config() {
  NEW="$1"
  OLD="$(dirname $NEW)/$(basename $NEW .new)"
  # If there's no config file by that name, mv it over:
  if [ ! -r $OLD ]; then
    mv $NEW $OLD
  elif [ "$(cat $OLD | md5sum)" = "$(cat $NEW | md5sum)" ]; then
    # toss the redundant copy
    rm $NEW
  fi
  # Otherwise, we leave the .new copy for the admin to consider...
}

if ! getent group taler >/dev/null; then
  groupadd taler \
    --system
fi

if ! getent group taler-merchant >/dev/null; then
  groupadd taler-merchant \
    --system
fi

if ! getent passwd taler-merchant >/dev/null; then
  useradd taler-merchant \
    --comment 'Merchant for accepting taler payments' \
    --gid taler-merchant \
    --groups taler \
    --system
fi

config etc/httpd/sites-available/taler-merchant.conf.new
config etc/rc.d/rc.taler-merchant.new
config etc/taler/conf.d/merchant.conf.new
config etc/taler/secrets/merchant-db.secret.conf.new

chown :taler etc/taler/secrets
chown :taler var/cache/taler
chown :taler var/lib/taler
chown :taler var/log/taler
chown :taler-merchant etc/taler/secrets/merchant-db.secret.conf.new