I want to initialize XPCOM using NS_Initiembedding but would like to specify a different directory for the GRE. I understand that I would> have to write my own implemenation of nsILocalFile but which functions
First, have you looked at xpcom/glue/standalone? If you want to specify custom GRE directories, you should probably write a custom version of the GREDirectoryService... you don't need to implement nsILocalFile... you can use NS_NewNativeLocalFile (which is avilable from the glue library).
--BDS
