Gets a resource value from the resource database. If file is #f, the platform-specific resource database is read, as determined by find-graphical-system-path with 'setup-file. (Under X, when file is #f, the user's .Xdefaults file is also read, or the file specified by the XENVIRONMENT environment variable.)
The resource value is keyed on the combination of section and entry. The "mred" section is reserved for PLT.
The return value is #t is a value is found, #f if it is not. The type of the value initially in the value box determines the way that the resource is interpreted, and value is filled with a new value of the same type if one is found.
See also write-resource.