DESCRIPTION
Lists all resources, which has been set so far. Resources are special
kind of parameters which are also set with PS_set_parameter(3). A
parameter becomes a resource if its value is itself a name/value pair
separated by an equal sign. Common resources are often files but can also
be properties of a character as for example the left and right margin
protusion. This function is mostly used for debugging. The output is
printed to stdout.