diff --git a/man4/vcs.4 b/man4/vcs.4 index 365663258..49cf6964d 100644 --- a/man4/vcs.4 +++ b/man4/vcs.4 @@ -30,28 +30,40 @@ .SH NAME vcs, vcsa \- virtual console memory .SH DESCRIPTION -\fI/dev/vcs0\fP is a character device with major number 7 and minor number +.I /dev/vcs0 +is a character device with major number 7 and minor number 0, usually of mode 0644 and owner root.tty. It refers to the memory of the currently displayed virtual console terminal. .LP -\fI/dev/vcs[1\-63]\fP are character devices for virtual console +.I /dev/vcs[1\-63] +are character devices for virtual console terminals, they have major number 7 and minor number 1 to 63, usually mode 0644 and owner root.tty. -\fI/dev/vcsa[0\-63]\fP are the same, but +.IR /dev/vcsa[0\-63] +are the same, but using .IR "unsigned short" s (in host byte order) that include attributes, and prefixed with four bytes giving the screen -dimensions and cursor position: \fIlines\fP, \fIcolumns\fP, \fIx\fP, \fIy\fP. -(\fIx\fP = \fIy\fP = 0 at the top left corner of the screen.) +dimensions and cursor position: +.IR lines , +.IR columns , +.IR x , +.IR y . +.RI ( x += +.I y += 0 at the top left corner of the screen.) When a 512-character font is loaded, the 9th bit position can be fetched by applying the .BR ioctl (2) -\fBVT_GETHIFONTMASK\fP operation +.B VT_GETHIFONTMASK +operation (available in Linux kernels 2.6.18 and above) -on \fI/dev/tty[1\-63]\fP; +on +.IR /dev/tty[1\-63] ; the value is returned in the .I "unsigned short" pointed to by the third @@ -88,13 +100,23 @@ requests are supported. Introduced with version 1.1.92 of the Linux kernel. .SH EXAMPLE You may do a screendump on vt3 by switching to vt1 and typing -\fIcat /dev/vcs3 >foo\fP. + + cat /dev/vcs3 >foo + Note that the output does not contain newline characters, so some processing may be required, like -in \fIfold \-w 81 /dev/vcs3 | lpr\fP or (horrors) -\fIsetterm \-dump 3 \-file /proc/self/fd/1\fP. +in + + old \-w 81 /dev/vcs3 | lpr + +or (horrors) + + xetterm \-dump 3 \-file /proc/self/fd/1 + .LP -The \fI/dev/vcsa0\fP device is used for Braille support. +The +.I /dev/vcsa0 +device is used for Braille support. This program displays the character and screen attributes under the cursor of the second virtual console, then changes the background color