add-with backslash.diff
diff -pruN a/post\image.txt b/post\image.txt
--- a/post\image.txt 1969-12-31 18:00:00.000000000 -0600
+++ b/post\image.txt 2010-08-18 20:13:31.692002255 -0500
@@ -0,0 +1 @@
+postimage
diff -pruN a/post\image.txt b/post\image.txt
--- a/post\image.txt 1969-12-31 18:00:00.000000000 -0600
+++ b/post\image.txt 2010-08-18 20:13:31.692002255 -0500
@@ -0,0 +1 @@
+postimage