Is that so? I used go to Umananda Island which is world's smallest river island and feed langurs using my own hands. They love cakes. They seem really friendly.
I know this doesn't sound realistic. I once feed langurs papri chat and puchka when I saw them on my trip to Kolkata. We had nothing. They randomly appeared a distance from my relatives house. We went out for snacks. So feed them what we had.