Extension is not all so interesting because, as you point out,
most of it is C code, and .h files are mostly like .c in that they
have structs and function prototype keywords. But sorting by
name buys:
-rw-r--r-- 1 jengelh users 45477128 Oct 12 18:47 linux-2.6.23.1.orig.tar.bz2
-rw-r--r-- 1 jengelh users 45560647 Oct 16 16:18 linux-2.6.23.1.new.tar.bz2
(actually, `find "$@" -print0 | sort -z | tar -T- --null --no-r --owner=root
--group=root -cvjf "$output";` was used)
-