X resources

In the X Window System, the X resources are parameters of computer programs such as the name of the font used in the buttons, the background color of menus, etc.

X resources are also used to specify parameters for the program that are not directly related to its widgets, using the same syntax.

Contrary to most databases, the stored data can be specified loosely (via wildcard characters), but the interrogation cannot.

During X display server execution, the X resources are stored in two standard locations, depending on whether they apply to all screens or to a particular one: X resources are stored in the server rather than in a configuration file to allow programs started from other computers to use them.

Indeed, a program connecting to an X display server from another computer can access the resources via the X protocol.

In particular, many X display server configurations run xrdb at start up, instructing it to read the resources from the .Xresources file in the user's home directory.

Xlib contains a number of convenience functions for accessing the resources on the server and manipulating them locally.

For the sake of efficiency, integers called quarks are defined to represent local strings.