Provided by: xpra_3.1-1build5_amd64 bug


       xpra - viewer for remote, persistent X applications


       xpra start [CONNECTIONSTRING] | xpra start-desktop [CONNECTIONSTRING] [OPTIONS..]
       xpra attach [CONNECTIONSTRING] [OPTIONS..]
       xpra shadow [CONNECTIONSTRING] [OPTIONS..]
       xpra proxy [:DISPLAY] [OPTIONS..]
       xpra  stop | xpra exit | xpra detach | xpra screenshot filename | xpra version | xpra info
       xpra control [CONNECTIONSTRING]  command  [arguments..]   [--ssh=CMD]  [--remote-xpra=CMD]
            [--socket-dir=DIR] [--socket-dirs=DIRS]
       xpra initenv [--socket-dir=DIR]
       xpra list [--socket-dir=DIR]
       xpra list-windows [--socket-dir=DIR]
       xpra showconfig [OPTIONS..]
       xpra showsetting [SETTING1..]
       xpra list-mdns
       xpra upgrade [:DISPLAY] [...any options accepted by xpra start...]
       xpra upgrade-desktop [:DISPLAY] [...any options accepted by xpra start-desktop...]


       Xpra  is  a  tool which allows you to run X programs — usually on a remote host — and then
       direct their display to your local machine, disconnect from these programs, and  reconnect
       from  the same or another machine, all without losing any state.  It differs from standard
       X forwarding in that it allows  disconnection  and  reconnection  without  disrupting  the
       forwarded application; it differs from VNC and similar remote display technologies in that
       xpra can run rootless: i.e., applications forwarded by xpra  appear  on  your  desktop  as
       normal  windows  managed  by  your window manager, rather than being all "trapped in a box
       together".  Xpra also uses a custom protocol that is self-tuning and  relatively  latency-
       insensitive,  and  thus is usable over network connections that are too slow or unreliable
       for standard X forwarding.  Xpra can also be used to shadow an existing X11 display, or in
       desktop mode where it behaves more like VNC.

       By  default the Xpra server announces available sessions (username and display number) via
       mDNS to the local network. Use mdns=no to disable it.


       Xpra supports many types of connection strings (some may  require  extra  packages  to  be

       Local displays: this is the simplest form and is only valid for the current local displays
       of the current user.

       TCP mode uses port numbers and not display numbers. If  multiple  displays  are  available
       through  a  single  TCP  port  (ie:  using  a proxy server), then one can also specify the
       display number.

       SSL adds a secure socket layer on top of the TCP mode.

       Almost identical to the TCP mode, but using AF_VSOCK for transport.

       Connect using websocket protocol.

       Connect using secure websocket protocol. (websocket with SSL)

       Connect using secure shell. (SSH)

       Further options can be specified using the --ssh command line option.  The QUERYSTRING can
       be  used  to specify an ssh proxy: ?proxy=ssh://[USERNAME[:PASSWORD]@]HOST[:SSH_PORT] xpra
       will then establish an SSH connection to the specified "proxy" host, and  from  that  host
       xpra will set up an SSH connection to the xpra server.

       For     backwards     compatibility,     SSH    mode    also    supports    the    syntax:
       ssh:[USERNAME[:PASSWORD]@]HOST:DISPLAY but this form does not support specifying  the  SSH
       port  number.   Older  versions  also  used  the  form  protocol:host:port,  but users are
       encouraged to move to a more standard URI format using :// as separator.

       The password need only be specified when the server  authentication  module  requires  it.
       (ie:  often  when  authenticating against MS Windows servers, or with multifile and sqlite
       authentication modules)


       xpra start :7
            Start an xpra server using display number :7.  Note: using DISPLAY=:7 xterm to  start
            applications  against  a  specific  display  is  not recommended. Always prefer using
            xpra's --start= command line option instead.  See this next example:

       xpra start --start=firefox
            Start an xpra server, choosing a display automatically  and  start  firefox  on  that
            virtual display.  No window will appear until you attach with xpra attach.  The start
            child commands will inherit an environment tailored for running under xpra.

       xpra start ssh://bigbox/7 --start=xterm
            Start an xpra server on bigbox with an xterm in it, and connect to it.

       xpra start-desktop --start=xfce4-session
            Start an xfce session in a nested X11 server on  an  automatically  assigned  display

       xpra list
            Show a list of xpra servers you have running on the current host.

       xpra list-windows
            Show  a  list  of  xpra  servers  you have running on the current host, including the
            session name and a list of windows.  (only if the session can be queried  using  xpra

       xpra list-mdns
            Show a list of xpra servers found via mDNS. (local network)

       xpra showconfig
            Shows  the  configuration  that  would  be  used with other sub-commands, taking into
            account the command line arguments.

       xpra showsetting [SETTING1..]
            Shows the value of a specific configuration setting and which configuration directory
            set this value.

       xpra attach :7
            Attach to the xpra server that is using local display number :7.  Any apps running on
            that server will appear on your screen.

       xpra attach ssh://foo@frodo/7
            Use ssh to attach to the xpra server that is running on machine frodo as user foo and
            using display :7.  Any apps running on that server will appear on your local screen.

       xpra start :7 --start=screen
            Start  an  xpra  server  and  a screen(1) session.  If any of the applications inside
            screen attempt to use X, they will be directed to the xpra server.


       Understanding the basic idea of displays is critical to using xpra successfully.

       The idea comes from standard X.  If you have multiple X servers running on the same  host,
       then there has to be some way to distinguish them.  X does this by assigning each server a
       small, unique integer called (perhaps confusingly) its "display".  In the common case of a
       desktop  machine  that  has  only  one X server running, that server uses display ":0" (or
       sometimes you'll see ":0.0", which is effectively the same).  When an  application  starts
       under  X, it needs to know how to find the right X server to use; it does this by checking
       the environment variable $DISPLAY.

       Xpra faces a similar problem — there may be multiple xpra  servers  running  on  the  same
       host,  as  well  as multiple X servers.  It solves this problem by re-using X's solution —
       each xpra server has a display associated with it.  This display functions as  both  an  X
       display  (for  when  xpra is talking to X applications) and as an identifier by which xpra
       clients (like xpra attach) can locate the xpra server.

       You may omit the display number when using xpra start: a display will be  chosen  for  you
       automatically.  The display number chosen will be shown in the log output, you should also
       be able to see it with xpra list.  On Microsoft Windows and Mac OSX,  the  display  number
       should be omitted.

       Otherwise,  when  starting an xpra server, you may want to specify the name of the display
       to use.  To do this, simply pick any number you like and stick a colon  in  front  of  it.
       For instance :7, :12, and :3117 are all valid display names.  Just keep in mind that:

       ·      Every  X  or  xpra  server that is running on a single machine must use a different
              display name.  If you pick a number that is already in use then xpra will not work.

       ·      The first few numbers (0, 1, 2) are commonly used by real X servers.

       ·      Everyone who connects to a given machine using ssh(1)  with  X  forwarding  enabled
              will  also  use a display number; ssh generally picks numbers near ten (10, 11, 12,

       When specifying an xpra server to a client program like xpra  attach,  xpra  detach,  xpra
       stop,  xpra exit, xpra version, xpra info, xpra list or xpra screenshot then you can use a
       display of the form :DISPLAY to refer to a server on the local host, or one  of  the  form
       ssh://[USER@]HOST/DISPLAY  to  refer to a server on a remote host; xpra will automatically
       connect to the remote host using ssh(1).  Generally, if you have  only  one  xpra  session
       running on a machine (which you can verify by running xpra list on that machine), then you
       can omit the number entirely; xpra attach alone will attach to the lone xpra server on the
       current machine regardless of its number, xpra attach ssh://frodo will similarly attach to
       the lone xpra session on a remote machine.

       Connecting using the display number assumes that  the  client  and  server  use  the  same
       configuration for socket directories, or at least that the client can find at least one of
       the directories used by the unix domain sockets (see bind, socket-dir and socket-dirs).

       If the xpra server was given the --bind-tcp, --bind-ssl --bind-udp=[HOST]:PORT, --bind-ws,
       --bind-wss  or  --bind-vsock  option  when started then you can also connect to it using a
       display    of    the    form     tcp://HOST:PORT[/DISPLAY],     udp://HOST:PORT[/DISPLAY],
       ssl://HOST:PORT[/DISPLAY],    ws://HOST:PORT[/DISPLAY],    wss://HOST:PORT[/DISPLAY]    or


   xpra start
       This command starts a new xpra server, including any necessary setup.   (When  starting  a
       remote server with the ssh://HOST/DISPLAY syntax, the new session will also be attached.)

   xpra start-desktop
       Starts a nested X11 server, all child commands will be started in the nested X11 server.

   xpra attach
       This  command  attaches to a running xpra server, and forwards any applications using that
       server to appear on your current screen.

   xpra detach
       Detaches the given xpra display.

   xpra screenshot
       Takes a screenshot and saves it to the filename specified.  Note: screenshots can only  be
       taken when a client is attached.

   xpra version
       Queries  the  server  version and prints it out.  Note: older servers may not support this

   xpra info
       Queries the server for version, status and statistics.

   xpra top
       Shows the server's key health attributes.

   xpra control
       Modify the server at runtime by issuing commands.  The list of commands can be obtained by
       specifying  "help"  as  command.   Some  of  those  commands  may  support  a  "help" mode

   xpra initenv
       This internal command creates the run-xpra script used with ssh connections.

   xpra stop
       This command  attaches  to  a  running  xpra  server,  and  requests  that  it  terminates
       immediately.   This  generally  causes  any applications using that server to terminate as

   xpra exit
       This command  attaches  to  a  running  xpra  server,  and  requests  that  it  terminates
       immediately.  Unlike xpra stop, the Xvfb process and its X11 clients (if any) will be left

   xpra showconfig
       This commands shows the configuration which would be used given  the  arguments  provided.
       You  can also specify as extra arguments the specific options that should be displayed, or
       use the special value all to display all the options including the ones which are normally
       not displayed because they are not relevant on the given system.

   xpra list
       This  command  finds  all  xpra  servers that have been started by the current user on the
       current machine, and lists them.

   xpra upgrade
       This command starts a new xpra server,  but  instead  of  creating  it  from  scratch,  it
       attaches  to  another  existing  server,  tells  it  to  exit, and takes over managing the
       applications that it was managing before.  As the name suggests, the main use case  is  to
       replace  a  server  running against an older version of xpra with a newer version, without
       having to restart your session.  Any currently-running xpra attach command will  exit  and
       need to be restarted.

   xpra upgrade-desktop
       Same  as  upgrade  but for servers started using start-desktop.  It is possible to upgrade
       seamless server into a desktop server and vice versa.

   xpra shadow
       This command shadows an existing X11 display. If there is only one X11 display active  and
       its number is below 10, it can be auto-detected.

       Note  that this mode of operation uses screenscraping which is far less efficient. Using a
       video encoder (h264 or vp8) is highly recommended for this mode of operation.

   xpra proxy
       This command allows a single server to proxy connections for multiple others,  potentially
       serving  as  a  load balancing or authentication entry point for many sessions.  The proxy
       server will spawn a new process for each proxy connection, this proxy process will  create
       an  unauthenticated  new  unix  domain socket which can be used with the subcommands info,
       version and stop.

   Important Note
       Some platforms and package managers may choose to  only  build  the  client  and  not  the
       server. In this case, only the attach subcommand will be available.


   General options
              Displays xpra's version number.

       -h, --help
              Displays a summary of command line usage.

       -d FILTER1,FILTER2,..., --debug=FILTER1,FILTER2,...
              Enable debug logging.  The special value all enables all debugging.

              Enable  or  disable  memory  mapped pixel data transfer.  By default it is normally
              enabled automatically if the server and the client reside on  the  same  filesystem
              namespace.   This  method  of data transfer offers much lower overheads and reduces
              both CPU consumption and local network  traffic.   When  attaching,  you  can  also
              specify an absolute path where the mmap file will be created.

              Sets  the  mmap file's gid to the group specified, and sets the permissions to 660.
              This is necessary to share the mmap file across user accounts.  You  can  also  use
              the special GROUP values:

              no     Disable  the  functionality,  the  mmap  file  will  use  the  default  file
                     permissions and default group ownership.

              SOCKET The group used will be the same one as found on the unix domain socket  file
                     the  client  connects  to.  Obviously, this can only work when connecting to
                     unix domain sockets.

              auto   Will use the 'xpra' group if  the  user  is  a  member,  otherwise  it  will
                     fallback to the same behaviour as SOCKET.

              Enable  or  disable  the forwarding of windows. This is usually the primary use for
              xpra and should be enabled.

              Sets the minimum size for all decorated windows.

              Sets the maximum size for all windows.

              Read only mode ignores all keyboard and mouse activity.

              Enable or disable clipboard synchronization.  If disabled on the server, no clients
              will  be able to use clipboard synchronization at all. If turned off on the client,
              only this particular connection will ignore clipboard data from the  server.   This
              can  also  be  used to specify a different clipboard implementation.  The clipboard
              types available will vary from platform to platform and also depend on  build  time
              environment  and  options  so  this  is  best  left on auto.  Other clipboard types
              available may include:

                     Clipboard which can translate from one type of selection to another

              GDK    The most complete clipboard implementation, includes full X11 support

                     Fallback clipboard, with limited X11 support

              OSX    OSX specific clipboard

              Choose the direction of the clipboard synchronization.

              Enable or disable the starting of a pulseaudio server with the session.

              Specifies the pulseaudio command to use to  start  the  pulseaudio  server,  unless
              disabled with pulseaudio=no.

              Sets  the name of this session. This value may be used in notifications, utilities,
              tray menu, etc.  Setting this value on the server provides a  default  value  which
              may be overridden on the client.

              This  specifies  the  image  encoding  to  use,  there  are  a  number of encodings
              supported: jpeg, png, png/P, png/L, webp, rgb, vp8, vp9, h264 and  h265  (some  may
              not be available in your environment).  The default option is auto which allows the
              server to select the best encoding automatically.

              auto   default mode: the built-in  heuristics  will  choose  the  most  appropriate

              png    compressed and lossless, can be quite slow.

              png/P  compressed  and  lossy:  it  uses  a  colour  palette,  which  means  better
                     compression but still slow.

              png/L  compressed and lossy: grayscale only using a palette.

              rgb    a raw pixel  format  (lossless)  compressed  with  lz4,  lzo  or  zlib  (see
                     compressors)  the  compression  ratio is lower, but it is by far the fastest
                     encoding available.

              webp   can be used in lossy or lossless mode, useful for graphical applications, it
                     compresses   better  than  jpeg  and  is  reasonably  fast  except  at  high

              jpeg   can be useful for graphical applications, it is lossy and usually very fast.

              vp8    lossy video encoding which always uses colour subsampling.  Fast at encoding
                     and decoding.

              vp9    Video  encoding  which  supports both lossy and lossless modes, available if
                     your ffmpeg library version is recent enough.

              h264   One of the best encoding available: it is fast, efficient  and  tunable  via
                     the quality and speed options.

              h265   Far too slow at encoding, avoid.

       The default encoding which is automatically selected if you do not specify one will depend
       on what options are available on both the server and the client: rgb is  always  available
       (builtin),  jpeg and png require the Python Imaging Library, vp8, vp9, webp, h264 and h265
       all require their respective shared libraries, as well as the xpra codec that uses them.

       Note: when selecting a video encoding (usually h264, vp8 or vp9), it will only be used  if
       the  screen  is  updating  quickly enough, some of the smaller screen updates will also be
       sent using one of the other non-video encodings.

              How much automatic video downscaling  should  be  used,  from  1  (rarely)  to  100
              (aggressively), 0 to disable.  Video scaling is normally used with video regions or
              very large windows (especially full screen windows) to try  to  maintain  a  decent
              framerate.   Video  downscaling  negatively  affects  visual quality and will cause
              automatic refreshes (if enabled), it is most useful on video content where it saves
              a considerable amount of bandwidth.

              Location  where  to write and look for the Xpra socket files.  The default location
              varies  from  platform  to  platform  ("~/.xpra"  on  most  Posix   systems).    If
              unspecified,  the  first  value  from  socket-dirs  will  be  used.  It may also be
              specified using the XPRA_SOCKET_DIR environment variable.

              When using the socket-dir option, it is generally necessary to  specify  socket-dir
              or socket-dirs on all following commands, for xpra to work with the open sessions.

              By  specifying  a  shared  directory  this  can  be coupled with the mmap-group and
              socket-permissions option to connect Xpra sessions across user accounts with shared
              memory acceleration.

              Specifies  the directories where to look for existing sockets if a specific one was
              not set using socket-dir.  You may specify each directory using a new --socket-dirs
              command  line argument, or joined together by the path separator (: on Posix).  The
              paths will be expanded.  (ie: --socket-dirs=~/.xpra:/tmp)

              Enable file transfers.

              This option may be used to allow the remote end to automatically open  files  after
              they  have  been  uploaded.   This  may be a security risk if you are using xpra to
              constrain what the clients can execute on the server.

              Intercept execution of xdg-open and forward the request to the client.

              The command to use for opening files and URLs.

              Restrict bandwidth usage to below the limit given.  The client's value cannot raise
              the  limit  of  the  server.   The value may be specified using standard units, ie:
              1Mbps or 500K.  In auto mode, the client will set the bandwidth limit value to  80%
              of the maximum speed of the network interface it is using to connect to the server.

   Options for start, start-desktop, upgrade, proxy and shadow
              By default, the xpra server puts itself into the background, i.e. 'daemonizes', and
              redirects its output to a log file.  This can be  used  to  prevent  that  behavior
              (useful mostly for debugging).

              Resize  the  virtual  display  to  match  the  resolution  of  the client currently
              connected.  This only applies to the start and start-desktop subcommands.

              Specify the path to the library which will be injected into  all
              the  child processes the server starts using LD_PRELOAD.  This can also be disabled
              or set to auto: the server will then try to locate the library itself.   This  only
              applies to the start subcommand.

              Change to this directory after daemonizing.

       --uid=UID and --gid=GID
              When  launching the server as root, these options can be used to drop privileges to
              the given UID / GID.

              Writes the server process ID to this file on startup.  If the  file  has  not  been
              replaced, it will be deleted when the server exits.

              Create  a local Unix domain socket (on Unix) or named-pipe (on MS Windows) for each
              bind option specified.

              This option can be specified multiple times to specify multiple  socket  locations.
              These  sockets  support  local  connections  with the :7-style display address, and
              remote connections with the ssh://frodo/7-style display address.

              Local sockets may also process HTTP / Websocket connections if the html  switch  is

              The location can take the form:

              none   do not create a socket

              auto   backwards compatible default which uses the current socket-dir

                     create  a socket in the directory specified, if the directory does not exist
                     then it will be created - you should include the trailing slash  to  prevent
                     the confusion with the PATH form:

              PATH   create the socket using the path specified

              Create  a  TCP socket for each --bind-tcp option specified.  If the host portion is
              omitted,  then  (localhost)  will  be  used.   If  you  wish  to  accept
              connections on all interfaces, pass for the host portion.

              Using  this  switch  without using the tcp-auth option is not recommended, and is a
              major security risk (especially when passing!  Anyone at all  may  connect
              to this port and access your session.

              TCP  sockets  may  also  process HTTP / Websocket connections if the html switch is
              enabled.  TCP sockets may also be upgraded to SSL sockets  if  the  ssl  switch  is

              Create  a  UDP socket for each --bind-udp option specified.  If the host portion is
              omitted,  then  (localhost)  will  be  used.   If  you  wish  to  accept
              connections on all interfaces, pass for the host portion.

              Using  this  switch  without using the udp-auth option is not recommended, and is a
              major security risk (especially when passing!  Anyone at all  may  connect
              to  this  port  and  access  your  session.  UDP sessions are trivial to hijack for
              anyone able to sniff even just a single packet, it should  only  be  used  in  very
              specific use-cases, and never over unsecured networks.

              Create  an  HTTP  /  Websocket  listener.   See bind-tcp for host restrictions, you
              should use the auth-ws to secure access.

              Create an HTTPS / Secure Websocket listener.  See bind-tcp for  host  restrictions,
              you should use the auth-wss to secure access.

              Just like --bind-tcp but for SSL sockets.  See ssl-auth and the other SSL options.

              Listens  for  RFB  connections on the given port.  These sockets are only supported
              with the start-desktop and shadow modes.

              Create a VSOCK socket for each --bind-vsock option specified.

              Specifies the authentication module to use for unix domain  sockets  created  using
              the  bind  switch.  Authentication  modules  can  validate  a username and password
              against a variety of backend modules:

              allow  always allows authentication - this is dangerous and should only be used for

              fail   always fails authentication, useful for testing

              env    matches against the environment variable specified by the name option (which
                     defaults to XPRA_PASSWORD).  ie: --auth=env:name=SOME_OTHER_ENV_VAR_NAME.

                     matches  against  the  password  specified  using  the  value  option.   ie:
                     --auth=password:value=YOURPASSWORD.   Note:  this command line option may be
                     exposed to other processes on the same system.

              file   checks the password against the password data found in  the  file  specified
                     using the filename option.  ie: --auth=file:filename=./password.txt.

                     The  contents  of  this  file  will  be treated as binary data, there are no
                     restrictions on character  encodings  or  file  size.   Beware  of  trailing
                     newline characters which will be included in the password data.

                     checks  the  username  and  password  against  the  file specified using the
                     filename option.  The file must contain each user credentials on one line of
                     the form:


                     It  is  not  possible  to  have  usernames or password that contain the pipe
                     character | which is used as delimiter, or newlines  and  carriage  returns.
                     This module is deprecated, sqlite should be used instead.



              sql    checks  the username and password against the sqlite database file specified
                     using the  filename  option  (for  the  sqlite  backend),  or  the  database
                     specified using the uri option (mysql and sql backends).  The authentication
                     will be processed using the following query (which is configurable using the
                     password_query  option):  SELECT password FROM users WHERE username=(?)  The
                     sessions  available  for  each  user  will  be  queried  using:   (this   is
                     configurable  using  the  sessions_query option): SELECT uid, gid, displays,
                     env_options,  session_options  FROM  users  WHERE   username=(?)    Multiple
                     displays may be specified as a comma separated list.

              hosts  checks  the  host using the system's tcp-wrappers library.  (Posix only, and
                     not available on Mac OS) See hosts.allow and hosts.deny for details.

              exec   Executes the command specified using the command attribute, the arguments to
                     this command are: a description of the access request and the timeout value.
                     (also configurable) If the command is not specified, the system will try  to
                     locate  and  use  the  auth_dialog  utility which is shipped with xpra.  The
                     command should return 0 to allow access, any other value will deny access.

                     checks the unix domain socket  peer  credentials  using  SO_PEERCRED.   This
                     authentication  module  is  only available on some Posix compliant operating
                     systems. This module will verify that the operating system provides the  uid
                     and  gid  of  the  process  that  initiated  the  connection.  Access can be
                     restricted by supplying a colon separated list of valid uids and  gids  that
                     are  allowed  to  connect.  Those id values may be specified using numerical
                     values or using the usernames / group names.  This module is different  from
                     the  others  in  that it will not require the client to supply a username or
                     password,  as  those  are  ignored.   Environment  variables   and   pseudo-
                     environment    variables    may    also    be    used    as    values,   eg:

              pam    validates the username and password using the PAM system

              win32  validates the username and password using Microsoft  Windows  authentication
                     (only available on this platform)

              sys    chooses  the  appropriate system authentication module automatically (either
                     pam or win32)

                     validates the username and password using kerberos authentication.  Warning:
                     this  module  does not use kerberos tickets and the password will be sent in
                     plain text to the server. This should only be used for testing.

                     validates a kerberos ticket obtained by the client.

              gss    validates a GSS ticket obtained by the client.

              u2f    requests a U2F token from the client.

              ldap   validates the username and  password  against  an  LDAP  server,  using  the
                     python-ldap library.

              ldap3  validates the username and password against an LDAP server, using the python
                     ldap3 library.

              Just like the auth switch, except this one only applies  to  TCP  sockets  (sockets
              defined using the bind-tcp switch).

              Just like the tcp-auth switch, except this one only applies to UDP sockets (sockets
              defined using the bind-udp switch).

              Just like the auth switch, except this one only  applies  to  ws  sockets:  sockets
              defined  using  the  bind-ws switch, or TCP sockets upgraded to websockets. (if the
              html option is enabled).

              Just like the auth switch, except this one only applies  to  wss  sockets:  sockets
              defined using the bind-wss switch, ws sockets upgraded to SSL (if the ssl option is
              enabled) or TCP sockets upgraded to SSL and then to wss.  (if both the ssl and html
              options are enabled).

              Just  like  the  auth  switch, except this one only applies to SSL sockets: sockets
              defined using the bind-ssl switch, or TCP sockets upgraded by ssl=auto or ssl=on.

              Authentication module to use for the bind-rfb sockets.

              Just like the auth switch, except this one only applies to VSOCK  sockets  (sockets
              defined using the bind-vsock switch).

              Configures which challenge handlers are used by the client and in which order. This
              option may be repeated to specify multiple handlers, which can  be  useful  if  the
              server  sends  more  than  one authentication challenge.  The default value is: all
              which corresponds to: uri,file,env,kerberos,gss,u2f,prompt.

              uri    Use the password specified on the connection string, if any.

              file   The filename used to store the password can be specified using the  filename
                     option.   If  this  option  is  not specified, it will fallback to using the
                     password filename specified with the password-file switch.

              env    Use the password specified using the environment  variable  specified  using
                     the name option, which defaults to XPRA_PASSWORD if unspecified.

                     Requests a kerberos token for the service specified.

              gss    Requests a gss token for the service specified.

              u2f    Requests a token from a U2F device.

              prompt Prompt  the  user  for the value.  Terminal clients prompt using text input,
                     GUI clients use a dialog.

              The minimum port number allowed when creating UDP and TCP sockets.  You can  use  a
              lower  value  to allow unprivileged users to bind to privileged ports when starting
              sessions via the system wide proxy server.  The default value is 1024 which is  the
              standard value for privileged ports.

              Enable or disable the publication of new sessions via mDNS.

              Start  the  session  within  a dbus-launch context, you can specify the dbus launch
              command to use, or turn it off completely.  Some  features  may  not  be  available
              without a dbus context.

              Allows the client to forward dbus calls to the server.

              Start a dbus server which can be used to interact with the server process.

   Options for start, start-desktop, upgrade
              A  wrapper  command  which  is prepended to all start commands.  Typically, this is
              used for starting all sub-commands via VirtualGL.

              After starting the server, runs the command  CMD  using  the  default  shell.   The
              command  is  run  with its $DISPLAY set to point to the newly-started server.  This
              option may be given multiple times to start multiple commands.

              Identical to --start, except that the commands are taken into  account  by  --exit-

              Wait for the first client to connect before starting the command.

              Wait for the first client to connect before starting the child command.  See start-

              Execute this command every time a client connects.

              Execute this child command every time a client connects.  See start-child.

              Execute this command every time a client disconnects and there are no other clients

              Execute  this  child command every time a client disconnects and there are no other
              clients left.  See start-child.

              On server stop, terminate all the child commands that  have  been  started  by  the
              server.  This  does  not  affect  server exit.  Most child commands are tied to the
              display so they are normally forced to shutdown anyway, but this  gives  them  more
              time  to  cleanup  properly and can be used to stop background commands that aren't
              tied to a display.

              This option may only be used if --start-child is also given.  If it is given,  then
              the  xpra  server will monitor the status of the children started by --start-child,
              and will automatically terminate itself when the last of them has exited.

              The server will terminate when the last client disconnects.

              Extra environment variables which will only affect commands started using fB--start
              or --start-child.

              Allow  clients  to  ask the server to execute new commands.  (this can also be used
              via the control channel)

              If enabled, the start and start-desktop subcommands will be delegated to the system
              wide proxy server instance.  With auto mode, this delegation will only occur if the
              system wide proxy server is found.

              Wrap server start commands with systemd-run.

              Command line arguments passed to systemd-run.

              Use an existing display rather than starting one with xvfb.   You  are  responsible
              for  starting  the  display  yourself.  This can also be used to rescue an existing
              display whose  xpra  server  instance  crashed  or  for  running  xpra  against  an
              accelerated X11 server.

              The  xpra  server  will  write the display number back on this file descriptor as a
              newline-terminated string.  This is most useful when  the  display  number  is  not
              specified with the xpra start or start-desktop subcommands.

              When  starting a seamless server, xpra starts a virtual X server to run the clients
              on.  If your Xvfb is installed in a funny location, or you want to use  some  other
              virtual  X server, then this switch allows you to specify how to run your preferred
              X server executable.  The default value used depends on your  platform.   For  more
              information, see:

              The  windows  are normally only displayed on the client(s), they are not painted on
              the virtual display.  Some applications like screen recorders may want  to  capture
              the window contents, you can use this option to enable painting with a configurable
              delay (in milliseconds).  Warning: this extra painting is expensive and quite slow,
              which is why it is not enabled by default.

              Once  the  server  has started, immediately connect a client to it.  With the value
              auto, a client is started for remote servers only. (servers specified via a network

   Options for start, start-desktop, upgrade, shadow
              Specifies  the  address  to  which non-xpra packets will be forwarded.  This can be
              used to share the same TCP port with another TCP servers,  usually  a  web  server.
              xpra  clients  will  connect  as usual, but any client that does not speak the xpra
              protocol will be forwarded to the alternative server.

              Respond to HTTP requests on the TCP port(s) and local sockets.   This  requires  at
              least one TCP or local socket to be configured using the matching bind option.  The
              auto mode will enable support if possible.  By  default  the  server  will  provide
              access  to  the  HTML5  client.   You  can  also  specify your own web root path as

              Allows RFB clients (ie: VNC) to connect to a plain  TCP  socket.   If  no  data  is
              received after DELAY seconds, the server will send a RFB handshake.  This option is
              only applicable to servers started in start-desktop or shadow modes.

              Specifies the video encoders to try to load.  By default, all of them  are  loaded,
              but  one  may want to specify a more restrictive list of encoders.  Use the special
              value 'help' to get a list of options.  Use the value 'none' to not load any  video

              Specifies  the  colourspace  conversion modules to try to load.  By default, all of
              them are loaded, but one may want to specify a more restrictive  list  of  modules.
              Use the special value 'help' to get a list of options.  Use the value 'none' to not
              load any colourspace conversion modules.

              Specifies the file permissions on the server's unix domain  sockets.   Defaults  to
              600. This is ignored when mmap-group is enabled.

   Options for start, start-desktop, upgrade and attach
              Specifies  the  cipher  to  use for securing the connection from prying eyes.  This
              option requires the use  of  the  --encryption-keyfile  option.   The  only  cipher
              supported  at  present is AES, if the client requests encryption it will be used by
              both the client and  server  for  all  communication  after  the  initial  password
              verification, but only if the server supports this feature too.  Note: this feature
              has not been extensively reviewed and as it is it should  not  be  considered  safe
              from determined attackers.

              Just  like  the  encryption  switch,  except  this  one only applies to TCP sockets
              (sockets defined using the bind-tcp switch).

              Specifies the key to use with the encryption cipher  specified  with  --encryption.
              The client and server must use the same keyfile contents.

              Just  like  the  encryption-keyfile  switch,  except  this  one only applies to TCP
              sockets (sockets defined using the bind-tcp switch).

              The connection will be terminated if there is no user activity (mouse clicks or key
              presses) for the given amount of time (in seconds). Use the value 0 to disable this

              The server will exit if there are no active connections for  the  given  amount  of
              time (in seconds).  Use the value 0 to disable this timeout.

              Name  of a file containing regular expressions, any clipboard data that matches one
              of these regular expressions will be dropped.  Note: at present this  only  applies
              to copying from the machine where this option is used, not to it.

              The  'dots  per  inch'  value  that client applications should try to honour.  This
              numeric value should be in the range 10 to 500 to  be  useful.   Many  applications
              will  only  read  this value when starting up, so connecting to an existing session
              started with a different DPI value may not have the desired effect.

              When starting a server, this switch controls the bits  per  pixel  of  the  virtual
              framebuffer.  Possible  values: 0 (auto), 16, 24, 30.  When starting a client, this
              switch controls the picture rendering with the opengl backend: values  higher  than
              24  will  enable deep color, the value 24 enables regular true color rendering. Use
              the value 0 to let the client decide if the rendering will benefit from using  deep
              color.  (this  is  only supported on some Posix clients) Other values should not be

              Enable  or  disable  forwarding  of  custom  application  mouse  cursors.    Client
              applications  may  change  the  mouse  cursor at any time, which will cause the new
              cursor's pixels to be sent to the client each time.  This disables the feature.

              Enable or disable forwarding of system notifications.  System notifications require
              the  xpra  server  to  have  its  own instance of a dbus daemon, if it is missing a
              warning will be printed on startup.  This switch disables the feature entirely, and
              avoids the warning.

              Specify  which  input  method  to  configure.   This  sets  a number of environment
              variables which should be honoured by applications  started  with  the  start-child

              The following METHODs are currently supported:

              none   Disable  input  methods  completely  and  prevent  it  from interfering with
                     keyboard input. This is the default.

              keep   Keeps the environment unchanged. You are  responsible  for  ensuring  it  is

              xim    Enables the X Input Method.

              IBus   Enables the Intelligent Input Bus.

              SCIM   Enables the Smart Common Input Method.

              uim    Enables the Universal Input Method.

       Any other value will also be set up, but will trigger a warning.

              Enable  or  disable  xsettings  synchronization.  Xsettings are only forwarded from
              posix clients connecting to real posix servers (not shadows).

              Enable or disable forwarding of system tray icons.  This  feature  requires  client
              support and may not be available on all platforms.

              Enable or disable forwarding of the system bell.

              Enable or disable webcam forwarding.

              Mouse  wheel  handling:  can be used to disable mouse wheel forwarding or to invert
              some or all axes.

              Allow the client to forward its log output to the server.  The client  can  specify
              the value both to both send it to the server and keep it locally.

              Enable  or  disable audio-video synchronization.  The video data will be delayed so
              that it is displayed in sync with the audio.  Note:  this  only  applies  to  video
              regions,  either  auto-detected  via  the builtin heuristics or specified using the
              dbus interface.

   Options for attach
              Honour modal windows.   This  may  have  undesirable  side  effects  when  multiple
              applications are forwarded through the same xpra server: modal windows will be made
              modal for all  the  applications  forwarded  by  xpra  rather  than  just  the  one
              application which owns that window.

              Supply the password to be used for connecting to a server that uses authentication.
              See auth, tcp-auth, ssl-auth and vsock-auth for details.   Alternatively,  you  may
              use the XPRA_PASSWORD environment variable.

              Use  OpenGL  accelerated  rendering on the client.  The default is to detect if the
              graphics card and drivers are supported (auto  mode),  but  one  can  also  disable
              OpenGL  (no)  or force it enabled (yes).  On some platforms, it is also possible to
              specify which backends should be used, only gtk and native are currently  supported
              and only on X11 platforms.  ie: opengl=yes:native, or opengl=auto:gtk,native.

              Enable  or  disable  webcam  forwarding.   The  webcam  device  to  use can also be

       -zLEVEL, --compress=LEVEL
              Select the level of compression xpra will  use  when  transmitting  data  over  the
              network.   With  the lz4 and lzo compressors, there are only two possible values: 0
              (meaning no compression) and 1 (compression enabled).  The zlib compressor supports
              values  between 0 (meaning no compression) and 9, inclusive. It should only be used
              when lz4 and lzo are not available.

              This compression is not used on pixel data (except when using the rgb encoding).

              This option sets a fixed image compression quality for lossy encodings (jpeg, webp,
              h264/h265  and  vp8/vp9).  First, one of those lossy encodings must be enabled with
              --encoding.  Values range from 1 (lowest  quality,  high  compression  -  generally
              unusable)  to  100  (highest quality, low compression).  Specify a value of zero to
              let the system tune the quality dynamically to achieve  the  best  bandwidth  usage
              possible.  It is usually best not to use this option and use min-quality instead.

              This  option  sets  the minimum encoding quality allowed when the quality option is
              set to automatic mode.

              This option sets the encoding speed.  Slower  compresses  more,  faster  will  give
              better  latency.   The  system normally uses a variable speed, this option forces a
              fixed speed setting to be used instead.  It is usually best not to use this  option
              and use min-speed instead.

              This option sets the minimum encoding speed allowed when the speed option is set to
              automatic mode.

              This option sets a delay after which the windows are automatically refreshed  using
              a  lossless  frame.   The delay is a floating-point number and is in seconds.  This
              option is enabled by default with a delay of 0.25 seconds.   This  option  is  only
              relevant when using a lossy encoding.

              Defines  the  default  shortcut  modifiers  required  by  the  key-shortcuts, these
              modifiers can then be referred  to  as  #.   The  default  value  is  'auto'  which
              evaluates to Meta+Shift on most platforms.

              Can  be specified multiple times to add multiple key shortcuts.  These keys will be
              caught by the client and trigger the action specified and the key presses will  not
              be passed on to the server.

              The  KEY  specification may include keyboard modifiers in the form [modifier+]*key,
              for example: Shift+F10 or Shift+Control+B.  You can refer to  the  shorcut-modifers
              option value using #, ie: #+F1.

              If  no  shortcuts are defined on the command line, the default builtin list will be

              Some of the actions may allow arguments (ie: the log action does),  in  which  case
              they are specified in the usual programming style syntax: ACTION(ARG1, ARG2, etc)
              String  arguments  must be quoted (both single and double quotes are supported) and
              numeric arguments must not be quoted.  Beware the the parenthesis and  quotes  must
              usually  be  escaped  when  used  from  a  shell  command  line.   Example:  --key-

              The following ACTIONs are currently defined:

              quit   Disconnect the xpra client.

                     Sends MESSAGE to the log.

                     Shows the session  information  window.  The  optional  TabName  allows  the
                     information  tab shown to be selected. Use the value help to get the list of

                     Shows the menu normally found in the system tray.

                     Shows the start new command dialog.

                     Placeholder which can be used by some client toolkits.

              void   Does not do anything, and can therefore  be  used  to  prevent  certain  key
                     combinations from ever being sent to the server.

                     Force the currently focused window to be refreshed.

                     Force all windows to be refreshed.

                     The keyboard will be grabbed / ungrabbed by the current window.

                     The pointer will be grabbed and confined to the current window.

                     Make the current window fullscreen / unfullscreen.

                     Turn debugging on or off.

                     Increase the current value of desktop-scaling.

                     Decrease the current value of desktop-scaling.

                     Reset the desktop-scaling to its original value.

                     Turn off desktop-scaling.

                     Increase  the  min-quality or quality setting (whichever one is currently in

                     Decrease the min-quality or quality setting (whichever one is  currently  in

                     Increase the min-speed or speed setting (whichever one is currently in use).

                     Decrease the min-speed or speed setting (whichever one is currently in use).

              Sharing  allows  more than one client to connect to the same session.  This must be
              enabled on both the server and all co-operating clients  to  function.   When  used
              server-side,  the  default  value  auto  allows  the  clients to decide if they are
              willing to share the session.   When  used  client-side,  the  default  value  auto
              evaluates  to  no.  To allow sharing to work with unix domain sockets (either using
              local connections or via ssh), you should create at least one  socket  in  a  group
              accessible  directory. On Posix with a default configuration, being a member of the
              xpra group should be enough to create a socket in /run/xpra. You must  also  ensure
              that  the  permissions  of  this  socket  file  allow  group  access,  see  socket-

              Locking allows a client to refuse to hand over the session to a  new  client.   The
              session  may  still  be  shared with multiple clients (see the sharing option), but
              otherwise the server will reject new clients.  When used server-side,  the  default
              value  auto  allows  the  clients to decide if they want to lock the session.  When
              used client-side, the default value auto evaluates to no.

              Normally the key presses and key release events are sent  to  the  server  as  they
              occur  so  that  the  server  can  maintain a consistent keyboard state.  Disabling
              synchronization can prevent keys from repeating unexpectedly on high latency  links
              but  it  may  also  disrupt applications which access the keyboard directly (games,

              Tells the server to process all keyboard input untranslated.  Both the  client  and
              the server must be using the same type of keyboard interface. (ie: both using X11)

              The keyboard layout is normally detected automatically.  This option overrides it.

              The list of keyboard layouts to enable.

              Override for the keyboard layout variant.

              Override for the keyboard layout variants.

              Override for the keyboard options sent to the server.

              This  option  only  applies to MacOS clients, it swaps the command and control keys
              and is enabled by default.

              Specifies the GStreamer sound plugin used for capturing  the  sound  stream.   This
              affects  "speaker  forwarding"  on  the  server, and "microphone" forwarding on the
              client.  To get a list of options  use  the  special  value  'help'.   It  is  also
              possible   to   specify  plugin  options  using  the  form:  --sound-source=  pulse

       --speaker=on|off|disabled and --microphone=on|off|disabled|on:DEVICE|off:DEVICE
              Sound input and output forwarding support: on will start the forwarding as soon  as
              the connection is established, off will require the user to enable it via the menu,
              disabled will prevent it from being used and the menu entry will be disabled.  With
              microphone forwarding, you may also be able to specify which device to use.

       --speaker-codec=CODEC and --microphone-codec=CODEC
              Specify the codec(s) to use for sound output (speaker) or input (microphone).  This
              parameter can be specified multiple times and the order in  which  the  codecs  are
              specified defines the preferred codec order.  Use the special value 'help' to get a
              list of options.  When unspecified, all the available codecs are  allowed  and  the
              first one is used.

              Sets  the  text  shown as window title.  The string supplied can make use of remote
              metadata placeholders which will be populated at runtime with the values  from  the
              remote server.  The default value used is "@title@ on @client-machine@".

              The following placeholders are defined:

                     Will be replaced by the remote window's title.

                     Will  be  replaced  by  the  hostname of the system where the application is
                     running, if provided, the xpra server's hostname otherwise.

                     Will be replaced by the hostname of the xpra server.

                     Will be replaced by the name of the display  on  which  the  application  is

              Specifies  the color and size of the border to draw inside every xpra window.  This
              can be used to easily distinguish xpra windows running on remote hosts  from  local
              windows.   The  BORDER  can  be  specified  using standard color names (ie: red, or
              orange) or using the web hexadecimal syntax (ie:  #F00  or  #FF8C00).  The  special
              color  name  "auto"  will  derive  the  color  from  the server target address (the
              connection string) so that connecting to the same target  should  always  give  the
              same  color.   You  may  also  specify  the  size  of  the  border  in  pixels, ie:

              Path to the default image which will be used for all windows.   This  icon  may  be
              shown  in the window's bar, its iconified state or task switchers.  This depends on
              the operating system, the window manage and the application may override this too.

              Choose what action to take when the window is closed by the client.  The  following
              actions can be used:

              auto   The  client  will figure out what is best based on the window type.  This is
                     the default.  ie: it will  use  disconnect  shadow  sessions,  Iforward  for
                     seamless windows.

                     The event will be forwarded to the server.

              ignore Do nothing.

                     Disconnect from the server.

                     Shutdown the server.

              Desktop  scaling  allows  the windows to be scaled by the client.  Downscaling will
              mostly waste bandwidth, upscaling allows the window's pixels to be  sent  over  the
              wire at a lower resolution, saving bandwidth and CPU time.  This option can also be
              used to request a specific scaling value.  For  best  results,  use  opengl  client
              rendering,  the  other  display  backends  may  show visual artifacts when scaling.
              Note: the scaling may also be adjusted at runtime  through  keyboard  shortcuts  if
              those are configured.

              The desktop-scaling value can take the form:

              off    scaling will be disabled

              on     scaling will be allowed, but it will start unscaled

              auto   scaling  will be allowed and a scaling value will be automatically chosen if
                     the client's desktop is large  (bigger  desktops  will  use  higher  scaling

                     scaling  will  be  enabled  and  use the given value, specified as a number,
                     fraction or percentage. ie: 2, 3/2 or 150%.

              pair   the scaling will be enabled and use a different value for the X and Y  axis.
                     ie: 3x2 or 3/2x4/3

                     the  scaling  will  be enabled and the server will render to the given size.
                     ie: 1600x1200

       --tray=yes|no Enable or disable the system tray.  Not available on OSX since the dock icon
       is always shown.

              Waits  for  the  first  window  or notification to appear before showing the system
              tray. (posix only)

              Specifies the icon shown in the dock/tray.  By default it  uses  a  simple  default
              'xpra' icon.  (On Microsoft Windows, the icon must be in ico format.)

              The  client and server will exchange ping and echo packets which are used to gather
              latency statistics.  Those statistics can be seen using the xpra info command.

   Options for attach, stop, info, screenshot, version
              When you use an ssh: address to connect to a remote display, xpra  runs  ssh(1)  to
              make  the  underlying  connection.  By default, it does this by running the command
              "ssh". If your ssh program is in an unusual location, has an unusual name,  or  you
              want  to  pass special options to change ssh's behavior, then you can use the --ssh
              switch to tell xpra how to run ssh.

              For example, if you want to use arcfour encryption, then you should run

                     xpra attach --ssh="ssh -c arcfour" ssh://frodo/7

              Note: Don't bother to enable ssh compression; this is  redundant  with  xpra's  own
              compression, and will just waste your CPU.  See also xpra's --compress switch.

              On  MS  Windows,  where  backslashes  are  used to separate path elements and where
              spaces are often used as part of paths, you need to add quotes around  paths.  (ie:
              ssh="C:\Program Files\Xpra\Plink.exe" -ssh -agent)

              Choose  whether  the  SSH  client  process  should be forcibly terminated when xpra
              disconnects from the server.  If you are using SSH connection sharing, you may want
              to avoid stopping the SSH master process instance spawned by xpra as it may be used
              by other SSH sessions.  Note: the exit-ssh=no detaches the  SSH  process  from  the
              terminal  which  prevents the SSH process from interacting with the terminal input,
              this disables the keyboard  interaction  required  for  password  input,  host  key
              verification, etc..

              When  connecting to a remote server over ssh, xpra needs to be able to find and run
              the xpra executable on the remote host.  If this executable is  in  a  non-standard
              location,  or  requires  special environment variables to be set before it can run,
              then accomplishing this may be non-trivial.  If running xpra  attach  ssh:something
              fails  because  it  cannot  find  the  remote xpra, then you can use this option to
              specify how to run xpra on the remote host.

              That said, this option should not be needed in normal usage, as  xpra  tries  quite
              hard  to  work  around  the above problems.  If you find yourself needing it often,
              then that may indicate a bug that we would appreciate hearing about.

   SSL Options
              Whether to enable SSL on TCP sockets and for what purpose.  The  TCP  sockets  will
              automatically be upgraded to SSL when SSL packets are received.

              auto   The  server  will  try  to  guess  what  protocol  to  use  for each new SSL
                     connection: either xpra's native protocol or https / websocket (wss)

              tcp    The SSL sockets will only be used for xpra's native protocol

              www    The SSL sockets will only be used for https and websocket (wss)
       If SSL is enabled, then a ssl-cert is required.  Authentication, if required, will use the
       ssl-auth  module  specified,  and  fallback  to  tcp-auth or auth unless the value none is

       The remaining options mirror the Python ssl  module  attributes.   Please  refer  to  that
       documentation  and  bear  in  mind  that  configuring SSL for security is not trivial, and
       definitely      not      just      a      matter      of      enabling      SSL.      See:  Some  options  may not be available with older
       versions of Python.

       Summary: --ssl-key=KEYFILE The key file to use.

              Certificate file, required for server SSL support.

              Specifies which version of the SSL protocol to use.

              The  ca_certs  file  contains  a  set  of  concatenated  'certification  authority'
              certificates. If a directory is specified, it should contain the certificates.

              Certificate data.

              Sets  the  available  ciphers,  it  should  be  a string in the OpenSSL cipher list

              Whether  to  try  to  verify  the  client's  certificates  and  how  to  behave  if
              verification fails.

              Whether  to  try  to  verify  the  server's  certificates  and  how  to  behave  if
              verification fails.

              The flags for certificate verification operations.

              Whether to match the peer cert's hostname.

              Set of SSL options enabled on this context.


              xpra start --start-child=... sets this variable in the environment of the child  to
              point to the xpra display.

              xpra  attach,  on the other hand, uses this variable to determine which display the
              remote applications should be shown on.

              fIXPRA_PASSWORD may be used with xpra attach instead of the password-file option.


       xpra.conf stores default values for most options.  There is a global configuration file in
       /etc  or  /usr/local/etc,  and  each user may override those defaults by creating the file
       .xpra/xpra.conf.  You can also split the options into multiple files by placing them in  a
       conf.d  directory  with  the  .conf extension.  Depending on OS and version, xpra uses the
       directory ~/.xpra or /run/<uid>/xpra to store a number of files.  (The examples below  are
       given for the display :7.)

              The  unix  domain socket that clients use to contact the xpra server, if the system
              configuration uses this directory.

              When run in daemon mode (the default), the xpra server directs all output  to  this
              file.  This includes all debugging output, if debugging is enabled.

              A  shell script that, when run, starts up xpra with the correct python interpreter,
              PYTHONPATH, PATH, location of the main xpra script, etc.   Automatically  generated
              by  xpra  initenv,  xpra  start and used by xpra attach (see also the discussion of


       Xpra has no test suite.

       Xpra does not fully handle all aspects of  the  X  protocol;  for  instance,  fancy  input
       features  like  pressure-sensitivity  on  tablets, some window manager hints, and probably
       other more obscure parts of the X protocol.  It does,  however,  degrade  gracefully,  and
       patches for each feature would be gratefully accepted.

       The  xpra  server allocates an over-large framebuffer when using Xvfb; this wastes memory.
       If the Xvfb does not support RandR this can also cause applications to misbehave (e.g.  by
       letting  menus  go  off-screen).  This is not a problem when using Xdummy, see the --xvfb=
       switch for details.  Conversely, if the framebuffer is ever insufficiently large,  clients
       will misbehave in other ways (e.g., input events will be misdirected).


       Send any questions or bugs reports to


       screen(1), winswitch_applet(1)