I doubt if there's any other tribe in the world that can beat yoruba, when it comes to greetings.
They have forms of greeting and salutation virtually for all spheres of social life.

Greeting is an important part of their customs and culture. Just like in the military, where you must always give compliment and salute your superior officer whenever you see him. Even when you saluted him now and after a minute he is passing by your side again, you will still give compliment. If you don't do, it is tantamount to insubordination and disloyalty. And you will begin to be suspected perhaps, you are planning a coup against your oga.

Among the yoruba, if someone don't greet, it means something is wrong somewhere and a lot of things will be attached to it.

There's no condition, position or situation you are, that Yoruba people don't have a form of greeting for it and there's also a form of prayer that goes with it. Whether you're rejoicing or grieving, you're working or not.

If you're sitting down, they will greet you: e ku ijoko
You are relaxing: e ku ikale
You're standing: e ku iduro
You're sleeping: e ku oju orun.
A group of people gather discussing: e ku apero
You just come from work or a short outing: e ku alobo
You have a visitor: e ku alejo
A relative of family member travels: e ku idele, he unites with you: e ku am'ojuba.
You arrived at a place before them: e ku w'aju,
you meet them: e ku'rin.
You celebrate with a celebrant: e ku ajoyo
You are making merry: e ku ariya
You are catching cold: e ku otutu

It is endless