2.shell script to check whether the given number is odd or even and whether it is positive, negative or zero

echo "Check the number if its EVEN/ODD/POSITIVE/NEGATIVE/ZERO"

echo "*******************************************************"

echo "enter a number"

read num

case $num in

   *[a-z]*)echo "Invalid input"

                        echo "Error!!!"

      exit

      ;;

   *)break

      ;;

esac

op=1

while [ $op -eq 1 ]

do

echo "-----------------------------------------------------------"

echo " 1. POSITIVE/NEGATIVE"

echo " 2. EVEN/ODD"

echo " 3. Zero"

echo "Choose the option you would like to check for your number"

read ch

case $ch in

1)         if [ $num -gt 0 ]

            then

                        echo " The number you have typed is a Positive Number"

            else

                        echo " The number you have typed is a Negative Number"

            fi

            ;;         

2)         if [ `expr $num % 2` -eq 0 ]

            then

                        echo " The number you have typed is an Even number"

            else

                        echo "The number you have typed is an Odd number"

            fi

            ;;

3)         if [  $num -eq 0 ]

            then

                        echo " The number you have typed is a ZERO!"

            else

                        echo "The number you have typed is not Zero!"

            fi

            ;;

*) break

esac

echo "Would you like to check for another option? y=1/n=0"

read op

done