Shell Scripting - double condition with two variables

Question

Good morning folks,

I have to do this for my class assignment and I don't quite grasp how to.

The script will ask the user for two separate statements which will fill two variables, L and C. I need to check if L and C, both, are between the range from 1 to 3. If either L or C has a value lower than 1 and/or higher then 3 (outside the range), the script has to print a warning and ask for new values.

printf "Please, enter L and C: "
read L C
while [[ $L -ge 1 -a $L -le 3 ]]; do
    while [[ $C -ge 1 -a $C -ge 3 ]]; do

This works as intended (the loop). Is there any way to better handle this?

Thanks,

Rafael

Answer 1

In the interest of readability, I would do something like:

checkrange() {
   if [[ "$1" -le 3 ]] && [[ "$1" -ge 1 ]]; then
      return 0
   else
      return 1
   fi
}

L=0
C=0
prompt="Please enter values for L and C >"
while ! ( checkrange "$L" && checkrange "$C" ); do
   read -p "$prompt" L C
   prompt="Invalid input; please enter new values for L and C >"
done