MySQL backup of Shell programming under Linux (for beginners)

1,shell Common Variable parsing:

The name of the current script

$n the nth parameter of the current script

$* all parameters of the current script (excluding the program itself)

$# the number of arguments to the current script (excluding the program itself)

$? After the execution of a command or program is completed, a general return of 0 indicates success.

$UID the ID of the current user

$PWD the directory where you are currently

-ne Not equal to

-eq equals

2, automatic backup MySQL script idea

①, backing up the DB command

mysqldump-h127.0.0.1-uroot-p123456 du >du_ ' date +%y%m%d '. sql

②, the mechanism of backup

③, backup targets and libraries

④, how many days ago data is deleted periodically

#!/bin/bash#auto backup mysql datebases. #by  2017#define db info pathsql_cmd = "/usr/bin/mysqldump" sql_host= "127.0.0.1" sql_usr= "root" sql_pwd= "123456" sql_db= "du" sql_dir= "/data/backup/" date  +%y%m%d ' "#判断是否为root用户if  [  $UID  -ne 0 ];thenecho " Only use root  to exec. " exit fi# determines if the path exists and does not exist to create a if [ ! -d  $SQL _dir ];thenmkdir -p  $SQL _dirfi #备份数据库 $SQL _cmd -h$sql_host -u$sql_usr -p$sql_pwd  $SQL _db > $SQL _dir/$SQL _db.sql# Determine if the backup succeeded, print out the path successfully if [ $? -eq 0 ];thenecho  "backup mysql already  Successful. " echo  "Backup path: $SQL _dir" elseecho  "backup mysql failed." fi# Delete backup files from 30 days ago cd  $SQL _dir/. / ; find . -mtime +30 -exec rm -rf {} \;echo  "Done" # Add the script to the crontab task plan grep  "MySQL"  /var/spool/cron/root >> /dev/nullif [ $? -ne 0 ];thenecho  "0 0 * * * /bin/bash /root/ Shell/mysql.sh > /tmp/mysql.log 2>&1 " >>/var/spool/cron/root/etc/init.d/ Crond restartfi

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MySQL backup of Shell programming under Linux (for beginners)