Re: [coreutils] [PATCH 1/2] stat: support printing birthtime

[Eric Blake]

On 10/01/2010 09:22 AM, Jim Meyering wrote:
> > > > +case $(stat --format %x a) in
> > > > +  *.000000000*) sleep 2;; # worst case file system is FAT
> > > > +  *) # FIXME: sleep .1 would be sufficient if %X showed nanoseconds
> > > > + sleep 1;; # should be adequate for any system with subsecond resolution
> > > > +esac
> > >
> > > We try hard to avoid sleeping in the common case.
> > > Any reason not to do what the FIXME suggests?
> > >
> > >       case $(stat --format %X a) in
> > >         *.000000000) sleep 1;;
> >
> > You need two seconds for FAT.
>
> Yes.  FAT is already handled.
> The case statement I suggested was intended to replace the "sleep 1" in
> the default case (handling the FIXME) above, not to replace the existing
> case statement.

I think you mis-parsed my FIXME conmment in patch 1/2.  The point is 
that prior to either patch, %X lacks nanoseconds altogether (that is, 
you will never match *.00000000 or even *.[0-9]* until after patch 2). 
Which is why patch 2/2 deletes the FIXME, and goes with sleep .1, 
because %X is fixed to add nanoseconds.  No second case statement needed.

--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org