Get fragment (value after hash '#') from a URL in php

If you want to get the value after the hash mark or anchor as shown in a user's browser: This isn't possible with "standard" HTTP as this value is never sent to the server (hence it won't be available in $_SERVER["REQUEST_URI"] or similar predefined variables). You would need some sort of JavaScript magic on the client side, e.g. to include this value as a POST parameter.

If it's only about parsing a known URL from whatever source, the answer by mck89 is perfectly fine though.

That part is called "fragment" and you can get it in this way:

$url=parse_url("http://domain.com/site/gallery/1#photo45 ");
echo $url["fragment"]; //This variable contains the fragment

A) already have url with #hash in PHP? Easy! Just parse it out !

if( strpos( $url, "#" ) === false ) echo "NO HASH !";
   else echo "HASH IS: #".explode( "#", $url )[1]; // arrays are indexed from 0

Or in "old" PHP you must pre-store the exploded to access the array:

$exploded_url = explode( "#", $url ); $exploded_url[1]; 

B) You want to get a #hash by sending a form to PHP?
    => Use some JavaScript MAGIC! (To pre-process the form)

var forms = document.getElementsByTagName('form'); //get all forms on the site
for (var i = 0; i < forms.length; i++) { //to each form...
    forms[i].addEventListener( // add a "listener"
        'submit', // for an on-submit "event"
        function () { //add a submit pre-processing function:
            var input_name = "fragment"; // name form will use to send the fragment
            // Try search whether we already done this or not
            // in current form, find every <input ... name="fragment" ...>
            var hiddens = form.querySelectorAll('[name="' + input_name + '"]');
            if (hiddens.length < 1) { // if not there yet
                //create an extra input element
                var hidden = document.createElement("input");
                //set it to hidden so it doesn't break view 
                hidden.setAttribute('type', 'hidden');
                //set a name to get by it in PHP
                hidden.setAttribute('name', input_name);
                this.appendChild(hidden); //append it to the current form
            } else {
                var hidden = hiddens[0]; // use an existing one if already there
            }

            //set a value of #HASH - EVERY TIME, so we get the MOST RECENT #hash :)
            hidden.setAttribute('value', window.location.hash);
        }
    );
}

Depending on your form's method attribute you get this hash in PHP by:
$_GET['fragment'] or $_POST['fragment']

Possible returns: 1. ""[empty string] (no hash) 2. whole hash INCLUDING the #[hash] sign (because we've used the window.location.hash in JavaScript which just works that way :) )

C) You want to get the #hash in PHP JUST from requested URL?

                                    YOU CAN'T !

...(not while considering regular HTTP requests)...

...Hope this helped :)