Does the question of “What is the man?” really ask about a person's occupation?

Dear all,

I remember when I was studying in junior high school, one of my English teacher said, “The question of “Who are you?” is asking about your name or your relationship with somebody. Therefore, you can reply, “I am John.” or “I am John’s brother.” However, the question of “What are you?” is asking about your job, so you have to answer like, “I’m a teacher.””

Nevertheless, during the time I staying in New Zealand, I’ve never heard anybody use “What are you?” to ask a person’s occupation. Instead of it, they’re more likely to use “What’s your job?”, “What do you do for living (or “for life”)?”

Does the question of “What is the man?” really ask about a person’s occupation? If so, is it popular for people to ask someone like this? (Because, I can’t find the same sentence on the Internet or any English books; only in Chinese English studying book.)

Frankly speaking, the more I study English, the more I doubt about the accuracy of these Chinese English studying books…