ConTRoL Characters: CTRL-W : deletes the current command line word you are typing (word=any sequence of non-blank characters). CTRL-D : end-of-file character. ctrl-C : interrupts current foreground process (In mail two ctrl-c characters kill the mail message and save it in dead.letter) CTRL-S : suspends output being printed to screen. CTRL-Q : resumes printing of suspended output. CTRL-R : moves to next line and redraws command line. CTRL-H : erases character just typed on command line. CTRL-S and CTRL-Q are used to control the flow of output to the terminal. CTRL-S tells the system not to send any more data to the screen until a CTRL-Q is pressed. You can use these to control fast scrolling output. Sometimes you press CTRL-S by mistake and your terminal appears to be frozen. Try pressing CTRL-Q first when your terminal appears stuck to cancel any mistakenly pressed CTRL-S (extra CTRL-Q's do not cause any harm).