David (and other cross-platform GX Developers), Alastair is correct in all he says. I imagine that you want to read files created on a Sun, or write files to be read on a Sun, and you know exactly the data structure of the file. Under 4.2 GX Developer, you really need to write your own DLL to handle the reading/writing and/or byte swapping appropriate for the file at hand. The up-coming 4.3 will be able to read/write in any byte order by adding a qualifier to the file data type in the BF read/write functions (this was not implemented in the 4.3 Beta 1, but will be in the final release). As for the XDR stuff, as Alastair points out, this is used internally to allow us to serialize and read our own data objects in a neutral format (lots of jargon for non-object oriented types). You really do not need to be aware of this. However, this does bring up a common request that we receive, which is to document the physical file format of our class objects (maps, gdb files, etc.). These are object-oriented files that use serialization techniques like XDR, our own forward/backward compatible versioning model, structured file storage (etc. - more jargon). What this means is that we can and do change the physical file format to allow us to expand and evolve as your needs change (the addition of compression in 4.3 for example). For all of our object files, you really need to use the GX API to open and use the contents of the files. This will insure that your GX's and programs can read past and future files as they change. Regards Ian _______________ Geosoft Inc. Ian MacLeod [EMAIL PROTECTED] (416) 369 0111 x323 Geosoft: Spatial Data Processing and Analysis Solutions http://www.geosoft.com _______________________________________________________ More mailing list info http://www.geosoft.com/support/listserv/index.html
