/**
 * 判断当前环境
 * @return boolean [description]
 */
function get_runtime_environment($to_verify_environment){

    // 是否在微信浏览器下
    if($to_verify_environment == 'MicroMessenger'){

        // 是否在微信环境下
        if ( strpos($_SERVER['HTTP_USER_AGENT'], 'MicroMessenger') !== false && strpos($_SERVER['HTTP_USER_AGENT'], 'wxwork') == false) {
            return true;
        }
        else
        {
            return false;
        }

    }
    // 是否在企业微信环境下
    else if($to_verify_environment == 'wxwork'){

        if ( strpos($_SERVER['HTTP_USER_AGENT'], 'wxwork') !== false ) {
            return true;
        }
        else
        {
            return false;
        }

    }

    return false;

}

调用

function test_env(){
    	var_dump(get_runtime_environment('MicroMessenger'));
    	var_dump(get_runtime_environment('wxwork'));
    	var_dump(get_runtime_environment('baidu'));

    }