CONSOLE
Section: Linux Programmer's Manual (4)
Updated: 1994-10-31
Index
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NAME
console - console terminal and virtual consoles
DESCRIPTION
A Linux system has up to 63
virtual consoles
(character devices with major number 4 and minor number 1 to 63),
usually called
/dev/ttyn
with 1 ≤
n
≤ 63.
The current console is also addressed by
/dev/console
or
/dev/tty0,
the character device with
major number 4 and minor number 0.
The device files
/dev/*
are usually created using the script MAKEDEV,
or using
mknod(1),
usually with mode 0622 and owner
root.tty.
Before kernel version 1.1.54 the number of virtual consoles was
compiled into the kernel (in
tty.h:
#define NR_CONSOLES 8)
and could be changed by editing and recompiling.
Since version 1.1.54 virtual consoles are created on the fly,
as soon as they are needed.
Common ways to start a process on a console are:
(a) tell
init(8)
(in
inittab(5))
to start a
mingetty(8)
(or
agetty(8))
on the console;
(b) ask
openvt(1)
to start a process on the console;
(c) start X---it will find the first unused console,
and display its output there.
(There is also the ancient
doshell(8).)
Common ways to switch consoles are: (a) use Alt+Fn or
Ctrl+Alt+Fn to switch to console
n;
AltGr+Fn
might bring you to console n+12 [here Alt and AltGr refer
to the left and right Alt keys, respectively];
(b) use Alt+RightArrow or Alt+LeftArrow to cycle through
the presently allocated consoles; (c) use the program
chvt(1).
(The key mapping is user settable, see
loadkeys(1);
the above mentioned key combinations are according to the default settings.)
The command
deallocvt(1)
(formerly
disalloc)
will free the memory taken by the screen buffers for consoles
that no longer have any associated process.
Properties
Consoles carry a lot of state.
I hope to document that some other time.
The most important fact is that the consoles simulate vt100 terminals.
In particular, a console is reset to the initial state by printing the two
characters ESC c.
All escape sequences can be found in
console_codes(4).
FILES
/dev/console
/dev/tty*
SEE ALSO
chvt(1),
deallocvt(1),
loadkeys(1),
mknod(1),
openvt(1),
console_codes(4),
console_ioctl(4),
tty(4),
ttyS(4),
charsets(7),
agetty(8),
init(8),
mapscrn(8),
mingetty(8),
resizecons(8),
setfont(8)
Index
- NAME
-
- DESCRIPTION
-
- Properties
-
- FILES
-
- SEE ALSO
-
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Time: 02:55:19 GMT, September 18, 2014