原文出处：

http://www.jbxue.com/article/13808.html (原创文章，转载请注明出处)

本节内容：

保留文件系统下剩余指定数目的文件

例子：

#!/bin/bash

#-------------------------------

#Description: Back up your files

#site: www.jbxue.com

#-------------------------------

#shell 变量

path_source=/mnt/fifth/shell

path_backup=/mnt/fifth/backup/shellbackup

path_delete=/mnt/fifth/tmp/rubbish/

limit_num=15

fileBackup()

{

set -x

#备份文件

#cp -r $1 $2/shell-`date +%Y-%m-%d-%H-%M-%S`

count=`ls $1 | wc -w`

if [ "$count" -gt "$3" ];then

echo "-----------------limit is : $3 ----------------------"

echo "-----------------The number of files is : $count -------"

num=`expr $count - $3`

echo "-----------------The excess number of files is : $num ---------"

#移动文件

ls $1 -1rt | head -n $num|xargs -n1 -i mv $1/{} $2

set +x

ls -1rt $2

echo "-----------------Moving end!-----------------"

else

ls -1rt $2

echo "-----------------The file is too little!-------------------"

fi

}

#备份shell脚本

fileBackup $path_backup $path_delete $limit_num