Consultor Eletrônico

Assuring that remote X servers properly load X resources

DRAFT COPY - Currently under review and edit.

INTRODUCTION:
=============

Remote X servers, such as those found on X terminals and in PC X
emulation, do not always load X resources automatically. Reference
books on X Windows might lead you to expect that this resource-loading
ALWAYS takes place automatically, while in fact it might be true only
when you work on the host console or a network with mounted file
systems. Since remote X servers usually do not have direct access to
a network disk, they typically require you to use some means of
forcing a resource load. Most of the products currently available
have built-in customized features for this process. To learn more
about these features, consult the manufacturer's documentation.

This notebook entry describes how to load X resources using an X
Window utility that should be available on any standard X environment.


WHY YOU NEED TO KNOW THIS:
===========================
X resource problems present themselves in a number of ways. You
might make a change to a valid X resource file and, when you start
PROGRESS, discover that the changes are not being recognized. Or,
when you try to use an ADE feature such as HyperHelp for the first
time, you might be confronted with a blank or completely blacked-out
display. If you are working with any kind of remote X server product,
then it is especially important to verify that X resources are being
loaded to your server properly.

PROCEDURAL APPROACH:
====================
The X executable "xrdb" provides a means for querying, merging, and
loading X resource files. This notebook entry describes some of
the uses for "xrdb", but it is not an exhaustive overview. For
more information, consult on-line X documentation or any of the
X reference guides available commercially.

NOTE: "xrdb" should be available on any standard X environment. If
you cannot locate this executable, consult your system administrator
to verify that the "xrdb" source was compiled when X was installed on
your host system.

Follow these steps to verify X resource loading:

1> Make sure that the $DISPLAY environment variable is properly set.
Any remote X server on a network is assigned a hostname and/or
IP address. In X Windows, the $DISPLAY variable setting for a
device is typically its hostname or IP address with a ":0" or
":0.0" appended to the end.

For example, for an X terminal with the hostname NCD15, the
$DISPLAY variable would be NCD15:0 or NCD15:0.0.

The $DISPLAY should NOT be set to point to the host
where PROGRESS is installed. It must point to the actual display
where PROGRESS will run. With remote X servers, the whole idea is
to run an X client (such as PROGRESS) on a dsipaly that is
separate from the host where it resides.


2> Use the "xrdb -query" command to verify what X resources are
loaded. Pipe this command into the UNIX "more" command to page
the output:

xrdb -query | more

3> If it is clear, from looking at the output of the xrdb -query h
command, that the X resources have not been completely loaded
into the X server, use the "xrdb - load" command to initiate a
load of an X resource file. Progress Software recommends that
you maintain a file for your own personal use that contains the
X default settings that you would like to use, and store this
file in your home directory. Such a file is commonly named
.Xdefaults or .Xresources, but when you use "xrdb", it can be
any filename that you prefer.

Use the "xrdb -load" command as follows:

xrdb -load <complete pathname for X resource file>

For example, if the X resource file is /home/user1/.Xdefaults,
the "xrdb" command would be:

xrdb -load /home/user1/.Xdefaults

4> Repeat step 2. The output should show that all of the X resources
listed in the file have been loaded to the server. If you still
have problems, check the resource names and/or values for:

- Mispelling.
- Improper use of lower- and upper-case letters.(X resources are
case-sensitive, and X does NOT generate errors when resources
are incorrectly named.)


ONLINE PROCEDURES OR UTILITIES:
===============================
None.


REFERENCES TO WRITTEN DOCUMENTATION:
====================================
Several references are commerically available which discuss X resource
processing. The one most widely recommended is Volume Three of the
X Window System series, "X Window System User's Guide," published by
O'Reilly and Associates, Inc. Volume 8 in this series, "X Window
System Administrator's Guide," is also very helpful in its discussion
of X resource issues which arise when networking servers across a
network.

Progress Software Technical Support Note # 12861