Search results
Results from the WOW.Com Content Network
The Xterm terminal emulator. In the early 1980s, large amounts of software directly used these sequences to update screen displays. This included everything on VMS (which assumed DEC terminals), most software designed to be portable on CP/M home computers, and even lots of Unix software as it was easier to use than the termcap libraries, such as the shell script examples below in this article.
Generally, an escape character is not a particular case of (device) control characters, nor vice versa.If we define control characters as non-graphic, or as having a special meaning for an output device (e.g. printer or text terminal) then any escape character for this device is a control one.
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 keyEsc (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+[).
In many programming languages such as C, Perl, PHP, Python and Unix scripting languages, and in many file formats such as JSON, the backslash is used as an escape character, to indicate that the character following it should be treated specially (if it would otherwise be treated literally), or literally (if it would otherwise be treated specially).
The sign is located on the left-top of a US or UK layout keyboard, next to the 1 key. [c] On older keyboards, the Escape key was at this location, and the backtick key was somewhere on the right side of the layout. Provision (if any) of the backtick on other keyboards varies by national keyboard layout and keyboard mapping.
The "escape" character (ESC, code 27), for example, was intended originally to allow sending of other control characters as literals instead of invoking their meaning, an "escape sequence". This is the same meaning of "escape" encountered in URL encodings, C language strings, and other systems where certain characters have a reserved meaning.
In C and many derivative programming languages, a string escape sequence is a series of two or more characters, starting with a backslash \. [3]Note that in C a backslash immediately followed by a newline does not constitute an escape sequence, but splices physical source lines into logical ones in the second translation phase, whereas string escape sequences are converted in the fifth ...
In computer data, a substitute character (␚) is a control character that is used to pad transmitted data in order to send it in blocks of fixed size, or to stand in place of a character that is recognized to be invalid, erroneous or unrepresentable on a given device. It is also used as an escape sequence in some programming languages.