自动备份mysql脚本

#!/bin/sh 
# mysql_backup.sh: backup mysql databases and keep newest 5 days backup. 
# 
# Last updated: 20 March 2006 
# ---------------------------------------------------------------------- 
# This is a free shell script under GNU GPL version 2.0 or above 
# Copyright (C) 2006 Sam Tang 
# Feedback/comment/suggestions : http://www.real-blog.com/ 
# ---------------------------------------------------------------------- 
# your mysql login information 
# db_user is mysql username 
# db_passwd is mysql password 
# db_host is mysql host 
# ----------------------------- 
db_user="root" 
db_passwd="password" 
db_host="localhost" 
# the directory for story your backup file. 
backup_dir="/home/mybackup" 
# date format for backup file (dd-mm-yyyy) 
time="$(date +"%d-%m-%Y")" 
# mysql, mysqldump and some other bin's path 
MYSQL="/usr/local/mysql/bin/mysql" 
MYSQLDUMP="/usr/local/mysql/bin/mysqldump" 
MKDIR="/bin/mkdir" 
RM="/bin/rm" 
MV="/bin/mv" 
GZIP="/bin/gzip" 
# check the directory for store backup is writeable 
test ! -w $backup_dir && echo "Error: $backup_dir is un-writeable." && exit 0 
# the directory for story the newest backup 
test ! -d "$backup_dir/backup.0/" && $MKDIR "$backup_dir/backup.0/" 
# get all databases 
all_db="$($MYSQL -u $db_user -h $db_host -p$db_passwd -Bse 'show databases')" 
for db in $all_db 
do 
$MYSQLDUMP -u $db_user -h $db_host -p$db_passwd $db | $GZIP -9 > "$backup_dir/backup.0/$time.$db.gz" 
done 
# delete the oldest backup 
test -d "$backup_dir/backup.5/" && $RM -rf "$backup_dir/backup.5" 
# rotate backup directory 
for int in 4 3 2 1 0 
do 
if(test -d "$backup_dir"/backup."$int") 
then 
next_int=`expr $int + 1` 
$MV "$backup_dir"/backup."$int" "$backup_dir"/backup."$next_int" 
fi 
done 
exit 0;