In computing and telecommunication, an escape character is a character which in a sequence of characters signifies that what is to follow takes an alternative interpretation.

• In alphabet coding schemes, a specially designated character, the occurrence of which in the data signifies that one or more of the characters to follow are from a different character code, i.e., have meanings other than normal.
• In a text-control sequence of characters, a control character that indicates the beginning of the sequence and the end of any preceding text. This is for instance used to control text terminals and printers (see escape sequence).
• In the ASCII character code, the character ESC with decimal code 27 and hexadecimal code 1B.

Escape characters are also used to sidestep a literal character when it would have a special meaning and you want the ordinary meaning. For example, in the string literals of programming languages, a double quote typically signifies the end of text unless it is preceded by a backslash which is the escape character.

Early reference to this term is found in Bob Bemer's IBM technical publications.

Some of this article is based on material from Federal Standard 1037C.

The Escape key is usually found on standard PC keyboards. However it is commonly deleted on keyboards for PDAs and other devices not designed primarily for ASCII communications, and not generally used as part of the common user interface for applications on the Windows operating system. The DEC VT220 series was one of the few popular keyboards that did not have a dedicated Esc key, instead using one of the keys above the main keypad, though it is debatable if this contributed to the failure of the DEC personal computer series that used this keyboard.

External links

• That Powerful ESCAPE Character -- Key and Sequences - Bob Bemer
• Escape sequences in Java, C, C++, VB, Python and other languages

See also

• Escape sequence
• ANSI escape code

Control characters

Maskierungszeichen