#! /bin/sh

set -e
var=${1?var}
val=$(
  sed -n "
    /^[	 ]*$var[	 ]*=[	 ]*\(.*[^	 ]\)\{0,1\}[	 ]*$/ {
      s//\1/; p; q
    }
  " ${MDWCONF-$HOME/.mdw.conf})
case "$val,$2" in
  "","") echo >&2 "$0: configuration variable $var not found."; exit 1 ;;
  "",*) val=$2 ;;
  "~/"*) val=$HOME/${val#\~/} ;;
esac
echo "$val"