Trying to get a full URL without filename in PHP

In your case, string manipulation is the best solution.

For Example:

substr($_SERVER['REQUEST_URI'], 0, strrpos($_SERVER['REQUEST_URI'], '/') + 1);

There are no defined variables for what you want.

You can use the code below to get the full base url:

// Base folder url
$myBase =  ( (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on')) ? 'https://' : 'http://' ) . $_SERVER['HTTP_HOST'] . dirname($_SERVER['PHP_SELF']);

but hopefully most times you won't require the full thing just use:

// Base folder server root path
$myBase = dirname($_SERVER['PHP_SELF']);

Just be careful if you're using some kind of routes system (mod_rewrite).

I can't seem to find a variable of $_SERVER array that has what I'm looking for.

because it's fictional string, existing only in the browser's address bar.
It's parts being sent to server separated.

I want to know if there's a var of the _server array

That's very easy to know. just print_r($_SERVER); really simple.

I know I could quite easily do this with some string manipulation

yeah. the code you have to write is less than this question text.

but with some manual magic it can be reduced to just one function.

There won't be one because it's not a useful attribute to track. If the current script is something other than index.* then it will not return the correct URL for the current script.

However, this might get you what you want:

echo '//'.$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']);

Edit:
Also, aside from installing the php.net online manual search tool for Firefox and setting it up with a search keyword (which will let you pull up the documentation on the $_SERVER global by typing something like "php $_server" into your URL bar), you should also know that var_dump() and print_r() lets you output the full contents of any variable, including arrays and objects. This is very useful for debugging.