Create Chess Board Using Nested For loop in UNIX SHELL SCRIPT

for (( i = 1; i <= 9; i++ )) ### Outer for loop ###

do

   for (( j = 1 ; j <= 9; j++ )) ### Inner for loop ###

   do

        tot=`expr $i + $j`

        tmp=`expr $tot % 2`

        if [ $tmp -eq 0 ]; then

            echo -e -n "\033[47m "

        else

            echo -e -n "\033[40m "

        fi

  done

 echo -e -n "\033[40m" #### set back background colour to black

 echo "" #### print the new line ###

done

output :~