On 5 June 2012 09:11, Michal Hlavinka <[email protected]> wrote: > 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.
<rant> Michal, I recall that Redhat staff once ridiculed and mocked a patch (...why add extra performance support for a dead OS [Solaris] ...) which added support for I_PEEK to bash2 and finally convinced the maintainers NOT to take it. So basically this issue is blocked from both sides, kernel and bash, by Redhat. Why? </rant> As for an implementation in the Linux fifo kernel module, the I_PEEK ioctl() can be implemented along the lines of a read() syscall but without disposing the data which have been read. An implementation should therefore be very easy and should give the shells in Linux a SERIOUS performance advantage. I'm wondering why Redhat isn't interested in performance. Oh yes, see <rant /> Ced -- Cedric Blancher <[email protected]> Institute Pasteur _______________________________________________ ast-developers mailing list [email protected] https://mailman.research.att.com/mailman/listinfo/ast-developers
