There is fortinos on Main St West and it's about a 10 minute walk from the Main St Entrance. There's also the Barn just outside westdale which is about a 15-20 minute walk (depending on how fast you walk) from the Sterling St Entrance.
By bus? Well unless it's cold it's not really worth the wait to go to fortinos, but the bus trip back (when you're loaded down) is less than 5 minutes to the main st entrance. Unfortunately the 52, nor the 5 will take you into campus from that end. The 10 beeline does go into campus from that entrance but it won't stop at the bus stop outside of fortinos cause it's an express.
From the Barn: it's about a 10 minute ride and you can take the 5, the 51, the 10 or the 1 King. All of these stop at the stops ON CAMPUS.
The trip planner works sometimes, other times it's a little stupid.
Fortinos on Main
The Barn in Westdale
Okay, after trying the Barn link, it's not taking you back to the actual store. The barn that you want is: Hamilton- 845 King St. W