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<!-- Copyright (c) 1995 Jim Van Zandt &lt;jrv@vanzandt.mv.com&gt; and aeb
Sun Feb 26 11:46:23 MET 1995 -->

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<!-- Modified, Sun Feb 26 15:04:20 1995, faith@cs.unc.edu
Modified, Thu Apr 20 22:08:17 1995, jrv@vanzandt.mv.com
Modified, Mon Sep 18 22:32:47 1995, hpa@storm.net (H. Peter Anvin)
FIXME The following are not documented:
KDFONTOP (since 2.1.111)
KDGKBDIACRUC (since 2.6.24)
KDSKBDIACR
KDSKBDIACRUC (since 2.6.24)
KDKBDREP (since 2.1.113)
KDMAPDISP (not implemented as at 2.6.27)
KDUNMAPDISP (not implemented as at 2.6.27)
VT_LOCKSWITCH (since 1.3.47, needs CAP_SYS_TTY_CONFIG)
VT_UNLOCKSWITCH (since 1.3.47, needs CAP_SYS_TTY_CONFIG)
VT_GETHIFONTMASK (since 2.6.18) -->

<refentryinfo><date>2009-02-28</date></refentryinfo>
<refmeta>
<refentrytitle>CONSOLE_IOCTL</refentrytitle>
<manvolnum>4</manvolnum>
<refmiscinfo class='date'>2009-02-28</refmiscinfo>
<refmiscinfo class='source'>Linux</refmiscinfo>
<refmiscinfo class='manual'>Linux Programmer's Manual</refmiscinfo>
</refmeta>
<refnamediv>
<refname>console_ioctl</refname>
<refpurpose>ioctl's for console terminal and virtual consoles</refpurpose>
</refnamediv>
<!-- body begins here -->

<refsect1 id='description'><title>DESCRIPTION</title>
<para>The following Linux-specific
<citerefentry><refentrytitle>ioctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
requests are supported.
Each requires a third argument, assumed here to be <emphasis remap='I'>argp</emphasis>.</para>
<variablelist remap='IP'>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGETLED</emphasis></term>
  <listitem>
<para>Get state of LEDs.
<emphasis remap='I'>argp</emphasis> points to a <emphasis remap='I'>char</emphasis>.
The lower three bits
of <emphasis remap='I'>*argp</emphasis> are set to the state of the LEDs, as follows:</para>

<informaltable pgwide='0' frame='none'>
  <tgroup cols='3' align='center'>
    <colspec colname='c1'/>
    <colspec colname='c2'/>
    <colspec colname='c3'/>
    <tbody>
      <row>
        <entry align='left'>LED_CAP </entry>
        <entry align='left'>0x04</entry>
        <entry align='left'>caps lock led</entry>
      </row>
      <row>
        <entry align='left'>LEC_NUM </entry>
        <entry align='left'>0x02</entry>
        <entry align='left'>num lock led</entry>
      </row>
      <row>
        <entry align='left'>LED_SCR </entry>
        <entry align='left'>0x01</entry>
        <entry align='left'>scroll lock led</entry>
      </row>
    </tbody>
  </tgroup>
</informaltable>



  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSETLED</emphasis></term>
  <listitem>
<para>Set the LEDs.
The LEDs are set to correspond to the lower three bits of
<emphasis remap='I'>argp</emphasis>.
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.</para>
  </listitem>
  </varlistentry>
</variablelist>

<para>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.</para>
<variablelist remap='IP'>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGKBLED</emphasis></term>
  <listitem>
<para>Get keyboard flags CapsLock, NumLock, ScrollLock (not lights).
<emphasis remap='I'>argp</emphasis> 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.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSKBLED</emphasis></term>
  <listitem>
<para>Set keyboard flags CapsLock, NumLock, ScrollLock (not lights).
<emphasis remap='I'>argp</emphasis> 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.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGKBTYPE</emphasis></term>
  <listitem>
<para>Get keyboard type.
This returns the value KB_101, defined as 0x02.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDADDIO</emphasis></term>
  <listitem>
<para>Add I/O port as valid.
Equivalent to <emphasis remap='I'>ioperm(arg,1,1)</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDDELIO</emphasis></term>
  <listitem>
<para>Delete I/O port as valid.
Equivalent to <emphasis remap='I'>ioperm(arg,1,0)</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDENABIO</emphasis></term>
  <listitem>
<para>Enable I/O to video board.
Equivalent to <emphasis remap='I'>ioperm(0x3b4, 0x3df-0x3b4+1, 1)</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDDISABIO</emphasis></term>
  <listitem>
<para>Disable I/O to video board.
Equivalent to <emphasis remap='I'>ioperm(0x3b4, 0x3df-0x3b4+1, 0)</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSETMODE</emphasis></term>
  <listitem>
<para>Set text/graphics mode.
<emphasis remap='I'>argp</emphasis> is one of these:</para>

<informaltable pgwide='0' frame='none'>
  <tgroup cols='2' align='center'>
    <colspec colname='c1'/>
    <colspec colname='c2'/>
    <tbody>
      <row>
        <entry align='left'>KD_TEXT    </entry>
        <entry align='left'>0x00</entry>
      </row>
      <row>
        <entry align='left'>KD_GRAPHICS</entry>
        <entry align='left'>0x01</entry>
      </row>
    </tbody>
  </tgroup>
</informaltable>



  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGETMODE</emphasis></term>
  <listitem>
<para>Get text/graphics mode.
<emphasis remap='I'>argp</emphasis> points to a <emphasis remap='I'>long</emphasis> which is set to one
of the above values.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDMKTONE</emphasis></term>
  <listitem>
<para>Generate tone of specified length.
The lower 16 bits of <emphasis remap='I'>argp</emphasis> 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, <emphasis remap='I'>argp</emphasis> = (125&lt;&lt;16) + 0x637 would specify
the beep normally associated with a ctrl-G.
(Thus since 0.99pl1; broken in 2.1.49-50.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KIOCSOUND</emphasis></term>
  <listitem>
<para>Start or stop sound generation.
The lower 16 bits of
<emphasis remap='I'>argp</emphasis> specify the period in clock cycles
(that is, <emphasis remap='I'>argp</emphasis> = 1193180/frequency).
<emphasis remap='I'>argp</emphasis> = 0 turns sound off.
In either case, control returns immediately.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>GIO_CMAP</emphasis></term>
  <listitem>
<para>Get the current default color map from kernel.
<emphasis remap='I'>argp</emphasis> points to
a 48-byte array.
(Since 1.3.3.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_CMAP</emphasis></term>
  <listitem>
<para>Change the default text-mode color map.
<emphasis remap='I'>argp</emphasis> 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.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>GIO_FONT</emphasis></term>
  <listitem>
<para>Gets 256-character screen font in expanded form.
<emphasis remap='I'>argp</emphasis> points to an 8192 byte array.
Fails with error code <emphasis role='strong' remap='B'>EINVAL</emphasis> if the
currently loaded font is a 512-character font, or if the console is
not in text mode.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>GIO_FONTX</emphasis></term>
  <listitem>
<para>Gets screen font and associated information.
<emphasis remap='I'>argp</emphasis> points to a
<emphasis remap='I'>struct consolefontdesc</emphasis> (see <emphasis role='strong' remap='B'>PIO_FONTX</emphasis>).
On call, the
<emphasis remap='I'>charcount</emphasis> field should be set to the maximum number of
characters that would fit in the buffer pointed to by <emphasis remap='I'>chardata</emphasis>.
On return, the <emphasis remap='I'>charcount</emphasis> and <emphasis remap='I'>charheight</emphasis> are filled with
the respective data for the currently loaded font, and the
<emphasis remap='I'>chardata</emphasis> array contains the font data if the initial value of
<emphasis remap='I'>charcount</emphasis> indicated enough space was available; otherwise the
buffer is untouched and <varname>errno</varname> is set to <emphasis role='strong' remap='B'>ENOMEM</emphasis>.
(Since 1.3.1.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_FONT</emphasis></term>
  <listitem>
<para>Sets 256-character screen font.
Load font into the EGA/VGA character
generator.
<emphasis remap='I'>argp</emphasis> points to a 8192 byte map, with 32 bytes per
character.
Only first <emphasis remap='I'>N</emphasis> of them are used for an 8x<emphasis remap='I'>N</emphasis> font
(0 &lt; <emphasis remap='I'>N</emphasis> &lt;= 32).
This call also invalidates the Unicode mapping.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_FONTX</emphasis></term>
  <listitem>
<para>Sets screen font and associated rendering information.
<emphasis remap='I'>argp</emphasis>
points to a</para>

<programlisting remap='.nf .ft CW'>
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 */
};
</programlisting> <!-- .fi -->

<para>If necessary, the screen will be appropriately resized, and
<emphasis role='strong' remap='B'>SIGWINCH</emphasis> sent to the appropriate processes.
This call also invalidates the Unicode mapping.
(Since 1.3.1.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_FONTRESET</emphasis></term>
  <listitem>
<para>Resets the screen font, size and Unicode mapping to the bootup
defaults.
<emphasis remap='I'>argp</emphasis> is unused, but should be set to NULL to
ensure compatibility with future versions of Linux.
(Since 1.3.28.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>GIO_SCRNMAP</emphasis></term>
  <listitem>
<para>Get screen mapping from kernel.
<emphasis remap='I'>argp</emphasis> 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.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>GIO_UNISCRNMAP</emphasis></term>
  <listitem>
<para>Get full Unicode screen mapping from kernel.
<emphasis remap='I'>argp</emphasis> 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.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_SCRNMAP</emphasis></term>
  <listitem>
<para>Loads the "user definable" (fourth) table in the kernel which maps
bytes into console screen symbols.
<emphasis remap='I'>argp</emphasis> points to an area of
size E_TABSZ.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_UNISCRNMAP</emphasis></term>
  <listitem>
<para>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.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>GIO_UNIMAP</emphasis></term>
  <listitem>
<para>Get Unicode-to-font mapping from kernel.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
struct unimapdesc {
    unsigned short  entry_ct;
    struct unipair *entries;
};
</programlisting> <!-- .fi -->

<para>where <emphasis remap='I'>entries</emphasis> points to an array of</para>

<programlisting remap='.nf .ft CW'>
struct unipair {
    unsigned short unicode;
    unsigned short fontpos;
};
</programlisting> <!-- .fi -->

<para>(Since 1.1.92.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_UNIMAP</emphasis></term>
  <listitem>
<para>Put unicode-to-font mapping in kernel.
    <emphasis remap='I'>argp</emphasis> points to a
<emphasis remap='I'>struct unimapdesc</emphasis>.
(Since 1.1.92)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>PIO_UNIMAPCLR</emphasis></term>
  <listitem>
<para>Clear table, possibly advise hash algorithm.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
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 */
};
</programlisting> <!-- .fi -->

<para>(Since 1.1.92.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGKBMODE</emphasis></term>
  <listitem>
<para>Gets current keyboard mode.
<emphasis remap='I'>argp</emphasis> points to a <emphasis remap='I'>long</emphasis> which is set to one
of these:</para>

<informaltable pgwide='0' frame='none'>
  <tgroup cols='2' align='center'>
    <colspec colname='c1'/>
    <colspec colname='c2'/>
    <tbody>
      <row>
        <entry align='left'>K_RAW      </entry>
        <entry align='left'>0x00</entry>
      </row>
      <row>
        <entry align='left'>K_XLATE    </entry>
        <entry align='left'>0x01</entry>
      </row>
      <row>
        <entry align='left'>K_MEDIUMRAW</entry>
        <entry align='left'>0x02</entry>
      </row>
      <row>
        <entry align='left'>K_UNICODE  </entry>
        <entry align='left'>0x03</entry>
      </row>
    </tbody>
  </tgroup>
</informaltable>



  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSKBMODE</emphasis></term>
  <listitem>
<para>Sets current keyboard mode.
<emphasis remap='I'>argp</emphasis> is a <emphasis remap='I'>long</emphasis> equal to one of the above values.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGKBMETA</emphasis></term>
  <listitem>
<para>Gets meta key handling mode.
<emphasis remap='I'>argp</emphasis> points to a <emphasis remap='I'>long</emphasis> which is
set to one of these:</para>

<informaltable pgwide='0' frame='none'>
  <tgroup cols='3' align='center'>
    <colspec colname='c1'/>
    <colspec colname='c2'/>
    <colspec colname='c3'/>
    <tbody>
      <row>
        <entry align='left'>K_METABIT  </entry>
        <entry align='left'>0x03</entry>
        <entry align='left'>set high order bit</entry>
      </row>
      <row>
        <entry align='left'>K_ESCPREFIX</entry>
        <entry align='left'>0x04</entry>
        <entry align='left'>escape prefix</entry>
      </row>
    </tbody>
  </tgroup>
</informaltable>



  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSKBMETA</emphasis></term>
  <listitem>
<para>Sets meta key handling mode.
<emphasis remap='I'>argp</emphasis> is a <emphasis remap='I'>long</emphasis> equal to one of the above values.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGKBENT</emphasis></term>
  <listitem>
<para>Gets one entry in key translation table (keycode to action code).
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
struct kbentry {
    unsigned char  kb_table;
    unsigned char  kb_index;
    unsigned short kb_value;
};
</programlisting> <!-- .fi -->

<para>with the first two members filled in:
<emphasis remap='I'>kb_table</emphasis> selects the key table (0 &lt;= <emphasis remap='I'>kb_table</emphasis> &lt; MAX_NR_KEYMAPS),
and <emphasis remap='I'>kb_index</emphasis> is the keycode (0 &lt;= <emphasis remap='I'>kb_index</emphasis> &lt; NR_KEYS).
<emphasis remap='I'>kb_value</emphasis> is set to the corresponding action code,
or K_HOLE if there is no such key,
or K_NOSUCHMAP if <emphasis remap='I'>kb_table</emphasis> is invalid.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSKBENT</emphasis></term>
  <listitem>
<para>Sets one entry in translation table.
<emphasis remap='I'>argp</emphasis> points to
a <emphasis remap='I'>struct kbentry</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGKBSENT</emphasis></term>
  <listitem>
<para>Gets one function key string.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
struct kbsentry {
    unsigned char kb_func;
    unsigned char kb_string[512];
};
</programlisting> <!-- .fi -->

<para><emphasis remap='I'>kb_string</emphasis> is set to the (null-terminated) string corresponding to
the <emphasis remap='I'>kb_func</emphasis>th function key action code.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSKBSENT</emphasis></term>
  <listitem>
<para>Sets one function key string entry.
<emphasis remap='I'>argp</emphasis> points to
a <emphasis remap='I'>struct kbsentry</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGKBDIACR</emphasis></term>
  <listitem>
<para>Read kernel accent table.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
struct kbdiacrs {
    unsigned int   kb_cnt;
    struct kbdiacr kbdiacr[256];
};
</programlisting> <!-- .fi -->

<para>where <emphasis remap='I'>kb_cnt</emphasis> is the number of entries in the array, each of which
is a</para>

<programlisting remap='.nf .ft CW'>
struct kbdiacr {
    unsigned char diacr;
    unsigned char base;
    unsigned char result;
};
</programlisting> <!-- .fi -->
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDGETKEYCODE</emphasis></term>
  <listitem>
<para>Read kernel keycode table entry (scan code to keycode).
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
struct kbkeycode {
    unsigned int scancode;
    unsigned int keycode;
};
</programlisting> <!-- .fi -->

<para><emphasis remap='I'>keycode</emphasis> is set to correspond to the given <emphasis remap='I'>scancode</emphasis>.
(89 &lt;= <emphasis remap='I'>scancode</emphasis> &lt;= 255 only.
For 1 &lt;= <emphasis remap='I'>scancode</emphasis> &lt;= 88, <emphasis remap='I'>keycode</emphasis>==<emphasis remap='I'>scancode</emphasis>.)
(Since 1.1.63.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSETKEYCODE</emphasis></term>
  <listitem>
<para>Write kernel keycode table entry.
<emphasis remap='I'>argp</emphasis> points to
a <emphasis remap='I'>struct kbkeycode</emphasis>.
(Since 1.1.63.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>KDSIGACCEPT</emphasis></term>
  <listitem>
<para>The calling process indicates its willingness to accept the signal
<emphasis remap='I'>argp</emphasis> when it is generated by pressing an appropriate key combination.
(1 &lt;= <emphasis remap='I'>argp</emphasis> &lt;= NSIG).
(See spawn_console() in linux/drivers/char/keyboard.c.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_OPENQRY</emphasis></term>
  <listitem>
<para>Returns the first available (non-opened) console.
<emphasis remap='I'>argp</emphasis> points to an <emphasis remap='I'>int</emphasis> which is set to the
number of the vt (1 &lt;= <emphasis remap='I'>*argp</emphasis> &lt;= MAX_NR_CONSOLES).</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_GETMODE</emphasis></term>
  <listitem>
<para>Get mode of active vt.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
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) */
};
</programlisting> <!-- .fi -->

<para>which is set to the mode of the active vt.
<emphasis remap='I'>mode</emphasis> is set to one of these values:</para>

<informaltable pgwide='0' frame='none'>
  <tgroup cols='2' align='center'>
    <colspec colname='c1'/>
    <colspec colname='c2'/>
    <tbody>
      <row>
        <entry align='left'>VT_AUTO   </entry>
        <entry align='left'>auto vt switching</entry>
      </row>
      <row>
        <entry align='left'>VT_PROCESS</entry>
        <entry align='left'>process controls switching</entry>
      </row>
      <row>
        <entry align='left'>VT_ACKACQ </entry>
        <entry align='left'>acknowledge switch</entry>
      </row>
    </tbody>
  </tgroup>
</informaltable>



  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_SETMODE</emphasis></term>
  <listitem>
<para>Set mode of active vt.
<emphasis remap='I'>argp</emphasis> points to
a <emphasis remap='I'>struct vt_mode</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_GETSTATE</emphasis></term>
  <listitem>
<para>Get global vt state info.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
struct vt_stat {
    unsigned short v_active;  /* active vt */
    unsigned short v_signal;  /* signal to send */
    unsigned short v_state;   /* vt bit mask */
};
</programlisting> <!-- .fi -->

<para>For each vt in use, the corresponding bit in the <emphasis remap='I'>v_state</emphasis> member is set.
(Kernels 1.0 through 1.1.92.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_RELDISP</emphasis></term>
  <listitem>
<para>Release a display.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_ACTIVATE</emphasis></term>
  <listitem>
<para>Switch to vt <emphasis remap='I'>argp</emphasis> (1 &lt;= <emphasis remap='I'>argp</emphasis> &lt;= MAX_NR_CONSOLES).</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_WAITACTIVE</emphasis></term>
  <listitem>
<para>Wait until vt <emphasis remap='I'>argp</emphasis> has been activated.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_DISALLOCATE</emphasis></term>
  <listitem>
<para>Deallocate the memory associated with vt <emphasis remap='I'>argp</emphasis>.
(Since 1.1.54.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_RESIZE</emphasis></term>
  <listitem>
<para>Set the kernel's idea of screensize.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
struct vt_sizes {
    unsigned short v_rows;       /* # rows */
    unsigned short v_cols;       /* # columns */
    unsigned short v_scrollsize; /* no longer used */
};
</programlisting> <!-- .fi -->

<para>Note that this does not change the videomode.
See
<citerefentry><refentrytitle>resizecons</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
(Since 1.1.54.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>VT_RESIZEX</emphasis></term>
  <listitem>
<para>Set the kernel's idea of various screen parameters.
<emphasis remap='I'>argp</emphasis> points to a</para>

<programlisting remap='.nf .ft CW'>
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 */
};
</programlisting> <!-- .fi -->

<para>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
<citerefentry><refentrytitle>resizecons</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
(Since 1.3.3.)</para>
  </listitem>
  </varlistentry>
</variablelist>

<para>The action of the following ioctls depends on the first byte in the struct
pointed to by <emphasis remap='I'>argp</emphasis>, referred to here as the <emphasis remap='I'>subcode</emphasis>.
These are legal only for the superuser or the owner of the current tty.</para>
<variablelist remap='IP'>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=0</emphasis></term>
  <listitem>
<para>Dump the screen.
Disappeared in 1.1.92.  (With kernel 1.1.92 or later, read from
/dev/vcsN or /dev/vcsaN instead.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=1</emphasis></term>
  <listitem>
<para>Get task information.
Disappeared in 1.1.92.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=2</emphasis></term>
  <listitem>
<para>Set selection.
<emphasis remap='I'>argp</emphasis> points to a</para>
<programlisting remap='.nf .ft CW'>

struct {
   char  subcode;
   short xs, ys, xe, ye;
   short sel_mode;
};

</programlisting> <!-- .fi -->
<para><emphasis remap='I'>xs</emphasis> and <emphasis remap='I'>ys</emphasis> are the starting column and row.
<emphasis remap='I'>xe</emphasis> and <emphasis remap='I'>ye</emphasis> are the ending
column and row.
(Upper left corner is row=column=1.)
<emphasis remap='I'>sel_mode</emphasis> 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.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=3</emphasis></term>
  <listitem>
<para>Paste selection.
The characters in the selection buffer are
written to <emphasis remap='I'>fd</emphasis>.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=4</emphasis></term>
  <listitem>
<para>Unblank the screen.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=5</emphasis></term>
  <listitem>
<para>Sets contents of a 256-bit look up table defining characters in a "word",
for word-by-word selection.
(Since 1.1.32.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=6</emphasis></term>
  <listitem>
<para><emphasis remap='I'>argp</emphasis> points to a char which is set to the value of the kernel
variable <emphasis remap='I'>shift_state</emphasis>.
(Since 1.1.32.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=7</emphasis></term>
  <listitem>
<para><emphasis remap='I'>argp</emphasis> points to a char which is set to the value of the kernel
variable <emphasis remap='I'>report_mouse</emphasis>.
(Since 1.1.33.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=8</emphasis></term>
  <listitem>
<para>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.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=9</emphasis></term>
  <listitem>
<para>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.)</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>TIOCLINUX, subcode=10</emphasis></term>
  <listitem>
<para>Handles the Power Saving
feature of the new generation of monitors.
VESA screen blanking mode is set to <emphasis remap='I'>argp</emphasis>[1], which governs what
screen blanking does:</para>

<para>    <literal>0</literal>: Screen blanking is disabled.</para>

<para>    <literal>1</literal>: 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.</para>

<para>    <literal>2</literal>: 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.
(<emphasis remap='I'>Caution:</emphasis> Powering down frequently will damage the monitor.)</para>

<para>(Since 1.1.76.)</para>
  </listitem>
  </varlistentry>
</variablelist>
</refsect1>

<refsect1 id='return_value'><title>RETURN VALUE</title>
<para>On success, 0 is returned.
On error -1 is returned, and <varname>errno</varname> is set.</para>
</refsect1>

<refsect1 id='errors'><title>ERRORS</title>
<para><varname>errno</varname> may take on these values:</para>
<variablelist remap='TP'>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>EBADF</emphasis></term>
  <listitem>
<para>The file descriptor is invalid.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>ENOTTY</emphasis></term>
  <listitem>
<para>The file descriptor is not associated with a character special device,
or the specified request does not apply to it.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>EINVAL</emphasis></term>
  <listitem>
<para>The file descriptor or <emphasis remap='I'>argp</emphasis> is invalid.</para>
  </listitem>
  </varlistentry>
  <varlistentry>
  <term><emphasis role='strong' remap='B'>EPERM</emphasis></term>
  <listitem>
<para>Insufficient permission.</para>
  </listitem>
  </varlistentry>
</variablelist>
</refsect1>

<refsect1 id='notes'><title>NOTES</title>
<para><emphasis role='strong' remap='B'>Warning</emphasis>:
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.)</para>

<para>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.</para>

<para>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.</para>

<para>Use POSIX functions.</para>
</refsect1>

<refsect1 id='see_also'><title>SEE ALSO</title>
<para><citerefentry><refentrytitle>dumpkeys</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>kbd_mode</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>loadkeys</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>mknod</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>setleds</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>setmetamode</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
<citerefentry><refentrytitle>fcntl</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
<citerefentry><refentrytitle>ioperm</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
<citerefentry><refentrytitle>termios</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>console</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>console_codes</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>mt</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>tty</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>tty_ioctl</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>ttyS</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>vcs</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>vcsa</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
<citerefentry><refentrytitle>charsets</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>mapscrn</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>resizecons</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>setfont</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<filename>/usr/include/linux/kd.h</filename>,
<filename>/usr/include/linux/vt.h</filename></para>
</refsect1>

<refsect1 id='colophon'><title>COLOPHON</title>
<para>This page is part of release 3.35 of the Linux
<emphasis remap='I'>man-pages</emphasis>
project.
A description of the project,
and information about reporting bugs,
can be found at
<ulink url='http://man7.org/linux/man-pages/'>http://man7.org/linux/man-pages/</ulink>.</para>
</refsect1>
</refentry>