testscript

#!/bin/bash
i=$(ls -1 /tmp | wc -l )

if [ $i -gt 20 ]

then

echo "number of files greater than limit excess file deletion in progress .."
for (( j=$i; j==20; j--))
do
 echo "fetching list of older files"
 find /tmp -type f -mtime +7 >> listofolderfiles.txt
 cat listofolderfiles.txt | xargs ls -1tr | head -1 | xargs rm
done

else

echo "number of files less than 20 exiting script"

fi