1X0VNCSERVER(1) TigerVNC Manual X0VNCSERVER(1)
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6 x0vncserver - TigerVNC Server for X displays
7
9 x0vncserver [options]
10 x0vncserver -version
11
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).
17 XDamage will be used if the existing X server supports it. Otherwise
19 x0vncserver will fall back to polling the screen for changes.
20
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).
28 There are several forms of specifying parameters in the command line
30 (here we use `SomeParameter' as an example parameter name):
31 -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 -SomeParameter=0
38 Disable the parameter, turn the feature off.
39 -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 Parameter names are case-insensitive, their order in the command line
46 can be arbitrary.
47
50 -display display
51 The X display name. If not specified, it defaults to the value
52 of the DISPLAY environment variable.
53 -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.
58 -UseIPv4
60 Use IPv4 for incoming and outgoing connections. Default is on.
61 -UseIPv6
63 Use IPv6 for incoming and outgoing connections. Default is on.
64 -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.
69 -rfbunixmode mode
71 Specifies the mode of the Unix domain socket. The default is
72 0600.
73 -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.
80 -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 -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 -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.
105 -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.
110 -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.
116 -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 -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 -X509Key path
126 Private key counter part to the certificate given in X509Cert.
127 Must also be in PEM format.
128 -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 -UseBlacklist
135 Temporarily reject connections from a host if it repeatedly
136 fails to authenticate. Default is on.
137 -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 -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 -QueryConnect
149 Prompts the user of the desktop to explicitly accept or reject
150 incoming connections. Default is off.
151 -QueryConnectTimeout seconds
153 Number of seconds to show the Accept Connection dialog before
154 rejecting the connection. Default is 10.
155 -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 -AlwaysShared
161 Always treat incoming connections as shared, regardless of the
162 client-specified setting. Default is off.
163 -NeverShared
165 Never treat incoming connections as shared, regardless of the
166 client-specified setting. Default is off.
167 -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 -AcceptKeyEvents
176 Accept key press and release events from clients. Default is on.
177 -AcceptPointerEvents
179 Accept pointer press and release events from clients. Default is
180 on.
181 -AcceptSetDesktopSize
183 Accept requests to resize the size of the desktop. Default is
184 on.
185 -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:
191 RemapKeys=0x22<>0x40
193 -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 -Protocol3.3
201 Always use protocol version 3.3 for backwards compatibility with
202 badly-behaved clients. Default is off.
203 -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 -MaxProcessorUsage percent
214 Maximum percentage of CPU time to be consumed when polling the
215 screen. Default is 35.
216 -PollingCycle milliseconds
218 Milliseconds per one polling cycle. Actual interval may be
219 dynamically adjusted to satisfy MaxProcessorUsage setting.
220 Default is 30.
221 -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.
228 -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 -UseSHM
235 Use MIT-SHM extension if available. Using that extension accel‐
236 erates reading the screen. Default is on.
237 -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 -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 -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 -MaxDisconnectionTime seconds
255 Terminate when no client has been connected for N seconds.
256 Default is 0.
257 -MaxConnectionTime seconds
259 Terminate when a client has been connected for N seconds.
260 Default is 0.
261 -MaxIdleTime seconds
263 Terminate after N seconds of user inactivity. Default is 0.
264 -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).
271 -AcceptCutText
273 -SendCutText
274 -MaxCutText
275 Currently unused.
276
279 Xvnc(1), vncpasswd(1),
280 https://www.tigervnc.org/
281
284 Constantin Kaplinsky and others.
285 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.
291TigerVNC X0VNCSERVER(1)