<?php

$filename = '/data/webroot/usercode/code/resource/test.txt';

if (is_writeable($filename)) {

    file_put_contents($filename, 'test');

}

if (is_readable($filename)) {

    echo 'readable';

}

//判断如果$filename文件存在的话 就输出文件内容

if(file_exists($filename)){

  $con = file_get_contents($filename);

  echo $con;

}