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man pages section 4: Device and Network Interfaces

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Updated: Thursday, June 13, 2019
 
 

wscons(4D)

Name

wscons - workstation console

Synopsis

#include <sys/strredir.h> 
ioctl(fd, SRIOCSREDIR, target);
ioctl(fd, SRIOCISREDIR, target);

Description

The wscons workstation console consists of a workstation keyboard and frame buffer that act together to emulate an ASCII terminal. It includes a redirection facility that allows I/O issued to the workstation console to be diverted to a STREAMS device, enabling window systems to redirect output that would otherwise appear directly on the frame buffer in corrupted form.

Redirection

The wscons redirection facility maintains a list of devices that are designated as redirection targets through the SRIOCSREDIR ioctl described below. Only the current entry is active; when the active entry is closed, the most recent remaining entry becomes active. The active entry acts as a proxy for the device being redirected and handles all read(2), write(2), ioctl(2), and poll(2) calls issued against the redirectee.

The ioctls described below control the redirection facility. In both cases, fd is a descriptor for the device being redirected (or workstation console) and target is a descriptor for a STREAMS device.

SRIOCSREDIR

Designates target as the source and destination of I/O ostensibly directed to the device denoted by fd.

SRIOCISREDIR

Returns 1 if target names the device currently acting as proxy for the device denoted by fd, and 0 if it is not.

ANSI Standard Terminal Emulation

The Solaris kernel terminal emulator provides ANSI X3.64 emulation both on SPARC and x86 systems.

On SPARC systems, the PROM monitor is used to emulate an ANSI X3.64 terminal if the kernel terminal emulator is not available for emulation. See visual_io(4I) for more details.

Note: The VT100 adheres the ANSI X3.64 standard. However, because the VT100 features nonstandard extensions to ANSI X3.64, it is incompatible with Sun terminal emulators.

The SPARC console displays 34 lines of 80 ASCII characters per line. The x86 console displays 25 lines of 80 ASCII characters per line. Devices with smaller text capacities may display less. On SPARC systems, the screen-#rows screen-#columns should be set to 34 or 80 respectively or text capacities will vary from those described above. On SPARC systems, the screen-#rows and screen-#columns fields are stored in NVRAM/EEPROM. See eeprom(8) for more information. Both SPARC and x86 consoles offer scrolling, (x, y) cursor addressing ability and a number of other control functions.

The console cursor marks the current line and character position on the screen. ASCII characters between 0x20(space) and 0x7E (tilde) inclusive are printing characters. When a print character is written to the console (and is not part of an escape sequence), it is displayed at the current cursor position and the cursor moves one position to the right on the current line.

On SPARC based systems, later PROM revisions have the full 8-bit ISO Latin-1 (ISO 8859-1) character set. Earlier PROM revisions display characters in the range 0xA0 through 0xFE as spaces.

When the cursor is at the right edge of the screen, it moves to the first character position on the next line. When the cursor is at the screen's right-bottom edge, the line-feed function is performed (see CTRL-J below). The line-feed function scrolls the screen up by one or more lines before moving the cursor to the first character position on the next line.

Control Sequence Syntax

The wscons console defines a number of control sequences that may occur during input. When a control sequence is written to the console, it affects one of the control functions described below. Control sequences are not displayed on screen.

A number of control sequences (or control character functions) are of the form:

CTRL-x

where x represents a singe character., such as CNTRL-J for a line feed.

Other ANSI control sequences are of the form:

ESC [ params char 

Note - Spaces are included only for readability; these characters must occur in the given sequence without the intervening spaces.
ESC

ASCII escape character (ESC, CTRL-[, 0x1B).

[

Left square bracket `[' (0x5B).

params

Sequence of zero or more decimal numbers made up of digits between 0 and 9, separated by semicolons. Parameters are represented by n in the syntax descriptions for escape sequence functions.

char

Function character, which is different for each control sequence and it represented by x in the syntax descriptions for control character functions.

In the following examples of syntactically valid escape sequences, ESC represent the single ASCII character, Escape:

ESC[m

Select graphic rendition with default parameter

ESC[7m

Select graphic rendition with reverse image

ESC[33;54H

Set cursor position

ESC[123;456;0;;3;B

Move cursor down

Syntactically valid control characters and ANSI escape sequences that are not currently interpreted by the console are ignored.

Each control function requires a specified number of parameters. If fewer parameters are supplied, the remaining parameters (with certain exceptions noted below) default to 1. If more parameters are supplied, the first n parameters are used by kernel terminal emulator. In contrast, only the last n parameters are used by PROM based emulator, where n is the number required by that particular command character.

Parameters which are omitted or set to 0 are reset to the default value of 1 (with certain exceptions). For example, the command character M requires one parameter. ESC[;M, ESC[0M, ESC[M and ESC[23;15;32;1M are all equivalent to ESC[1M and provide a parameter value of 1. Note that ESC[;5M (interpreted as `ESC[5M') is not equivalent to ESC[5;M (interpreted as `ESC[5;1M') which is ultimately interpreted as `ESC[1M').

ANSI Control Functions

The following paragraphs specify the ANSI control functions implemented by the console. Each description provides:

  • Control sequence syntax

  • Hexadecimal equivalent of control characters where applicable

  • Control function name and ANSI or Sun abbreviation (if any).

  • Description of parameters required, if any

  • Description of the control function

  • Initial setting of the mode for functions that set a mode. To restore the initial settings, use the SUNRESET escape sequence.

Control Character Functions

The wscons control character functions are:

Bell (BEL),
CTRL-G
0x7

Used for consoles that are not equipped with an audible bell. Current Sun workstation models also flash the screen if the keyboard is not the console input device.

Backspace (BS),
CTRL-H,
0x8

The cursor moves one position to the left on the current line. If it is already at the left edge of the screen, no change takes place.

Tab (TAB),
CTRL-I,
0x9

The cursor moves right on the current line to the next tab stop. The tab stops are fixed at every multiple of eight columns. If the cursor is already at the right edge of the screen, nothing change takes place. Otherwise, the cursor moves right a minimum of one and a maximum of eight character positions.

Line-feed (LF),
CTRL-J,
0xA

The cursor, while remaining at the same character position on the line, moves down one line. If the cursor is at the bottom line, the screen either scrolls up or wraps around depending on the setting of an internal variable n (initially 1) . The internal variable can be changed using the ESC[r control sequence. If n is greater than zero, the entire screen (including the cursor) is scrolled up by n lines before executing the line-feed. The top n lines scroll off the screen and are lost. New blank lines n scroll onto the bottom of the screen. After scrolling, move the cursor down one line to execute the line feed.

If n is zero, wrap-around mode is entered. The ESC [ 1 r exits back to scroll mode. If a line-feed occurs on the bottom line in wrap mode, the cursor goes to the same character position in the top line of the screen. During line-feeds, the line that the cursor moves to is cleared and no scrolling occurs. Wrap-around mode is not implemented in the window system.

On SPARC based systems, the speed at which the screen scrolls is dependent on the amount of data waiting to be printed. Whenever a scroll occurs and the console is in normal scroll mode (ESC [ 1 r), it scans the rest of the data awaiting printing to see how many line-feeds occur in it. This scan stops when the console finds a control character from the set {VT, FF, SO, SI, DLE, DC1, DC2, DC3, DC4, NAK, SYN, ETB, CAN, EM, SUB, ESC, FS, GS, RS, US} . At that point, the screen is scrolled by n lines (n ≥ 1) and processing continues. The scanned text is processed normally and fills in the newly created lines. As long as escape codes or other control characters are not intermixed with the text, this results in faster scrolling

Reverse Line-feed,
CTRL-K,
0xB

With kernel terminal emulator (while remaining at the same character position on the line), the cursor moves down one line. However, with PROM based emulator (while remaining at the same character position on the line), the cursor moves up one line. If the cursor is already at the top line, no change takes place.

Form-feed (FF)
CTRL-L,
0xC

The cursor is positioned to the home position (upper-left corner) and the entire screen is cleared.

Return (CR),
CTRL-M,
0xD

The cursor moves to the leftmost character position on the current line.

Escape Sequence Functions

The wscons escape sequence functions are:

Escape (ESC),
CTRL-[,
0x1B

The escape character. Escape initiates a multi-character control sequence.

Insert Character (ICH)
ESC[#@

Takes one parameter, n (default 1). Inserts n spaces at the current cursor position. The current line, starting at the current cursor position inclusive, is shifted to the right by n character positions to make room for the spaces. The rightmost n character positions shift off the line and are lost. The position of the cursor is unchanged.

Cursor Up (CUU),
ESC[#A

Takes one parameter, n (default 1). Moves the cursor up n lines. If the cursor is fewer than n lines from the top of the screen, moves the cursor to the topmost line on the screen. The character position of the cursor on the line is unchanged.

Cursor Down (CUD),
ESC[#B

Takes one parameter, (default 1). Moves the cursor down n lines. If the cursor is fewer than n lines from the bottom of the screen, move the cursor to the last line on the screen. The character position of the cursor on the line is unchanged.

Cursor Forward (CUF),
ESC[#C

Takes one parameter, n (default 1). Moves the cursor to the right by n character positions on the current line. If the cursor is fewer than n positions from the right edge of the screen, moves the cursor to the rightmost position on the current line.

Cursor Backward (CUB),
ESC[#D

Takes one parameter, n (default 1). Moves the cursor to the left by n character positions on the current line. If the cursor is fewer than n positions from the left edge of the screen, moves the cursor to the leftmost position on the current line.

Cursor Next Line (CNL),
ESC[#E

Takes one parameter, n (default 1). Positions the cursor at the leftmost character position on the n-th line below the current line. If the current line is less than n lines from the bottom of the screen, positions the cursor at the leftmost character position on the bottom line.

Horizontal and Vertical Position (HVP),
ESC[#1;#2f

or

Cursor Position (CUP),
ESC[#1;#2H

Takes two parameters, n1 and n2 (default 1, 1). Moves the cursor to the n2-th character position on the n1-th line. Character positions are numbered from 1 at the left edge of the screen; line positions are numbered from 1 at the top of the screen. Hence, if both parameters are omitted, the default action moves the cursor to the home position (upper left corner). If only one parameter is supplied, the cursor moves to column 1 of the specified line.

Erase in Display (ED),
ESC[J

Takes no parameters. Erases from the current cursor position inclusive to the end of the screen, that is, to the end of the current line and all lines below the current line. The cursor position is unchanged.

Erase in Line (EL),
ESC[K

Takes no parameters. Erases from the current cursor position inclusive to the end of the current line. The cursor position is unchanged.

Insert Line (IL),
ESC[#L

Takes one parameter, n (default 1). Makes room for n new lines starting at the current line by scrolling down by n lines the portion of the screen from the current line inclusive to the bottom. The n new lines at the cursor are filled with spaces; the bottom n lines shift off the bottom of the screen and are lost. The position of the cursor on the screen is unchanged.

Delete Line (DL),
ESC[#M

Takes one parameter, n (default 1). Deletes n lines beginning with the current line. The portion of the screen from the current line inclusive to the bottom is scrolled upward by n lines. The n new lines scrolling onto the bottom of the screen are filled with spaces; the n old lines beginning at the cursor line are deleted. The position of the cursor on the screen is unchanged.

Delete Character (DCH),
ESC[#P

Takes one parameter, n (default 1). Deletes n characters starting with the current cursor position. Shifts the tail of the current line to the left by n character positions from the current cursor position, inclusive, to the end of the line. Blanks are shifted into the rightmost n character positions. The position of the cursor on the screen is unchanged.

Select Graphic Rendition (SGR),
ESC[#m

Takes one parameter, n (default 0). Note that unlike most escape sequences, the parameter defaults to zero if omitted. Invokes the graphic rendition specified by the parameter. All following printing characters in the data stream are rendered according to the parameter until the next occurrence of this escape sequence in the data stream. With PROM-based emulator, only two graphic renditions are defined:

0

Normal rendition

7

Negative (reverse) image

Negative image displays characters as white-on-black if the screen mode is currently black-on white, and vice-versa. Any non-zero value of n is currently equivalent to 7 and selects the negative image rendition.

In addition to the two renditions mentioned above, the following ISO 6429-1983 graphic rendition values support color text with kernel terminal emulator:

30

black foreground

31

red foreground

32

green foreground

33

brown foreground

34

blue foreground

35

magenta foreground

36

cyan foreground

37

white foreground

40

black background

41

red background

42

green background

43

brown background

44

blue background

45

magenta background

46

cyan background

47

white background

Black On White (SUNBOW),
ESC[p

Takes no parameters. On SPARC, sets the screen mode to black-on-white. If the screen mode is already black-on-white, has no effect. In this mode, spaces display as solid white, other characters as black-on-white. The cursor is a solid black block. Characters displayed in negative image rendition (see `Select Graphic Rendition' above) are white-on-black. This comprises the initial setting of the screen mode on reset. On x86 systems, use ESC[q to set black-on-white.

White On Black (SUNWOB),
ESC[q

Takes no parameters. On SPARC, sets the screen mode to white-on-black. If the screen mode is already white-on-black, has no effect. In this mode spaces display as solid black, other characters as white-on-black. The cursor is a solid white block. Characters displayed in negative image rendition (see `Select Graphic Rendition' above) are black-on-white. Initial setting of the screen mode on reset is black on white. On x86 systems, use ESC[p to set white-on-black.

ESC[#r
Set Scrolling (SUNSCRL)

Takes one parameter, n (default 0). Sets to n an internal register which determines how many lines the screen scrolls up when a line-feed function is performed with the cursor on the bottom line. A parameter of 2 or 3 introduces a small amount of jump when a scroll occurs. A parameter of 34 clears the screen rather than scrolling. The initial setting is 1 on reset.

A parameter of zero initiates wrap mode instead of scrolling. If a linefeed occurs on the bottom line during wrap mode, the cursor goes to the same character position in the top line of the screen. When a line feed occurs, the line that the cursor moves to is cleared and no scrolling occurs. ESC [ 1 r exits back to scroll mode.

For more information, see the description of the Line-feed (CTRL-J) control function above.

ESC[s
Reset terminal emulator (SUNRESET)

Takes no parameters. Resets all modes to default, restores current font from PROM. Screen and cursor position are unchanged.

Return Values

When there are no errors, the redirection ioctls have return values as described above. Otherwise, they return −1 and set errno to indicate the error. If the target stream is in an error state, errno is set accordingly.

If the target stream is in an error state, errno is set accordingly.

Errors

EBADF

target does not denote an open file.

ENOSTR

target does not denote a STREAMS device.

Files

/dev/wscons

Workstation console, accessed via the redirection facility

/dev/systty

Devices that must be opened for the SRIOCSREDIR and SRIOCISREDIR ioctls.

/dev/syscon

Access system console

/dev/console

Access system console

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed

See Also

ioctl(2), poll(2), read(2), write(2), console(4D), visual_io(4I), eeprom(8)

Warnings

The redirection ioctls block while there is I/O outstanding on the device instance being redirected. If you try to redirect the workstation console while there is a outstanding read, the workstation console will hang until the read completes.