I would like to take an extremely large file (multi-gigabyte) and edit
it by removing a chunk out of the middle.  This is easy enough by
reading in the entire file and spitting it back out again, but it's
hardly efficent to read in an 8GB file just to remove a 100MB segment.

Is there another way to do this?

Is it possible to modify the inode structure of the underlying
filesystem to free blocks in the middle?  (What to do with the half-full
blocks that are left?)  Has anyone written a tool to do something like
this?

Is there a way to do this in a filesystem-independent manner?

Thanks,
-- Bob

Bob McElrath (rsmcelrath@students.wisc.edu) 
Univ. of Wisconsin at Madison, Department of Physics