control code

character A character which is input or output to cause some

special action rather than to appear as part of the data.

Most control characters are input by holding down (either of)

the "Control" key(s) on the keyboard and simultaneously

pressing another key which may be a letter or (depending on

the keyboard and operating system) certain punctuation

characters. Some control codes usually have their own special

keys: escape, tab, delete, backspace, return and can

thus be entered with a single keypress.

Different operating systems and programs have different

conventions for what effect typing certain control codes will

have, such as interrupting the current process or suspending

output.

Control codes may be output for their effect on the output

device, e.g. moving the cursor or print head to the start of a

new line.

See control-O, control-Q, control-S.

(1995-03-23)