-command -v wget >/dev/null 2>&1 || { echo "$(basename "$0"): command 'wget' is needed." ; exit 1; }
-command -v 7z >/dev/null 2>&1 || { echo "$(basename "$0"): command '7z' is needed." ; exit 1; }
+command -v wget >/dev/null 2>&1 || { echo "$(basename "$0"): command 'wget' is needed." 1>&2 ; exit 1; }
+command -v 7z >/dev/null 2>&1 || { echo "$(basename "$0"): command '7z' is needed." 1>&2; exit 1; }