I have a Linux machine with an Nvidia GPU (GeForce GTX 760). Is there a tool, rather than writing your own, that can currently mine Bitcoin using CUDA on Linux?
There is a program called CudaMiner that can be compiled to run on Linux.
I've also written some more notes about compiling CudaMiner here http://www.fractured-state.com/2014/03/scrypt-mining-on-aws-nvidia-gpu-with-cudaminer/
The second link is dead already, but a similar tutorial is detailed in this thread: https://www.reddit.com/r/dogemining/comments/1y3ygr/dogecoin_guide_for_mining_on_linux_ubuntumint/