Esc key
Encyclopedia
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
keyboard
Keyboard (computing)
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
s, the Esc key is a key labeled Esc or Escape that is used to generate the ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
Escape character
Escape character
In computing and telecommunication, an escape character is a character which invokes an alternative interpretation on subsequent characters in a character sequence. An escape character is a particular case of metacharacters...
(Control
Control key
In computing, a Control key is a modifier key which, when pressed in conjunction with another key, will perform a special operation ; similar to the Shift key, the Control key rarely performs any function when pressed by itself...
-[, ASCII code 27 in decimal), the character code traditionally used to initiate an escape sequence
Escape sequence
An escape sequence is a series of characters used to change the state of computers and their attached peripheral devices. These are also known as control sequences, reflecting their use in device control. Some control sequences are special characters that always have the same meaning...
. It is generally placed in the top left corner of the keyboard, which placement dates at least to the original IBM PC keyboard
IBM PC keyboard
The keyboards for IBM PC compatible computers are standardized. However, during the 3-plus decades of PC architecture being constantly updated, multiple types of keyboard layout variations have been developed....
, though the key itself dates to teletypewriters.
The key is indicated as a circle with an arrow through it (U+238B, ⎋) as defined in ISO 9995.
Uses
As most computer users no longer are concerned with the details of controlling their computer's peripherals, the task for which the escape sequences were originally designed, the escape key was appropriated by applicationApplication software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
programmers, most often to mean Stop. This use continues today in Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
's use of escape as a shortcut in dialog boxes for No, Quit, Exit, Cancel, or Abort, as well as a common shortcut key for the Stop button in many web browsers.
On machines running Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
, prior to the implementation of the Windows key
Windows key
The Windows logo key—also known as the Windows key, the home key, the meta key, the start key, MOD4, or the flag key —is a keyboard key which was originally introduced on the Microsoft Natural keyboard before the release of Windows 95. This key became a standard key on PC keyboards...
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 7.
Microsoft Windows makes use of "Esc" for many key shortcuts. Many of these shortcuts have been present since Windows 3.0
Windows 3.0
Windows 3.0, a graphical environment, is the third major release of Microsoft Windows, and was released on 22 May 1990. It became the first widely successful version of Windows and a rival to Apple Macintosh and the Commodore Amiga on the GUI front...
, through Windows XP
Windows XP
Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
, Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
, and now Windows 7.
In Mac OS X, Esc usually closes or cancels a dialog box or sheet. The Command
Command key
The Command key, also historically known as the Apple key, open-Apple key or meta key is a modifier key present on Apple Keyboards. The Command key's purpose is to allow the user to enter keyboard shortcut commands to GUI applications...
-Option-Esc combination opens the Force Quit dialog box, allowing users to end non-responsive programs. 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.
Vi
vi is a screen-oriented text editor originally created for the Unix operating system. The portable subset of the behavior of vi and programs based on it, and the ex editor language supported within these programs, is described by the Single Unix Specification and POSIX.The original code for vi...
family of text editors, escape is used to switch modes. This usage is due to escape being conveniently placed in what is now the tab position on the ADM3A terminal keyboard used to develop vi, though it is now inconveniently placed. This is similar to how the extensive modifier keys in emacs
Emacs
Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...
were easily used on the original keyboard, being placed together, but these keys have now been spread around the keyboard, becoming more difficult to use.