为我解释这个rsync脚本 – Linux备份

我不懂Linux，更谈不上编程，所以请原谅我的无知。

我有这个脚本，并希望有人向我解释内部。

我明白这个语法：

30 1 * * * /root/dobackup.daily /shared/svnrepos WOWSERVER /shared/backup/svnrepos 

在服务器上的/ shared / svnrepos的1:30处执行rysnc备份到远程WOWSERVER，并将其放置在WOWSERVER上的/ shared / backup / snvrepos中。

• 数据错误（循环冗余校验）
• 如果源不可访问，则停止rsync
• 什么是控制活动数据库的一部分版本的好工具/方法？
• 如何查看Windows 7备份是否已通过batch file完成
• 在PHP或shell中编写备份脚本会更好吗？

但是，我不明白脚本中的“选项/variables/等”，希望有人能为我分解。

这是脚本：

 #!/bin/sh # This script does personal backups to a rsync backup server. You will end up # with a 7 day rotating incremental backup. The incrementals will go # into subdirectories named after the day of the week, and the current # full backup goes into a directory called "current" # tridge@linuxcare.com # directory to backup if [ $# != 3 ]; then echo "Syntax is \"dobackup.daily {LocalDir} {RemoteServer} {RemoteDir}\"" exit fi #RDIR=/shared/backup/CADData RDIR=$3 # excludes file - this contains a wildcard pattern per line of files to exclude EXCLUDES= # the name of the backup machine #RSERVER=TESTSERVER RSERVER=$2 #LDIR=/shared/CADData LDIR=$1 # your password on the backup server #export RSYNC_PASSWORD=XXXXXX ######################################################################## TODAY=`date +%A` YESTERDAY=`date --date=yesterday +%A` #TODAY=test3 #YESTERDAY=Monday OPTS="--link-dest=../$YESTERDAY --timeout=999 -aAz" export PATH=$PATH:/bin:/usr/bin:/usr/local/bin # the following line clears the last weeks incremental directory # [ -d $HOME/emptydir ] || mkdir $HOME/emptydir # rsync --delete -aAz -e 'ssh -c blowfish -i /root/.ssh/backup -ax -o ClearAllForwardings=yes' $HOME/emptydir/ $RSERVER:$RDIR/$BACKUPDIR/ # rmdir $HOME/emptydir # now the actual transfer rsync $OPTS -e 'ssh -c blowfish -i /root/.ssh/4to5 -ax -o ClearAllForwardings=yes' $LDIR/ $RSERVER:$RDIR/$TODAY/