You can create a Utils class that will have those functions in there and get it from there. For instance:
require 'library/Utils.php';
// Statically (personally I hate static calls)
$var1 = Utils::myFunc();
$var2 = Utils::yourFunc();
or you can register it in the DI container:
require 'library/Utils.php';
$di['utils'] = function () {
return new Utils();
}
and then from a controller:
$var1 = $this->utils->myFunc();
$var2 = $this->utils->yourFunc();
The above will not use statically defined functions.