.TH VNC 1
.SH NAME
vncs, vncv \- remote frame buffer server and viewer for Virtual Network Computing (VNC)
.SH SYNOPSIS
.B vncs
[
.B -v ] [ -g
.I width
.B X
.I height
.B ]
.B [ -d
.I :display
.B ] 
.B [command [args ...]]
.PP
.B vncs -k
.I :display
.PP
.B vncv
[
.B -e
.I encodings
]
[
.B -csv
]
.IR host [\fL: n ]
.SH DESCRIPTION
.I vncs
starts a new virtual frame buffer in memory and waits for connections from remote viewers.
Each viewer is authenticated using challenge and response. APOP password is used as the
private key. A display number 
.I :n
in the global name space is printed to stderr. A viewer must use the same display number 
in order to contact the desired server. Multiple VNC servers can co-exist on the same host,
each with a unique display number.
.PP
One frame buffer can have simultaneous viewers if the viewers are started with the -s option,
see below. Otherwise, starting a new viewer would cause the server to disconnect from all 
existing viewers. Killing the viewers will not affect the remote server. Therefore, the same desktop
can migrate from one location to another without restarting the window system.
.PP
The server options are:
.TP
.B -v
causes verbose output to stderr.
.TP
.B -g " widthXheight
specifies the frame buffer geometry. Default is 1024x768. The depth is fixed
at 16 bits per pixel (r5g6b5).
.TP
.B -d 
chooses a display number
.RI : n .
The server aborts if the display is not available. If not specified, the server hunts for 
the first available on that host interface.
.TP
.I command [args ...]
By default, the server starts with a terminal similar to that of drawterm. RC is
executed on behalf of the owner of the vncs process. The user can specify any program
to start the VNC server, e.g. rio.
.TP
.B -k " :display
shutdown the VNC server and all of its connected clients on 
.RI : display .
Note, kill vncs | rc will kill ALL servers running on that host.
.PP
.I Vncv
provides access to remote frame buffer
.I n
on 
.I host
using the VNC (Virtual Network Computing)
protocol.
It resizes its window to be the smaller of the
remote frame buffer size and the local screen.
.PP
The 
.B -e
option specifies an ordered list of rectangle
encodings to allow in the protocol.
The default (and full set) is 
.IP
.EX
copyrect corre hextile rre raw
.EE
.PP
By default, connecting to a display closes 
any other connections to that display.
The
.B -s
option allows the other connections to share the display.
.PP
The
.B -v
option causes verbose output.
.PP
.I Vncv
negotiates with the VNC server to settle on a true-color pixel format.
For true-color displays, this is the native display pixel format.
On eight bit color-mapped displays,
.I vncv
requests 
.B r3g3b2
pixels and upon receipt translates them to the nearest
color in the map.
This does not cover the color map particularly well.
When invoked with the
.B -c
option,
.I vncv
requests
.B r4g4b4
pixels instead.  This consumes more bandwidth
but results in better matching to the available colors.
.PP
.I Vncv
correctly handles the typing of control characters
and shifted keystrokes.
To support systems that require the use
of modifiers like Alt, Ctl, and Shift on
things like mouse events,
typing the sequences
.B Alt
.B Z
.B A
(for Alt), 
.B Alt
.B Z
.B C
(for Ctrl),
and
.B Alt
.B Z
.B S
(for Shift)
will send a ``key down'' message for
the given key (see
.IR keyboard (6)).
A corresponding ``key up'' message
will be sent after the next key is pressed,
or when the sequence is retyped,
whichever happens first.
.SH SOURCE
.B /sys/src/cmd/vnc
.SH "SEE ALSO
.IR drawterm (8)
.br
.B http://www.uk.research.att.com/vnc
.SH BUGS
If the remote frame buffer is larger than the local screen,
only the upper left corner can be accessed.