misc commands 

$ yes 1234567 | head -3
1234567
1234567
1234567
Broken Pipe
$ echo tht{33,44,555}afaf
tht33afaf tht44afaf tht555afaf
$ stty -echo; cat -v; stty echo
  -- press any key then CR
$ long_foreground_task
^Z # suspend it
bg # revoke bk ground task