x0tigervncserver(1)

NAME
x0tigervncserver - start or stop a TigerVNC scraping server

SYNOPSIS
x0tigervncserver [:display#|-display :display#] [-rfbport rfbport#] [-localhost [yes|no]] [-SecurityTypes sec-types] [-PasswordFile|-rfbauth passwd-file] [-PlainUsers user-list] [-PAMService|-pam_service service-name] [-X509Key cert-key-file] [-X509Cert cert-file] [-fg] [-useold] [-verbose] [-dry-run] [-Geometry <width>x<height>[{+,-}<xoffset>{+,-}<yoffset>]] [X0tigervnc options...]
x0tigervncserver -kill [{:display#,:*}|-display {:display#,:*}] [-rfbport rfbport#] [-dry-run] [-verbose] [-clean]
x0tigervncserver -list [{:display#,:*}|-display {:display#,:*}] [-rfbport rfbport#] [-cleanstale]
x0tigervncserver -version

DESCRIPTION
The x0tigervncserver wrapper script is used to start the X0tigervnc server that makes an X display remotely accessible via VNC (Virtual Network Computing). Unlike Xtigervnc, this server does not create a virtual display. Instead, it just shares an existing X server (typically, that one connected to the physical screen). The XDamage extension will be used if the existing X server supports it. Otherwise, X0tigervnc will fall back to polling the screen for changes. As usual, the VNC desktop can be connected to with the xtigervncviewer VNC viewer or any other VNC viewer. For details, see the xtigervncviewer(1) man page or execute "xtigervncviewer -help". System defaults for this wrapper script are found in /etc/tigervnc/vncserver-config-defaults. These defaults can be overwritten by the user defaults given in ~/.vnc/tigervnc.conf (see the tigervnc.conf(5x) man page). Next, command-line options overwrite the settings in both tigervnc configuration files. Finally, options from /etc/tigervnc/vncserver-config-mandatory have the highest priority overwriting all previous settings. WARNING! There is nothing stopping users from constructing their own wrapper script that calls X0tigervnc directly to bypass any options defined in the /etc/tigervnc/vncserver-config-mandatory configuration file.

OPTIONS
You can get a list of options by giving -h as an option to x0tigervncserver. In addition to the options listed below, any unrecognized options will be passed to X0tigervnc – see the X0tigervnc(1) man page or "X0tigervnc -help" for details.

:display#|-display :display#
    Specifies the X11 display to be shared by the X0tigervnc server.

-rfbport rfbport#
    Specifies the TCP port on which X0tigervnc listens for connections from viewers (the protocol used in VNC is called RFB – "remote framebuffer"). The default is 5900 plus the display number display#.

-localhost [yes|no]
    Should the TigerVNC server only listen on localhost for incoming TigerVNC connections. Useful if you use SSH and want to stop non-SSH connections from any other hosts. If the option is not specified, then the behavior is as follows: We will only listen on localhost if the sec-types list does not contain any TLS* or X509* security types or if the list contains at least one *None security type. Otherwise, we will listen on all network addresses of the machine.

-SecurityTypes sec-types
    Specify which security scheme to use for incoming connections. Valid values are a comma separated list of None, VncAuth, Plain, TLSNone, TLSVnc, TLSPlain, X509None, X509Vnc, and X509Plain. Default is VncAuth if -localhost is not given and VncAuth,TLSVnc if -localhost no is given.

-PasswordFile passwd-file | -rfbauth passwd-file
    Specifies the file containing the password used to authenticate viewers for the security types VncAuth, TLSVnc, and X509Vnc. The passwd-file is accessed each time a connection comes in, so it can be changed on the fly via tigervncpasswd(1). The default password file is ~/.vnc/passwd.

-PlainUsers user-list
    A comma separated list of user names that are allowed to authenticate via any of the *Plain security types (i.e., Plain, TLSPlain, etc.). Specify * to allow any user to authenticate using this security type. Default is to only allow the user that has started the x0tigervncserver wrapper script.

-PAMService service-name | -pam_service service-name
    PAM service name to use when authenticating users using any of the *Plain security types. Default is vnc if /etc/pam.d/vnc is present and tigervnc otherwise. The tigervnc-common package ships the /etc/pam.d/tigervnc PAM service configuration for use by x0tigervncserver.

-X509Cert cert-path and -X509Key key-path
    Path to a X509 certificate in PEM format to be used for all X509 based security types (i.e., X509None, X509Vnc, etc.) as well as its private key also in PEM format. If the certificate and its key are not provided via the -X509Cert and -X509Key command-line options or their corresponding configuration parameters in /etc/tigervnc/vncserver-config-defaults, ~/.vnc/tigervnc.conf, or /etc/tigervnc/vncserver-config-mandatory, then the x0tigervncserver wrapper script auto generates a self signed certificate. The auto generated self signed certificates are stored in the files ~/.vnc/host-SrvCert.pem and ~/.vnc/host-SrvKey.pem.

-fg Runs the X0tigervnc server as a foreground process. Thus, the server can be aborted with CTRL-C.

-useold
    Only start a new TigerVNC server if a VNC server for your account is not already running on the requested display number display# and RFB port rfbport#. If no display number is requested, a new TigerVNC server will only be started if there is no TigerVNC server running under your user account. In any case, information about the newly started TigerVNC server or the reused TigerVNC server session will be printed.

-verbose
    This will turn on some debug output.

-dry-run
    Do not actually do anything, but only perform the checks if the requested action would be possible. For example, there will be checks performed for the availability of the requested display number display#.

-Geometry <width>x<height>[{+,-}<xoffset>{+,-}<yoffset>]
    Specifies the screen area that will be shown to VNC clients, e.g., 640x480+320+240. The format is <width>x<height>+<xoffset>+<yoffset>, where `+' signs can be replaced with `-' signs to specify offsets from the right and/or from the bottom of the screen. Offsets are optional, +0+0 is assumed by default (top left corner). If the argument is empty, full screen is shown to VNC clients (this is the default).

-kill [ :{display#,*} | -display :{display#,*} ] [ -rfbport rfbport# ]
    This kills a TigerVNC server previously started with x0tigervncserver or tigervncserver. It does this by killing the VNC server process, whose process ID is stored in the file ~/.vnc/host:rfbport#.pid. If :* is given, then x0tigervncserver tries to kill all VNC server processes with pidfiles in ~/.vnc on the local machine. If no display number is given, then x0tigervncserver tries to kill the VNC server process of the user on the local machine if only one such process is running and has a pidfile in ~/.vnc.

-clean
    If given with -kill, then the logfile ~/.vnc/host:rfbport#.log is also removed.

-list [ :{display#,*} | -display :{display#,*} ] [ -rfbport rfbport# ]
    This lists all running TigerVNC servers previously started with x0tigervncserver or tigervncserver. Stale entries are marked with (stale) in the output.

-cleanstale
    If given with -list, then stale entries – resulting from missed cleanups of pidfiles in ~/.vnc as well as stale X11 locks and sockets in /tmp due to Xtigervnc or X0tigervnc server crashes – are cleaned up and not shown in the output of -list.

FILES
Several TigerVNC-related files are found in the ~/.vnc directory:

~/.vnc/tigervnc.conf
    The user configuration file for x0tigervncserver.

~/.vnc/passwd
    The TigerVNC password file for the security types VncAuth, TLSVnc, and X509Vnc.

~/.vnc/<host>:<rfbport#>.log
    The log file for the VNC server.

~/.vnc/<host>:<rfbport#>.pid
    Identifies the VNC server process ID, used by the -kill option.

~/.vnc/<host>-SrvCert.pem and <host>-SrvKey.pem
    The security types X509None, X509Vnc, and X509Plain need a certificate and the corresponding private key. If these are not provided via the -X509Cert and -X509Key command-line options or their corresponding configuration parameters in /etc/tigervnc/vncserver-config-defaults, ~/.vnc/tigervnc.conf, or /etc/tigervnc/vncserver-config-mandatory, then the x0tigervncserver wrapper script auto generates a self signed certificate for the -X509Cert and -X509Key options of the VNC server. The auto generated self signed certificates are stored in the above given two files. If the user wants their own certificate – instead of the on demand auto generated one – they can either specify it via the -X509Cert and -X509Key options to the x0tigervncserver wrapper script or replace the auto generated files ~/.vnc/host-SrvCert.pem and ~/.vnc/host-SrvKey.pem. These files will not be overwritten once generated by the x0tigervncserver wrapper script.

Furthermore, there are global configuration files for x0tigervncserver in the /etc/tigervnc directory:

/etc/tigervnc/vncserver-config-defaults
    The global configuration file specifying the defaults for x0tigervncserver.

/etc/tigervnc/vncserver-config-mandatory
    If this file exists and defines options to be passed to X0tigervnc, they will override any of the same options defined in a user's tigervnc.conf file or ones given on the command line of this wrapper script. This file offers a mechanism to establish some basic form of system-wide policy. WARNING! There is nothing stopping users from constructing their own wrapper script that calls X0tigervnc directly to bypass any options defined in the /etc/tigervnc/vncserver-config-mandatory configuration file.

SEE ALSO
tigervnc.conf(5x), tigervncpasswd(1), X0tigervnc(1), xtigervncviewer(1), tigervncserver(1)
https://www.tigervnc.org/

AUTHOR
Joachim Falk, Constantin Kaplinsky and others. VNC was originally developed by the RealVNC team while at Olivetti Research Ltd / AT&T Laboratories Cambridge. TightVNC additions were implemented by Constantin Kaplinsky. Many other people have since participated in development, testing and support. This manual is part of the TigerVNC Debian packaging project.