Are the French rude?

The French are no more ruder than any other nationality. They may come across as abrupt but as in any other country, you will still have encounters that are less than courteous. I would recommend you have a look at the Expat Arrivals section on Culture Shock in France as it explains some of the challenges that visitors to France may come up against when in France.

I concur with Afriq Wanderlust, but I think the French are generally receptive to most people who show interest in their country and culture.

I think French are perceived rude because they feel insecure of speaking another language other than French. So, they tend to answer very curtly and with the only few English words they know or even yet, they answer you in French. However, once you try asking in French, even if it is not correct, but just showing that you're doing an effort, they are pretty helpful and accommodating.