Multiple read commands and check for input of each

Question

I would like to ask for user input on multiple questions and then store the inputs inside variables but also making sure that the input entered for each question is not empty or else it repeats the question

So far I have

input() {
        if [ ! -z "$db*" ]; then
                echo "Nothing entered" >&2;
                return
        else
                break
        fi
}

read -ep 'Enter your name >> [y/N]: ' name &&
input
read -ep 'Enter your email >> [y/N]: ' email &&
input
read -ep 'Enter your password >> [y/N]: ' password
input

Answer 1

Use an until statement and check for non-empty with [:

until [ "$NAME" ]; do
  printf "Name: "
  read NAME
done

The [ "$VAR" ] construction of the test command allows you to test whether the variable is non-empty¹.

Answer 2

I'm using the following combination of read and eval where you call the input-function with a variable to save input in and a message to be printed (input_not_empty "INPUTVAR" "message")

input()
{
    local foo
    echo -n "$2: "
    read foo
    eval "$1=\"$foo\""
}

input_not_empty()
{
    input $1 "$2"
    if [ -z "$(eval echo \$$1)" ]; then
        echo "ERROR: input empty..."
        exit 1
    fi
}

input_not_empty NAME "your full name"
input_not_empty EMAIL "your full email"

echo "name is $NAME"
echo "email is $EMAIL

but be careful with eval!