统的登陆界面服务端的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#define PORT 8080
#define MAX_CLIENTS 30

typedef struct {
    char username[20];
    char password[20];
} User;

User users[] = {{"user1", "password1"}, {"user2", "password2"}, {"user3", "password3"}};

int validate_user(char *username, char *password) {
    for (int i = 0; i < sizeof(users) / sizeof(User); i++) {
        if (strcmp(users[i].username, username) == 0 && strcmp(users[i].password, password) == 0) {
            return 1;
        }
    }
    return 0;
}

int main() {
    int server_fd, new_socket;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[1024] = {0};
    char *message = "Welcome to the employee management system!\nPlease enter your username and password, separated by a space.\n";
    int max_clients = MAX_CLIENTS;
    int client_sockets[MAX_CLIENTS] = {0};

    // Create server socket
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    // Set socket options
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt failed");
        exit(EXIT_FAILURE);
    }

    // Set server address
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    // Bind socket to address
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // Listen for incoming connections
    if (listen(server_fd, 3) < 0) {
        perror("listen failed");
        exit(EXIT_FAILURE);
    }

    // Accept incoming connections
    while (1) {
        if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {
            perror("accept failed");
            exit(EXIT_FAILURE);
        }

        // Send welcome message to client
        send(new_socket, message, strlen(message), 0);

        // Receive username and password from client
        read(new_socket, buffer, 1024);

        // Validate username and password
        char *username = strtok(buffer, " ");
        char *password = strtok(NULL, " ");
        if (validate_user(username, password)) {
            send(new_socket, "Login successful!\n", strlen("Login successful!\n"), 0);
        } else {
            send(new_socket, "Invalid username or password.\n", strlen("Invalid username or password.\n"), 0);
        }

        // Add client socket to array
        for (int i = 0; i < max_clients; i++) {
            if (client_sockets[i] == 0) {
                client_sockets[i] = new_socket;
                break;
            }
        }
    }

    return 0;
}

这个代码演示了如何创建一个简单的TCP服务器，以便用户可以通过套接字连接到它，并在终端中输入用户名和密码来进行身份验证。在这个例子中，我们使用了一个硬编码的用户列表，但是在实际应用中，你需要从数据库或其他存储中读取用户信息。