quiet:
--- a/foo	Mon Jan 12 13:46:40 1970 +0000
+++ b/foo	Mon Jan 12 13:46:41 1970 +0000
@@ -1,1 +1,1 @@ bar
-bar
+foobar

normal:
diff -r 74de3f1392e2 -r b8b5f023a6ad foo
--- a/foo	Mon Jan 12 13:46:40 1970 +0000
+++ b/foo	Mon Jan 12 13:46:41 1970 +0000
@@ -1,1 +1,1 @@ bar
-bar
+foobar

verbose:
diff -r 74de3f1392e2 -r b8b5f023a6ad foo
--- a/foo	Mon Jan 12 13:46:40 1970 +0000
+++ b/foo	Mon Jan 12 13:46:41 1970 +0000
@@ -1,1 +1,1 @@ bar
-bar
+foobar

debug:
diff -r 74de3f1392e2d67856fb155963441f2610494e1a -r b8b5f023a6ad77fc378bd95cf3fa00cd1414d107 foo
--- a/foo	Mon Jan 12 13:46:40 1970 +0000
+++ b/foo	Mon Jan 12 13:46:41 1970 +0000
@@ -1,1 +1,1 @@ bar
-bar
+foobar