screen(4)

NAME

screen - pc display interface

DESCRIPTION

Access to the virtual consoles are obtained through the de

vice files
/dev/ttyv0 - /dev/ttyvb. Each of these files correspond to

a separate
virtual console. All virtual console devices can be open at

once, but
only one is active at a time. The active virtual console

"owns" the keyboard and display screen.

Output to a virtual console that not currently is on the

display is saved
in a buffer that holds a "screenfull" (normally 25) lines.

Any output
written to /dev/console (the original console device) is

echoed to
/dev/ttyv0.

To switch between the virtual consoles one uses the sequence

ALT+Fn,
which means hold down ALT and press one of the function

keys. The virtual console with the same number as the function key is

then selected as
the current virtual console, and given exclusive use of the

keyboard and
display. This switch sequence can be changed via the key

board mapping
ioctl call (see keyboard(4)).

The console allows entering values that are not physically

present on the
keyboard via a special keysequence. To use this facility

press and hold
down ALT, then enter a decimal number from 0-255 via the nu

merical keypad, then release ALT. The entered value is then used as

the ASCII value
for one character. This way it is possible to enter any

ASCII value.
The console driver also includes a history function. It is

activated by
pressing the scroll-lock key. This holds the display, and

enables the
cursor arrows for scrolling up and down through the last

scrolled out
lines.

The console understands a subset of the ANSI x3.64 character

sequences.
For compatibility with the old pccons, the PC3 character se

quences are
also supported.

ANSI Seq Function

Termcap entry
======= ======= =====================================

==============

-- E7 Save cursor position sc

-- E8 Restore saved cursor position rc

-- Ec Reset rs

-- EM move cursor up 1 line, -

scroll if at top

CUU E[nA move cursor up n lines

up/UP (ku)

CUD E[nB move cursor down n lines

do/DO (kd)

CUF E[nC move cursor right n characters

nd/RI (kr)

CUB E[nD move cursor left n characters

--/LE (kl)

HPA E[n` move cursor to character position n ch

HPR E[na move cursor right n characters -

VPA E[nd move cursor to line n cv

VPR E[ne move cursor down n lines -

CPL E[nF move cursor to start of line, -

(@7)

n lines up

CNL E[nE move cursor to start of line, nw

n lines down

CUP E[y;xH Move cursor to x, y cm

HVP E[y;xf Move cursor to x, y -

CBT E[nZ Move cursor back n tab stops bt

(kB)

IL E[nL Insert n blank lines

al/AL

ICH E[n@ Insert n blank characters

ic/IC

DL E[nM Delete n lines

dl/DL

DCH E[nP Delete n characters

dc/DC

ED E[nJ Erase part or all of display: cd

n=0 from cursor to end of display,
n=1 from begin of display to cursor,
n=2 entire display.

EL E[nK Erase part or all of line: ce

n=0 from cursor to end of line,
n=1 from begin of line to cursor,
n=2 entire line.

ECH E[nX Erase n characters ec

SU E[nS Scroll display n lines up (forward)

sf/SF

SD E[nT Scroll display n lines down (reverse)

sr/SR

SGR E[nm Set character attributes: -

n= 0 normal attribute (all off)
n= 1 bold (highlight)
n= 4 underscore (if supported by HW)
n= 5 blink (if supported by HW)
n= 7 reverse
n= 22 remove bold
n= 24 remove underscore
n= 25 remove blink
n= 27 remove reverse
n= 3X set ANSI foreground color

(see table)

n= 4X set ANSI background color

(see table)

X=0 black X=1 red
X=2 green X=3 brown
X=4 blue X=5 magenta
X=6 cyan X=7 light grey
X=9 reset to the normal color

-- E[s Save cursor position sc

-- E[u Restore saved cursor position rc

-- E[x Reset normal colors and attributes -

to their default values

-- E[nz Switch to virtual console n -

-- E[1;nx Set normal ANSI background color -

to n (see table)

-- E[2;nx Set normal ANSI foreground color -

to n (see table)

-- E[3;nx Set normal video attribute directly -

to n (n from 0 to 255)

-- E[5;nx Set normal ANSI reverse background -

color to n (see table)

-- E[6;nx Set normal ANSI reverse foreground -

color to n (see table)

n= 0 black n= 8 dark grey
n= 1 red n= 9 light red
n= 2 green n=10 light green
n= 3 brown n=11 yellow
n= 4 blue n=12 light blue
n= 5 magenta n=13 light magenta
n= 6 cyan n=14 light cyan
n= 7 light grey n=15 white

-- E[7;nx Set normal reverse video attribute -

directly to n (n from 0 to 255)

-- E[=p;dB Set bell pitch (p) and duration (d), -

pitch is in units of 840 nS,
duration is units of 0,1 S.

-- E[=tC Set global cursor type (see table) -

t=0 normal non-blinking
t=1 normal blinking
t=2 custom non-blinking
t=3 custom blinking
t=4 reset cursor (resets custom

cursor shape and sets current
cursor type to 0)

t=5 hide cursor

-- E[=s;eC Set custom cursor shape, where -

s is the starting and e is the ending
scanlines of the cursor.

-- E[=s;e;dC -

Same as above, except d specifies the
direction. If 0, scanlines are counted
from the top to the bottom. If 1, from
the bottom to the top.

-- E[=tS Set local cursor type (see table) -

t=0 normal (global) ve
t=1 invisible vi
t=2 very visible vs

-- E[=nA Set the border color to n -

(see table) (if supported by HW)

-- E[=nF Set normal foreground color to n -

(see table)

-- E[=nG Set normal background color to n -

(see table)

-- E[=nH Set normal reverse foreground color -

to n (see table)

-- E[=nI Set normal reverse background color -

to n (see table)

n= 0 black n= 8 dark grey
n= 1 blue n= 9 light blue
n= 2 green n=10 light green
n= 3 cyan n=11 light cyan
n= 4 red n=12 light red
n= 5 magenta n=13 light magenta
n= 6 brown n=14 yellow
n= 7 light grey n=15 white

note: the first E in the sequences stands for ESC (0x1b)

AUTHORS

Soren Schmidt <sos@FreeBSD.org>

BSD October 6, 2000

BSD