How do I produce a unified diff searching only for a specific string between source and original. I want to patch my kernel-2.4.spec with hz1000. Like search for lines containing "hz1000", but there is more changes between in the specs files but I only want to diff the hz1000 stuff. # diff -u kernel-2.4-hz1000.spec kernel-2.4spec Any hints would be greatly appreciated. Cheers, Chris