Hello, Could you please advise me whether there is presently any passport control by immigration at Dublin Airport? By this I mean not the airline staff or security checks, but checks after security by immigration officers of the sort being reintroduced in the UK to penalize departing overstayers ...

He needs to obtain a visa to enter the republic of Ireland. However, he will be able to leave because there are no real border checks (random checks are occasionally carried out on trains and buses) and no exit controls, but he will not be able to return to Dublin without having the necesarry visa ...