.\" Copyright (c) 1995 Jim Van Zandt <jrv@vanzandt.mv.com> and aeb

.\" Sun Feb 26 11:46:23 MET 1995

.\"

.\" %%%LICENSE_START(GPLv2+_DOC_FULL)

.\" This is free documentation; you can redistribute it and/or

.\" modify it under the terms of the GNU General Public License as

.\" published by the Free Software Foundation; either version 2 of

.\" the License, or (at your option) any later version.

.\"

.\" The GNU General Public License's references to "object code"

.\" and "executables" are to be interpreted as the output of any

.\" document formatting or typesetting system, including

.\" intermediate and printed output.

.\"

.\" This manual is distributed in the hope that it will be useful,

.\" but WITHOUT ANY WARRANTY; without even the implied warranty of

.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

.\" GNU General Public License for more details.

.\"

.\" You should have received a copy of the GNU General Public

.\" License along with this manual; if not, see

.\" <http://www.gnu.org/licenses/>.

.\" %%%LICENSE_END

.\"

.\" Modified, Sun Feb 26 15:04:20 1995, faith@cs.unc.edu

.\" Modified, Thu Apr 20 22:08:17 1995, jrv@vanzandt.mv.com

.\" Modified, Mon Sep 18 22:32:47 1995, hpa@storm.net (H. Peter Anvin)

.\" FIXME The following are not documented:

.\"     KDFONTOP (since 2.1.111)

.\"     KDGKBDIACRUC (since 2.6.24)

.\"     KDSKBDIACR

.\"     KDSKBDIACRUC (since 2.6.24)

.\"     KDKBDREP (since 2.1.113)

.\"     KDMAPDISP (not implemented as at 2.6.27)

.\"     KDUNMAPDISP (not implemented as at 2.6.27)

.\"     VT_LOCKSWITCH (since 1.3.47, needs CAP_SYS_TTY_CONFIG)

.\"     VT_UNLOCKSWITCH (since 1.3.47, needs CAP_SYS_TTY_CONFIG)

.\"     VT_GETHIFONTMASK (since 2.6.18)

.\"

.TH IOCTL_CONSOLE 2 2017-09-15 "Linux" "Linux Programmer's Manual"

.SH NAME

ioctl_console \- ioctls for console terminal and virtual consoles

.SH DESCRIPTION

The following Linux-specific

.BR ioctl (2)

requests are supported for console terminals and virtual consoles.

Each requires a third argument, assumed here to be

.IR argp .

.TP

.B KDGETLED

Get state of LEDs.

.I argp

points to a

.IR char .

The lower three bits

of

.I *argp

are set to the state of the LEDs, as follows:

.TS

l l l.

LED_CAP 	0x04	caps lock led

LED_NUM 	0x02	num lock led

LED_SCR 	0x01	scroll lock led

.TE

.TP

.B KDSETLED

Set the LEDs.

The LEDs are set to correspond to the lower three bits of the

unsigned long integer in

.IR argp .

However, if a higher order bit is set,

the LEDs revert to normal: displaying the state of the

keyboard functions of caps lock, num lock, and scroll lock.

.PP

Before Linux 1.1.54, the LEDs just reflected the state of the corresponding

keyboard flags, and KDGETLED/KDSETLED would also change the keyboard

flags.

Since Linux 1.1.54 the LEDs can be made to display arbitrary

information, but by default they display the keyboard flags.

The following two ioctls are used to access the keyboard flags.

.TP

.B KDGKBLED

Get keyboard flags CapsLock, NumLock, ScrollLock (not lights).

.I argp

points to a char which is set to the flag state.

The low order three bits (mask 0x7) get the current flag state,

and the low order bits of the next nibble (mask 0x70) get

the default flag state.

(Since Linux 1.1.54.)

.TP

.B KDSKBLED

Set keyboard flags CapsLock, NumLock, ScrollLock (not lights).

.I argp

is an unsigned long integer that has the desired flag state.

The low order three bits (mask 0x7) have the flag state,

and the low order bits of the next nibble (mask 0x70) have

the default flag state.

(Since Linux 1.1.54.)

.TP

.B KDGKBTYPE

Get keyboard type.

This returns the value KB_101, defined as 0x02.

.TP

.B KDADDIO

Add I/O port as valid.

Equivalent to

.IR ioperm(arg,1,1) .

.TP

.B KDDELIO

Delete I/O port as valid.

Equivalent to

.IR ioperm(arg,1,0) .

.TP

.B KDENABIO

Enable I/O to video board.

Equivalent to

.IR "ioperm(0x3b4, 0x3df\-0x3b4+1, 1)" .

.TP

.B KDDISABIO

Disable I/O to video board.

Equivalent to

.IR "ioperm(0x3b4, 0x3df\-0x3b4+1, 0)" .

.TP

.B KDSETMODE

Set text/graphics mode.

.I argp

is an unsigned integer containing one of:

.TS

l l.

KD_TEXT	0x00

KD_GRAPHICS	0x01

.TE

.TP

.B KDGETMODE

Get text/graphics mode.

.I argp

points to an

.I int

which is set to one

of the values shown above for

.BR KDSETMODE .

.TP

.B KDMKTONE

Generate tone of specified length.

The lower 16 bits of the unsigned long integer in

.I argp

specify the period in clock cycles,

and the upper 16 bits give the duration in msec.

If the duration is zero, the sound is turned off.

Control returns immediately.

For example,

.I argp

= (125<<16) + 0x637 would specify

the beep normally associated with a ctrl-G.

(Thus since Linux 0.99pl1; broken in Linux 2.1.49-50.)

.TP

.B KIOCSOUND

Start or stop sound generation.

The lower 16 bits of

.I argp

specify the period in clock cycles

(that is,

.I argp

= 1193180/frequency).

.I argp

= 0 turns sound off.

In either case, control returns immediately.

.TP

.B GIO_CMAP

Get the current default color map from kernel.

.I argp

points to

a 48-byte array.

(Since Linux 1.3.3.)

.TP

.B PIO_CMAP

Change the default text-mode color map.

.I argp

points to a

48-byte array which contains, in order, the Red, Green, and Blue

values for the 16 available screen colors: 0 is off, and 255 is full

intensity.

The default colors are, in order: black, dark red, dark

green, brown, dark blue, dark purple, dark cyan, light grey, dark

grey, bright red, bright green, yellow, bright blue, bright purple,

bright cyan and white.

(Since Linux 1.3.3.)

.TP

.B GIO_FONT

Gets 256-character screen font in expanded form.

.I argp

points to an 8192-byte array.

Fails with error code

.B EINVAL

if the

currently loaded font is a 512-character font, or if the console is

not in text mode.

.TP

.B GIO_FONTX

Gets screen font and associated information.

.I argp

points to a

.I "struct consolefontdesc"

(see

.BR PIO_FONTX ).

On call, the

.I charcount

field should be set to the maximum number of

characters that would fit in the buffer pointed to by

.IR chardata .

On return, the

.I charcount

and

.I charheight

are filled with

the respective data for the currently loaded font, and the

.I chardata

array contains the font data if the initial value of

.I charcount

indicated enough space was available; otherwise the

buffer is untouched and

.I errno

is set to

.BR ENOMEM .

(Since Linux 1.3.1.)

.TP

.B PIO_FONT

Sets 256-character screen font.

Load font into the EGA/VGA character

generator.

.I argp

points to an 8192-byte map, with 32 bytes per

character.

Only the first

.I N

of them are used for an 8x\fIN\fP font

(0 <

.I N

<= 32).

This call also invalidates the Unicode mapping.

.TP

.B PIO_FONTX

Sets screen font and associated rendering information.

.I argp

points to a

.IP

.in +4n

.EX

struct consolefontdesc {

    unsigned short charcount;  /* characters in font

                                  (256 or 512) */

    unsigned short charheight; /* scan lines per

                                  character (1\-32) */

    char          *chardata;   /* font data in

                                  expanded form */

};

.EE

.in

.IP

If necessary, the screen will be appropriately resized, and

.B SIGWINCH

sent to the appropriate processes.

This call also invalidates the Unicode mapping.

(Since Linux 1.3.1.)

.TP

.B PIO_FONTRESET

Resets the screen font, size and Unicode mapping to the bootup

defaults.

.I argp

is unused, but should be set to NULL to

ensure compatibility with future versions of Linux.

(Since Linux 1.3.28.)

.TP

.B GIO_SCRNMAP

Get screen mapping from kernel.

.I argp

points to an area of size

E_TABSZ, which is loaded with the font positions used to display each

character.

This call is likely to return useless information if the

currently loaded font is more than 256 characters.

.TP

.B GIO_UNISCRNMAP

Get full Unicode screen mapping from kernel.

.I argp

points to an

area of size

.IR "E_TABSZ*sizeof(unsigned short)" ,

which is loaded with the

Unicodes each character represent.

A special set of Unicodes,

starting at U+F000, are used to represent "direct to font" mappings.

(Since Linux 1.3.1.)

.TP

.B PIO_SCRNMAP

Loads the "user definable" (fourth) table in the kernel which maps

bytes into console screen symbols.

.I argp

points to an area of

size E_TABSZ.

.TP

.B PIO_UNISCRNMAP

Loads the "user definable" (fourth) table in the kernel which maps

bytes into Unicodes, which are then translated into screen symbols

according to the currently loaded Unicode-to-font map.

Special Unicodes starting at U+F000 can be used to map directly to the font

symbols.

(Since Linux 1.3.1.)

.TP

.B GIO_UNIMAP

Get Unicode-to-font mapping from kernel.

.I argp

points to a

.IP

.in +4n

.EX

struct unimapdesc {

    unsigned short  entry_ct;

    struct unipair *entries;

};

.EE

.in

.IP

where

.I entries

points to an array of

,IP

.in +4n

.EX

struct unipair {

    unsigned short unicode;

    unsigned short fontpos;

};

.EE

.in

.IP

(Since Linux 1.1.92.)

.TP

.B PIO_UNIMAP

Put unicode-to-font mapping in kernel.

.I argp

points to a

.IR "struct unimapdesc" .

(Since Linux 1.1.92)

.TP

.B PIO_UNIMAPCLR

Clear table, possibly advise hash algorithm.

.I argp

points to a

.IP

.in +4n

.EX

struct unimapinit {

    unsigned short advised_hashsize;  /* 0 if no opinion */

    unsigned short advised_hashstep;  /* 0 if no opinion */

    unsigned short advised_hashlevel; /* 0 if no opinion */

};

.EE

.in

.IP

(Since Linux 1.1.92.)

.TP

.B KDGKBMODE

Gets current keyboard mode.

.I argp

points to a

.I long

which is set to one

of these:

.TS

l l.

K_RAW	0x00  /* Raw (scancode) mode */

K_XLATE	0x01  /* Translate keycodes using keymap */

K_MEDIUMRAW	0x02  /* Medium raw (scancode) mode */

K_UNICODE	0x03  /* Unicode mode */

K_OFF	0x04  /* Disabled mode; since Linux 2.6.39 */

.\" K_OFF: commit 9fc3de9c83565fcaa23df74c2fc414bb6e7efb0a

.TE

.TP

.B KDSKBMODE

Sets current keyboard mode.

.I argp

is a

.I long

equal to one of the values shown for

.BR KDGKBMODE .

.TP

.B KDGKBMETA

Gets meta key handling mode.

.I argp

points to a

.I long

which is

set to one of these:

.TS

l l l.

K_METABIT	0x03	set high order bit

K_ESCPREFIX	0x04	escape prefix

.TE

.TP

.B KDSKBMETA

Sets meta key handling mode.

.I argp

is a

.I long

equal to one of the values shown above for

.BR KDGKBMETA .

.TP

.B KDGKBENT

Gets one entry in key translation table (keycode to action code).

.I argp

points to a

.IP

.in +4n

.EX

struct kbentry {

    unsigned char  kb_table;

    unsigned char  kb_index;

    unsigned short kb_value;

};

.EE

.in

.IP

with the first two members filled in:

.I kb_table

selects the key table (0 <=

.I kb_table

< MAX_NR_KEYMAPS),

and

.IR kb_index

is the keycode (0 <=

.I kb_index

< NR_KEYS).

.I kb_value

is set to the corresponding action code,

or K_HOLE if there is no such key,

or K_NOSUCHMAP if

.I kb_table

is invalid.

.TP

.B KDSKBENT

Sets one entry in translation table.

.I argp

points to a

.IR "struct kbentry" .

.TP

.B KDGKBSENT

Gets one function key string.

.I argp

points to a

.IP

.in +4n

.EX

struct kbsentry {

    unsigned char kb_func;

    unsigned char kb_string[512];

};

.EE

.in

.IP

.I kb_string

is set to the (null-terminated) string corresponding to

the

.IR kb_func th

function key action code.

.TP

.B KDSKBSENT

Sets one function key string entry.

.I argp

points to a

.IR "struct kbsentry" .

.TP

.B KDGKBDIACR

Read kernel accent table.

.I argp

points to a

.IP

.in +4n

.EX

struct kbdiacrs {

    unsigned int   kb_cnt;

    struct kbdiacr kbdiacr[256];

};

.EE

.in

.IP

where

.I kb_cnt

is the number of entries in the array, each of which

is a

.IP

.in +4n

.EX

struct kbdiacr {

    unsigned char diacr;

    unsigned char base;

    unsigned char result;

};

.EE

.in

.TP

.B KDGETKEYCODE

Read kernel keycode table entry (scan code to keycode).

.I argp

points to a

.IP

.in +4n

.EX

struct kbkeycode {

    unsigned int scancode;

    unsigned int keycode;

};

.EE

.in

.IP

.I keycode

is set to correspond to the given

.IR scancode .

(89 <=

.I scancode

<= 255 only.

For 1 <=

.I scancode

<= 88,

.IR keycode == scancode .)

(Since Linux 1.1.63.)

.TP

.B KDSETKEYCODE

Write kernel keycode table entry.

.I argp

points to a

.IR "struct kbkeycode" .

(Since Linux 1.1.63.)

.TP

.B KDSIGACCEPT

The calling process indicates its willingness to accept the signal

.I argp

when it is generated by pressing an appropriate key combination.

(1 <=

.I argp

<= NSIG).

(See

.IR spawn_console ()

in

.IR linux/drivers/char/keyboard.c .)

.TP

.B VT_OPENQRY

Returns the first available (non-opened) console.

.I argp

points to an

.I int

which is set to the

number of the vt (1 <=

.I *argp

<= MAX_NR_CONSOLES).

.TP

.B VT_GETMODE

Get mode of active vt.

.I argp

points to a

.IP

.in +4n

.EX

struct vt_mode {

    char  mode;    /* vt mode */

    char  waitv;   /* if set, hang on writes if not active */

    short relsig;  /* signal to raise on release req */

    short acqsig;  /* signal to raise on acquisition */

    short frsig;   /* unused (set to 0) */

};

.EE

.in

.IP

which is set to the mode of the active vt.

.I mode

is set to one of these values:

.TS

l l.

VT_AUTO	auto vt switching

VT_PROCESS	process controls switching

VT_ACKACQ	acknowledge switch

.TE

.TP

.B VT_SETMODE

Set mode of active vt.

.I argp

points to a

.IR "struct vt_mode" .

.TP

.B VT_GETSTATE

Get global vt state info.

.I argp

points to a

.IP

.in +4n

.EX

struct vt_stat {

    unsigned short v_active;  /* active vt */

    unsigned short v_signal;  /* signal to send */

    unsigned short v_state;   /* vt bit mask */

};

.EE

.in

.IP

For each vt in use, the corresponding bit in the

.I v_state

member is set.

(Kernels 1.0 through 1.1.92.)

.TP

.B VT_RELDISP

Release a display.

.TP

.B VT_ACTIVATE

Switch to vt

.IR argp

(1 <=

.I argp

<= MAX_NR_CONSOLES).

.TP

.B VT_WAITACTIVE

Wait until vt

.I argp

has been activated.

.TP

.B VT_DISALLOCATE

Deallocate the memory associated with vt

.IR argp .

(Since Linux 1.1.54.)

.TP

.B VT_RESIZE

Set the kernel's idea of screensize.

.I argp

points to a

.IP

.in +4n

.EX

struct vt_sizes {

    unsigned short v_rows;       /* # rows */

    unsigned short v_cols;       /* # columns */

    unsigned short v_scrollsize; /* no longer used */

};

.EE

.in

.IP

Note that this does not change the videomode.

See

.BR resizecons (8).

(Since Linux 1.1.54.)

.TP

.B VT_RESIZEX

Set the kernel's idea of various screen parameters.

.I argp

points to a

.IP

.in +4n

.EX

struct vt_consize {

    unsigned short v_rows;  /* number of rows */

    unsigned short v_cols;  /* number of columns */

    unsigned short v_vlin;  /* number of pixel rows

                               on screen */

    unsigned short v_clin;  /* number of pixel rows

                               per character */

    unsigned short v_vcol;  /* number of pixel columns

                               on screen */

    unsigned short v_ccol;  /* number of pixel columns

                               per character */

};

.EE

.in

.IP

Any parameter may be set to zero, indicating "no change", but if

multiple parameters are set, they must be self-consistent.

Note that this does not change the videomode.

See

.BR resizecons (8).

(Since Linux 1.3.3.)

.PP

The action of the following ioctls depends on the first byte in the struct

pointed to by

.IR argp ,

referred to here as the

.IR subcode .

These are legal only for the superuser or the owner of the current terminal.

.TP

.B "TIOCLINUX, subcode=0"

Dump the screen.

Disappeared in Linux 1.1.92.  (With kernel 1.1.92 or later, read from

.I /dev/vcsN

or

.I /dev/vcsaN

instead.)

.TP

.B "TIOCLINUX, subcode=1"

Get task information.

Disappeared in Linux 1.1.92.

.TP

.B "TIOCLINUX, subcode=2"

Set selection.

.I argp

points to a

.IP

.in +4n

.EX

struct {

    char  subcode;

    short xs, ys, xe, ye;

    short sel_mode;

};

.EE

.in

.IP

.I xs

and

.I ys

are the starting column and row.

.I xe

and

.I ye

are the ending

column and row.

(Upper left corner is row=column=1.)

.I sel_mode

is 0 for character-by-character selection,

1 for word-by-word selection,

or 2 for line-by-line selection.

The indicated screen characters are highlighted and saved

in the static array sel_buffer in

.IR devices/char/console.c .

.TP

.B "TIOCLINUX, subcode=3"

Paste selection.

The characters in the selection buffer are

written to

.IR fd .

.TP

.B "TIOCLINUX, subcode=4"

Unblank the screen.

.TP

.B "TIOCLINUX, subcode=5"

Sets contents of a 256-bit look up table defining characters in a "word",

for word-by-word selection.

(Since Linux 1.1.32.)

.TP

.B "TIOCLINUX, subcode=6"

.I argp

points to a char which is set to the value of the kernel

variable

.IR shift_state .

(Since Linux 1.1.32.)

.TP

.B "TIOCLINUX, subcode=7"

.I argp

points to a char which is set to the value of the kernel

variable

.IR report_mouse .

(Since Linux 1.1.33.)

.TP

.B "TIOCLINUX, subcode=8"

Dump screen width and height, cursor position, and all the

character-attribute pairs.

(Kernels 1.1.67 through 1.1.91 only.

With kernel 1.1.92 or later, read from

.I /dev/vcsa*

instead.)

.TP

.B "TIOCLINUX, subcode=9"

Restore screen width and height, cursor position, and all the

character-attribute pairs.

(Kernels 1.1.67 through 1.1.91 only.

With kernel 1.1.92 or later, write to

.I /dev/vcsa*

instead.)

.TP

.B "TIOCLINUX, subcode=10"

Handles the Power Saving

feature of the new generation of monitors.

VESA screen blanking mode is set to

.IR argp[1] ,

which governs what

screen blanking does:

.RS

.IP 0: 3

Screen blanking is disabled.

.IP 1:

The current video adapter

register settings are saved, then the controller is programmed to turn off

the vertical synchronization pulses.

This puts the monitor into "standby" mode.

If your monitor has an Off_Mode timer, then

it will eventually power down by itself.

.IP 2:

The current settings are saved, then both the vertical and horizontal

synchronization pulses are turned off.

This puts the monitor into "off" mode.

If your monitor has no Off_Mode timer,

or if you want your monitor to power down immediately when the

blank_timer times out, then you choose this option.

.RI ( Caution:

Powering down frequently will damage the monitor.)

(Since Linux 1.1.76.)

.RE

.SH RETURN VALUE

On success, 0 is returned.

On error, \-1 is returned, and

.I errno

is set.

.SH ERRORS

.I errno

may take on these values:

.TP

.B EBADF

The file descriptor is invalid.

.TP

.B EINVAL

The file descriptor or

.I argp

is invalid.

.TP

.B ENOTTY

The file descriptor is not associated with a character special device,

or the specified request does not apply to it.

.TP

.B EPERM

Insufficient permission.

.SH NOTES

.BR Warning :

Do not regard this man page as documentation of the Linux console ioctls.

This is provided for the curious only, as an alternative to reading the

source.

Ioctl's are undocumented Linux internals, liable to be changed

without warning.

(And indeed, this page more or less describes the

situation as of kernel version 1.1.94;

there are many minor and not-so-minor

differences with earlier versions.)

.PP

Very often, ioctls are introduced for communication between the

kernel and one particular well-known program (fdisk, hdparm, setserial,

tunelp, loadkeys, selection, setfont, etc.), and their behavior will be

changed when required by this particular program.

.PP

Programs using these ioctls will not be portable to other versions

of UNIX, will not work on older versions of Linux, and will not work

on future versions of Linux.

.PP

Use POSIX functions.

.SH SEE ALSO

.BR dumpkeys (1),

.BR kbd_mode (1),

.BR loadkeys (1),

.BR mknod (1),

.BR setleds (1),

.BR setmetamode (1),

.BR execve (2),

.BR fcntl (2),

.BR ioctl_tty (2),

.BR ioperm (2),

.BR termios (3),

.BR console_codes (4),

.BR mt (4),

.BR sd (4),

.BR tty (4),

.BR ttyS (4),

.BR vcs (4),

.BR vcsa (4),

.BR charsets (7),

.BR mapscrn (8),

.BR resizecons (8),

.BR setfont (8)

.PP

.IR /usr/include/linux/kd.h ,

.I /usr/include/linux/vt.h

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,