index.php

<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2019 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

// [ 应用入口文件 ]
namespace think;

/*
 * 不在tp加载后判断，为了安全的使用exit()
 * 使用绝对路径，确保花里胡哨的url均能正确判定和跳转
 */
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    header("Access-Control-Allow-Credentials: true");
    header("Access-Control-Max-Age: 86400");
    header("Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE, OPTIONS");
    header("Access-Control-Allow-Headers: " . $_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']);
    header("Access-Control-Allow-Origin: *");
    exit();
}

$rootPath = $_SERVER['DOCUMENT_ROOT'] . DIRECTORY_SEPARATOR;
$server   = isset($_REQUEST['server']) || isset($_SERVER['HTTP_SERVER']) || substr($_SERVER['REQUEST_URI'], 1, 9) == 'index.php';
if (!$server) {
    // 用户访问前端

    // 安装检测-s
    if (!is_file($rootPath . 'install.lock') && is_file($rootPath . 'install' . DIRECTORY_SEPARATOR . 'index.html')) {
        header("location:" . DIRECTORY_SEPARATOR . 'install' . DIRECTORY_SEPARATOR);
        exit();
    }
    // 安装检测-e

    /*
     * 检测是否已编译前端-s
     * 如果存在 index.html 则访问 index.html
     */
    if (is_file($rootPath . 'index.html')) {
        header("location:" . DIRECTORY_SEPARATOR . 'index.html');
        exit();
    }
    // 检测是否已编译前端-e
}

require __DIR__ . '/../vendor/autoload.php';

// 执行HTTP应用并响应
$http = (new App())->http;

$response = $http->run();

$response->send();

$http->end($response);