Bash: show prompts if arguments weren't provided What is the best way of supporting in the script prompts and arguments at the same time? I want to show prompts if arguments weren't provided. Is there something better/shorter than this? ⇩ PROJECT_DIR=$1 SITE_NAME=$2 ADMIN_PWD=$3 THEME_DIR=$4 THEME_NAME=$5 if [ -z "${PROJECT_DIR}" ]; then echo "Directory where project resides:" read PROJECT_DIR fi if [ -z "${SITE_NAME}" ]; then echo "Name of the website:" read SITE_NAME fi if [ -z "${ADMIN_PWD}" ]; then echo "Admin password:" read ADMIN_PWD fi if [ -z "${THEME_DIR}" ]; then echo "Directory of the theme:" read THEME_DIR fi if [ -z "${THEME_NAME}" ]; then echo "Name of the theme:" read THEME_NAME fi

You can shorten it a bit by using a function:


#!/bin/bash

ask()
{
declare -g $1="$2"
if [ -z "${!1}" ]; then
echo "$3"
read $1
fi
}

ask PROJECT_DIR "$1" "Directory where project resides:"
ask SITE_NAME "$2" "Name of the website:"
ask ADMIN_PWD "$3" "Admin password:"
ask THEME_DIR "$4" "Directory of the theme:"
ask THEME_NAME "$5" "Name of the theme:"

echo "$PROJECT_DIR $SITE_NAME"


This requires `bash` though and won't work in `sh`.