Evening holiday outfits for men

[MelonMelonMelon]

We're going away next month and I just googled the dress code for the hotel restaurants in the evenings, and men have to wear trousers and no sandals. DH usually just wears shorts, a shirt and sandals.

They have to wear closed shoes and can't wear 3/4 length trousers. So, we're on the hunt for trousers and closed shoes for him. What kind of thing should we be looking for? My mind's gone blank! Any links would be great too. Thanks for any help :)

I've just done what I should have before I started this thread- checked to see what he already has. He has 4 pairs of linen trousers and loads of shirts, including a few linen ones. What works best with linen trousers? And what kind of shoes to wear with them? I'd have said Birkenstocks, but I doubt they would be allowed . Thanks!