XRX(1)

NAME
       xrx - RX helper program

SYNOPSIS
       xrx [-toolkitoption ...] filename

DESCRIPTION
       The  helper  program  may  be used with any Web browser to
       interpret documents in the RX MIME type format  and  start
       remote applications.

       xrx  reads  in  the RX document specified by its filename,
       from which it gets the list of  services  the  application
       wants to use. Based on this information, xrx sets the var-
       ious requested services, including creating  authorization
       keys  if your X server supports the SECURITY extension. It
       then passes the relevant data, such as the X display name,
       to  the  application  through  an  HTTP GET request of the
       associated CGI script. The Web server  then  executes  the
       CGI  script  to  start the application. The client runs on
       the web server host connected to your X server.

INSTALLATION
       You need to configure your web browser to use xrx  for  RX
       documents.    Generally   the   following   line  in  your
       $HOME/.mailcap is enough:
             application/x-rx; xrx %s

       However, you may need to refer to your web browser's docu-
       mentation  for  exact  instructions  on configuring helper
       applications.

       Once correctly configured, your browser will activate  the
       helper  program  whenever you retrieve any document of the
       MIME type application/x-rx.

OPTIONS
       The xrx helper program  accepts  all  of  the  standard  X
       Toolkit command line options such as:

       -xrm resourcestring
               This  option  specifies  a  resource  string to be
               used. There  may  be  several  instances  of  this
               option on the command line.

RESOURCES
       The  application  class name of the xrx program is Xrx and
       it understands the following  application  resource  names
       and classes:

       xrxHasFirewallProxy (class XrxHasFirewallProxy)
               Specifies  whether an X server firewall proxy (see
               xfwp) is running and should be  used.  Default  is
               ``False.''

       xrxInternalWebServers (class XrxInternalWebServers)
               The  web  servers  for which the X server firewall
               proxy should not be used (only relevant when  xrx-
               HasFirewallProxy  is  ``True'').  Its  value  is a
               comma separated list of  mask/value  pairs  to  be
               used  to  filter  internal  web  servers, based on
               their address. The mask part specifies which  seg-
               ments  of the address are to be considered and the
               value part specifies what the result should match.
               For instance the following list:
                     255.255.255.0/198.112.45.0,
               255.255.255.0/198.112.46.0
               matches  the  address   sets:   198.112.45.*   and
               198.112.46.*. More precisely, the test is (address
               & mask) == value.

       xrxFastWebServers (class XrxFastWebServers)
               The web servers for which LBX should not be  used.
               The resource value is a list of address mask/value
               pairs, as previously described.

       xrxTrustedWebServers (class XrxTrustedWebServers)
               The web servers  from  which  remote  applications
               should  be  run as trusted clients. The default is
               to run remote applications as  untrusted  clients.
               The resource value is a list of address mask/value
               pairs, as previously described.

ENVIRONMENT
       The xrx helper program uses  the  standard  X  environment
       variables  such as ``DISPLAY'' to get the default X server
       host and display number. If the RX document requests X-UI-
       LBX  service  and  the default X server does not advertise
       the LBX extension, xrx will look for the environment vari-
       able  ``XREALDISPLAY''  to get a second address for your X
       server and look for the LBX extension there. When  running
       your browser through lbxproxy you will need to set XREALD-
       ISPLAY to the actual address of your server  if  you  wish
       remote  applications  to  be  able  to  use LBX across the
       Internet.

       If the RX document requests XPRINT service, xrx looks  for
       the  variable  ``XPRINTER''  to get the printer name and X
       Print server address to use. If the server address is  not
       specified  as  part  of  XPRINTER,  xrx uses the first one
       specified through the variable ``XPSERVERLIST'' when it is

       set. When it is not xrx then tries to use the video server
       as the print server. If the printer name is not  specified
       via   XPRINTER,   xrx   looks  for  it  in  the  variables
       ``PDPRINTER'', then ``LPDEST'', and finally ``PRINTER'',

       Finally, if you are using a firewall proxy, xrx will  look
       for  ``PROXY_MANAGER''  to  get  the address of your proxy
       manager (see proxymngr). When not specified  it  will  use
       ":6500" as the default.

KNOWN BUG
       When an authorization key is created for a remote applica-
       tion to use the X Print service, the helper program has to
       create the key with an infinite timeout since nobody knows
       when the application will actually connect to the X  Print
       server.  Therefore, in this case, the helper program stays
       around to revoke the key when the  application  goes  away
       (that  is  when  its  video  key expires). However, if the
       helper program dies unexpectedly the  print  authorization
       key will never get revoked.

SEE ALSO
       libxrx(1) xfwp(1) lbxproxy(1) proxymngr(1) The RX 
       Document specification

AUTHOR
       Arnaud Le Hors, X Consortium