[php] how to call url of any other website in php

The simplest way would be to use FOpen or one of FOpen's Wrappers.

$page = file_get_contents("http://www.domain.com/filename");

This does require FOpen which some web hosts disable and some web hosts will allow FOpen, but not allow access to external files. You may want to check where you are going to run the script to see if you have access to External FOpen.