#!/bin/sh

# This is what I use to make kernel patches and things like that.
# It's very similar to the `gendiff' script distributed with
# Red Hat's RPM, but you don't have to specify a directory (the
# current one will do as default), and it's much faster.
#
# -- Jamie Lokier, April 1999

case "$#" in
  2) ext="$2" dir="$1" ;;
  1) ext="$1" dir="`pwd | sed -e 's:.*/::'`"; cd .. ;;
  *)
    echo "usage: $0 [<directory>] <diff-extension>" 1>&2
    exit 1 ;;
esac

# Quote $ext for use in regular expression.
ext=`echo "x$ext"|sed -e 's/^x//; s/[\[\.\*\\\^\$]/\\\\&/g'`

treescan -- "$dir" |
  sed -e "s/$ext//;t;d" |
  sort |
  while read f; do
        if ! test -e "$f"; then
	    echo "diff -u $f$ext $f"
	    diff -u "$f$ext" /dev/null
	elif ! cmp -s "$f$ext" "$f"; then
	    echo "diff -u $f$ext $f"
	    diff -u "$f$ext" "$f"
	fi
  done