Homework & Coursework Questions

num="109"
for ((i=0;i<3;i++)); do
    echo ${num:$i:1};
done

read -p "Write your student ID: " ID              #write your variable $ID, you can use yours
if ! echo $ID | egrep "^[0-9][0-9][0-9]$"          
then
   echo "Write your ID, I'm NOT joking"
   exit 1
fi

When this script is run, one parameter/argument is passed to the script.

id=109
for ((i = 1; i <= 3; i++)); do
        digit=$(echo $id | cut -c${i})
done

cp ~a2/Pictures/linux-pic${digit} ~/public_html/