参数文件：config.sh

#!/usr/bin/env bash

mysql_user="root" #MySQL备份用户
mysql_password="tan" #MySQL备份用户的密码
mysql_host="localhost"
mysql_port="3306"
mysql_charset="utf8mb4" #MySQL编码
backup_db_arr=("test" "game") #要备份的数据库名称，多个用空格分开隔开 如("db1" "db2" "db3")
backup_location=/var/www/mysql  #备份数据存放位置，末尾请不要带"/",此项可以保持默认，程序会自动创建文件夹
expire_backup_delete="OFF" #是否开启过期备份删除 ON为开启 OFF为关闭
expire_days=3 #过期时间天数 默认为三天，此项只有在expire_backup_delete开启时有效

# 本行开始以下不需要修改
backup_time=`date +%Y%m%d%H%M`  #定义备份详细时间
backup_Ymd=`date +%Y-%m-%d` #定义备份目录中的年月日时间
backup_3ago=`date -d '3 days ago' +%Y-%m-%d` #3天之前的日期
backup_dir=${backup_location}/${backup_Ymd}  #备份文件夹全路径
welcome_msg="Welcome to use MySQL backup tools!" #欢迎语

执行脚本：test_backup.sh

#!/usr/bin/env bash
DIR=`dirname PWD`
source $DIR/config.sh
#set -xv

# 判断MYSQL是否启动,mysql没有启动则备份退出
check_mysql_is_start(){
    mysql_ps=`ps -ef |grep mysql |wc -l`
    mysql_listen=`netstat -an |grep LISTEN |grep $mysql_port|wc -l`
    if [ $mysql_ps -eq 0 ]
    then
            echo "ERROR:MySQL is not running! backup stop!"
            exit
    fi
    if [ $mysql_listen -eq 0 ];then
            echo "ERROR:MySQL is not running! backup stop!"
            exit
    fi
    echo $welcome_msg
}

# 连接到mysql数据库，无法连接则备份退出
check_connect_mysql_is_ok(){
    mysql -h$mysql_host -P$mysql_port -u$mysql_user -p$mysql_password <<end
    use mysql;
    select host,user from user where user='root' and host='localhost';
    show databases;
    exit
end
}


start(){
        echo "MySQL connect ok! Please wait......"
        # 判断有没有定义备份的数据库，如果定义则开始备份，否则退出备份
        if [ "$backup_db_arr" != "" ];then
                #dbnames=$(cut -d ',' -f1-5 $backup_database)
                #echo "arr is (${backup_db_arr[@]})"
                for dbname in ${backup_db_arr[@]}
                do
                        echo "database $dbname backup start..."
                        `mkdir -p $backup_dir`
                        `mysqldump -h$mysql_host -P$mysql_port -u$mysql_user -p$mysql_password $dbname --default-character-set=$mysql_charset | gzip > $backup_dir/$dbname-$backup_time.sql.gz`
                        flag=`echo $?`
                        if [ $flag == "0" ];then
                                echo "database $dbname success backup to $backup_dir/$dbname-$backup_time.sql.gz"
                        else
                                echo "database $dbname backup fail!"
                        fi

                done
        else
                echo "ERROR:No database to backup! backup stop"
                exit
        fi

}


# 如果开启了删除过期备份，则进行删除操作
delete_old_backup(){
        if [ "$expire_backup_delete" == "ON" -a  "$backup_location" != "" ];then
            #`find $backup_location/ -type d -o -type f -ctime +$expire_days -exec rm -rf {} \;`
            `find $backup_location/ -type d -mtime +$expire_days | xargs rm -rf`
            echo "Expired backup data delete complete!"
        fi
        echo "All database backup success! Thank you!"
        exit
}


main(){
    check_mysql_is_start;
    check_connect_mysql_is_ok
    if [ $? != 0 ]; then
            echo "ERROR:Can't connect mysql server! backup stop!"
            exit
    else
           start;
           delete_old_backup;
    fi
}

main

创建定时任务执行

• */2 * * * root /home/tan/backup/backup_sh/test_backup.sh | tee /home/a.txt

查看cron日志及重定向文件内容

tail -f /var/log/cron.log

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cat /home/a.txt

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原因：

image.png