#!/bin/bash

#
# Read a reply from the user, then check it's not zero length
#
read -r -p "Please enter a string: " reply
if [[ ${#reply} -eq 0 ]]; then
    echo "Please provide a non-empty reply"
else
    echo "You said: $reply"
fi

#
# Read a reply from the user, then check it's not zero length
#
read -r -p "Please enter a string: " reply
if [[ -z $reply ]]; then
    echo "Please provide a non-empty reply"
else
    echo "You said: $reply"
fi