ControlCharacters

```
public interface ControlCharacters
```
Represents all the control characters (the first 32 codes + SPACE and DELETE).

Field Summary

Fields
Modifier and Type	Field and Description
`static char`	`ACKNOWLEDGEMENT` Response to an Enquiry, or an indication of successful receipt of a message.
`static char`	`BACK_SPACE` Move the cursor one position leftwards.
`static char`	`BELL` Originally used to sound a bell on the terminal.
`static char`	`CANCEL` Indicates that the data preceding it are in error or are to be disregarded.
`static char`	`CARRIAGE_RETURN` Originally used to move the cursor to column zero while staying on the same line.
`static char`	`DATA_LINK_ESCAPE` Cause the following octets to be interpreted as raw data, not as control codes or graphic characters.
`static char`	`DELETE` Not technically part of the C0 control character range, this was originally used to mark deleted characters on paper tape, since any character could be changed to all ones by punching holes everywhere.
`static char`	`DEVICE_CONTROL1` These four control codes are reserved for device control, with the interpretation dependent upon the device they were connected.
`static char`	`DEVICE_CONTROL2`
`static char`	`DEVICE_CONTROL3`
`static char`	`DEVICE_CONTROL4`
`static char`	`END_OF_MEDIUM` Intended as means of indicating on paper or magnetic tapes that the end of the usable portion of the tape had been reached.
`static char`	`END_OF_TEXT` Often used as a "break" character (Ctrl-C) to interrupt or terminate a program or process.
`static char`	`END_OF_TRANSMISSION` Used on Unix to signal end-of-file condition on, or to log out from a terminal.
`static char`	`END_OF_TRANSMISSION_BLOCK` Indicates the end of a transmission block of data when data are divided into such blocks for transmission purposes.
`static char`	`ENQUIRY` Signal intended to trigger a response at the receiving end, to see if it is still present.
`static char`	`ESCAPE` The Esc key on the keyboard will cause this character to be sent on most systems.
`static char`	`FILE_SEPARATOR` Can be used as delimiters to mark fields of data structures.
`static char`	`FORM_FEED` On printers, load the next page.
`static char`	`GROUP_SEPARATOR` Same as `FILE_SEPARATOR`.
`static char`	`HORIZONTAL_TAB` Position to the next character tab stop.
`static char`	`LINE_FEED` On typewriters, printers, and some terminal emulators, moves the cursor down one row without affecting its column position.
`static char`	`NEGATIVE_ACKNOWLEDGEMENT` Sent by a station as a negative response to the station with which the connection has been set up.
`static char`	`NULL` Originally used to allow gaps to be left on paper tape for edits.
`static char`	`RECORD_SEPARATOR` Same as `FILE_SEPARATOR`.
`static char`	`SHIFT_IN` Return to regular character set after Shift Out.
`static char`	`SHIFT_OUT` Switch to an alternative character set.
`static char`	`SPACE` Space is a graphic character.
`static char`	`START_OF_HEADING` First character of message header.
`static char`	`START_OF_TEXT` First character of message text, and may be used to terminate the message heading.
`static char`	`SUBSTITUTE` Originally intended for use as a transmission control character to indicate that garbled or invalid characters had been received.
`static char`	`SYNCHRONOUS_IDLE` Used in synchronous transmission systems to provide a signal from which synchronous correction may be achieved between data terminal equipment, particularly when no other character is being transmitted.
`static char`	`UNIT_SEPARATOR` Same as `FILE_SEPARATOR`.
`static char`	`VERTICAL_TAB` Position the form at the next line tab stop.

- Field Detail
  - NULL
```
static final char NULL
```
    Originally used to allow gaps to be left on paper tape for edits. Later used for padding after a code that might take a terminal some time to process (e.g. a carriage return or line feed on a printing terminal). Now often used as a string terminator.
    
    See Also:
    
    Constant Field Values
  - START_OF_HEADING
```
static final char START_OF_HEADING
```
    First character of message header.
    
    See Also:
    
    Constant Field Values
  - START_OF_TEXT
```
static final char START_OF_TEXT
```
    First character of message text, and may be used to terminate the message heading.
    
    See Also:
    
    Constant Field Values
  - END_OF_TEXT
```
static final char END_OF_TEXT
```
    Often used as a "break" character (Ctrl-C) to interrupt or terminate a program or process.
    
    See Also:
    
    Constant Field Values
  - END_OF_TRANSMISSION
```
static final char END_OF_TRANSMISSION
```
    Used on Unix to signal end-of-file condition on, or to log out from a terminal.
    
    See Also:
    
    Constant Field Values
  - ENQUIRY
```
static final char ENQUIRY
```
    Signal intended to trigger a response at the receiving end, to see if it is still present.
    
    See Also:
    
    Constant Field Values
  - ACKNOWLEDGEMENT
```
static final char ACKNOWLEDGEMENT
```
    Response to an Enquiry, or an indication of successful receipt of a message.
    
    See Also:
    
    Constant Field Values
  - BELL
```
static final char BELL
```
    Originally used to sound a bell on the terminal. Later used for a beep on systems that didn't have a physical bell. May also quickly turn on and off inverse video (a visual bell).
    
    See Also:
    
    Constant Field Values
  - BACK_SPACE
```
static final char BACK_SPACE
```
    Move the cursor one position leftwards. On input, this may delete the character to the left of the cursor. On output, where in early computer technology a character once printed could not be erased, the backspace was sometimes used to generate accented characters in ASCII. For example, à could be produced using the three character sequence a BS ` (or, using the characters’ hex values, 0x61 0x08 0x60). This usage is now deprecated and generally not supported. To provide disambiguation between the two potential uses of backspace, the cancel character control code was made part of the standard C1 control set.
    
    See Also:
    
    Constant Field Values
  - HORIZONTAL_TAB
```
static final char HORIZONTAL_TAB
```
    Position to the next character tab stop.
    
    See Also:
    
    Constant Field Values
  - LINE_FEED
```
static final char LINE_FEED
```
    On typewriters, printers, and some terminal emulators, moves the cursor down one row without affecting its column position. On Unix, used to mark end-of-line. In DOS, Windows, and various network standards, LF is used following CR as part of the end-of-line mark.
    
    See Also:
    
    Constant Field Values
  - VERTICAL_TAB
```
static final char VERTICAL_TAB
```
    Position the form at the next line tab stop.
    
    See Also:
    
    Constant Field Values
  - FORM_FEED
```
static final char FORM_FEED
```
    On printers, load the next page. Treated as whitespace in many programming languages, and may be used to separate logical divisions in code. In some terminal emulators, it clears the screen. It still appears in some common plain text files as a page break character, such as the RFCs published by IETF.
    
    See Also:
    
    Constant Field Values
  - CARRIAGE_RETURN
```
static final char CARRIAGE_RETURN
```
    Originally used to move the cursor to column zero while staying on the same line. On Mac OS (pre-OS X), as well as in earlier systems such as the Apple II and Commodore 64, used to mark end-of-line. In DOS, Windows, and various network standards, it is used preceding LF as part of the end-of-line mark. The Enter or Return key on a keyboard will send this character, but it may be converted to a different end-of-line sequence by a terminal program.
    
    See Also:
    
    Constant Field Values
  - SHIFT_OUT
```
static final char SHIFT_OUT
```
    Switch to an alternative character set.
    
    See Also:
    
    Constant Field Values
  - SHIFT_IN
```
static final char SHIFT_IN
```
    Return to regular character set after Shift Out.
    
    See Also:
    
    Constant Field Values
  - DATA_LINK_ESCAPE
```
static final char DATA_LINK_ESCAPE
```
    Cause the following octets to be interpreted as raw data, not as control codes or graphic characters. Returning to normal usage would be implementation dependent.
    
    See Also:
    
    Constant Field Values
  - DEVICE_CONTROL1
```
static final char DEVICE_CONTROL1
```
    These four control codes are reserved for device control, with the interpretation dependent upon the device they were connected. DC1 and DC2 were intended primarily to indicate activating a device while DC3 and DC4 were intended primarily to indicate pausing or turning off a device. In actual practice DC1 and DC3 (known also as XON and XOFF respectively in this usage) quickly became the de facto standard for software flow control.
    
    See Also:
    
    Constant Field Values
  - DEVICE_CONTROL2
```
static final char DEVICE_CONTROL2
```
    See Also:
    
    DEVICE_CONTROL1, Constant Field Values
  - DEVICE_CONTROL3
```
static final char DEVICE_CONTROL3
```
    See Also:
    
    DEVICE_CONTROL1, Constant Field Values
  - DEVICE_CONTROL4
```
static final char DEVICE_CONTROL4
```
    See Also:
    
    DEVICE_CONTROL1, Constant Field Values
  - NEGATIVE_ACKNOWLEDGEMENT
```
static final char NEGATIVE_ACKNOWLEDGEMENT
```
    Sent by a station as a negative response to the station with which the connection has been set up. In binary synchronous communication protocol, the NAK is used to indicate that an error was detected in the previously received block and that the receiver is ready to accept retransmission of that block. In multipoint systems, the NAK is used as the not-ready reply to a poll.
    
    See Also:
    
    Constant Field Values
  - SYNCHRONOUS_IDLE
```
static final char SYNCHRONOUS_IDLE
```
    Used in synchronous transmission systems to provide a signal from which synchronous correction may be achieved between data terminal equipment, particularly when no other character is being transmitted.
    
    See Also:
    
    Constant Field Values
  - END_OF_TRANSMISSION_BLOCK
```
static final char END_OF_TRANSMISSION_BLOCK
```
    Indicates the end of a transmission block of data when data are divided into such blocks for transmission purposes.
    
    See Also:
    
    Constant Field Values
  - CANCEL
```
static final char CANCEL
```
    Indicates that the data preceding it are in error or are to be disregarded.
    
    See Also:
    
    Constant Field Values
  - END_OF_MEDIUM
```
static final char END_OF_MEDIUM
```
    Intended as means of indicating on paper or magnetic tapes that the end of the usable portion of the tape had been reached.
    
    See Also:
    
    Constant Field Values
  - SUBSTITUTE
```
static final char SUBSTITUTE
```
    Originally intended for use as a transmission control character to indicate that garbled or invalid characters had been received. It has often been put to use for other purposes when the in-band signaling of errors it provides is unneeded, especially where robust methods of error detection and correction are used, or where errors are expected to be rare enough to make using the character for other purposes advisable.
    
    See Also:
    
    Constant Field Values
  - ESCAPE
```
static final char ESCAPE
```
    The Esc key on the keyboard will cause this character to be sent on most systems. It can be used in software user interfaces to exit from a screen, menu, or mode, or in device-control protocols (e.g., printers and terminals) to signal that what follows is a special command sequence rather than normal text. In systems based on ISO/IEC 2022, even if another set of C0 control codes are used, this octet is required to always represent the escape character.
    
    See Also:
    
    Constant Field Values
  - FILE_SEPARATOR
```
static final char FILE_SEPARATOR
```
    Can be used as delimiters to mark fields of data structures. If used for hierarchical levels, US is the lowest level (dividing plain-text data items), while RS, GS, and FS are of increasing level to divide groups made up of items of the level beneath it.
    
    See Also:
    
    Constant Field Values
  - GROUP_SEPARATOR
```
static final char GROUP_SEPARATOR
```
    Same as FILE_SEPARATOR.
    
    See Also:
    
    Constant Field Values
  - RECORD_SEPARATOR
```
static final char RECORD_SEPARATOR
```
    Same as FILE_SEPARATOR.
    
    See Also:
    
    Constant Field Values
  - UNIT_SEPARATOR
```
static final char UNIT_SEPARATOR
```
    Same as FILE_SEPARATOR.
    
    See Also:
    
    Constant Field Values
  - SPACE
```
static final char SPACE
```
    Space is a graphic character. It has a visual representation consisting of the absence of a graphic symbol. It causes the active position to be advanced by one character position. In some applications, Space can be considered a lowest-level "word separator" to be used with the adjacent separator characters.
    
    See Also:
    
    Constant Field Values
  - DELETE
```
static final char DELETE
```
    Not technically part of the C0 control character range, this was originally used to mark deleted characters on paper tape, since any character could be changed to all ones by punching holes everywhere. On VT100 compatible terminals, this is the character generated by the key labelled ⌫, usually called backspace on modern machines, and does not correspond to the PC delete key.
    
    See Also:
    
    Constant Field Values

Interface ControlCharacters

Field Summary

Field Detail

NULL

START_OF_HEADING

START_OF_TEXT

END_OF_TEXT

END_OF_TRANSMISSION

ENQUIRY

ACKNOWLEDGEMENT

BELL

BACK_SPACE

HORIZONTAL_TAB

LINE_FEED

VERTICAL_TAB

FORM_FEED

CARRIAGE_RETURN

SHIFT_OUT

SHIFT_IN

DATA_LINK_ESCAPE

DEVICE_CONTROL1

DEVICE_CONTROL2

DEVICE_CONTROL3

DEVICE_CONTROL4

NEGATIVE_ACKNOWLEDGEMENT

SYNCHRONOUS_IDLE

END_OF_TRANSMISSION_BLOCK

CANCEL

END_OF_MEDIUM

SUBSTITUTE

ESCAPE

FILE_SEPARATOR

GROUP_SEPARATOR

RECORD_SEPARATOR

UNIT_SEPARATOR

SPACE

DELETE