shell-自定义rm

<<COMMENT
功能介绍：
1.删除操作执行前先获取文件或目录的大小，然后对比系统中的磁盘空间
2.如果有多余空间，则创建对应的隐藏目录，并备份
3.如果没有足够的空间，可以提醒用户是否放弃备份，如果放弃，则直接删除
COMMENT
filename=$1
d=`date +'%Y%m%d%H%M'`
f_size=`du -sk $1|awk '{print $1}'`
disk_size=`LANG=en; df -k |grep -iv filesystem |awk '{print $4}' |sort -n |tail -n 1`
big_filesystem=`LANG=en; df -k |grep -iv filesystem |sort -n -k4 |tail -n 1 |awk '{print $NF}'`
if [ $f_size -lt $disk_size ]; then
  read -p "Are U sure delete the file or directory $1 y|n:" c
  if [ $c=="y" ] || [ $c=="Y" ]; then
    mkdir -p $big_filesystem/.$d && rsync -aR $1 $big_filesystem/.$d/ && /bin/rm -rf $1
  elif [ $c=="n" ] || [ $c=="N" ]; then
    exit 0
  fi
else
  echo "The disk size is not enough to backup the files $1"
  read -p "Do you want to delete "$1"? y|n:" c
  if [ $c=="y" ] || [ $c=="Y" ]; then
    echo "It will delete "$1" after 5 seconds whitout backup"
    for i in `seq 1 5`; do echo -ne "."; sleep 1;done
  echo 
    /bin/rm -rf $1
  elif [ $c=="n" ] || [ $c=="N" ]; then
    echo "It will not delete $1."
    exit 0
  else
    echo "Please input 'y' or 'n'"
  fi
fi