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



NAME
       console ioctl - ioctl's for console terminal and virtual consoles

DESCRIPTION
       The  following  Linux-peculiar  ioctl()  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  informa-
       tion,  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 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 colour map from kernel.  argp points to
              a 48-byte array.  (Since 1.3.3.)


       PIO_CMAP
              Change the default text-mode  colour  map.   argp  points  to  a
              48-byte array which contains, in order, the Red, Green, and Blue
              values for the 16 available screen colours: 0 is off, and 255 is
              full  intensity.  The default colours 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 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 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 map-
              ping.


       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 SIG-
              WINCH sent to the appropriate processes.  This call also invali-
              dates 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  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 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 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 {
                  u_char kb_func;
                  u_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 { u_char diacr, base, result; };


       KDGETKEYCODE
              Read  kernel  keycode  table entry (scan code to keycode).  argp
              points to a

              struct kbkeycode { unsigned int scancode, keycode; };

              keycode is set to correspond to  the  given  scancode.   (89  <=
              scancode  <=  255 only.  For 1 <= scancode <= 88, keycode==scan-
              code.)  (Since 1.1.63.)


       KDSETKEYCODE
              Write kernel keycode table entry.  argp points to struct  kbkey-
              code.  (Since 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 {
                  ushort v_active;  /* active vt */
                  ushort v_signal;  /* signal to send */
                  ushort v_state;   /* vt bitmask */
              };

              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  resize-
              cons(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  resize-
              cons(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 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 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 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 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.

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), setmeta-
       mode(1), execve(2), fcntl(2), ioperm(2), termios(3),  console(4),  con-
       sole_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



Linux                             1995-09-18                 CONSOLE_IOCTLS(4)