Shell Programming and Scripting

ls -lSr|cat -n/*gives the detailed description o files with a serial number concatenated*/
i=0
n=10
j=$n
if [ "$n%2" == 0 ]
then
while [ $i -ne $j ]
do
(sh -C sub.sh $i $j)&
((i++))
((j--))
done
fi
if [ "$n%2" != 0 ]
then
while [ $i -ne $j ]
do
(sh -C sub.sh $i $j)&
((i++))
((j--))
done
fi
sub.sh
echo $1
echo $2
ls -l| tail -10 | cat -n| tr -s ' ' >> file9.txt
a= sed -n "$1 p" file9.txt | cut -f9
echo " $a "
echo " a executed"
b= sed -n "$2 p" file9.txt | cut -f9
echo "$b"
cp -r /home/$a /home/$b
echo "done"