#!/bin/sh

# Sets a password environment variable

if test "$#" -lt 1; then

    echo "Usage: . $0 env_var_name (note the \".\" at the beginning)"

    exit 2

fi

if test -z "${!1+t}"; then # env var with name $1 is unset

    read -s -p "Enter $1: "; echo

    export "$1"="$REPLY"

fi