Allow unique $_GET request only? Generate, verify, forbid values : <p>Hello everyone again here,
I want to create a PHP script for my software which generates and returns the specific code using one $_GET request with a string and using another verificates this code, then forbid running same string.</p>

<p>Something what should work like this:
1st user's software runs "<a href="http://example.com/codes.php?create=" rel="nofollow noreferrer">http://example.com/codes.php?create=</a>" and string like "abc".
and script returns code based on "abc", e.g. "4aO45k", "12sdF4" etc.
2nd user's software runs "<a href="http://example.com/codes.php?verify=" rel="nofollow noreferrer">http://example.com/codes.php?verify=</a>" and this code.
If this code exists, return true and remove it FOREVER, meaning this code will never be generated again. If this code doesn't exist, return false.
If 1st user's software will run "<a href="http://example.com/codes.php?create=abc" rel="nofollow noreferrer">http://example.com/codes.php?create=abc</a>" another code will be generated.</p>

<p>In simple words:</p>

<pre><code>if $_GET is create, then
    generate random alphanumeric string, save it and return
if $_GET is verify, then
    check if this string exists, if so, then
        return true, remove from saved
    otherwise
        return false
</code></pre>

<p>Possible without databases, SQL, mySQL, FireBird...?
How do I make it using .ini files as storage?</p>

<p>Thanks.</p>
