Re: Fwd: Default pg_autovacuum config glitches - Mailing list pgsql-bugs

On Fri, 26 Mar 2004, Matthew T. O'Connor wrote:

> Bruno Wolff III wrote:
>
> >On Thu, Mar 25, 2004 at 16:08:49 +0100,
> >  Martin Pitt <martin@piware.de> wrote:
> >
> >
> >>A while ago we received the bug report below against pg_autovacuum.
> >>Since it runs as a daemon, it should detach from its controlling
> >>terminal by executing sth like
> >>
> >>        int nullfd = open("/dev/null", O_RDWR);
> >>        dup2(nullfd, 0);
> >>        dup2(nullfd, 1);
> >>        dup2(nullfd, 2);
> >>        if (nullfd != 0 && nullfd != 1 && nullfd != 2)
> >>                close(nullfd);
> >>
> >>(taken from syslog-ng which does it properly).
> >>
> >>
> >
> >That doesn't look like a good idea. This will prevent any logging to
> >stdout or stderr.
> >
> >If you don't want that ability you can redirect the stdin, stdout and
> >stderr yourself.
> >
>
> I have stayed quiet about this since I wanted to hear what others
> thought of the above suggest fix.  I took the detach code straight from
> the postmaster daemonize function.  Perhaps I didn't do something right

The postmaster's seems to have a section that does a null device open,
dup2s and a close at the end of pmdaemonize in the 7.4 and 7.5 versions on
my box:

        i = open(NULL_DEV, O_RDWR | PG_BINARY);
        dup2(i, 0);
        dup2(i, 1);
        dup2(i, 2);
        close(i);