Write tamil characters in a file

Hello,

I want to write some unicode “இயற்கை” values into a file in its real format like “இயற”

Actually the browser prints the charactes in correct format, but I want it to be same in view source or browser source(இயற) but now the he browser displays it as (இயற்கை)

$text = "இயற்கை";
$rest = utf8_decode($text);
echo "$rest";

How to achieve this?
Decode

இயற்கை