On 17/01/2008, Paul de Weerd <[EMAIL PROTECTED]> wrote:
> On Thu, Jan 17, 2008 at 12:14:59PM +0000, Andreas Kahari wrote:
> | The afterboot(8) manual says to use "ln -fs", e.g.
> |
> | ln -fs /usr/share/zoneinfo/Canada/Atlantic /etc/localtime
> |
> | That way, the /etc/localtime will never not be there (it will not be
> | there for a short time between 'rm' and 'ln -s' if you do it that
> | way).
>
> Sorry, but there will be a short time where the link is not there,
> even with ln -sf, there is no way to atomically change a symlink that
> I know of.
>
> From the source (/usr/src/bin/ln/ln.c) :
>
> /*
> * If the file exists, and -f was specified, unlink it.
> * Attempt the link.
> */
> if ((fflag && unlink(source) < 0 && errno != ENOENT) ||
> (*linkf)(target, source)) {
> warn("%s", source);
> return (1);
> }
>
> First unlink(source), then link. It's a short period, but it's not 0.
>
> Cheers,
>
> Paul 'WEiRD' de Weerd
Ok, but at least the time will be fair bit shorter...
--
Andreas Kahari
Somewhere in the general Cambridge area, UK
