xref: /freebsd/share/man/man4/screen.4 (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1.\"
2.\" $FreeBSD$
3.\"
4.Dd October 6, 2000
5.Dt SCREEN 4
6.Os
7.Sh NAME
8.Nm screen
9.Nd pc display interface
10.Sh DESCRIPTION
11Access to the
12.Em virtual consoles
13are obtained through the device files
14.Pa /dev/ttyv0
15-
16.Pa /dev/ttyvb .
17Each of these files correspond to a separate
18virtual console.
19All virtual console devices can be open at once, but only one is
20active at a time.
21The active virtual console "owns" the keyboard and
22display screen.
23.Pp
24Output to a virtual console that not currently is on the display is
25saved in a buffer that holds a "screenfull" (normally 25) lines.
26Any output written to
27.Pa /dev/console
28(the original console device) is echoed to
29.Pa /dev/ttyv0 .
30.Pp
31To switch between the virtual consoles one uses the sequence
32.Em ALT+Fn ,
33which means hold down ALT and press one of the function keys.
34The
35virtual console with the same number as the function key is then
36selected as the current virtual console, and given exclusive use of
37the keyboard and display.
38This switch sequence can be changed via
39the keyboard mapping ioctl call (see
40.Xr keyboard 4 ) .
41.Pp
42The console allows entering values that are not physically
43present on the keyboard via a special keysequence.
44To use this facility press and hold down ALT,
45then enter a decimal number from 0-255 via the numerical keypad, then
46release ALT.
47The entered value is then used as the ASCII value for one
48character.
49This way it is possible to enter any ASCII value.
50The console driver also includes a history function.
51It is activated by
52pressing the scroll-lock key.
53This holds the display, and enables the cursor
54arrows for scrolling up and down through the last scrolled out lines.
55.Pp
56The console understands a subset of the ANSI x3.64 character
57sequences.
58For compatibility with the old pccons, the PC3 character
59sequences are also supported.
60.Bd -literal
61ANSI	Seq	Function				Termcap entry
62======= ======= =====================================   ==============
63
64--	E7	Save cursor position			sc
65
66--	E8	Restore	saved cursor position		rc
67
68--	Ec	Reset					rs
69
70--	EM	move cursor up 1 line,			--
71		scroll if at top
72
73CUU     E[nA    move cursor up n lines                  up/UP (ku)
74
75CUD     E[nB    move cursor down n lines                do/DO (kd)
76
77CUF     E[nC    move cursor right n characters          nd/RI (kr)
78
79CUB     E[nD    move cursor left n characters           --/LE (kl)
80
81HPA     E[n`    move cursor to character position n     ch
82
83HPR	E[na	move cursor right n characters 		--
84
85VPA     E[nd    move cursor to line n                   cv
86
87VPR	E[ne	move cursor down n lines		--
88
89CPL     E[nF    move cursor to start of line,           -- (@7)
90		n lines up
91
92CNL     E[nE    move cursor to start of line,           nw
93		n lines down
94
95CUP	E[y;xH	Move cursor to x, y			cm
96
97HVP	E[y;xf	Move cursor to x, y			--
98
99CBT     E[nZ    Move cursor back n tab stops            bt (kB)
100
101IL      E[nL    Insert n blank lines                    al/AL
102
103ICH     E[n@    Insert n blank characters               ic/IC
104
105DL      E[nM    Delete n lines                          dl/DL
106
107DCH     E[nP    Delete n characters                     dc/DC
108
109ED	E[nJ	Erase part or all of display:		cd
110		n=0 from cursor to end of display,
111		n=1 from begin of display to cursor,
112		n=2 entire display.
113
114EL	E[nK	Erase part or all of line:		ce
115		n=0 from cursor to end of line,
116		n=1 from begin of line to cursor,
117		n=2 entire line.
118
119ECH     E[nX    Erase n characters                      ec
120
121SU      E[nS    Scroll display n lines up (forward)     sf/SF
122
123SD      E[nT    Scroll display n lines down (reverse)   sr/SR
124
125
126SGR	E[nm	Set character attributes:		--
127		n= 0  normal attribute (all off)
128		n= 1  bold (highlight)
129		n= 4  underscore (if supported by HW)
130		n= 5  blink (if supported by HW)
131		n= 7  reverse
132		n= 22 remove bold
133		n= 24 remove underscore
134		n= 25 remove blink
135		n= 27 remove reverse
136		n= 3X set ANSI foreground color
137		      (see table)
138		n= 4X set ANSI background color
139		      (see table)
140
141		   X=0 black 	X=1 red
142		   X=2 green	X=3 brown
143		   X=4 blue	X=5 magenta
144		   X=6 cyan	X=7 light grey
145		   X=9 reset to the normal color
146
147--	E[s	Save cursor position			sc
148
149--	E[u	Restore	saved cursor position		rc
150
151--      E[x     Reset normal colors and attributes      --
152		to their default values
153
154--	E[nz	Switch to virtual console n		--
155
156--      E[1;nx  Set normal ANSI background color        --
157		to n (see table)
158
159--      E[2;nx  Set normal ANSI foreground color        --
160		to n (see table)
161
162--      E[3;nx  Set normal video attribute directly     --
163		to n (n	from 0 to 255)
164
165--      E[5;nx  Set normal ANSI reverse background      --
166		color to n (see	table)
167
168--      E[6;nx  Set normal ANSI reverse foreground      --
169		color to n (see	table)
170
171		   n= 0	black	   n= 8	dark grey
172		   n= 1	red	   n= 9	light red
173		   n= 2	green	   n=10	light green
174		   n= 3	brown	   n=11	yellow
175		   n= 4	blue	   n=12	light blue
176		   n= 5	magenta	   n=13	light magenta
177		   n= 6	cyan	   n=14	light cyan
178		   n= 7	light grey n=15	white
179
180--      E[7;nx  Set normal reverse video attribute      --
181		directly to n (n from 0	to 255)
182
183--	E[=p;dB	Set bell pitch (p) and duration (d),	--
184			pitch is in units of 840 nS,
185			duration is units of 0,1 S.
186
187--	E[=tC	Set global cursor type (see table)	--
188
189		   t=0 normal non-blinking
190		   t=1 normal blinking
191		   t=2 custom non-blinking
192		   t=3 custom blinking
193		   t=4 reset cursor (resets custom
194		       cursor shape and sets current
195		       cursor type to 0)
196		   t=5 hide cursor
197
198--	E[=s;eC	Set custom cursor shape, where		--
199		s is the starting and e is the ending
200		scanlines of the cursor.
201
202--	E[=s;e;dC					--
203		Same as above, except d specifies the
204		direction.  If 0, scanlines are counted
205		from the top to the bottom.  If 1, from
206		the bottom to the top.
207
208--	E[=tS	Set local cursor type (see table)	--
209
210		   t=0 normal (global)			ve
211		   t=1 invisible			vi
212		   t=2 very visible			vs
213
214--      E[=nA   Set the border color to n               --
215		(see table) (if supported by HW)
216
217--      E[=nF   Set normal foreground color to n        --
218		(see table)
219
220--      E[=nG   Set normal background color to n        --
221		(see table)
222
223--      E[=nH   Set normal reverse foreground color     --
224		to n (see table)
225
226--      E[=nI   Set normal reverse background color     --
227		to n (see table)
228
229		   n= 0	black	   n= 8	dark grey
230		   n= 1	blue	   n= 9	light blue
231		   n= 2	green	   n=10	light green
232		   n= 3	cyan	   n=11	light cyan
233		   n= 4	red	   n=12	light red
234		   n= 5	magenta	   n=13	light magenta
235		   n= 6	brown	   n=14	yellow
236		   n= 7	light grey n=15	white
237
238note: the first E in the sequences stands for ESC (0x1b)
239.Ed
240.Sh AUTHORS
241.An S\(/oren Schmidt Aq Mt sos@FreeBSD.org
242