As you may know, the /proc/stat file contain the numbers of ticks the different CPU's have spent their time. Same goes to /proc/pid/stat where the tics are measured based on pid (process id)
But when I'm running a process I want to capture the stat file of a given process and see the number of ticks the process used in for example kernel-, user mode etc. For the time the process took to finish.
As of now, the PID file in /stat/ dissapears whenever the process has finished.