I have Samsung Galaxy S4 mini i9192
Today i rooted it without tripping Knox with help of XDA member drnag.
All credits to him i'm just sharing What i did.
First Download Kingo app from their website (Google it)
Then install it and run.
You should be connected to internet in pc the connect your mobile to pc with debugging mode.
After sometime it will ask that "Kingo will now root device by installing custom recovery...."
Now you device will restart in odin.
and it will be rooted.
This Worked for me but i dont know about other's devices. Try at your own risk.