#!/bin/bash

# Sets a password environment variable

self="$(readlink -f -- "$BASH_SOURCE")"

out=/dev/tty

function echo2() { echo "$@" >"$out";}

store=

test _"$1" = _- && { store=1; shift;}

if ! test "$#" -ge 1; then

    echo2 "Usage: . $self env_var [desc] (note initial \".\")"|fold -s >"$out"

    exit 2

fi

desc="$2"

test -n "$desc" || desc="the $1 password"

function trace()

{

    { for arg in "$@"; do printf "%q " "$arg"; done; echo;} >"$out"

}

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

    if test -n "$store"; then

        echo2 " To change the saved value for $desc, run: " >"$out"

    else

        echo2 " You must first store $desc. At the shell, run: "

    fi

    trace . "$self" - "$@"

    test -z "$store" && exit 1 # just direct user how to store password

    read -s -p "Enter $desc password: " 2>"$out"; echo2

    export "$1"="$REPLY"

fi