Linux mysql backup shell script

mysql-backup.sh

#!/bin/bash

export PGCLIENTENCODING="UTF8"
DBLIST="$@"

if [ -z "${DBLIST}" ]; then
  DBLIST="all"
fi
#backup directory
BACKUP=/var/backup/database/mysql/
ARCHNAME=`date +%Y%m%d-%H`

YEARMONTH=`date +%y%m`
TODAY=`date +%d`

mkdir -p ${BACKUP}/${YEARMONTH}/${TODAY}
for DBNAME in ${DBLIST} ; do
    BACKFILE=${DBNAME}.${ARCHNAME}.sql
    if [ -f ${BACKUP}/${YEARMONTH}/${TODAY}/${BACKFILE} ]; then
        continue
    fi
    mysqldump -u root --password=edyna168 --all-databases --skip-opt -h mysql.citytalk.tw  > ${BACKUP}/${YEARMONTH}/${TODAY}/${BACKFILE}
    bzip2 -z ${BACKUP}/${YEARMONTH}/${TODAY}/${BACKFILE}
done