.\"
.TH CONSOLE_IOCTL 4 2009-02-28 "Linux" "Linux Programmer's Manual"
.SH NAME
-console_ioctl \- ioctl's for console terminal and virtual consoles
+console_ioctl \- ioctls for console terminal and virtual consoles
.SH DESCRIPTION
The following Linux-specific
.BR ioctl (2)
requests are supported.
-Each requires a third argument, assumed here to be \fIargp\fP.
-.IP \fBKDGETLED\fP
+Each requires a third argument, assumed here to be
+.IR argp .
+.TP
+.B KDGETLED
Get state of LEDs.
-\fIargp\fP points to a \fIchar\fP.
+.I argp
+points to a
+.IR char .
The lower three bits
-of \fI*argp\fP 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
-.IP \fBKDSETLED\fP
+of
+.I *argp
+are set to the state of the LEDs, as follows:
+.TS
+l l l.
+LED_CAP 0x04 caps lock led
+LEC_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
-\fIargp\fP.
+.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.
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
+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.
-.IP \fBKDGKBLED\fP
+The following two ioctls are used to access the keyboard flags.
+.TP
+.B KDGKBLED
Get keyboard flags CapsLock, NumLock, ScrollLock (not lights).
-\fIargp\fP points to a char which is set to the flag state.
+.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 1.1.54.)
-.IP \fBKDSKBLED\fP
+.TP
+.B KDSKBLED
Set keyboard flags CapsLock, NumLock, ScrollLock (not lights).
-\fIargp\fP has the desired flag state.
+.I 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.)
-.IP \fBKDGKBTYPE\fP
+.TP
+.B KDGKBTYPE
Get keyboard type.
This returns the value KB_101, defined as 0x02.
-.IP \fBKDADDIO\fP
+.TP
+.B KDADDIO
Add I/O port as valid.
-Equivalent to \fIioperm(arg,1,1)\fP.
-.IP \fBKDDELIO\fP
+Equivalent to
+.IR ioperm(arg,1,1) .
+.TP
+.B KDDELIO
Delete I/O port as valid.
-Equivalent to \fIioperm(arg,1,0)\fP.
-.IP \fBKDENABIO\fP
+Equivalent to
+.IR ioperm(arg,1,0) .
+.TP
+.B KDENABIO
Enable I/O to video board.
-Equivalent to \fIioperm(0x3b4, 0x3df-0x3b4+1, 1)\fP.
-.IP \fBKDDISABIO\fP
+Equivalent to
+.IR "ioperm(0x3b4, 0x3df-0x3b4+1, 1)" .
+.TP
+.B KDDISABIO
Disable I/O to video board.
-Equivalent to \fIioperm(0x3b4, 0x3df-0x3b4+1, 0)\fP.
-.IP \fBKDSETMODE\fP
+Equivalent to
+.IR "ioperm(0x3b4, 0x3df-0x3b4+1, 0)" .
+.TP
+.B KDSETMODE
Set text/graphics mode.
-\fIargp\fP is one of these:
-
- KD_TEXT 0x00
- KD_GRAPHICS 0x01
-.IP \fBKDGETMODE\fP
+.I argp
+is one of these:
+
+.TS
+l l.
+KD_TEXT 0x00
+KD_GRAPHICS 0x01
+.TE
+.TP
+.B KDGETMODE
Get text/graphics mode.
-\fIargp\fP points to a \fIlong\fP which is set to one
+.I argp
+points to a
+.I long
+which is set to one
of the above values.
-.IP \fBKDMKTONE\fP
+.TP
+.B KDMKTONE
Generate tone of specified length.
-The lower 16 bits of \fIargp\fP specify the period in clock cycles,
+The lower 16 bits of
+.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, \fIargp\fP = (125<<16) + 0x637 would specify
+For example,
+.I argp
+= (125<<16) + 0x637 would specify
the beep normally associated with a ctrl-G.
(Thus since 0.99pl1; broken in 2.1.49-50.)
-.IP \fBKIOCSOUND\fP
+.TP
+.B KIOCSOUND
Start or stop sound generation.
The lower 16 bits of
-\fIargp\fP specify the period in clock cycles
-(that is, \fIargp\fP = 1193180/frequency).
-\fIargp\fP = 0 turns sound off.
+.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.
-.IP \fBGIO_CMAP\fP
+.TP
+.B GIO_CMAP
Get the current default color map from kernel.
-\fIargp\fP points to
+.I argp
+points to
a 48-byte array.
(Since 1.3.3.)
-.IP \fBPIO_CMAP\fP
+.TP
+.B PIO_CMAP
Change the default text-mode color map.
-\fIargp\fP points to a
+.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.
grey, bright red, bright green, yellow, bright blue, bright purple,
bright cyan and white.
(Since 1.3.3.)
-.IP \fBGIO_FONT\fP
+.TP
+.B GIO_FONT
Gets 256-character screen font in expanded form.
-\fIargp\fP points to an 8192 byte array.
-Fails with error code \fBEINVAL\fP if the
+.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.
-.IP \fBGIO_FONTX\fP
+.TP
+.B GIO_FONTX
Gets screen font and associated information.
-\fIargp\fP points to a
-\fIstruct consolefontdesc\fP (see \fBPIO_FONTX\fP).
+.I argp
+points to a
+.I "struct consolefontdesc"
+(see
+.BR PIO_FONTX ).
On call, the
-\fIcharcount\fP field should be set to the maximum number of
-characters that would fit in the buffer pointed to by \fIchardata\fP.
-On return, the \fIcharcount\fP and \fIcharheight\fP are filled with
+.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
-\fIchardata\fP array contains the font data if the initial value of
-\fIcharcount\fP indicated enough space was available; otherwise the
-buffer is untouched and \fIerrno\fP is set to \fBENOMEM\fP.
+.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 1.3.1.)
-.IP \fBPIO_FONT\fP
+.TP
+.B PIO_FONT
Sets 256-character screen font.
Load font into the EGA/VGA character
generator.
-\fIargp\fP points to a 8192 byte map, with 32 bytes per
+.I argp
+points to a 8192 byte map, with 32 bytes per
character.
-Only first \fIN\fP of them are used for an 8x\fIN\fP font
-(0 < \fIN\fP <= 32).
+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.
-.IP \fBPIO_FONTX\fP
+.TP
+.B PIO_FONTX
Sets screen font and associated rendering information.
-\fIargp\fP
+.I argp
points to a
.in +4n
.in
If necessary, the screen will be appropriately resized, and
-\fBSIGWINCH\fP sent to the appropriate processes.
+.B SIGWINCH
+sent to the appropriate processes.
This call also invalidates the Unicode mapping.
(Since 1.3.1.)
-.IP \fBPIO_FONTRESET\fP
+.TP
+.B PIO_FONTRESET
Resets the screen font, size and Unicode mapping to the bootup
defaults.
-\fIargp\fP is unused, but should be set to NULL to
+.I argp
+is unused, but should be set to NULL to
ensure compatibility with future versions of Linux.
(Since 1.3.28.)
-.IP \fBGIO_SCRNMAP\fP
+.TP
+.B GIO_SCRNMAP
Get screen mapping from kernel.
-\fIargp\fP points to an area of size
+.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.
-.IP \fBGIO_UNISCRNMAP\fP
+.TP
+.B GIO_UNISCRNMAP
Get full Unicode screen mapping from kernel.
-\fIargp\fP points to an
-area of size E_TABSZ*sizeof(unsigned short), which is loaded with the
+.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 1.3.1.)
-.IP \fBPIO_SCRNMAP\fP
+.TP
+.B PIO_SCRNMAP
Loads the "user definable" (fourth) table in the kernel which maps
bytes into console screen symbols.
-\fIargp\fP points to an area of
+.I argp
+points to an area of
size E_TABSZ.
-.IP \fBPIO_UNISCRNMAP\fP
+.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 1.3.1.)
-.IP \fBGIO_UNIMAP\fP
+.TP
+.B GIO_UNIMAP
Get Unicode-to-font mapping from kernel.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.fi
.in
-where \fIentries\fP points to an array of
+where
+.I entries
+points to an array of
.in +4n
.nf
.in
(Since 1.1.92.)
-.IP \fBPIO_UNIMAP\fP
+.TP
+.B PIO_UNIMAP
Put unicode-to-font mapping in kernel.
- \fIargp\fP points to a
-\fIstruct unimapdesc\fP.
+.I argp
+points to a
+.IR "struct unimapdesc" .
(Since 1.1.92)
-.IP \fBPIO_UNIMAPCLR\fP
+.TP
+.B PIO_UNIMAPCLR
Clear table, possibly advise hash algorithm.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.in
(Since 1.1.92.)
-.IP \fBKDGKBMODE\fP
+.TP
+.B KDGKBMODE
Gets current keyboard mode.
-\fIargp\fP points to a \fIlong\fP which is set to one
+.I argp
+points to a
+.I long
+which is set to one
of these:
- K_RAW 0x00
- K_XLATE 0x01
- K_MEDIUMRAW 0x02
- K_UNICODE 0x03
-.IP \fBKDSKBMODE\fP
+.TS
+l l.
+K_RAW 0x00
+K_XLATE 0x01
+K_MEDIUMRAW 0x02
+K_UNICODE 0x03
+.TE
+.TP
+.B KDSKBMODE
Sets current keyboard mode.
-\fIargp\fP is a \fIlong\fP equal to one of the above values.
-.IP \fBKDGKBMETA\fP
+.I argp
+is a
+.I long
+equal to one of the above values.
+.TP
+.B KDGKBMETA
Gets meta key handling mode.
-\fIargp\fP points to a \fIlong\fP which is
+.I argp
+points to a
+.I long
+which is
set to one of these:
- K_METABIT 0x03 set high order bit
- K_ESCPREFIX 0x04 escape prefix
-.IP \fBKDSKBMETA\fP
+.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.
-\fIargp\fP is a \fIlong\fP equal to one of the above values.
-.IP \fBKDGKBENT\fP
+.I argp
+is a
+.I long
+equal to one of the above values.
+.TP
+.B KDGKBENT
Gets one entry in key translation table (keycode to action code).
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.in
with the first two members filled in:
-\fIkb_table\fP selects the key table (0 <= \fIkb_table\fP < MAX_NR_KEYMAPS),
-and \fIkb_index\fP is the keycode (0 <= \fIkb_index\fP < NR_KEYS).
-\fIkb_value\fP is set to the corresponding action code,
+.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 \fIkb_table\fP is invalid.
-.IP \fBKDSKBENT\fP
+or K_NOSUCHMAP if
+.I kb_table
+is invalid.
+.TP
+.B KDSKBENT
Sets one entry in translation table.
-\fIargp\fP points to
-a \fIstruct kbentry\fP.
-.IP \fBKDGKBSENT\fP
+.I argp
+points to a
+.IR "struct kbentry" .
+.TP
+.B KDGKBSENT
Gets one function key string.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.fi
.in
-\fIkb_string\fP is set to the (null-terminated) string corresponding to
-the \fIkb_func\fPth function key action code.
-.IP \fBKDSKBSENT\fP
+.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.
-\fIargp\fP points to
-a \fIstruct kbsentry\fP.
-.IP \fBKDGKBDIACR\fP
+.I argp
+points to a
+.IR "struct kbsentry" .
+.TP
+.B KDGKBDIACR
Read kernel accent table.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.fi
.in
-where \fIkb_cnt\fP is the number of entries in the array, each of which
+where
+.I kb_cnt
+is the number of entries in the array, each of which
is a
.in +4n
};
.fi
.in
-.IP \fBKDGETKEYCODE\fP
+.TP
+.B KDGETKEYCODE
Read kernel keycode table entry (scan code to keycode).
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.fi
.in
-\fIkeycode\fP is set to correspond to the given \fIscancode\fP.
-(89 <= \fIscancode\fP <= 255 only.
-For 1 <= \fIscancode\fP <= 88, \fIkeycode\fP==\fIscancode\fP.)
+.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 1.1.63.)
-.IP \fBKDSETKEYCODE\fP
+.TP
+.B KDSETKEYCODE
Write kernel keycode table entry.
-\fIargp\fP points to
-a \fIstruct kbkeycode\fP.
+.I argp
+points to a
+.IR "struct kbkeycode" .
(Since 1.1.63.)
-.IP \fBKDSIGACCEPT\fP
+.TP
+.B KDSIGACCEPT
The calling process indicates its willingness to accept the signal
-\fIargp\fP when it is generated by pressing an appropriate key combination.
-(1 <= \fIargp\fP <= NSIG).
-(See spawn_console() in linux/drivers/char/keyboard.c.)
-.IP \fBVT_OPENQRY\fP
+.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.
-\fIargp\fP points to an \fIint\fP which is set to the
-number of the vt (1 <= \fI*argp\fP <= MAX_NR_CONSOLES).
-.IP \fBVT_GETMODE\fP
+.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.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.in
which is set to the mode of the active vt.
-\fImode\fP is set to one of these values:
-
- VT_AUTO auto vt switching
- VT_PROCESS process controls switching
- VT_ACKACQ acknowledge switch
-.IP \fBVT_SETMODE\fP
+.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.
-\fIargp\fP points to
-a \fIstruct vt_mode\fP.
-.IP \fBVT_GETSTATE\fP
+.I argp
+points to a
+.IR "struct vt_mode" .
+.TP
+.B VT_GETSTATE
Get global vt state info.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.fi
.in
-For each vt in use, the corresponding bit in the \fIv_state\fP member is set.
+For each vt in use, the corresponding bit in the
+.I v_state
+member is set.
(Kernels 1.0 through 1.1.92.)
-.IP \fBVT_RELDISP\fP
+.TP
+.B VT_RELDISP
Release a display.
-.IP \fBVT_ACTIVATE\fP
-Switch to vt \fIargp\fP (1 <= \fIargp\fP <= MAX_NR_CONSOLES).
-.IP \fBVT_WAITACTIVE\fP
-Wait until vt \fIargp\fP has been activated.
-.IP \fBVT_DISALLOCATE\fP
-Deallocate the memory associated with vt \fIargp\fP.
+.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 1.1.54.)
-.IP \fBVT_RESIZE\fP
+.TP
+.B VT_RESIZE
Set the kernel's idea of screensize.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
See
.BR resizecons (8).
(Since 1.1.54.)
-.IP \fBVT_RESIZEX\fP
+.TP
+.B VT_RESIZEX
Set the kernel's idea of various screen parameters.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
(Since 1.3.3.)
.PP
The action of the following ioctls depends on the first byte in the struct
-pointed to by \fIargp\fP, referred to here as the \fIsubcode\fP.
+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.
-.IP "\fBTIOCLINUX, subcode=0\fP"
+.TP
+.B "TIOCLINUX, subcode=0"
Dump the screen.
Disappeared in 1.1.92. (With kernel 1.1.92 or later, read from
-/dev/vcsN or /dev/vcsaN instead.)
-.IP "\fBTIOCLINUX, subcode=1\fP"
+.I /dev/vcsN
+or
+.I /dev/vcsaN
+instead.)
+.TP
+.B "TIOCLINUX, subcode=1"
Get task information.
Disappeared in 1.1.92.
-.IP "\fBTIOCLINUX, subcode=2\fP"
+.TP
+.B "TIOCLINUX, subcode=2"
Set selection.
-\fIargp\fP points to a
+.I argp
+points to a
.in +4n
.nf
.fi
.in
-\fIxs\fP and \fIys\fP are the starting column and row.
-\fIxe\fP and \fIye\fP are the ending
+.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.)
-\fIsel_mode\fP is 0 for character-by-character selection,
+.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 devices/char/console.c.
-.IP "\fBTIOCLINUX, subcode=3\fP"
+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 \fIfd\fP.
-.IP "\fBTIOCLINUX, subcode=4\fP"
+written to
+.IR fd .
+.TP
+.B "TIOCLINUX, subcode=4"
Unblank the screen.
-.IP "\fBTIOCLINUX, subcode=5\fP"
+.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 1.1.32.)
-.IP "\fBTIOCLINUX, subcode=6\fP"
-\fIargp\fP points to a char which is set to the value of the kernel
-variable \fIshift_state\fP.
+.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 1.1.32.)
-.IP "\fBTIOCLINUX, subcode=7\fP"
-\fIargp\fP points to a char which is set to the value of the kernel
-variable \fIreport_mouse\fP.
+.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 1.1.33.)
-.IP "\fBTIOCLINUX, subcode=8\fP"
+.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 /dev/vcsa* instead.)
-.IP "\fBTIOCLINUX, subcode=9\fP"
+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 /dev/vcsa* instead.)
-.IP "\fBTIOCLINUX, subcode=10\fP"
+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 \fIargp\fP[1], which governs what
+VESA screen blanking mode is set to
+.IR argp[1] ,
+which governs what
screen blanking does:
-
- \fI0\fP: Screen blanking is disabled.
-
- \fI1\fP: The current video adapter
+.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.
-
- \fI2\fP: The current
-settings are saved, then both the vertical and horizontal
+.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.
-(\fICaution:\fP Powering down frequently will damage the monitor.)
-
+.RI ( Caution:
+Powering down frequently will damage the monitor.)
(Since 1.1.76.)
+.RE
.SH RETURN VALUE
On success, 0 is returned.
-On error \-1 is returned, and \fIerrno\fP is set.
+On error, \-1 is returned, and
+.I errno
+is set.
.SH ERRORS
-\fIerrno\fP may take on these values:
+.I errno
+may take on these values:
.TP
.B EBADF
The file descriptor is invalid.
or the specified request does not apply to it.
.TP
.B EINVAL
-The file descriptor or \fIargp\fP is invalid.
+The file descriptor or
+.I argp
+is invalid.
.TP
.B EPERM
Insufficient permission.
.SH NOTES
.BR Warning :
-Do not regard this man page as documentation of the Linux console ioctl's.
+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
there are many minor and not-so-minor
differences with earlier versions.)
-Very often, ioctl's are introduced for communication between the
+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.
-Programs using these ioctl's will not be portable to other versions
+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.
.IR /usr/include/linux/kd.h ,
.I /usr/include/linux/vt.h
+.SH COLOPHON
+This page is part of release 3.65 of the Linux
+.I man-pages
+project.
+A description of the project,
+and information about reporting bugs,
+can be found at
+\%http://www.kernel.org/doc/man\-pages/.
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