#!/bin/sh
# Given (local) "source" and (remote) "destination" directories,
# generate an "intermediate" directory containing all the files from the
# source that need updating in the destination. This lets you
# synchronise two directory trees on machines connected by a slow link
# by carrying a hard disk around.
# Adam Sampson <ats@offog.org>

usage () {
	echo "Usage: sneakersync [-e SSH] [-n] SOURCE DESTINATION INTERMEDIATE"
	echo "e.g.   sneakersync -e 'ssh -A gatehost ssh' music host:/u1/music /disk/music"
}

eopt="-essh"
nopt=""
while getopts "e:n" c; do
	case $c in
	e)
		eopt="-e$OPTARG"
		;;
	n)
		nopt="-n"
		;;
	\?)
		usage
		exit 0
		;;
	esac
done
shift `expr $OPTIND - 1`

source="$1"
dest="$2"
inter="$3"

if [ "$3" = "" ]; then
	usage
	exit 1
fi

tempfile="/tmp/sneakersync$$"
trap "rm -f $tempfile" 0

rsync "$eopt" -nav $source/ $dest \
	| egrep -v '(^building file list|^$|^sent [0-9]|^total size is|/$)' \
	>$tempfile

rsync $nopt -av --partial --files-from $tempfile $source/ $inter