Esc key

Source: Wikipedia, the free encyclopedia.
For other uses, see ESC.
Not to be confused with Escape character.
A computer keyboard with the Esc key in the top-left corner
IBM 83-key keyboard (1981), with Esc in the top-left corner of the alphanumeric section

On

computer keyboards, the Esc key Esc (named Escape key in the international standard series ISO/IEC 9995) is a key used to generate the escape character (which can be represented as ASCII code 27 in decimal, Unicode U+001B, or Ctrl+[). The escape character, when sent from the keyboard to a computer, often is interpreted by software as "stop", "cancel" or "exit", and when sent from the computer to an external device (including many printers since the 1980s, computer terminals and Linux consoles, for example) marks the beginning of an escape sequence
to specify operating modes or characteristics generally.

It is now generally placed at the top left corner of the keyboard, a convention dating at least to the original

teletypewriters
.

Symbol

ISO keyboard symbol for "Escape"

The keyboard symbol for the ESC key (which may be used when the usual Latin lettering is not preferred for labelling the key) is standardized in ISO/IEC 9995-7 as symbol 29, and in ISO 7000 "Graphical symbols for use on equipment" as symbol ISO-7000-2029. This symbol is encoded in Unicode as U+238B broken circle with northwest arrow (⎋).

Origins

The name of the equivalent key on some early

escape sequences
often would take more than one following byte as part of a special sequence.

Uses

As most modern computer users are no longer concerned with controlling

web browsers, and to cancel drag and drop operations.[1][2][3]

On machines running Microsoft Windows, prior to the implementation of the Windows key on keyboards, the typical practice for invoking the "start" button was to hold down the Control key and press escape. This key combination still works as of Windows 11.[4]

Microsoft Windows makes use of "Esc" for many key shortcuts.[5] Many of these shortcuts have been present since Windows 3.0, through Windows XP and later.

In macOS, "Esc" usually closes or cancels a dialog box or sheet. The

Force Quit dialog box, allowing users to end non-responsive applications. Another use for the Esc key, in combination with the Command key, is switching to Front Row
, if installed.

In most computer games, the escape key is used as a pause button and/or as a way to bring up the in-game menu, usually containing ways to exit the program. This is despite the existence of a separate

Pause/Break key
.

ADM-3A keyboard layout used in vi development, with escape in what is now the Tab ↹ position

In the

top row on the ADM-3A terminal keyboard used to develop vi, in what on modern keyboards is now the tab position – yet on modern keyboards, Esc is now inconveniently located, most often in the function keys row. This is similar to how the extensive modifier keys in Emacs were easily used on the original keyboard (the space-cadet keyboard
)—being placed together—but these keys have now been spread around the keyboard, and hence become more difficult to use.

The TECO editor uses ESCape as a delimiter when used once, and as an execute key when used twice in a row.[6]

Escape sequences on KSR terminals

Old keyboard Send/Receive (KSR) printers, and

ANSI Escape sequences very similar to the 1970s VT100, is implemented in both ANSI.SYS and other more modern pseudo-terminal interfaces used in Unix-like environments, one example being Linux consoles
, meaning newer, higher-level abstractions haven't changed the fact that typing the escape key followed by something like the six characters [32;1m affects subsequently text in output, in this case turning it green.

References

  1. ^ "Netscape for UNIX keybindings". Archived from the original on 2006-09-19. Retrieved 2009-02-07.
  2. ^ "Internet Explorer 7 Quick Reference Guide". Archived from the original on 2009-02-18. Retrieved 2009-02-07.
  3. ^ "Cheat Sheet for Mozilla FireFox (Key Board Short Cuts)". scribd.com. Retrieved 4 December 2016.
  4. ^ "Ctrl+Esc, U, Enter: Shutdown Windows (XP and earlier)". Archived from the original on 18 July 2017. Retrieved 26 April 2012.
  5. ^ "Keyboard shortcuts in Windows". support.microsoft.com.
  6. ^ "Survival TECO".
  7. ^ "About Unicode and Character Sets", Joel Spolsky, Joel on Software
IBM PC keyboard (Windows, ANSI US layout)
Esc F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 PrtScn/
SysRq 		Scroll
Lock 		Pause/
Break
TildeExclamation markAt signNumber signDollar signPercent signCaretAmpersandAsteriskParenthesisParenthesisUnderscorePlus signBackspaceBacktick1 (number)2 (number)3 (number)4 (number)5 (number)6 (number)7 (number)8 (number)9 (number)0Hyphen-minusEquals signBackspaceTab keyQWERTYUIOPCurly bracketCurly bracketVertical barTab keyQWERTYUIOPSquare bracketSquare bracketBackslashCaps lockASDFGHJKLColon (punctuation)Quotation markEnter keyCaps lockASDFGHJKLSemicolonApostropheEnter keyShift keyZXCVBNMBracketBracketQuestion markShift keyShift keyZXCVBNMComma (punctuation)Full stopSlash (punctuation)Shift keyControl keyWindows keyAlt keySpace barAlt keythumbMenu keyControl key
 Insert Home PgUp
Num
Lock
 ∕ ∗
−
Delete End PgDn 7 8 9
+
4 5 6
↑ 1 2 3 Enter
← ↓ →    0
   Ins 		 . 
Del
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