diff-normalize

#!/bin/sh
##
## Normalize diff output to diff diff outputs
## Copyright (c) SATOH Fumiyasu @ OSS Technology Corp., Japan
##
## License: GNU General Public License version 3
##

set -u

sed \
  -e '/^=/d' \
  -e '/^index /d' \
  -e '/^new file mode /d' \
  -e '/^deleted file mode /d' \
  -e '/^-- /,/^$/d' \
  -e 's/^From .*/======================================================================/' \
  -e 's|^Index: [^/]*\/\(.*\)$|diff --git a/\1 b/\1|' \
  -e 's|^\(--- .*\)\t.*|\1|' \
  -e 's|^--- [^/]*/\(.*\)$|--- a/\1|' \
  -e 's|^\(+++ .*\)\t.*|\1|' \
  -e 's|^+++ [^/]*/\(.*\)$|+++ b/\1|' \
  -e 's/^\(@@.*\)(.*/\1/' \
  "$@" \
;