Inessential Resources for Techno-Dweebs
This document assumes you have some knowledge and experience with the X
window system, your favorite text editor, and some UNIX commands and file
conventions. Having stated that disclaimer, now to answer the question
above. As stated in the X man page, "To make the tailoring of applications
to personal preferences easier, X supports several mechanisms for storing
default values for program resources (e.g. background color, window title,
etc.)" In other words, X resources exist so users can easily make
customizations to their X session's interface.
X resources should be located in a file titled .Xresources in your
home directory. If you are new to using X resources, you probably
won't have this file. Fret not; just create one with your favorite
text editor. And away you go. Oh, don't forget to make sure the
capitalization and spelling are correct. One last thing that you
should remember is that the dot in front of the filename also makes it
invisible to a casual
If it is not evident already, X resources provide a powerful and easy to use
tool for customizing your X session. Some of the more astute readers may have
noticed that you can also use command line options to customize programs
(often in many more ways than available as X resources). While command
line options are powerful, and better for customizing individual
instantiations of programs, X resources are much better for setting general
For example, say you wanted red text on a black background for all your
Xterm windows. You could remember to type
red -bg black & everytime you want a new xterm window. Or you could
just add the lines
to your .Xresources file. Then whenever you type
xterm &, your
xterm window will automatically be customized. This is a rather simple and
pointless example, but it is quite easy to see other uses (such as zwgc or
emacs) for which X resources are a much more practical tool than command line
X resources are specified by the name of the application followed by a
variable name followed by a colon, space, and a value. It usually
looks like this:
Capitalization is important, and make sure that there is a space
between the colon and the assigned value. And of course, don't forget the
colon; although it may not seem that significant, without the colon
your X resource assignment will be ignored. Also, from now on, the
subresources mentioned above will be referred to as widgets, as they
are called in the X specification.
Okay. So it's not entirely as simple as that. No primer on X resources
would be complete without a discussion of classes. Each part of a resource has a
class associated with it. Classes are there to make it easier to
modify many X resources with a single command. For instance, if you
were modifying xclock and you wanted to make the foreground tic marks
and the hands dark blue, you could type
Or you could note that all three resources are in the class Foreground
(class names have the first letter capitalized by convention) and just type
This command will set all the components of the class Foreground to
dark blue, saving you time and typing. Classes can also make your
changes much easier to understand and implement. Isn't that neat? :)
The X system also provide a few options for maintaining and
with X resources.
For starters, all programs written with the X toolkit intrinsics
support two additional switches that allow you to modify programs on
launch with X resources (essentially combining the flexibility of
switches with the power of X resources). This is a wonderful way to test X resources
before adding them to your .Xresources file (hint, hint). These two
switches that are available are:
The xrdb program is an X
program that allows you to manage and update the environment from
your X resource files. This program is automatically invoked with your
.Xresources file on startup, but can be called later at any time. A
few of the available switches to use in xrdb are:
- -xrm "X resource"
- This switch allows you to specify on a command line an X resource
in quotes to modify the instantiation on launch.
- -name filename
- This switch allows you to design and specify a special group of X
resources to modify a file on launch.
- -load filename
- This loads the file into the internal X resources database and
interprets it appropriately.
- Using this switch displays all of the X resource modifications
from the defaults that are currently loaded and in use. It does not
display default X resources (and you should be thankful for that,
since it would scroll quite a bit).
- -merge filename
- This switch is very similar to -load. Except it only loads into
the database resources not already modified. No current resources are
changed by it.
Every application that uses X Toolkit Intrinsics should support
some of the following few X resources, unless they are extremely absurd
or flaky (both of which are probably a bad idea to modify with X
resources anyway). Just
precede them with the name of the application you are modifying.
- number - a numerical value
- logical - a logical value. This may be on/off, true/false, t/f,
1/0, etc. (
- color - A color can be specified by name or RGB value
specified in hexadecimal. A
large online listing
which contains the names of all the colors referenced by name in the X window
system with decimal values (from 0 to 255) is also available.
- font - a system font (
- string - a string of characters
- coordinates - Mainly used by the geometry resource, this value
data type has two parts. The first part is heightxwidth.
The second part is +/-x+/-y; a negative x or y means from the
right (or bottom) instead of from the left (or top). Either part may be
left out. (
In addition to specifying customizations on a program by program basis,
you can change the resources based on X variables. To see a list of the
variables which are set, and their values, for a specific platform use
xrdb -symbols. This gives a list of items of the form
-Dvariable=value; each of these means that variable
is set to value.
- background: color
- Use this switch to set the color of the background of a window.
- borderWidth: number
- This resource allows you to set the width in pixels of the border
around the window.
- borderColor: color
- This is the resource that sets the color of the aforementioned
- foreground: color
- Most applications also support this resource, which allows you to
set the color of foreground text and occaisionally graphics.
- geometry: coordinates
- This is also supported by most applications, and lets you specify
the position and size.
To take advantage of these, you can use the following: (these
are just standard C preprocessor constructs)
- This will only load resources if variable is set, and
other-resources otherwise. The
#'s must be the first
characters on their lines. The
#else is optional.
- This does the opposite of
#ifdef, i.e. it loads
resources if variable is not defined.
- This loads resources if comparison is true.
comparison can be a C comparison statement, and can include variables,
#if WIDTH < 1000 ....
- The value of variable will be substituted. For example, you could
xterm*title: HOST to have the title of all xterm's be the
name of the host you are on.
- This will include the file filename in the resources being loaded
as if it were typed right there. Again, the
# must be the first
character in its line.
Additional X Resources
In addition to the standard X resources supported by practically all
applications, some applictions also have additional X resources that can be
modified. Below you can find a few applications and some of the x resources
you can modify for them. It is by no means a definitive list, nor does
it cover all applications, but it should answer most of your needs.
Here are some customizations you can make to the Athena Dash program.
(All resources preceded by
These resources allow you to make cosmetic changes to the powerful and
popular emacs text editor. (resources preceded by
- autoRaise: logical
- If set to true, any menu window from dash will automatically be
brought forward to the front of the screen whenever the mouse enters
it. (Default: false)
- overrideRedirect: logical
- This resource sets whether windows in dash are created with
override redirect set, an option which most window managers interpret
by not letting the user drag around or decorate the window. (Default:
on for the Dash menu bar itself, off for any other windows)
- rude: logical
- Sets whether Dash keeps the mouse grabbed when a menu is opened or
not. (Default: true)
- verify: logical
- Sets whether dash will ask for confirmation before running most menu
items. (Default: true)
"For the love of God, montressor!"
These are some important resources to change Mosaic, the popular and
splufty web browser from NCSA. Enjoy. (All resources preceded by
- Font: font
- Sets the window's text font. (Default: fixed)
- ReverseVideo: logical
- If set to on, the window will be displayed in reverse video
- iconsUseBitmap: logical
- If set to on, the emacs window will iconify to the "kitchen sink"
- BorderWidth: number
- Sets the width of the window border in pixels
- CursorColor: color
- Set the color of the text cursor (default: black)
- PointerColor: color
- Set the color of the window's mouse cursor. (default: black)
Xclock uses the Athena clock widget, and can be modified in the
following ways. (Preceded by a
- annotationsOnTop: logical
- Indicates whether to prepend inlined document annotation
hyperlinks to the document as opposed to postpending them. (Default:
- autoPlaceWindows: logical
- If this resource is set to false, any new document windows will
not be positioned automatically by Mosaic, but rather left for your
window manager to handle. (Default: true)
- confirmExit: logical
- Toggle for whether or not Mosaic prompts you with the window
asking that you're really, really sure that you want to quit.
- defaultHeight: number
- Default height in pixels for a Document view window. (Default: 680)
- defaultHotListFile: string
- The name of the file that stores the default hotlist. (Default: a
file .mosaic-hotlist-default in your home directory)
- defaultWidth: number
- The default width of a Documents window. (Default: 620)
- delayImageLoads: logical
- For users with slow net connections or an aversion to graphics
loading. When this option is activated, Mosaic will substitute a small
representative icon with an additional arrow icon above if it is a
link. Clicking the representative icon will load the image, and
clicking on the arrow will follow the link. This can also be changed
for individual windows from the menu. (Default: false)
- fancySelections: logical
- Changes the formatting of cut and paste operations performed in
the Mosaic document window. (Default: false)
- homeDocument: string
- The location of the file that Mosaic starts up in when you run it.
Use this to start up Mosaic in your home page for instance. (Default
here at MIT: "http://www.mit.edu:8001/")
- imageCacheSize: logical
- Used to set the size of the inlined-image cache in kilobytes. (Default: 2048 Kb)
- initialWindowIconic: logical
- If set to true, Mosaic will be iconfied when first opened. (Default: false)
- printCommand: string
- This is the name of the default command used by the Print menu
option. This can also be changed in the print options dialog.
- reloadReloadsImages: logical
- If this option is activated, Mosaic will delete cached image data
for a document on a Reload command, meaning it reloads not only text
but also graphics. Useful for developers. (Default: false)
- simpleInterface: Boolean
- Makes Mosaics menu bar and bottom line options much fewer, for the
complexly challenged. (Default: false)
- trackfullURLs: logical
- Activates that neat function of displaying destination URLs
when you move the mouse over hotlinks. (Default: true)
- trackVisitedAnchors: logical
- Will display visited links in a different format from unvisited
links if true. (Default: true)
Here are a few resources to modify the xload program, used by the
really cool computer nerds on campus. It's a great program to impress
the desired sex to be sure. (all resources preceded by
- width: number (class Width)
- Use this resource to specify the width of the clock window in pixels.
(Default: 164 for analog clocks, as large as needed for digital)
- height: number (class Height)
- This resource specifies the height of the clock in pixels.
(Default: 164 for analog, and as large as necessary for digital)
- update: number (class Interval)
- This number specifies the frequency in seconds that the time
should be redisplayed and updated.
- foreground: color (class Foreground)
- This X resource allows you to specify the color of those wonderful
tic marks on the clock that let you read the time accurately.
(Default: if reversevideo is on, white. Otherwise, it is black.)
- hands: color (class Foreground)
- Use this resource to specify the color inside the clock hands.
(Default: same as for foreground)
- highlight: color (class Foreground)
- This determines the color of the outside border of those clock
hands. (Default: same as for foreground)
- analog: boolean (class Boolean)
- Toggles whether the clock is analog (true) or digital (false).
- chime: boolean (class Boolean)
- This resource toggles whether the chime rings on the hour and half
hour or not. (Default: true)
- padding: number (class Margin)
- This resources sets the size of the window margin in pixels.
- font: font (class Font)
- Use this to specify the font used for the digital clock.
These let you play with how your xmh looks and acts. (all resources preceded
- showLabel: Boolean (class Boolean)
- This resource toggles whether the machine name is displayed as a
label on the load diagram. (Default: true)
Put something in here.
- banner: string
- This controls the text at the top of the window. (Default:
"xmh MIT X Consortium R5")
- compGeometry: coordinates
- The size and/or position for composition windows.
- draftsFolder: string
- The folder used for message drafts. (Default: drafts)
- hideBoringHeaders: boolean
- If set, then xmh will attempt to skip the boring header lines
in a message by scrolling them off the top of the view. (Default: true)
- initialFolder: string
- Which folder to display on startup. (Default: inbox)
- replyInsertFilter: string
- A shell (sh) command to be executed when the Insert button is
activated in a composition window. The full path and filename of the
source message is appended to the command before it is run. You can
use something like sed 's/^/> /' to insert "> " in front of each line.
- showOInInc: boolean
- Whether to automatically show the first new message after incorporating
new mail. (Default: true)
- skipCopied: boolean
- skipDeleted: boolean
- skipMoved: boolean
- Sets whether messages which have been marked for copying, deleting, or
moving, respectively, will be skipped when view next or previous message
is selected. (Default: true)
- tocPercentage: number
- The percentage of the main window that is use to display the
table of contents (Default: 33)
When most people ask me questions about X resources, it's usually to
mess around with their zephyrgrams. This is definitely the most popular
customization used. (Resources preceded by
- title: string
- cursorColor: color (class: Foreground)
- (Default: black)
- font: font
- jumpScroll: boolean
- (Default: true)
- pointerColor: color (class: Foreground)
- pointerColorBackground: color (class: Background)
- pointerShape: cursor
- (Default: "xterm")
- saveLines: number
- (Default: 64)
- scrollBar: boolean
- (Default: false)
- scrollTtyOutput: boolean
- (Default: true)
- scrollKey: boolean
- (Default: false)
- visualBell: boolean
- (Default: false)
- cursorCode: number
- Number of a code from the cursorfont to use for the windows
- pointerColor: color
- Primary mouse pointer color (default: foreground color)
- reverseVideo: logical
- Activates reverse video. (default: off)
- borderWidth: number
- Use this resource to specify the primary border width
in pixels. (default: 1)
- internalBorder: number
- Width of the primary border width between edge and text. (default: 2)
- resetSaver: logical
- Force screen to unsave when a message first appears (default: true)
- reverseStack: logical
- Specifying true here instructs zwgc to attempt to reverse the
message stack so that older messages appear on top of the stack.
Some window managers may ignore this, and stifle zwgc's attempts to
restack, leading to strange results. In other words, not guaranteed.
- title: string
- Primary window title (default: last pathname component of the program name, usually "zwgc")
- minTimeToLive: number
- This parameter sets the minimum amount of time in
milliseconds that a Windowgram must be on screen before it can be
destroyed. Very usueful to avoid accidentally clicking away zephyrs.
- cursorCode: number
- Character number in the cursor font to use for the mouse cursor
in zephyr windows; should be even (Default: 8)
- style.stylename.geometry: coordinates
- style.stylename.background: color
- stylename is class.instance.recipient of the zephyrs to be
affected, with .'s replaced by _'s and all letters in lowercase. As
always, wildcards can be used. Example: zwgc*style.sipb*geometry: -0+0
will display all zephyrs on class sipb in the upper-right corner of the
Okay, now that you know everything you could possible care about on X
resources, you sit down and hack your X session to be truly hideous.
But then you notice something is wrong...
Some general things which might help:
- ignore customizations
- use more/less specific resource name (more/fewer wildcards)
This document was meant to be only a basic primer in using X resources
and not a comprehensive reference. If you want more depth, more
resource options, or just a different source, there are several
options you can use.
- For greater insight into the workings of the X window system,
there are various references available. SIPB recommends the guides by
O'Reilly and Associates. Look for useful books at a local bookstore,
library, or stop by the SIPB office and browse our selections.
Read all you want; our only demand is that the book must stay in the office.
- For more information on a particular program's X resources and a
good online reference, check out the program's manual. Even better,
look for the program's man page either by using the UNIX man command,
or even by browsing the web!
As before, you can also ask at the SIPB office for specific information.
- If you have noticed any glaring oversights or you just want me to answer
your question personally or tell me how cool/essential/stupid/pathetic
(select which one applies) this document is, feel free to send me email at
firstname.lastname@example.org. Thank you. And have fun.
Last modified: Tues Jan 24 1995 by email@example.com