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
--
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