This function returns the “current working directory” of the processor. This function takes no arguments and does not depend on the context. This function should only be implemented by processors for which the concept of a “current working directory” is coherent.

There are no standard XProc steps that change the working directory, so this function is likely to return the same value every time it is called. However, there is nothing which prevents an extension step from being defined which changes the current working directory, so it is not necessarily the case that the same value will always be returned.