1X0VNCSERVER(1) TigerVNC Manual X0VNCSERVER(1)
2
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 ac‐
14 cessible 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 de‐
27 scription 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 -desktop desktop-name
51 Each desktop has a name which may be displayed by the viewer. It
52 defaults to "<user>@<hostname>".
53 -display display
55 The X display name. If not specified, it defaults to the value
56 of the DISPLAY environment variable.
57 -rfbport port
59 Specifies the TCP port on which x0vncserver listens for connec‐
60 tions from viewers (the protocol used in VNC is called RFB -
61 "remote framebuffer"). The default port is 5900. Listening on
62 TCP port can be disabled with -fbport=-1.
63 -UseIPv4
65 Use IPv4 for incoming and outgoing connections. Default is on.
66 -UseIPv6
68 Use IPv6 for incoming and outgoing connections. Default is on.
69 -rfbunixpath path
71 Specifies the path of a Unix domain socket on which x0vncserver
72 listens for connections from viewers.
73 -rfbunixmode mode
75 Specifies the mode of the Unix domain socket. The default is
76 0600.
77 -Log logname:dest:level
79 Configures the debug log settings. dest can currently be
80 stderr, stdout or syslog, and level is between 0 and 100, 100
81 meaning most verbose output. logname is usually * meaning all,
82 but you can target a specific source file if you know the name
83 of its "LogWriter". Default is *:stderr:30.
84 -HostsFile filename
86 This parameter allows to specify a file name with IP access con‐
87 trol rules. The file should include one rule per line, and the
88 rule format is one of the following: +address/prefix (accept
89 connections from the specified address group), -address/prefix
90 (reject connections) or ?address/prefix (query the local user).
91 The first rule matching the IP address determines the action to
92 be performed. Rules that include only an action sign (+, - or
93 ?) will match any IP address. Prefix is optional and is speci‐
94 fied as a number of bits (e.g. /24). Default is to accept con‐
95 nections from any IP address.
96 -SecurityTypes sec-types
98 Specify which security scheme to use for incoming connections.
99 Valid values are a comma separated list of None, VncAuth, Plain,
100 TLSNone, TLSVnc, TLSPlain, X509None, X509Vnc and X509Plain. De‐
101 fault is VncAuth,TLSVnc.
102 -rfbauth passwd-file, -PasswordFile passwd-file
104 Password file for VNC authentication. There is no default, you
105 should specify the password file explicitly. Password file
106 should be created with the vncpasswd(1) utility. The file is
107 accessed each time a connection comes in, so it can be changed
108 on the fly.
109 -Password password
111 Obfuscated binary encoding of the password which clients must
112 supply to access the server. Using this parameter is insecure,
113 use PasswordFile parameter instead.
114 -PlainUsers user-list
116 A comma separated list of user names that are allowed to authen‐
117 ticate via any of the "Plain" security types (Plain, TLSPlain,
118 etc.). Specify * to allow any user to authenticate using this
119 security type. Default is to deny all users.
120 -pam_service name, -PAMService name
122 PAM service name to use when authentication users using any of
123 the "Plain" security types. Default is vnc.
124 -X509Cert path
126 Path to a X509 certificate in PEM format to be used for all X509
127 based security types (X509None, X509Vnc, etc.).
128 -X509Key path
130 Private key counter part to the certificate given in X509Cert.
131 Must also be in PEM format.
132 -GnuTLSPriority priority
134 GnuTLS priority string that controls the TLS session’s handshake
135 algorithms. See the GnuTLS manual for possible values. Default
136 is NORMAL.
137 -UseBlacklist
139 Temporarily reject connections from a host if it repeatedly
140 fails to authenticate. Default is on.
141 -BlacklistThreshold count
143 The number of unauthenticated connection attempts allowed from
144 any individual host before that host is black-listed. Default
145 is 5.
146 -BlacklistTimeout seconds
148 The initial timeout applied when a host is first black-listed.
149 The host cannot re-attempt a connection until the timeout ex‐
150 pires. Default is 10.
151 -QueryConnect
153 Prompts the user of the desktop to explicitly accept or reject
154 incoming connections. Default is off.
155 -QueryConnectTimeout seconds
157 Number of seconds to show the Accept Connection dialog before
158 rejecting the connection. Default is 10.
159 -localhost
161 Only allow connections from the same machine. Useful if you use
162 SSH and want to stop non-SSH connections from any other hosts.
163 -interface IP address
165 Listen on interface. By default x0vncserver listens on all
166 available interfaces.
167 -AlwaysShared
169 Always treat incoming connections as shared, regardless of the
170 client-specified setting. Default is off.
171 -NeverShared
173 Never treat incoming connections as shared, regardless of the
174 client-specified setting. Default is off.
175 -DisconnectClients
177 Disconnect existing clients if an incoming connection is non-
178 shared. Default is on. If DisconnectClients is false, then a new
179 non-shared connection will be refused while there is a client
180 active. When combined with NeverShared this means only one
181 client is allowed at a time.
182 -AcceptKeyEvents
184 Accept key press and release events from clients. Default is on.
185 -AcceptPointerEvents
187 Accept pointer press and release events from clients. Default is
188 on.
189 -AcceptSetDesktopSize
191 Accept requests to resize the size of the desktop. Default is
192 on.
193 -RemapKeys mapping
195 Sets up a keyboard mapping. mapping is a comma-separated string
196 of character mappings, each of the form char->char, or
197 char<>char, where char is a hexadecimal keysym. For example, to
198 exchange the " and @ symbols you would specify the following:
199 RemapKeys=0x22<>0x40
201 -RawKeyboard
203 Send keyboard events straight through and avoid mapping them to
204 the current keyboard layout. This effectively makes the keyboard
205 behave according to the layout configured on the server instead
206 of the layout configured on the client. Default is off.
207 -Protocol3.3
209 Always use protocol version 3.3 for backwards compatibility with
210 badly-behaved clients. Default is off.
211 -Geometry geometry
213 This option specifies the screen area that will be shown to VNC
214 clients. The format is widthxheight+xoffset+yoffset , where `+'
215 signs can be replaced with `-' signs to specify offsets from the
216 right and/or from the bottom of the screen. Offsets are op‐
217 tional, +0+0 is assumed by default (top left corner). If the
218 argument is empty, full screen is shown to VNC clients (this is
219 the default).
220 -MaxProcessorUsage percent
222 Maximum percentage of CPU time to be consumed when polling the
223 screen. Default is 35.
224 -PollingCycle milliseconds
226 Milliseconds per one polling cycle. Actual interval may be dy‐
227 namically adjusted to satisfy MaxProcessorUsage setting. De‐
228 fault is 30.
229 -FrameRate fps
231 The maximum number of updates per second sent to each client. If
232 the screen updates any faster then those changes will be aggre‐
233 gated and sent in a single update to the client. Note that this
234 only controls the maximum rate and a client may get a lower rate
235 when resources are limited. Default is 60.
236 -CompareFB mode
238 Perform pixel comparison on framebuffer to reduce unnecessary
239 updates. Can be either 0 (off), 1 (always) or 2 (auto). Default
240 is 2.
241 -UseSHM
243 Use MIT-SHM extension if available. Using that extension accel‐
244 erates reading the screen. Default is on.
245 -ZlibLevel level
247 Zlib compression level for ZRLE encoding (it does not affect
248 Tight encoding). Acceptable values are between 0 and 9. De‐
249 fault is to use the standard compression level provided by the
250 zlib(3) compression library.
251 -ImprovedHextile
253 Use improved compression algorithm for Hextile encoding which
254 achieves better compression ratios by the cost of using slightly
255 more CPU time. Default is on.
256 -IdleTimeout seconds
258 The number of seconds after which an idle VNC connection will be
259 dropped. Default is 0, which means that idle connections will
260 never be dropped.
261 -MaxDisconnectionTime seconds
263 Terminate when no client has been connected for N seconds. De‐
264 fault is 0.
265 -MaxConnectionTime seconds
267 Terminate when a client has been connected for N seconds. De‐
268 fault is 0.
269 -MaxIdleTime seconds
271 Terminate after N seconds of user inactivity. Default is 0.
272
275 Xvnc(1), vncpasswd(1),
276 https://www.tigervnc.org/
277
280 Constantin Kaplinsky and others.
281 VNC was originally developed by the RealVNC team while at Olivetti Re‐
283 search Ltd / AT&T Laboratories Cambridge. TightVNC additions were im‐
284 plemented by Constantin Kaplinsky. Many other people have since partic‐
285 ipated in development, testing and support. This manual is part of the
286 TigerVNC software suite.
287TigerVNC X0VNCSERVER(1)