1X0VNCSERVER(1)                  TigerVNC Manual                 X0VNCSERVER(1)
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NAME

6       x0vncserver - TigerVNC Server for X displays
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SYNOPSIS

9       x0vncserver [options]
10       x0vncserver -version
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DESCRIPTION

13       x0vncserver  is  a  TigerVNC  Server which makes any X display remotely
14       accessible via VNC, TigerVNC or compatible viewers.  Unlike Xvnc(1), it
15       does not create a virtual display.  Instead, it just shares an existing
16       X server (typically, that one connected to the physical screen).
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18       XDamage will be used if the existing X server  supports  it.  Otherwise
19       x0vncserver will fall back to polling the screen for changes.
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OPTIONS

23       x0vncserver  interprets  the  command line as a list of parameters with
24       optional values.  Running x0vncserver -h will show a list of all  valid
25       parameters  with  short descriptions.  All parameters are optional, but
26       normally you would have to use  the  PasswordFile  parameter  (see  its
27       description below).
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29       There  are  several  forms of specifying parameters in the command line
30       (here we use `SomeParameter' as an example parameter name):
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32
33       -SomeParameter
34              Enable the parameter, turn the feature on.   This  form  can  be
35              used with parameters that simply enable or disable some feature.
36
37       -SomeParameter=0
38              Disable the parameter, turn the feature off.
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40       -SomeParameter=value
41              Assign  the  specified value to the parameter.  The leading dash
42              can be omitted, or it can be doubled if desired  (like  in  GNU-
43              style long options).
44
45       Parameter  names  are case-insensitive, their order in the command line
46       can be arbitrary.
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PARAMETERS

50       -display display
51              The X display name.  If not specified, it defaults to the  value
52              of the DISPLAY environment variable.
53
54       -rfbport port
55              Specifies  the TCP port on which x0vncserver listens for connec‐
56              tions from viewers (the protocol used in VNC  is  called  RFB  -
57              "remote framebuffer").  The default port is 5900.
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59       -UseIPv4
60              Use IPv4 for incoming and outgoing connections. Default is on.
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62       -UseIPv6
63              Use IPv6 for incoming and outgoing connections. Default is on.
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65       -rfbunixpath path
66              Specifies  the path of a Unix domain socket on which x0vncserver
67              listens for connections from viewers, instead of listening on  a
68              TCP port.
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70       -rfbunixmode mode
71              Specifies  the  mode  of the Unix domain socket.  The default is
72              0600.
73
74       -Log logname:dest:level
75              Configures the  debug  log  settings.   dest  can  currently  be
76              stderr,  stdout  or  syslog, and level is between 0 and 100, 100
77              meaning most verbose output.  logname is usually * meaning  all,
78              but  you  can target a specific source file if you know the name
79              of its "LogWriter".  Default is *:stderr:30.
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81       -HostsFile filename
82              This parameter allows to specify a file name with IP access con‐
83              trol  rules.  The file should include one rule per line, and the
84              rule format is one of  the  following:  +address/prefix  (accept
85              connections  from  the specified address group), -address/prefix
86              (reject connections) or ?address/prefix (query the local  user).
87              The  first rule matching the IP address determines the action to
88              be performed.  Rules that include only an action sign (+,  -  or
89              ?)  will match any IP address.  Prefix is optional and is speci‐
90              fied as a number of bits (e.g. /24).  Default is to accept  con‐
91              nections from any IP address.
92
93       -SecurityTypes sec-types
94              Specify  which  security scheme to use for incoming connections.
95              Valid values are a comma separated list of None, VncAuth, Plain,
96              TLSNone,  TLSVnc,  TLSPlain,  X509None,  X509Vnc  and X509Plain.
97              Default is VncAuth,TLSVnc.
98
99       -rfbauth passwd-file, -PasswordFile passwd-file
100              Password file for VNC authentication.  There is no default,  you
101              should  specify  the  password  file  explicitly.  Password file
102              should be created with the vncpasswd(1) utility.   The  file  is
103              accessed  each  time a connection comes in, so it can be changed
104              on the fly.
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106       -Password password
107              Obfuscated binary encoding of the password  which  clients  must
108              supply  to access the server.  Using this parameter is insecure,
109              use PasswordFile parameter instead.
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111       -PlainUsers user-list
112              A comma separated list of user names that are allowed to authen‐
113              ticate  via  any of the "Plain" security types (Plain, TLSPlain,
114              etc.). Specify * to allow any user to  authenticate  using  this
115              security type. Default is to deny all users.
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117       -pam_service name, -PAMService name
118              PAM  service  name to use when authentication users using any of
119              the "Plain" security types. Default is vnc.
120
121       -X509Cert path
122              Path to a X509 certificate in PEM format to be used for all X509
123              based security types (X509None, X509Vnc, etc.).
124
125       -X509Key path
126              Private  key  counter part to the certificate given in X509Cert.
127              Must also be in PEM format.
128
129       -GnuTLSPriority priority
130              GnuTLS priority string that controls the TLS session’s handshake
131              algorithms.   See the GnuTLS manual for possible values. Default
132              is NORMAL.
133
134       -UseBlacklist
135              Temporarily reject connections from  a  host  if  it  repeatedly
136              fails to authenticate. Default is on.
137
138       -BlacklistThreshold count
139              The  number  of unauthenticated connection attempts allowed from
140              any individual host before that host is  black-listed.   Default
141              is 5.
142
143       -BlacklistTimeout seconds
144              The  initial  timeout applied when a host is first black-listed.
145              The host  cannot  re-attempt  a  connection  until  the  timeout
146              expires.  Default is 10.
147
148       -QueryConnect
149              Prompts  the  user of the desktop to explicitly accept or reject
150              incoming connections. Default is off.
151
152       -QueryConnectTimeout seconds
153              Number of seconds to show the Accept  Connection  dialog  before
154              rejecting the connection.  Default is 10.
155
156       -localhost
157              Only  allow connections from the same machine. Useful if you use
158              SSH and want to stop non-SSH connections from any other hosts.
159
160       -AlwaysShared
161              Always treat incoming connections as shared, regardless  of  the
162              client-specified setting. Default is off.
163
164       -NeverShared
165              Never  treat  incoming  connections as shared, regardless of the
166              client-specified setting. Default is off.
167
168       -DisconnectClients
169              Disconnect existing clients if an incoming  connection  is  non-
170              shared. Default is on. If DisconnectClients is false, then a new
171              non-shared connection will be refused while there  is  a  client
172              active.   When  combined  with  NeverShared  this means only one
173              client is allowed at a time.
174
175       -AcceptKeyEvents
176              Accept key press and release events from clients. Default is on.
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178       -AcceptPointerEvents
179              Accept pointer press and release events from clients. Default is
180              on.
181
182       -AcceptSetDesktopSize
183              Accept  requests  to  resize the size of the desktop. Default is
184              on.
185
186       -RemapKeys mapping
187              Sets up a keyboard mapping.  mapping is a comma-separated string
188              of   character   mappings,  each  of  the  form  char->char,  or
189              char<>char, where char is a hexadecimal keysym. For example,  to
190              exchange the " and @ symbols you would specify the following:
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192                 RemapKeys=0x22<>0x40
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194       -RawKeyboard
195              Send  keyboard events straight through and avoid mapping them to
196              the current keyboard layout. This effectively makes the keyboard
197              behave  according to the layout configured on the server instead
198              of the layout configured on the client. Default is off.
199
200       -Protocol3.3
201              Always use protocol version 3.3 for backwards compatibility with
202              badly-behaved clients. Default is off.
203
204       -Geometry geometry
205              This  option specifies the screen area that will be shown to VNC
206              clients.  The format is widthxheight+xoffset+yoffset , where `+'
207              signs can be replaced with `-' signs to specify offsets from the
208              right and/or  from  the  bottom  of  the  screen.   Offsets  are
209              optional,  +0+0 is assumed by default (top left corner).  If the
210              argument is empty, full screen is shown to VNC clients (this  is
211              the default).
212
213       -MaxProcessorUsage percent
214              Maximum  percentage  of CPU time to be consumed when polling the
215              screen.  Default is 35.
216
217       -PollingCycle milliseconds
218              Milliseconds per one polling  cycle.   Actual  interval  may  be
219              dynamically   adjusted  to  satisfy  MaxProcessorUsage  setting.
220              Default is 30.
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222       -FrameRate fps
223              The maximum number of updates per second sent to each client. If
224              the  screen updates any faster then those changes will be aggre‐
225              gated and sent in a single update to the client. Note that  this
226              only controls the maximum rate and a client may get a lower rate
227              when resources are limited. Default is 60.
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229       -CompareFB mode
230              Perform pixel comparison on framebuffer  to  reduce  unnecessary
231              updates.  Can be either 0 (off), 1 (always) or 2 (auto). Default
232              is 2.
233
234       -UseSHM
235              Use MIT-SHM extension if available.  Using that extension accel‐
236              erates reading the screen.  Default is on.
237
238       -ZlibLevel level
239              Zlib  compression  level  for  ZRLE encoding (it does not affect
240              Tight  encoding).   Acceptable  values  are  between  0  and  9.
241              Default is to use the standard compression level provided by the
242              zlib(3) compression library.
243
244       -ImprovedHextile
245              Use improved compression algorithm for  Hextile  encoding  which
246              achieves better compression ratios by the cost of using slightly
247              more CPU time.  Default is on.
248
249       -IdleTimeout seconds
250              The number of seconds after which an idle VNC connection will be
251              dropped.   Default  is 0, which means that idle connections will
252              never be dropped.
253
254       -MaxDisconnectionTime seconds
255              Terminate when no client  has  been  connected  for  N  seconds.
256              Default is 0.
257
258       -MaxConnectionTime seconds
259              Terminate  when  a  client  has  been  connected  for N seconds.
260              Default is 0.
261
262       -MaxIdleTime seconds
263              Terminate after N seconds of user inactivity.  Default is 0.
264
265       -ClientWaitTimeMillis time
266              Time in milliseconds to wait for a viewer which is blocking  the
267              server.  This is necessary because the server is single-threaded
268              and sometimes blocks until the viewer has  finished  sending  or
269              receiving  a  message  -  note that this does not mean an update
270              will be aborted after this time.  Default is 20000 (20 seconds).
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272       -AcceptCutText
273       -SendCutText
274       -MaxCutText
275              Currently unused.
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SEE ALSO

279       Xvnc(1), vncpasswd(1),
280       https://www.tigervnc.org/
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282

AUTHOR

284       Constantin Kaplinsky and others.
285
286       VNC was originally developed by the  RealVNC  team  while  at  Olivetti
287       Research  Ltd  /  AT&T Laboratories Cambridge.  TightVNC additions were
288       implemented by Constantin Kaplinsky. Many other people have since  par‐
289       ticipated  in  development, testing and support. This manual is part of
290       the TigerVNC software suite.
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294TigerVNC                                                        X0VNCSERVER(1)
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