Determine filetype then echo text

Ok I'm a really really bad newbie here, but I'm trying like heck to learn this language.

this is a very elementary problem but I'm sure you can help.

I have an upload program written in PHP. It supports uploading many different file TYPES.

On a results page (that does define the filename) i have a couple echo lines that I wrote, so people can just copy and paste the output to a forum, and it will place the right tags for [IMG] tags, and display <img src lines below it.

My problem is that the text i describe shows up regardless of what the file type is.

So what I'm really looking for, is eith a single statement that will grab a list of file extensions and match the uploaded file.

If the extensions match, show the image code, if not, continue.

This should be pretty simple, but the problem I have, is looking at php.net anything i can see corresponding to any image extensions just points to php code on how to create and manipulate the files.

Does this make sense?

$type = explode("/",mime_content_type($file));
if($type[0]=="image"){
//disply html image tags
}

And this should be in the PHP section.