grep alias to safely ignore multiple directories

The day to day usage is: grep -rIn pattern directory There are some files that I want to avoid, they are in directories that have this kind of path in them at some point: app/lib/bower/lodash, app/lib/bower/paho-mqtt-js, app/lib/bower/socket-io-client. Ideal solution is to detect app/lib/bower/ in the path, but it's hard. Is it possible? I've come up with: alias grep='grep --exclude-dir={lodash,paho-mqtt-js,socket-io-client}' Good enough (though needs maintenance when new stuff is added). How to at least add a short warning into stderr if the directory is excluded by grep?