Does mac os x have any command tool like pidstat in linux? It can tell me the current status of a process, for example, whether it is still running or has been terminated.
I'm not sure there is a list of terminated processes, but for a list of processes and their current state you can use the "top" command. It's fairly user-friendly for a Unix tool.

There is also the "Activity Monitor" (in the /Applications/Utilities folder) that is basically top with a GUI.