if语句编写Mysql备份脚本

#!/bin/bash
#auto bakcup mysql db
#by authors zgh
#define backup path

BAK_DIR=/data/backup/`date +%Y%m%d`
MYSQLDB=mysql
MYSQLUSR=root
MYSQLPW=
MYSQLCMD=/usr/bin/mysqldump

if [ $UID -ne  ];then

        echo "Must to be use root for exec Shell."
        exit
fi

if [ -d $BAK_DIR ];then

        echo "This $BAK_DIR is exists..."
else
        mkdir -p $BAK_DIR
        echo -e "\033[32m The $BAK_DIR Create Suessfully!\033[0m"
fi

#Mysql BACKUP COMMAND
$MYSQLCMD -u$MYSQLUSR -p$MYSQLPW -d $MYSQLDB >$BAK_DIR/$MYSQLDB.sql

if [ $? -eq  ];then
        echo -e "\033[32m The mysql Backup $MYSQLDB Successfully!\033[0m"
else
        echo -e "\033[32m The mysql Backup $MYSQLDB Failed,Please check.\033[0m"
fi