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Re: fflush & close behavior not well-defined
From: |
Chet Ramey |
Subject: |
Re: fflush & close behavior not well-defined |
Date: |
Thu, 1 Oct 2020 10:10:42 -0400 |
User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 |
On 10/1/20 8:43 AM, Andrew J. Schorr wrote:
>
> But I still don't understand the inconsistency in strace output. In my
> test, I saw this:
>
> --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=3899, si_uid=300,
> si_status=SIGPIPE, si_utime=0, si_stime=0} ---
>
> And when you ran strace, you got this:
>
> --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=29075, si_uid=1000,
> si_status=141, si_utime=0, si_stime=0} ---
>
> Notice that my child process exited due to the signal with CLD_KILLED, whereas
> yours exited with CLD_EXITED. One child bash shell exited due to SIGPIPE,
> whereas the other seems to have trapped it and then exited in a more orderly
> fashion, I guess. I don't know whether this is a race condition or some other
> subtle issue relating to which child process received the SIGPIPE (bash vs
> cat).
It looks like a race condition that's dependent on whether the writer
process gets killed by the the SIGPIPE before the cat exits and the shell
reaps it normally.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet@case.edu http://tiswww.cwru.edu/~chet/
- Re: fflush & close behavior not well-defined, arnold, 2020/10/01
- Re: fflush & close behavior not well-defined, Andrew J. Schorr, 2020/10/01
- Re: fflush & close behavior not well-defined, arnold, 2020/10/01
- Re: fflush & close behavior not well-defined, Andrew J. Schorr, 2020/10/01
- Re: fflush & close behavior not well-defined, Chet Ramey, 2020/10/01
- Re: fflush & close behavior not well-defined, arnold, 2020/10/01
- Re: fflush & close behavior not well-defined, Chet Ramey, 2020/10/01
- Re: fflush & close behavior not well-defined, arnold, 2020/10/02
Re: fflush & close behavior not well-defined,
Chet Ramey <=