Want to modify the middle of a file without messing with the rest of the file?
Let's say you have a 1MB file and some contents at offset 999335 (because you looked in xxd -g 1 and found it on offset line 999328 and was 7 entries over).
Here goes (just make sure you don't exceed the region you want to write to):
That's it. If you leave off conv=notrunc then your file gets truncated. If you use skip instead of seek then you'll wind up with a zero size file.
Now if I can just get this to work on /dev/mem or /dev/kmem then I'll be happy. Looks like I'll have to take the time to make a kernel module to do this for me.
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