xrx - RX helper program
xrx [-toolkitoption ...] filename
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 various 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
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; /usr/bin/X11/xrx %s
However, you may need to refer to your web browser's documentation 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
The xrx helper program accepts all of the standard X Toolkit command
line options such as:
This option specifies a resource string to be used. There may
be several instances of this option on the command line.
The application class name of the xrx program is Xrx and it
understands the following application resource names and classes:
xrxFastWebServers (class XrxFastWebServers)
The web servers for which LBX should not be used. Its value is
a comma separated list of mask/value pairs to be used to
filter web servers, based on their address. The mask part
specifies which segments of the address are to be considered
and the value part specifies what the result should match. For
instance the following list:
- 1 - Formatted: August 2, 2006
matches the address sets: 198.112.45.* and 198.112.46.*. More
precisely, the test is (address & mask) == value.
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.
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 variable ``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 XREALDISPLAY 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'',
When an authorization key is created for a remote application 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.
The Open Group
libxrx (1), lbxproxy (1), proxymngr (1)
- 2 - Formatted: August 2, 2006