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Annotated edit history of vcsa(4) version 1, including all changes. View license author blame.
Rev Author # Line
1 perry 1 VCS
2 !!!VCS
3 NAME
4 DESCRIPTION
5 EXAMPLES
6 FILES
7 AUTHOR
8 HISTORY
9 SEE ALSO
10 ----
11 !!NAME
12
13
14 vcs, vcsa - virtual console memory
15 !!DESCRIPTION
16
17
18 __/dev/vcs0__ is a character device with major number 7
19 and minor number 0, usually of mode 0644 and owner root.tty.
20 It refers to the memory of the currently displayed virtual
21 console terminal.
22
23
24 __/dev/vcs[[1-63]__ are character devices for virtual
25 console terminals, they have major number 7 and minor number
26 1 to 63, usually mode 0644 and owner root.tty.
27 __/dev/vcsa[[0-63]__ are the same, but including
28 attributes, and prefixed with four bytes giving the screen
29 dimensions and cursor position: ''lines'',
30 ''columns'', ''x'', ''y''. (''x'' = ''y'' = 0
31 at the top left corner of the screen.)
32
33
34 These replace the screendump ''ioctl''s of
35 console(4), so the system administrator can control
36 access using file system permissions.
37
38
39 The devices for the first eight virtual consoles may be
40 created by:
41
42
43 for x in 0 1 2 3 4 5 6 7 8; do
44 mknod -m 644 /dev/vcs$x c 7 $x;
45 mknod -m 644 /dev/vcsa$x c 7 $[[$x+128];
46 done
47 chown root:tty /dev/vcs*
48 No ''ioctl''() requests are supported.
49 !!EXAMPLES
50
51
52 You may do a screendump on vt3 by switching to vt1 and
53 typing ''cat /dev/vcs3 ''. Note that the output
54 does not contain newline characters, so some processing may
55 be required, like in ''fold -w 81 /dev/vcs3 | lpr'' or
56 (horrors) ''setterm -dump 3 -file
57 /proc/self/fd/1''.
58
59
60 The ''/dev/vcsa0'' device is used for Braille
61 support.
62
63
64 This program displays the character and screen attributes
65 under the cursor of the second virtual console, then changes
66 the background color there:
67
68
69 #include
70 !!FILES
71
72
73 /dev/vcs[[0-63]
74 /dev/vcsa[[0-63]
75 !!AUTHOR
76
77
78 Andries Brouwer
79 !!HISTORY
80
81
82 Introduced with version 1.1.92 of the Linux
83 kernel.
84 !!SEE ALSO
85
86
87 console(4), tty(4), ttys(4),
88 selection(1)
89 ----
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