Programs running under the X Window System organize their user options under a hierarchy of classes and resources. You can specify default values for these options in your X resources file, usually named ~/.Xdefaults.
Each line in the file specifies a value for one option or for a collection of related options, for one program or for several programs (optionally even for all programs).
Programs define named resources with particular meanings. They also define how to group resources into named classes. For instance, in Emacs, the internalBorder resource controls the width of the internal border, and the borderWidth resource controls the width of the external border. Both of these resources are part of the BorderWidth class. Case distinctions are significant in these names.
In ~/.Xdefaults, you can specify a value for a single resource on one line, like this:
Or you can use a class name to specify the same value for all resources in that class. Here's an example:
If you specify a value for a class, it becomes the default for all resources in that class. You can specify values for individual resources as well; these override the class value, for those particular resources. Thus, this example specifies 2 as the default width for all borders, but overrides this value with 4 for the external border:
emacs.Borderwidth: 2 emacs.borderwidth: 4
The order in which the lines appear in the file does not matter. Also, command-line options always override the X resources file.
The string emacs in the examples above is also a resource name. It actually represents the name of the executable file that you invoke to run Emacs. If Emacs is installed under a different name, it looks for resources under that name instead of emacs.
Use name as the resource name (and the title) for the initial Emacs frame. This option does not affect subsequent frames, but Lisp programs can specify frame names when they create frames.
If you don't specify this option, the default is to use the Emacs executable's name as the resource name.
Specify X resource values for this Emacs job (see below).
For consistency, -name also specifies the name to use for other resource values that do not belong to any particular frame.
The resources that name Emacs invocations also belong to a class; its name is Emacs. If you write Emacs instead of emacs, the resource applies to all frames in all Emacs jobs, regardless of frame titles and regardless of the name of the executable file. Here is an example:
Emacs.BorderWidth: 2 Emacs.borderWidth: 4
You can specify a string of additional resource values for Emacs to use with the command line option -xrm resources. The text resources should have the same format that you would use inside a file of X resources. To include multiple resource specifications in resources, put a newline between them, just as you would in a file. You can also use #include "filename" to include a file full of resource specifications. Resource values specified with -xrm take precedence over all other resource specifications.
The following table lists the resource names that designate options for Emacs, each with the class that it belongs to:
Background color name.
Use a bitmap icon (a picture of a gnu) if on, let the window manager choose an icon if off.
Color name for the external border.
Width in pixels of the external border.
Color name for text cursor (point).
Font name for text (or fontset name, Section 20.9).
Color name for text.
Window size and position. Be careful not to specify this resource as emacs*geometry, because that may affect individual menus as well as the Emacs frame itself.
If this resource specifies a position, that position applies only to the initial Emacs frame (or, in the case of a resource for a specific frame name, only that frame). However, the size if specified here applies to all frames.
Name to display in the icon.
Width in pixels of the internal border.
Additional space (leading) between lines, in pixels.
Give frames menu bars if on; don't have menu bars if off.
Number of lines to reserve for the tool bar. A zero value suppresses the tool bar. If the value is non-zero and auto-resize-tool-bars is non-nil, the tool bar's size will be changed automatically so that all tool bar items are visible.
If none, don't make a minibuffer in this frame. It will use a separate minibuffer frame instead.
Font name for menu pane titles, in non-toolkit versions of Emacs.
Color of the mouse cursor.
Switch foreground and background default colors if on, use colors as specified if off.
Gamma correction for colors, equivalent to the frame parameter screen-gamma.
Run Emacs in synchronous mode if on. Synchronous mode is useful for debugging X problems.
Name to display in the title bar of the initial Emacs frame.
Give frames scroll bars if on; don't have scroll bars if off.
Here are resources for controlling the appearance of particular faces (Section 13.1):
Font for face face.
Foreground color for face face.
Background color for face face.
Underline flag for face face. Use on or true for yes.