Shell Programming and Scripting

lastfile=$(ls -rt | tail -1)

 for allfile in $(ls | grep -v |$lastfile)
 do
     echo > $allfile
    mv <all existing file> X
done

lastfile=$(ls -rt | tail -1)
lastfile=$(ls -rt | tail -1)
for file in $(ls | grep -v $lastfile)
do
    echo $lfile
    mv $file X
done

for file in $(ls | sed '$d')
do
    echo $file 
    mv $file X
done

ls -rt | sed '$d' | xargs -I{} mv {} X

ls -rt | sed '$d' | xargs -I{} mv {} X

ls -rt | grep -v '^X$' | sed '$d' | xargs -I{} mv {} X