UNIX understands several control-key commands, commands you enter by holding down the control key (Ctrl) while striking a second key.
CTRL + U - cut text from cursor position to the beginning of the command line
CTRL + S - freezes the screen and stops any display on the screen from continuing
CTRL + Q - un-freezes the screen and lets screen display continue
CTRL + C - interrupts a running program
CTRL + \ - same as CTRL - C but stronger (used when terminal doesn't respond)
CTRL + Z - suspends a running program (use the fg command to continue the program)
CTRL + H - deletes last character typed
CTRL + W - deletes last word typed
CTRL + U - deletes last line typed
CTRL + R - searches text from history
CTRL + D - ends text input for many UNIX programs, including mail and write.
CTRL + Y - paste the string in buffer/clipboard