rpm-build/gendiff

#!/bin/sh

PROG="${0##*/}"

if [ -z "$1" -o -z "$2" ]; then
	echo "usage: $PROG <directory> <diff-extension>" >&2
	exit 1
fi

: ${RPM:=/usr/src/RPM}

[ -z "$3" ] || echo >"$RPM/SOURCES/$1-$3.patch"

find "$1" \( -name "*$2" -o -name ".*$2" \) -print |
while read fin; do
	fou=`echo "$fin" |sed -e "s/$2\$//"`;
	[ -r "$fin" ] || fin="/dev/null"
	[ -r "$fou" ] || fou="/dev/null"
	if [ -z "$3" ]; then
		diff -u "$fin" "$fou"
	else
		diff -u "$fin" "$fou" |tee -a "$RPM/SOURCES/$1-$3.patch"
	fi
done