file_get_contents not actually grabbing file? Blank?

Try this sample code I threw together to illustrate a point:

<?php 
$url = "http://www.amazon.com/gp/offer-listing/B003WSNV4E/";
$html = file_get_contents($url);
echo($html);
?>

The amazon homepage works fine using this method (it is echoed开发者_运维知识库 in the browser), but this page just doesn't output anything. Is there a reason for this, and how can I fix it?

I think your problem is that you're misunderstanding your own code.

You made this comment on the question (emphasis mine):

I've never used those utilities before, so maybe I'm doing it wrong but it only seems to be downloading this page: https://www.amazon.com/gp/offer-listing/B003WSNV4E/ref=dp_olp_new?ie=UTF8&condition=new

This implies to me that an Amazon page is appearing in your browser when you run this code. This is entirely expected.

When you try to download https://rads.stackoverflow.com/amzn/click/B003WSNV4E, you're being redirected to https://www.amazon.com/gp/offer-listing/B003WSNV4E/ref=dp_olp_new?ie=UTF8&condition=new which is the intent of StackOverflow's RADS system.

What happens from there is your code is loading the raw HTML into your $html variable and dumping it straight to the browser. Because you're passing raw HTML to the browser, the browser is interpreting it as such, and it tries (and succeeds) in rendering the page.

If you just want to see the code, but not render it, then you need to convert it into html entities first:

echo htmlentities($html);