将文件名传递给隐藏字段？

How can i grab whatever the value of is in this line of code e.g. the value would be file.php

include filter_input(INPUT_POST, 'name', FILTER_SANITIZE_STRING);

and then place it in to a hidden field that looks like this

 <input type="hidden" name="file_name" value="">

so that the placed value can be used to save to whatever the input is to a file?

Try:

$name = filter_input(INPUT_POST, 'name', FILTER_SANITIZE_STRING);

<input type="hidden" name="file_name" value="<?php echo $name; ?>">

or if you have short_tags turned on

<input type="hidden" name="file_name" value="<?=$name?>">