wxgzh/bootstrap/environment.php

<?php
$env = $app->detectEnvironment(function () use($app) {
    $environmentPath = $app->environmentPath();//.env所在目录
    // putenv("APP_ENV=$setEnv");//写入env     //getenv('APP_ENV');//获取env
    $setEnv = trim(file_get_contents($environmentPath.'/.env'));//获取.env文件内容
    if(file_exists($environmentPath)) {
        $app->loadEnvironmentFrom('.env.'.$setEnv);
    }
});

?>