Alters inbound URL requests.
$path: The path being constructed, which, if a path alias, has been resolved to a Drupal path by the database, and which also may have been altered by other modules before this one.
$original_path: The original path, before being checked for path aliases or altered by any modules.
$path_language: The language of the path.
\Drupal\Core\Path\AliasManager::getSystemPath()
function hook_url_inbound_alter(&$path, $original_path, $path_language) {
// Create the path user/me/edit, which allows a user to edit their account.
if (preg_match('|^user/me/edit(/.*)?|', $path, $matches)) {
global $user;
$path = 'user/' . $user->uid . '/edit' . $matches[1];
}
}