如何改进以下空间问题编码

Question

当我运行下面的脚本时它没有返回任何内容...期望提示输出..

#!/bin/sh
cd /dla
op=`df -k  /dla/ |awk '{print $5}' |grep '%' |cut -d '%' -f1`
if[ $op -ge 80 ]
then
echo ' dla is more tha 80% - Purge started'
find /dla/ -name '20[0-9][0-9]*' -type d -print |sort |cut -d '/' -f7 |grep 20 | sort | uniq -c |head -20 > /tmp/file_list.dat 
for i in cat /tmp/file_list.dat |awk '{print $@}'
do
 find /dla -name $i -type d -exec rm -rf [] \;

 newop='df -k /dla/ |awk '{print $5}' |grep '%' |cut -d '%' -f1'
 if [$newop -le 80]
 then 
 echo 'dla is 80% -Purge stopped'
 exit 0
 fi 
 done
 else 
 echo 'dla is less than 80% - No Purge Required'
 fi