.js, .jpg files link to .html pages

In some pages I have seen (like those of GitHub and Wikipedia), there are some links that end in .js, .jpg etc. which means clicking them should show me the JS file or the image (and so on). But, as we all know, they display a page (the needed resources are on the page, anyway)开发者_如何学运维.

Can anyone please explain how this is done? Does it have anything to do with renaming a link?

If it's server-side coding (which I think it is), I use PHP. Thanks in advance.

---

It'll use URL re-writing with mod_rewrite. See http://httpd.apache.org/docs/current/mod/mod_rewrite.html

---

In order for those links to be mapped to your PHP scripts, you need mod_rewrite (Assuming you are on Apache)

The http header called Content-Type tells the browser how to interpret the data. If it is set to text/html, it will render as a webpage.

In PHP, you can use the header() function:

header("Content-Type: text/html");

Similarly, you can have a PHP script output an image:

header("Content-Type: image/jpeg");

This type definition is called MIME Type.