In the computer world, “CTRL + S” is used as the Save command in all the applications. CTRL+S actually does XOFF, which means the terminal / software applications will accept key strokes, but terminal won’t show any output on the screen. If you are using putty terminal, putty session locks up and becomes unresponsive after you pressed “CTRL + S”.
Solution: To restore current putty session, press “CTRL + q” to turn flow-control on (XON).
