waitpid and strace -f

[Mike Coleman]

"Alexander V. Lukyanov" <lav en long.yar.ru> writes:
> The following program receives ECHILD for waitpid when it is run with
> `strace -f'. WNOHANG and `-f' are required. I'm not sure if it is
> kernel or strace problem.

AFAIK, this is correct behavior.  As soon as the child runs, it exits, so
depending on the order that the parent and child run in, the child may already
be gone by the time the waitpid takes place.  Thus the ECHILD.

--Mike


>    pid=fork();
>    if(pid==0)
>       _exit(0);
>    if(waitpid(pid,&st,WNOHANG)==-1)
>       perror("waitpid");

-- 
Any sufficiently adverse technology is indistinguishable from Microsoft.

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