4 ms·Have you seen the spec for .doc and .xls ?by brianwawok 10y agoHave you seen the spec for .doc and .xls ?maxxxxx 10y agoI don't even want to know :)grkvlt 10y agoOh, you really do! The format for COM object based documents like XLS and DOC is actually a FAT filesystem: https://en.wikipedia.org/wiki/Compound_File_Binary_Format https://en.wikipedia.org/wiki/Compound_File_Binary_Format