(git) diff output relative path?

Question

I need to get some diffs in my repo that are not relative to the base of the repo, but instead relative to a given base or given path.

By default I get:

Answer 1

Seems like --src-prefix and --dst-prefix are what you're asking for:

$ cd .../git/builtin
$ ed - var.c << end
> 0a
> xxx
> .
> wq
> end
$ git diff
diff --git a/builtin/var.c b/builtin/var.c
index aedbb53..5210013 100644
--- a/builtin/var.c
+++ b/builtin/var.c
@@ -1,3 +1,4 @@
+xxx
 /*
  * GIT - The information manager from hell
  *

(so far, pretty standard; now:)

$ git diff --src-prefix=a/new/ --dst-prefix=b/new/
diff --git a/new/builtin/var.c b/new/builtin/var.c
index aedbb53..5210013 100644
--- a/new/builtin/var.c
+++ b/new/builtin/var.c
@@ -1,3 +1,4 @@
+xxx
 /*
  * GIT - The information manager from hell
  *

You can combine this with --relative:

$ git diff --relative --src-prefix=a/new/ --dst-prefix=b/new/
diff --git a/new/var.c b/new/var.c
index aedbb53..5210013 100644
--- a/new/var.c
+++ b/new/var.c
@@ -1,3 +1,4 @@
+xxx
 /*
  * GIT - The information manager from hell
  *
$