#!/bin/bash

### Periodic unison sync with one or more machines ###
# Copyright 2009 Ertug Karamatli

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

### USAGE ###
# 1. Create unison profile files in this format: ~/.unison/<hostname>.prf
# 2. Add the hosts you want to sync in HOSTS variable below.

### SETTINGS ###
# Space seperated list of hosts (hostname or ip)
HOSTS="laptop netbook"
# Time to wait between syncing (seconds)
WAIT=(60 * 5)

### TODO ###
# Check hosts in list faster and if a host becomes online sync it first then wait for it (make it threaded)


logger -s -t $0 "started."
while [ 1 ]; do
	if [ -z "$(ps -e|grep unison)" ]; then
		for h in $HOSTS; do
			nc -z $h 22
			if [ $? == 0 ]; then
				logger -s -t $0 "$h is online, starting unison..."
				unison -batch $h
				UNISON_RETCODE=$?
				if [ $UNISON_RETCODE == 0 ]; then
					logger -s -t $0 "synced $h successfully."
				else
					logger -s -t $0 "an error was occured while syncing $h, unison returned $UNISON_RETCODE"
				fi
			fi
		done
	else
		logger -s -t $0 "unison is already running, waiting it to end..."
	fi
	sleep $WAIT
done