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VCS
!!!VCS
NAME
DESCRIPTION
EXAMPLES
FILES
AUTHOR
HISTORY
SEE ALSO
----
!!NAME


vcs, vcsa - virtual console memory
!!DESCRIPTION


__/dev/vcs0__ is a character device with major number 7
and minor number 0, usually of mode 0644 and owner root.tty.
It refers to the memory of the currently displayed virtual
console terminal.


__/dev/vcs[[1-63]__ are character devices for virtual
console terminals, they have major number 7 and minor number
1 to 63, usually mode 0644 and owner root.tty.
__/dev/vcsa[[0-63]__ are the same, but including
attributes, and prefixed with four bytes giving the screen
dimensions and cursor position: ''lines'',
''columns'', ''x'', ''y''. (''x'' = ''y'' = 0
at the top left corner of the screen.)


These replace the screendump ''ioctl''s of
console(4), so the system administrator can control
access using file system permissions.


The devices for the first eight virtual consoles may be
created by:


     for x in 0 1 2 3 4 5 6 7 8; do
mknod -m 644 /dev/vcs$x c 7 $x;
mknod -m 644 /dev/vcsa$x c 7 $[[$x+128];
done
chown root:tty /dev/vcs*
No ''ioctl''() requests are supported.
!!EXAMPLES


You may do a screendump on vt3 by switching to vt1 and
typing ''cat /dev/vcs3 ''. Note that the output
does not contain newline characters, so some processing may
be required, like in ''fold -w 81 /dev/vcs3 | lpr'' or
(horrors) ''setterm -dump 3 -file
/proc/self/fd/1''.


The ''/dev/vcsa0'' device is used for Braille
support.


This program displays the character and screen attributes
under the cursor of the second virtual console, then changes
the background color there:


     #include
!!FILES


/dev/vcs[[0-63]
/dev/vcsa[[0-63]
!!AUTHOR


Andries Brouwer
!!HISTORY


Introduced with version 1.1.92 of the Linux
kernel.
!!SEE ALSO


console(4), tty(4), ttys(4),
selection(1)
----

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Last edited on Tuesday, June 4, 2002 12:25:04 am by "perry"

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