Useful learning about linux shell

Q. How to unfreeze a shell (frozen due to Ctrl + s command)

Ans:

This can happen if you accidentally press Ctrl + s or Ctrl +S in a shell. To unfreeze and continue, press Ctrl+q or Ctrl+Q

Useful link

http://unix.stackexchange.com/questions/12107/how-to-unfreeze-after-accidentally-pressing-ctrl-s-in-a-terminal

Reference

http://unix.stackexchange.com/questions/12107/how-to-unfreeze-after-accidentally-pressing-ctrl-s-in-a-terminal