About ESC


Integer ASCII code: 27
Binary code: 0001 1011
Octal code: 33
Hexadecimal code: 1B
Group: control
Seq: ^[

Unicode symbol: , int code: 9243 (html &#9243) hex code: 241B (html &#x241B)


Information


Pressing the Escape key on the keyboard will make this character to be sent on most systems. It can be used in software user interfaces in the function of the exit from a screen, menu, or operating mode, or in device-control protocols (like printers and terminals). In this function it lets the person know, that what comes next is a special command sequence rather than normal text. It doesn't matter if systems based on ISO/IEC 2022 use another set of C0 control codes. This octet is necessarily required to always represent the escape character.

The escape character is widely used in computing and telecommunication. In this role an escape character is a character, which applies to a different interpretation on subsequent characters in a character sequence. In context of escape character we can talk about metacharacters. It's believed that escape can be called a kind if metacharacter. In most cases, the judgment of whether something is an escape character or not depends on context.

Definition


All escape sequences strictly have at least two characters just because an escape character may not have its own meaning.

Escape characters make a part of the syntax for lots of programming languages, data formats, and communication protocols. If we're talking about a given alphabet, here an escape character's aim is to start character sequences (so called escape sequences). The things is that they have to be interpreted in a different way from the same characters appeared without the prefixed escape character.

Commonly escape sequences have two functions. The first one is to encode a syntactic realia, for example device commands or special data, which can't be represented by the alphabet itself in the clear form. The second function (by the way, it is called character quoting) is to reflect characters, typing of which is impossible in current context, or would have an adverse, wrong interpretation. In the latter case an escape sequence is represented by a digraph, which consists of an escape character itself and a "quoted" character.

Control character


Usually an escape character is neither a special case of (device) control characters, nor vice versa. Imagine, that we determine control characters to be non-graphic, or as possessing a particular meaning for an output device (like printer or text terminal). This way, any escape character for this device is a control one, which is quite ambiguous, since escape characters used in programming (such as the backslash, '\') are graphic characters, deprived of any control function. On the contrary, most (but not all) of the ASCII "control characters" have some concealed control function, therefore are not escape characters.

Besides, an escape character forms some escape sequences in lots of programming languages. All of them are connected to control characters. For example, line break has an escape sequence of .


Hash


input value base type output hash
ESC char MD5 f616c83f2f0f188265c7004d81d45723
ESC char SHA1 27f57cb359a8f86acf4af811c47a6380b4bb4209
27 dec MD5 02e74f10e0327ad868d138f2b4fdd6f0
27 dec SHA1 bc33ea4e26e5e1af1408321416956113a4658763
00011011 bin MD5 78baf048fe4c5bffa0242d6c1c844418
00011011 bin SHA1 d84fc085fbed699ce73f81e97d3eb6e650204294
0001 1011 bin MD5 557138e03b700aa016d1ec5e1e288054
0001 1011 bin SHA1 8d541dcc947add380c964c71d6f13810e05eedad
33 oct MD5 182be0c5cdcd5072bb1864cdee4d3d6e
33 oct SHA1 b6692ea5df920cad691c20319a6fffd7a4a766b8
1B hex MD5 aeaf67915b97d360e4d26f0659dd9b2a
1B hex SHA1 36190e2986c28785e4e77e380b48697fe1e06845
0x1B hex MD5 c47a704c5aae67ef92124ad2bcb7ff76
0x1B hex SHA1 8a4251cdadf6f852dcb73f168fee60ca5f7ccf8b
Back to ASCII table

 2018 © Dmytro Koshovyi. Ukraine, Mykolayiv.