Edit: see the updated list instead.

At present the function list is rather short, but there is all what it needs to read SM's:

static function_entry gnokii_functions[] = {
        PHP_FE(gnokii_identify, NULL)
        PHP_FE(gnokii_lasterror, NULL)
        PHP_FE(gnokii_version, NULL)
        PHP_FE(gnokii_getsmsstatus, NULL)
        PHP_FE(gnokii_getsms, NULL)
        PHP_FE(gnokii_deletesms, NULL)
        PHP_FE(gnokii_reset, NULL)
        {NULL, NULL, NULL}
};

A nice addition could be getting more than one SM at a time, e.g.

$all_sms = gnokii_getsms('IN', 1, 'end');

or

$all_sms = gnokii_getallsms('IN');

A way of getting the right memory type for SMS Inbox would be nice too.