$ backup.sh [<options>]
-s
source directory-d
distination directory-n
number of backup stores [default: 30]-l
log file path [default: /var/log/rsync-backup.log]-r
rsync executable path [default: /usr/bin/rsync]-e
exclude path [example: /aaa /bbb]-o
rsync option [default: -avz --delete]-x
execute mode [default: dry run mode]