CAIRO - "Any rice?" says the woman, leaning into a shop in Cairo and brandishing a green smartcard that carries her family's food credits. The shopkeeper shakes his head: "Only sugar."Behind him, more than half the shelves are empty. Rice and cooking oil are nowhere to be seen.Tens of millions of Egyptians rely on state subsidies provided as credits on smartcards they redeem against household staples each month. But in recent weeks, imported commodities like cooking oil have been in short supply as a dollar shortage makes it harder for state importers to secure regular supplies.