Re: idea: SIGDIRCH, ftpd, efs

Dave Cole (
Fri, 9 May 1997 14:25:56 +1000 (EST)

On Wed, 7 May 1997, Alan Cox wrote:

> > > Now let's say you expand the proposal to include presenting a list of
> > > directories to watch, you still have problems with NFS and ftp. And
> > > then you'll ned some mechanism to tell which directory changed, or
> > > you'll just have to scan them all.
> >
> >select() on directories instead of a signal?
> This was proposed at Usenix (and various other times too). I think its the
> right answer and at Usenix Linus said if someone did it he'd consider the
> code..
> He did object went I suggested you could then select on /proc and wait
> for processes to die/create ;)

If the kernel was enhanced to allow you to use select() to notice
directory updates, doesn't this also mean you could use select() to be
notified of file updates?

>From my understanding, we currently have no option but to poll the
file/directory. If we could select() on files, then 'tail -f', for
instance, could use select() instead of a timer.

If this functionality was introduced, would Linux then be the only Unix
that had this capability?

- Dave