CONSOLE_IOCTL(4)	   Linux Programmer's Manual	      CONSOLE_IOCTL(4)



NAME
       console_ioctl - ioctls for console terminal and virtual consoles

DESCRIPTION
       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 char.  The lower three bits
	      of *argp are set to the state of the LEDs, as follows:

	      LED_CAP	 0x04	caps lock led
	      LED_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 Linux 1.1.54, the LEDs just reflected the state  of  the	corre-
       sponding	 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.

       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 Linux 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 Linux
	      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 an int which is set to
	      one of the values shown above for KDSETMODE.

       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  Linux  0.99pl1; broken in Linux
	      2.1.49-50.)

       KIOCSOUND
	      Start or stop sound generation.  The lower 16 bits of argp spec-
	      ify  the	period	in  clock cycles (that is, argp = 1193180/fre-
	      quency).	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 Linux 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 Linux 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 cur-
	      rently 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 Linux 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 the 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 {
		      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 */
		  };

	      If necessary, the screen will be appropriately resized, and SIG-
	      WINCH sent to the appropriate processes.	This call also invali-
	      dates the Unicode mapping.  (Since Linux 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	 Linux
	      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 informa-
	      tion 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 Linux 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 Linux 1.3.1.)

       GIO_UNIMAP
	      Get Unicode-to-font mapping from kernel.	argp points to a

		  struct unimapdesc {
		      unsigned short  entry_ct;
		      struct unipair *entries;
		  };

	      where entries points to an array of

		  struct unipair {
		      unsigned short unicode;
		      unsigned short fontpos;
		  };

	      (Since Linux 1.1.92.)

       PIO_UNIMAP
	      Put unicode-to-font mapping in kernel.  argp points to a	struct
	      unimapdesc.  (Since Linux 1.1.92)

       PIO_UNIMAPCLR
	      Clear table, possibly advise hash algorithm.  argp points to a

		  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 */
		  };

	      (Since Linux 1.1.92.)

       KDGKBMODE
	      Gets  current keyboard mode.  argp points to a long which is set
	      to one of these:

	      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 */

       KDSKBMODE
	      Sets current keyboard mode.  argp is a long equal to one of  the
	      values shown for KDGKBMODE.

       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
	      values shown above for KDGKBMETA.

       KDGKBENT
	      Gets  one	 entry	in  key	 translation  table (keycode to action
	      code).  argp points to a

		  struct kbentry {
		      unsigned char  kb_table;
		      unsigned char  kb_index;
		      unsigned 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 key-
	      code (0 <= kb_index < NR_KEYS).  kb_value is set to  the	corre-
	      sponding	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 {
		      unsigned char kb_func;
		      unsigned char kb_string[512];
		  };

	      kb_string	 is  set to the (null-terminated) string corresponding
	      to the kb_functh 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 {
		      unsigned char diacr;
		      unsigned char base;
		      unsigned 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==scan-
	      code.)  (Since Linux 1.1.63.)

       KDSETKEYCODE
	      Write  kernel keycode table entry.  argp points to a struct kbk-
	      eycode.  (Since Linux 1.1.63.)

       KDSIGACCEPT
	      The calling process indicates its willingness to accept the sig-
	      nal  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 {
		      unsigned short v_active;	/* active vt */
		      unsigned short v_signal;	/* signal to send */
		      unsigned short 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 Linux
	      1.1.54.)

       VT_RESIZE
	      Set the kernel's idea of screensize.  argp points to a

		  struct vt_sizes {
		      unsigned short v_rows;	   /* # rows */
		      unsigned short v_cols;	   /* # columns */
		      unsigned short v_scrollsize; /* no longer used */
		  };

	      Note that this does  not	change	the  videomode.	  See  resize-
	      cons(8).	(Since Linux 1.1.54.)

       VT_RESIZEX
	      Set the kernel's idea of various screen parameters.  argp points
	      to a

		  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 */
		  };

	      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 Linux 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 terminal.

       TIOCLINUX, subcode=0
	      Dump  the	 screen.   Disappeared	in Linux 1.1.92.  (With kernel
	      1.1.92 or later, read from /dev/vcsN or /dev/vcsaN instead.)

       TIOCLINUX, subcode=1
	      Get task information.  Disappeared in Linux 1.1.92.

       TIOCLINUX, subcode=2
	      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 indi-
	      cated screen characters are highlighted and saved in the	static
	      array sel_buffer in devices/char/console.c.

       TIOCLINUX, subcode=3
	      Paste  selection.	  The  characters  in the selection buffer are
	      written to fd.

       TIOCLINUX, subcode=4
	      Unblank the screen.

       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.)

       TIOCLINUX, subcode=6
	      argp  points  to	a char which is set to the value of the kernel
	      variable shift_state.  (Since Linux 1.1.32.)

       TIOCLINUX, subcode=7
	      argp points to a char which is set to the value  of  the	kernel
	      variable report_mouse.  (Since Linux 1.1.33.)

       TIOCLINUX, subcode=8
	      Dump screen width and height, cursor position, and all the char-
	      acter-attribute pairs.  (Kernels	1.1.67	through	 1.1.91	 only.
	      With kernel 1.1.92 or later, read from /dev/vcsa* instead.)

       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.)

       TIOCLINUX, subcode=10
	      Handles  the Power Saving feature of the new generation of moni-
	      tors.  VESA screen blanking mode is set to argp[1],  which  gov-
	      erns 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  syn-
		 chronization  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 Linux 1.1.76.)

RETURN VALUE
       On success, 0 is returned.  On error, -1 is returned, and errno is set.

ERRORS
       errno may take on these values:

       EBADF  The file descriptor is invalid.

       EINVAL The file descriptor or argp is invalid.

       ENOTTY The  file	 descriptor is not associated with a character special
	      device, or the specified request does not apply to it.

       EPERM  Insufficient permission.

NOTES
       Warning: Do not regard this man page as documentation of the Linux con-
       sole  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.)

       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 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.

       Use POSIX functions.

SEE ALSO
       dumpkeys(1), kbd_mode(1), loadkeys(1), mknod(1),	 setleds(1),  setmeta-
       mode(1),	 execve(2), fcntl(2), ioperm(2), termios(3), 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

COLOPHON
       This  page  is  part of release 4.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest	  version     of     this    page,    can    be	   found    at
       https://www.kernel.org/doc/man-pages/.



Linux				  2016-12-12		      CONSOLE_IOCTL(4)