How to detect that a child process has crashed?

Question

A child process can:

Exit normally (by exiting using exit(0),exit(22), exit(23)) -- This is obviously specific to my application
Exit abnormally (code throws an exception, receives an unhandled signal, core dumps, etc...)

I am doing a fork/exec from a parent process and looping on waitpid, when I detect that child process has exited I would like to determine the reason it exited.

Currently I check WEXITSTATUS(status) (where status is returned by waitpid) to determine exit code.

Is there a way to reliably detect if child exited abnormally?

score 5 · Accepted Answer · edited May 23 '17 at 12:23

5

You can check for WIFSIGNALED(status). For testing this check out Test cases in C for WIFSIGNALED, WIFSTOPPED, WIFCONTINUED.

Of course you can also do a positive check for normal termination with WIFEXITED(status).

edited May 23 '17 at 12:23

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answered Dec 17 '15 at 15:55

Werner Henze

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would that be enough to detect if process has crashed without receiving a signal? – Kam Dec 17 '15 at 15:56
@Kam: There's no such thing. "Crash" is not technical concept. – Kerrek SB Dec 17 '15 at 15:58
@Kam If your program crashes it should do so for example with a SIGSEGV or a SIGBUS. – Werner Henze Dec 17 '15 at 16:01
@Kam You are welcome. Feel free to accept my answer when you tested that my suggestions work for you. – Werner Henze Dec 17 '15 at 16:08

How to detect that a child process has crashed?

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