General :: Find Out How Much Time An Already Running Process Is Spending In User And Kernel Spac?

I am currently struggling with one of my tasks.I was asked to find a way how to determine how much time an _already running_ process is spending in user and kernel space.E.G. <some tool> <pid>[Control] + [c]<pid> spent 12.1 seconds in user and 1.52 seconds in kernel space.Does something like this exist? Basically I guess I am looking for something similar to time, except that the process is already running.So..a) Is there a tool which fulfills this task?b) Is there a way to write your own software which does the job? Is it even possible to code something I am looking for?I recently found strace -c -p <pid>, but well, this is not exactly what I was looking for.