備份——腳本

備份——腳本

題目描述：
每天上午和下午下班前必須對數據進行雙硬盤備份，且要求保存最近3次備份。待備份數據存放在/home/user/workdata中，最近三次備份文件分別命名爲worknewdata.tar、work2nddata.tar和work3rddata.tar，雙硬盤備份的功能。

 #! /bin/bash
  2 dir_source="/home/user/workdata"
  3 dir1_backup="/home/user/dir1_backup"
  4 dir2_backup="/home/user/dir2_backup"
  5 
  6 if [  -f $dir1_backup/work3rddata.tar ]
  7 then
  8         rm $dir1_backup/work3rddata.tar
  9         mv $dir1_backup/work2nddata.tar $dir1_backup/work3rddata.tar
 10         mv $dir1_backup/worknewdata.tar $dir1_backup/work2nddata.tar
 11         tar -cf $dir1_backup/worknewdata.tar $dir1_source/*
 12 elif [ -f $dir1_backup/work2nddata.tar ]
 13 then
 14         tar -cf $dir1_backup/work3rddata.tar $dir1_source/*
 15 elif [ -f $dir1_backup/worknewdata.tar ]
 16 then
 17         tar -cf $dir1_backup/work2nddata.tar $dir1_source/*
 18 else
 19 then
 20         tar -cf $dir1_backup/worknewdata.tar $dir1_source/*
 21 fi
 22 
 23 rm -f $dir2_backup/*
 24 cp $dir1_backup/* $dir2_backup
 25 echo " &dir_source finished !"