console ioctl — ioctl's for console terminal and virtual consoles
The following Linux-specific ioctl(2) requests are
supported. Each requires a third argument, assumed here to be
argp
.
KDGETLED
Get state of LEDs. argp
points to a long
int. The lower three bits of *argp
are set to the
state of the LEDs, as follows:
LED_CAP
0x04 caps lock led LEC_NUM
0x02 num lock led LED_SCR
0x01 scroll lock led
KDSETLED
Set the LEDs. The LEDs are set to correspond to the
lower three bits of 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.
Before 1.1.54, the LEDs just reflected the state of the corresponding keyboard flags, and KDGETLED/KDSETLED would also change the keyboard flags. Since 1.1.54 the leds can be made to display arbitrary information, but by default they display the keyboard flags. The following two ioctl's are used to access the keyboard flags.
KDGKBLED
Get keyboard flags CapsLock, NumLock, ScrollLock
(not lights). 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 1.1.54.)
KDSKBLED
Set keyboard flags CapsLock, NumLock, ScrollLock
(not lights). argp
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
1.1.54.)
KDGKBTYPE
Get keyboard type. This returns the value KB_101, defined as 0x02.
KDADDIO
Add I/O port as valid. Equivalent to ioperm(arg,1,1).
KDDELIO
Delete I/O port as valid. Equivalent to ioperm(arg,1,0).
KDENABIO
Enable I/O to video board. Equivalent to ioperm(0x3b4, 0x3df-0x3b4+1, 1).
KDDISABIO
Disable I/O to video board. Equivalent to ioperm(0x3b4, 0x3df-0x3b4+1, 0).
KDSETMODE
Set text/graphics mode. argp
is one of
these:
KD_TEXT
0x00 KD_GRAPHICS
0x01
KDGETMODE
Get text/graphics mode. argp
points to a long
which is set to one of the above values.
KDMKTONE
Generate tone of specified length. The lower 16 bits
of 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, argp
= (125<<16)
+ 0x637 would specify the beep normally associated with
a ctrl-G. (Thus since 0.99pl1; broken in
2.1.49-50.)
KIOCSOUND
Start or stop sound generation. The lower 16 bits of
argp
specify
the period in clock cycles (that is, argp
=
1193180/frequency). argp
= 0 turns sound
off. In either case, control returns immediately.
GIO_CMAP
Get the current default color map from kernel.
argp
points
to a 48-byte array. (Since 1.3.3.)
PIO_CMAP
Change the default text-mode color map. 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 1.3.3.)
GIO_FONT
Gets 256-character screen font in expanded form.
argp
points
to an 8192 byte array. Fails with error code
EINVAL if the currently
loaded font is a 512-character font, or if the console
is not in text mode.
GIO_FONTX
Gets screen font and associated information.
argp
points
to a struct
consolefontdesc (see PIO_FONTX
). On call, the charcount
field should
be set to the maximum number of characters that would
fit in the buffer pointed to by chardata
. On return,
the charcount
and charheight
are filled
with the respective data for the currently loaded font,
and the chardata
array contains
the font data if the initial value of charcount
indicated
enough space was available; otherwise the buffer is
untouched and errno
is set
to ENOMEM. (Since
1.3.1.)
PIO_FONT
Sets 256-character screen font. Load font into the
EGA/VGA character generator. argp
points to a 8192
byte map, with 32 bytes per character. Only first
N
of them are used for an
8xN
font (0 <
N
<= 32). This call
also invalidates the Unicode mapping.
PIO_FONTX
Sets screen font and associated rendering
information. argp
points to a
struct | consolefontdesc { | |||
u_short | charcount ; |
/* characters in font (256 or 512) */
|
||
u_short | charheight ; |
/* scan lines per character (1-32) */
|
||
char | * | chardata ; |
/* font data in expanded form */
|
|
}; |
If necessary, the screen will be appropriately
resized, and SIGWINCH
sent to the appropriate processes. This call also
invalidates the Unicode mapping. (Since 1.3.1.)
PIO_FONTRESET
Resets the screen font, size and Unicode mapping to
the bootup defaults. argp
is unused, but
should be set to NULL to ensure compatibility with
future versions of Linux. (Since 1.3.28.)
GIO_SCRNMAP
Get screen mapping from kernel. 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.
GIO_UNISCRNMAP
Get full Unicode screen mapping from kernel.
argp
points
to an area of size 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 1.3.1.)
PIO_SCRNMAP
Loads the ``user definable'' (fourth) table in the
kernel which maps bytes into console screen symbols.
argp
points
to an area of size E_TABSZ.
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 1.3.1.)
GIO_UNIMAP
Get Unicode-to-font mapping from kernel. argp
points to a
struct | unimapdesc { | |||
u_short | entry_ct ; |
|||
struct unipair | * | entries ; |
||
}; |
where entries
points to an
array of
struct | unipair { | |||
u_short | unicode ; |
|||
u_short | fontpos ; |
|||
}; |
(Since 1.1.92.)
PIO_UNIMAP
Put unicode-to-font mapping in kernel. argp
points to a
struct
unimapdesc. (Since 1.1.92)
PIO_UNIMAPCLR
Clear table, possibly advise hash algorithm.
argp
points
to a
struct | unimapinit { | |||
u_short | advised_hashsize ; |
/* 0 if no opinion */
|
||
u_short | advised_hashstep ; |
/* 0 if no opinion */
|
||
u_short | advised_hashlevel ; |
/* 0 if no opinion */
|
||
}; |
(Since 1.1.92.)
KDGKBMODE
Gets current keyboard mode. argp
points to a long
which is set to one of these:
K_RAW
0x00 K_XLATE
0x01 K_MEDIUMRAW
0x02 K_UNICODE
0x03
KDSKBMODE
Sets current keyboard mode. argp
is a long equal to
one of the above values.
KDGKBMETA
Gets meta key handling mode. argp
points to a long
which is set to one of these:
K_METABIT
0x03 set high order bit K_ESCPREFIX
0x04 escape prefix
KDSKBMETA
Sets meta key handling mode. argp
is a long equal to
one of the above values.
KDGKBENT
Gets one entry in key translation table (keycode to
action code). argp
points to a
struct | kbentry { | |||
u_char | kb_table ; |
|||
u_char | kb_index ; |
|||
u_short | kb_value ; |
|||
}; |
with the first two members filled in: kb_table
selects the
key table (0 <= kb_table
<
MAX_NR_KEYMAPS), and kb_index
is the keycode
(0 <= kb_index
< NR_KEYS).
kb_value
is
set to the corresponding action code, or K_HOLE if
there is no such key, or K_NOSUCHMAP if kb_table
is
invalid.
KDSKBENT
Sets one entry in translation table. argp
points to a
struct
kbentry.
KDGKBSENT
Gets one function key string. argp
points to a
struct | kbsentry { | |||
u_char | kb_func ; |
|||
u_char | kb_string [512]; |
|||
}; |
kb_string
is set to the (NULL terminated) string corresponding to
the kb_func
th
function key action code.
KDSKBSENT
Sets one function key string entry. argp
points to a
struct
kbsentry.
KDGKBDIACR
Read kernel accent table. argp
points to a
struct | kbdiacrs { | |||
unsigned int | kb_cnt ; |
|||
struct kbdiacr | kbdiacr [256]; |
|||
}; |
where kb_cnt
is the number of
entries in the array, each of which is a
struct | kbdiacr { | |||
u_char | diacr ; |
|||
u_char | base ; |
|||
u_char | result ; |
|||
}; |
KDGETKEYCODE
Read kernel keycode table entry (scan code to
keycode). argp
points to a
struct | kbkeycode { | |||
unsigned int | scancode ; |
|||
unsigned int | keycode ; |
|||
}; |
keycode
is
set to correspond to the given scancode
. (89 <=
scancode
<= 255 only. For 1 <= scancode
<= 88,
keycode
==scancode
.) (Since
1.1.63.)
KDSETKEYCODE
Write kernel keycode table entry. argp
points to a
struct
kbkeycode. (Since 1.1.63.)
KDSIGACCEPT
The calling process indicates its willingness to
accept the signal argp
when it is
generated by pressing an appropriate key combination.
(1 <= argp
<= NSIG). (See spawn_console() in
linux/drivers/char/keyboard.c.)
VT_OPENQRY
Returns the first available (non-opened) console.
argp
points
to an int which is set to the number of the vt (1 <=
*argp
<=
MAX_NR_CONSOLES).
VT_GETMODE
Get mode of active vt. argp
points to a
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) */
|
||
}; |
which is set to the mode of the active vt.
mode
is set
to one of these values:
VT_AUTO
auto vt switching VT_PROCESS
process controls switching VT_ACKACQ
acknowledge switch
VT_SETMODE
Set mode of active vt. argp
points to a
struct
vt_mode.
VT_GETSTATE
Get global vt state info. argp
points to a
struct | vt_stat { | |||
ushort | v_active ; |
/* active vt */
|
||
ushort | v_signal ; |
/* signal to send */
|
||
ushort | v_state ; |
/* vt bit mask */
|
||
}; |
For each vt in use, the corresponding bit in the
v_state
member is set. (Kernels 1.0 through 1.1.92.)
VT_RELDISP
Release a display.
VT_ACTIVATE
Switch to vt argp
(1 <=
argp
<=
MAX_NR_CONSOLES).
VT_WAITACTIVE
Wait until vt argp
has been
activated.
VT_DISALLOCATE
Deallocate the memory associated with vt argp
. (Since
1.1.54.)
VT_RESIZE
Set the kernel's idea of screensize. argp
points to a
struct | vt_sizes { | |||
ushort | v_rows ; |
/* # rows */
|
||
ushort | v_cols ; |
/* # columns */
|
||
ushort | v_scrollsize ; |
/* no longer used */
|
||
}; |
Note that this does not change the videomode. See resizecons(8). (Since 1.1.54.)
VT_RESIZEX
Set the kernel's idea of various screen parameters.
argp
points
to a
struct | vt_consize { | |||
ushort | v_rows ; |
/* number of rows */
|
||
ushort | v_cols ; |
/* number of columns */
|
||
ushort | v_vlin ; |
/* number of pixel rows on screen */
|
||
ushort | v_clin ; |
/* number of pixel rows per character */
|
||
ushort | v_vcol ; |
/* number of pixel columns on screen */
|
||
ushort | v_ccol ; |
/* number of pixel columns per character */
|
||
}; |
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 resizecons(8). (Since 1.3.3.)
The action of the following ioctls depends on the first
byte in the struct pointed to by argp
, referred to here as the
subcode
. These are
legal only for the superuser or the owner of the current
tty.
Dump the screen. Disappeared in 1.1.92. (With kernel 1.1.92 or later, read from /dev/vcsN or /dev/vcsaN instead.)
Get task information. Disappeared in 1.1.92.
Set selection. argp
points to a
struct | { | |||
char | subcode ; |
|||
short | xs , |
|||
ys , |
||||
xe , |
||||
ye ; |
||||
short | sel_mode ; |
|||
}; |
xs
and
ys
are the
starting column and row. xe
and ye
are the ending
column and row. (Upper left corner is row=column=1.)
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
devices/char/console.c.
Paste selection. The characters in the selection
buffer are written to fd
.
Unblank the screen.
Sets contents of a 256-bit look up table defining characters in a "word", for word-by-word selection. (Since 1.1.32.)
argp
points to a char which is set to the value of the
kernel variable shift_state
. (Since
1.1.32.)
argp
points to a char which is set to the value of the
kernel variable report_mouse
. (Since
1.1.33.)
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 /dev/vcsa* instead.)
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 /dev/vcsa* instead.)
Handles the Power Saving feature of the new
generation of monitors. VESA screen blanking mode is
set to argp
[1], which governs
what screen blanking does:
0
: Screen blanking is
disabled.
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.
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. (Caution:
Powering down
frequently will damage the monitor.)
(Since 1.1.76.)
errno
may take on these
values:
The file descriptor is invalid.
ENOTTY The file descriptor is not associated with a character special device, or the specified request does not apply to it.
The file descriptor or argp
is invalid.
Insufficient permission.
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Warning |
---|---|
Do not regard this man page as documentation of the Linux console ioctl's. 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.) |
Very often, ioctl's 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.
Programs using these ioctl's 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.
Use POSIX functions.
dumpkeys(1), kbd_mode(1), loadkeys(1), mknod(1), setleds(1), setmetamode(1), execve(2), fcntl(2), ioperm(2), termios(3), console(4), console_codes(4),
mt(4), sd(4), tty(4), tty_ioctl(4), ttyS(4), vcs(4), vcsa(4), charsets(7), mapscrn(8), resizecons(8), setfont(8), /usr/include/linux/kd.h
, /usr/include/linux/vt.h
Copyright (c) 1995 Jim Van Zandt <jrvvanzandt.mv.com> and aeb Sun Feb 26 11:46:23 MET 1995 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. Modified, Sun Feb 26 15:04:20 1995, faithcs.unc.edu Modified, Thu Apr 20 22:08:17 1995, jrvvanzandt.mv.com Modified, Mon Sep 18 22:32:47 1995, hpastorm.net (H. Peter Anvin) " |