What does the cls < NUL command do?

Question

cmd/bat

What does the cls < NUL command do? I know sort of that the system command ( cls ) clears the console. But why is there < NUL? What is he doing?

Answer 1

Well, in general, < is a redirection of program input, just like > is a redirection of the standard output of a program. NUL is a device (pseudo file), or rather an empty device. Output to it does nothing, and input is equivalent to reading an empty file.
That's just why it's cls...