"Don't cry" is often said in a soft, caring way. It's something I would say when I am trying to comfort someone. "Don't you cry" sounds more like a command - something that an angry mother would say to a child when they are pretending to be hurt in order to get attention. It depends on the context and the tone of voice too, but most often this is the difference between them. Hope this helped. Let me know if you have any more questions! Cheers :)

short or long version with same meaning. but normal to use don't cry don't scream don't do something