Useful command in TclX for getting the amount of user and system time taken by both yourself and by your child processes. Great for doing billing for computation time. Returns a list of four items:
The utime is the amount of time actually spent executing in the process in user-space, in milliseconds. The stime is the amount of time spent in the OS kernel on behalf of the process, also in milliseconds. The cutime and cstime values are the same, but also count the time taken by all (finished and reaped) subprocesses.