PHP和CGI的会话管理技术：如何保持用户登录状态

session_start();

// 检查用户是否已经登录
if(isset($_SESSION['user_id'])){
    echo "欢迎回来，" . $_SESSION['username'];
} else {
    echo "请先登录";
}

// 处理用户登录请求
if($_SERVER['REQUEST_METHOD'] == 'POST'){
    $username = $_POST['username'];
    $password = $_POST['password'];

    // 验证用户凭据
    if($username == "admin" && $password == "password"){
        // 将用户ID和用户名存储在会话中
        $_SESSION['user_id'] = 1;
        $_SESSION['username'] = $username;

        echo "登录成功";
    } else {
        echo "用户名或密码错误";
    }
}

use CGI::Session;

# 创建会话
my $session = CGI::Session->new();

# 获取或创建会话ID
my $session_id = $session->id();

# 存储用户登录状态
if($username eq "admin" && $password eq "password"){
    $session->param("user_id", 1);
    $session->param("username", $username);

    print "登录成功";
} else {
    print "用户名或密码错误";
}

# 读取用户登录状态
if($session->param("user_id")){
    print "欢迎回来，" . $session->param("username");
} else {
    print "请先登录";
}