On 06/01/2012 02:32 PM, Irek Szczesniak wrote:
Michal, did anyone ever filed a bug against Linux's FIFO/PIPE implementations to support I_PEEK? As far as I can check all SystemV derivatives (including Solaris), AIX and HP/UX support I_PEEK on pipes and fifos.
I don't know if there was any official attempt. I asked a few kernel developers in person and they told me that no one will bother with this.
Just Linux does not. Irek ---------- Forwarded message ---------- From: Lionel Cons<[email protected]> Date: Thu, May 31, 2012 at 10:38 PM Subject: Re: [ast-users] ksh: command pipe -- connection reset To: "Nemeth, Michael Kenneth (Mike)"<[email protected]> Cc: "[email protected]"<[email protected]> On 31 May 2012 21:48, Nemeth, Michael Kenneth (Mike) <[email protected]> wrote:Hello, We are using ksh93u (2011-02-08) source compiled on rhel5.0 and we are experiencing intermittent connect reset errors with typical unix command pipelines. Example: min=`grep -v "^#" $infile | head -1 | nawk '{printf("%.3f\n",$3)}'` will produce error: grep: writing output: Connection reset by peer I reviewed all ast-user, ast-developers archives, and other forums I have come to the following topics: bug#9089: [1003.1(2008)/Issue 7 0000205]: Shell pipeline connection requirement too vague http://lists.gnu.org/archive/html/bug-coreutils/2011-07/msg00090.html http://lists.gnu.org/archive/html/bug-coreutils/2011-07/msg00089.html Is there a solution to this issue?Yes, get the Linux kernel to support I_PEEK on pipes and fifos like Solaris does. AFAIK sockets are used because pipes on Linux do not support I_PEEK, and without I_PEEK the shell would have to read the streams byte by byte, i.e. one syscall per byte. Solaris allows I_PEEK on pipes, fifos and sockets and gets a huge performance benefit from that. Lionel _______________________________________________ ast-users mailing list [email protected] https://mailman.research.att.com/mailman/listinfo/ast-users
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