How to restrict computing resources of a program?

I wish to implement an online judge system in Linux using python. I need to restrict computing resource(time, memory) for process. Process should terminate when it uses开发者_StackOverflow more resources than given.

Also, when a program terminates, I need to know whether it terminates normally, or terminates because of run time error (stack over flow, divide by zero, accessing invalid address), or using more resource than given.

How to do it in python?

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resource.setrlimit()

http://docs.python.org/library/resource.html

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Linux ulimit.

http://linux.die.net/man/1/ulimit

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There is a "safeexec" program on github that does a pretty decent job of this. It is pretty fidgety to get it working from scratch.