I can confirm that all national police officers and gendarmes are indeed armed when they're on duty. They don't have assault rifles or shotguns in the trunk of their patrol cars, but they have a 9mm pistol holstered at all times.
Just for the heads-up, the 18-year-old student who surrendered to the police yesterday evening after seeing his name circulating on social media has apparently nothing to do with the shooting in Paris.
Also, a municipal police officer (a woman) was killed at the scene of a traffic accident after being shot by a man wielding an automatic weapon south of the capital city this morning. A construction worker who was nearby was also wounded. The man, who wasn't involved in yesterday's attack according to the reports, has, AFAIK, not been apprehended yet.