Could a homeless student theoretically live at school?

I have a home, but I was just thinking, if a student was homeless but wanted to get out of poverty, could he or she live at school while taking classes? Say, if they got student loans and were on welfare, so they had a little money, could they join the gym and use the showers there, and study in the library until they passed out every night? The only things they would need are food and a laundromat.