PHP file_get_contents - Make a temporary local file?
<p>Yes, I know the title is confusing enough, but here is what I want to do:</p>

<p>I have created 3 websites (for clients. I have no control over them). All of these sites load a certain page of my main website. (with PHP file_get_contents - lets name it www.mainsite/x.php).</p>

<p>The problem here is the bandwidth. I'd like the 10 websites to create some temporary local file with that x.php file, rather then load the www.mainsite/x.php file every time. However I may make some changes to that x.php file so the local file should update itself every week or so.</p>

<p>Again what I mean is:
website 1,2 and 3 has a PHP file_get_contents of www.mainsite/x.php. On first load it should create a x.html file with the contents of x.php (i.e: www.website1/x.html). After a week website 1,2 and 3 should load www.mainsite/x.php again and create a new x.html file if changes have been made to the www.mainsite/x.php file.</p>
