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



NAME
       console ioctl - ioctl's 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
                  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 {
                      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 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 cur-
              rently 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 {
                      unsigned short  entry_ct;
                      struct unipair *entries;
                  };

              where entries points to an array of

                  struct unipair {
                      unsigned short unicode;
                      unsigned 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 {
                      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 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 {
                      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 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 {
                      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==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/key-
              board.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 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 resizecons(8).  (Since 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 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.

       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.)

       TIOCLINUX, subcode=1
              Get task information.  Disappeared in 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 indicated 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 1.1.32.)

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

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

       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.)

       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 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.)

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.

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

       EINVAL The file descriptor or argp is invalid.

       EPERM  Insufficient permission.

NOTES
       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.

SEE ALSO
       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

COLOPHON
       This page is part of release 3.22 of the Linux man-pages project.  A description of the project,  and  informa-
       tion about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



Linux                             2009-02-28                  CONSOLE_IOCTL(4)