The opposite of diff
turns out to be sdiff
which is distributed in the same package.
Use it like this:
sdiff --output=./merged file1 file2
It will open up a prompt that has commands. Use v
or s
to merge common lines automatically and eb
to edit changes in your EDITOR
.
There used be a merge
command as part of the RCS package. But nobody uses RCS anymore so it's not available.