Understanding resources

Precedence rules for resource specifications

Because of the great flexibility you have in defining resource specifications, it is not uncommon to create specifications that conflict with each other. For example, take the following resource specifications for a hypothetical client, xclient:

   xclient*Buttons*background:  blue
   xclient*help*background:     red

The first resource specification sets the background color of all buttons to blue. The second resource specification overrides the value specified in the first specification, but only for the instance of widgets with the name ``help.'' In the event of conflicting specifications such as this, there are a number of rules that the resource manager follows in deciding which resource specification should have priority. In the case of a conflict, the most specific resource definition is used.

The precedence rules are as follows:

The dot delimiter takes precedence over the asterisk delimiter. For example, XTerm.VT100.geometry is more specific than XTerm*geometry.
Instance names take precedence over class names. For example, *foreground is more specific than *Foreground.
An instance or class name that is stated explicitly takes precedence over one that is omitted. Specifying a component is more specific than omitting it. For example, the following definition:

ScoTerm*XmMenuShell*XmRowColumn*XmLabel*fontList
is more specific than:

ScoTerm*fontList.

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SCO OpenServer Release 5.0.7 -- 11 February 2003