How to generate the alias using PHP code

The dream would be that it automatically checks if the alias already exists, and if necessary adds a prefix (or suffix) to ensure each alias is always unique.

this old-fashioned code (shame on me) can make it work, until the api is 100% complete :
<?php

$title = 'Title of the document';

makeAlias($title);

function makeAlias($url){

        $url    = no_accent($url);

        $url    = ereg_replace("[^a-z A-Z0-9-]*","",$url);

        $url    = ereg_replace("-{2,}","-",$url);

        $url    = ereg_replace(' ','-',$url);

        $url    = trim(strtolower($url));

        $url    = ltrim($url,'-');

        $url    = rtrim($url,'-');

        return $url;

}

function no_accent($filename) {

        $str = strtr(utf8_decode($filename),utf8_decode("ÀÁÂÃÄÅÇÑñÇçÈÉÊËÌÍÎÏÒÓÔÕÖØÙÚÛÜÝàáâãäåçèéêëìíîïðòóôõöøùúûüýÿ' "),"AAAAAACNnCcEEEEIIIIOOOOOOUUUUYaaaaaaceeeeiiiiooooooouuuuyy--" );

        return $str;

    }
?>