在可能接受输入时继续执行循环

I am trying to make a simple Tetris game in C. I have come to the input part and ran into trouble. I made a loop that moves the new piece down by every second. Now I want this to happen but I want the player to be able to push a button to move the piece, as is the object of the game of course. These two things should not interfere. The game loop isI am trying to make a simple Tetris game in C.