Question

I want to patch whole directory tree. Although diff finds all differences, patch does apply these to relevant files. When I change a file in subdir I can see patch crate that file one level above it should in the directory tree being patched.

I use command:

diff -Nur extern/ local/ | patch -d extern

what is wrong with that?

Answer 1

Since you’re passing -d dir (“Change to the directory dir immediately, before doing anything else.”) you also need to tell patch to strip off one level of directories with -p:

diff -Nur extern/ local/ | patch -d extern -p1

That’s because diff’s output will look something like this:

+++  extern/foo.x
---  local/foo.x
@@ -21,7 +21,9 @@

- yyy
+ xxx

… so you need to get rid of that first prefix in the path.