Does a guy kind of like you if he is the one always saying hi or bye to you eventhough you both hardly talk to each other?

There could be a possibility that he likes you, or he is just being nice. I like to say hi to everyone I see, but it doesn't mean I like them (regardless of what my girlfriend says). If it is just a hi that he says to you, most likely he is just being nice. If it is more than just a "hi" and he actually stops and talks to you more, there could be potential there for a relationship other than acquaintances.