#!/bin/sh

[ -z "$1" -o -z "$2" ] && {

# usage

  echo "usage: $0 <directory> <diff-extension>" 1>&2

  exit 1

}

: ${DIFF:=diff}

: ${GENDIFF_DIFF_ARGS:=-up}

: ${GENDIFF_DIFF_CHANGELOG_ARGS:=-U0}

find $1 \( -name "*$2" -o -name ".*$2" \) -print | sort |

while read f; do

    U="${GENDIFF_DIFF_ARGS}"

    [ "`basename $f`" = "ChangeLog$2" ] && U="${GENDIFF_DIFF_CHANGELOG_ARGS}"

    F=/dev/null

    [ -r "${f}" ] && F="${f}"

    echo "${DIFF} ${U} ${F} ${f%$2}"

    ${DIFF} ${U} "${F}" "${f%$2}"

done