Backup script using rsync and ssh

backup.sh

#!/bin/sh

if [ $# != 2 ]
then
	echo usage: $0 SOURCE HOST
	exit 1
fi

SOURCE=$1
BACKUP_DIR=backup
HOST=$2							# place this in ~/.ssh/config
EXCLUDE=$HOME/.rsync/exclude
DATE_FORMAT='%Y-%m-%d-%H:%M'	# see man date for additional info
###############################################################################

DATE=$(date "+$DATE_FORMAT")
LOG_TMP='/tmp/backup_log_'$DATE
OPTIONS='-azP -e ssh --delete --delete-excluded --exclude-from='$EXCLUDE' --link-dest=../current --log-file='$LOG_TMP
CMD='rsync '$OPTIONS' '$SOURCE'/ '$HOST':'$BACKUP_DIR'/incomplete_back_'$DATE

# create backup directory if necessary
ssh $HOST 'if [[ ! -e '$BACKUP_DIR' ]]; then mkdir '$BACKUP_DIR'; fi; if [[ ! -e '$BACKUP_DIR'/logs ]]; then mkdir '$BACKUP_DIR'/logs; fi;'

# actually do the backup
if $CMD  # if backup is succesful move 
then
	SSH_CMD="'mv $BACKUP_DIR/incomplete_back_"$DATE" "$BACKUP_DIR"/back-"$DATE" && rm -f "$BACKUP_DIR"/current && ln -s back-"$DATE" "$BACKUP_DIR"/current'"
	ssh $HOST "'"$SSH_CMD"'"
fi

# send logfile
if [ -e $LOG_TMP ]
then
	scp $LOG_TMP $HOST:$BACKUP_DIR/logs/log_$DATE &> /dev/null
	rm $LOG_TMP
fi