I'm running
diff -rq linux-4.15-rc9/ ubuntu-bionic/ > ubuntu.diff
but the output is just a bunch of lines with:
Files linux-4.15-rc9/tools/perf/util/metricgroup.c and ubuntu-bionic/tools/perf/util/metricgroup.c differ
I wanted a large file with all the actual diffs (line insertions and deletions) between each file
You don't want the -q option since that is what is generating your list of files that are different.
Something like
diff -Naur /path/to/original /path/to/changed
Should generate what you want. If it does, simply redirect output to a file to use used as a patch.
diff -Naur /path/to/original /path/to/changed > /path/to/my_changes.patch
