optional_depends GETTEXT \
                 "" \
                 "--without-gettext" \
                 "for an gettext usage" &&
optional_depends gtk+2 \
                 "" \
                 "--without-gtk" \
                 "for a gtk UI" &&
optional_depends ncurses \
                 "" \
                 "--without-curses" \
                 "for a curses UI"  &&
optional_depends pcre \
                 "--with-pcre" \
                 "" \
                 "for PCRE library usage"
