Subversion Repositories planix.SVN

.TH VNC 1

.SH NAME

vncs, vncv \- remote frame buffer server and viewer for Virtual Network Computing (VNC)

.SH SYNOPSIS

.B vncs

[

.B -v

]

[

.B -c

.I cert

]

[

.B -d

.BI : display

]

[

.B -g

.IB width x height

]

[

.B -p

.I pixfmt

]

[

.B -x

.I net

]

[

.I cmd

[

.I args

...

]

]

.PP

.B vncs

.B -k

.BI : display

[

.B -x

.I net

]

.PP

.B vncv

[

.B -cstv

]

[

.B -e

.I encodings

]

[

.B -k

.I keypattern

]

.IR host [\fL: n ]

.SH DESCRIPTION

VNC is a lightweight protocol

for accessing graphical applications

remotely.  The protocol allows one or more

clients to connect to a server.

While connected, clients display the frame buffer

presented by the server and can send mouse events,

keyboard events, and exchange snarf buffers.

The server persists across viewer sessions, so that

the virtual application can be accessed from various locations

as its owner moves around.

.PP

VNC displays have names of the form

.IB host : n \fR,

where

.I host

is the machine's network name and

.I n

is a small integer identifier; display

.I n

is served on TCP port

.RI 5900+ n .

.PP

.I Vncs

starts a new virtual frame buffer in memory, simulating

a Plan 9 terminal running

.I cmd

.IR args ,

by default an interactive shell.

As viewers connect, each is authenticated using a 

(rather breakable) challenge-response protocol using

the user's Inferno/POP password.

.PP

The options are:

.TF "\fL-p \fIpixfmt"

.PD

.TP

.B -c \fIcert

start TLS on each viewer connection using the certificate

in the file

.IR cert .

The corresponding private key must be loaded into

the server's

.IR factotum (4).

When serving TLS connections, the base port is

35729 rather than 5900.

.TP

.B -d :\fIn

run on display

.I n ;

without this option, the server searches

for an unused display.

.TP

.B -g \fIwidth\fBx\fIheight\fR

set the virtual frame buffer to be

.IB width x height

(default

1024x768)

pixels.

.TP

.B -p \fIpixfmt

set the virtual frame buffer's internal pixel format to

.I pixfmt

(default

.BR r5g6b5 ).

.TP

.B -v

print verbose output to standard error.

.TP

.B -x \fInet

announce on an alternate network interface.

Because of the weak authentication protocol and

default lack of encryption, this option must

be accompanied by

.BR -c .

.PD

.PP

The command

.B vncs

.B -k

.BI : n

kills the VNC server running on display

.IR n .

.PP

.I Vncv

provides access to remote display

.IB host : n \fR.

It resizes its window to be the smaller of the

remote frame buffer size and the local screen.

.PP

The options are:

.TP

.B -c

when connecting to 8-bit displays, request

.B r4g4b4

pixels rather than 

.B r3g3b2

pixels.

This takes up more bandwidth but usually gives

significantly better matching to the Plan 9 color map.

.TP

.B -e \fIencodings

set the ordered list of allowed frame buffer update encodings.

The default (and full) set is

.B copyrect

.B corre

.B hextile

.B rre

.BR raw .

The encodings should be given as a single space-separated argument

(quoted when using the shell).

.TP

.B -k \fIkeypattern

add 

.I keypattern

to the pattern used to select a key from 

.IR factotum (4).

.TP

.B -s

share the display with extant viewers;

by default extant viewers are closed

when a new viewer connects.

.TP

.B -t

start TLS on the connection.

.TP

.B -v

print verbose output to standard error.

.PD

.PP

The VNC protocol represents keyboard input as

key up/down events.

Plan 9 does not expose the state of the

Ctl and Shift keys except as it can be inferred

from receipt of control or shifted characters.

It does not expose the state of the Alt key at all,

since the Alt key is used to compose Unicode characters

(see

.IR keyboard (6)).

.I Vncv

correctly handles the sending of control and shifted

characters.

To support systems that use key sequences like Alt-X

(or worse, Alt-mouse-click), typing the Plan 9 compose

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.

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.

.PP

.I Vncv

does no verification of the TLS certificate presented

by the server.

.PP

.I Vncv

supports only version 3.3 of the RFB protocol.