End-of-transmission Character

In telecommunication, an end-of-transmission character (EOT) is a transmission control character. Its intended use is to indicate the conclusion of a transmission that may have included one or more texts and any associated message headings.

An EOT is often used to initiate other functions, such as releasing circuits, disconnecting terminals, or placing receive terminals in a standby condition. Its most common use today is to cause a Unix terminal driver to signal end of file and thus exit programs that are awaiting input.

In ASCII and Unicode, the character is encoded at U+0004 . It can be referred to as control-D, ^D in caret notation. Unicode provides the character U+2404 ␄ symbol for end of transmission (HTML: ␄) for when EOT needs to be displayed graphically.