#!/bin/sh

# Copyright © 2011, 2012 Jakub Wilk <jwilk@debian.org>

# Redistribution and use in source and compiled forms, with or without
# modification, are permitted under any circumstances. No warranty.

if [ $# -ne 2 ]
then
    printf 'Usage: %s <deb1> <deb2>\n' "$0"
    exit 1
fi

set -e

deb1="$1"
deb2="$2"
base1=$(basename "$deb1" .deb)
base2=$(basename "$deb2" .deb)
tmpdir=$(mktemp -t -d)
if which git >/dev/null 2>&1; then
    git init "$tmpdir/repo" >/dev/null 2>&1
    (cd "$tmpdir/repo";
	touch emptyfile;
	git add emptyfile;
	git commit -m'initial commit' >/dev/null 2>&1;
	git checkout -b "$base1"  >/dev/null 2>&1;
    );
    dpkg-deb --raw-extract "$deb1" "$tmpdir/repo"
    (cd "$tmpdir/repo";
	git add * >/dev/null 2>&1;
	git rm emptyfile >/dev/null 2>&1;
	git commit -m"add $base1" >/dev/null 2>&1;
	git checkout master >/dev/null 2>&1;
	git checkout -b "$base2" >/dev/null 2>&1;
    );
    dpkg-deb --raw-extract "$deb2" "$tmpdir/repo"
    (cd "$tmpdir/repo";
	git add * >/dev/null 2>&1;
	git rm emptyfile >/dev/null 2>&1;
	git commit -m"add $base2" >/dev/null 2>&1;
	git diff "$base1" "$base2" --;
    );
    rm -rf "$tmpdir";    
else
    mkdir -p "$tmpdir/a/$base1/"
    dpkg-deb --raw-extract "$deb1" "$tmpdir/a/$base1/"
    mkdir -p "$tmpdir/b/$base2/"
    dpkg-deb --raw-extract "$deb2" "$tmpdir/b/$base2/"
    cd "$tmpdir"
    diff -urN "a/$base1/" "b/$base2/"
    cd /
    rm -rf "$tmpdir"
fi;

# vim:ts=4 sw=4 et