xref: /freebsd/share/man/man4/screen.4 (revision ae83180158c4c937f170e31eff311b18c0286a93)
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 is also supported.
60.Pp
61.Bd -literal
62ANSI	Seq	Function				Termcap entry
63======= ======= =====================================   ==============
64
65--	E7	Save cursor position			sc
66
67--	E8	Restore	saved cursor position		rc
68
69--	Ec	Reset					rs
70
71--	EM	move cursor up 1 line,			--
72		scroll if at top
73
74CUU     E[nA    move cursor up n lines                  up/UP (ku)
75
76CUD     E[nB    move cursor down n lines                do/DO (kd)
77
78CUF     E[nC    move cursor right n characters          nd/RI (kr)
79
80CUB     E[nD    move cursor left n characters           --/LE (kl)
81
82HPA     E[n`    move cursor to character position n     ch
83
84HPR	E[na	move cursor right n characters 		--
85
86VPA     E[nd    move cursor to line n                   cv
87
88VPR	E[ne	move cursor down n lines		--
89
90CPL     E[nF    move cursor to start of line,           -- (@7)
91		n lines up
92
93CNL     E[nE    move cursor to start of line,           nw
94		n lines down
95
96CUP	E[y;xH	Move cursor to x, y			cm
97
98HVP	E[y;xf	Move cursor to x, y			--
99
100CBT     E[nZ    Move cursor back n tab stops            bt (kB)
101
102IL      E[nL    Insert n blank lines                    al/AL
103
104ICH     E[n@    Insert n blank characters               ic/IC
105
106DL      E[nM    Delete n lines                          dl/DL
107
108DCH     E[nP    Delete n characters                     dc/DC
109
110ED	E[nJ	Erase part or all of display:		cd
111		n=0 from cursor to end of display,
112		n=1 from begin of display to cursor,
113		n=2 entire display.
114
115EL	E[nK	Erase part or all of line:		ce
116		n=0 from cursor to end of line,
117		n=1 from begin of line to cursor,
118		n=2 entire line.
119
120ECH     E[nX    Erase n characters                      ec
121
122SU      E[nS    Scroll display n lines up (forward)     sf/SF
123
124SD      E[nT    Scroll display n lines down (reverse)   sr/SR
125
126
127SGR	E[nm	Set character attributes:		--
128		n= 0  normal attribute (all off)
129		n= 1  bold (highlight)
130		n= 4  underscore (if supported by HW)
131		n= 5  blink (if supported by HW)
132		n= 7  reverse
133		n= 22 remove bold
134		n= 24 remove underscore
135		n= 25 remove blink
136		n= 27 remove reverse
137		n= 3X set ANSI foreground color
138		      (see table)
139		n= 4X set ANSI background color
140		      (see table)
141
142		   X=0 black 	X=1 red
143		   X=2 green	X=3 brown
144		   X=4 blue	X=5 magenta
145		   X=6 cyan	X=7 light grey
146		   X=9 reset to the normal color
147
148--	E[s	Save cursor position			sc
149
150--	E[u	Restore	saved cursor position		rc
151
152--      E[x     Reset normal colors and attributes      --
153		to their default values
154
155--	E[nz	Switch to virtual console n		--
156
157--      E[1;nx  Set normal ANSI background color        --
158		to n (see table)
159
160--      E[2;nx  Set normal ANSI foreground color        --
161		to n (see table)
162
163--      E[3;nx  Set normal video attribute directly     --
164		to n (n	from 0 to 255)
165
166--      E[5;nx  Set normal ANSI reverse background      --
167		color to n (see	table)
168
169--      E[6;nx  Set normal ANSI reverse foreground      --
170		color to n (see	table)
171
172		   n= 0	black	   n= 8	dark grey
173		   n= 1	red	   n= 9	light red
174		   n= 2	green	   n=10	light green
175		   n= 3	brown	   n=11	yellow
176		   n= 4	blue	   n=12	light blue
177		   n= 5	magenta	   n=13	light magenta
178		   n= 6	cyan	   n=14	light cyan
179		   n= 7	light grey n=15	white
180
181--      E[7;nx  Set normal reverse video attribute      --
182		directly to n (n from 0	to 255)
183
184--	E[=p;dB	Set bell pitch (p) and duration (d),	--
185			pitch is in units of 840 nS,
186			duration is units of 0,1 S.
187
188--	E[=tC	Set global cursor type (see table)	--
189
190		   t=0 normal non-blinking
191		   t=1 normal blinking
192		   t=2 custom non-blinking
193		   t=3 custom blinking
194		   t=4 reset cursor (resets custom
195		       cursor shape and sets current
196		       cursor type to 0)
197		   t=5 hide cursor
198
199--	E[=s;eC	Set custom cursor shape, where		--
200		s is the starting and e is the ending
201		scanlines of the cursor.
202
203--	E[=s;e;dC					--
204		Same as above, except d specifies the
205		direction.  If 0, scanlines are counted
206		from the top to the bottom.  If 1, from
207		the bottom to the top.
208
209--	E[=tS	Set local cursor type (see table)	--
210
211		   t=0 normal (global)			ve
212		   t=1 invisible			vi
213		   t=2 very visible			vs
214
215--      E[=nA   Set the border color to n               --
216		(see table) (if supported by HW)
217
218--      E[=nF   Set normal foreground color to n        --
219		(see table)
220
221--      E[=nG   Set normal background color to n        --
222		(see table)
223
224--      E[=nH   Set normal reverse foreground color     --
225		to n (see table)
226
227--      E[=nI   Set normal reverse background color     --
228		to n (see table)
229
230		   n= 0	black	   n= 8	dark grey
231		   n= 1	blue	   n= 9	light blue
232		   n= 2	green	   n=10	light green
233		   n= 3	cyan	   n=11	light cyan
234		   n= 4	red	   n=12	light red
235		   n= 5	magenta	   n=13	light magenta
236		   n= 6	brown	   n=14	yellow
237		   n= 7	light grey n=15	white
238
239note: the first E in the sequences stands for ESC (0x1b)
240.Ed
241.Sh AUTHORS
242.An S\(/oren Schmidt Aq sos@FreeBSD.org
243