>> A simple stat() would show that the inode number of the file hasn't changed.
> Is stat() more expensive than time()?
I suspect that it's fairly likely that I can answer that for most (all ?)
systems ... Yes.
It may not be much, so some people may tailor the time to be 0 ...
> That is what it seems to come down to.
It is configuable !
> Either stat() for each log write to see if the file has changed,
... by setting the interval to 0 ...
> or check the time()
Yup.
> and close/reopen after a certain period
No -- I meant
IF time expired
AND stat shows that the filke has moved
AND open of the file works
THEN replace the old fd with the new
> (possibly only after a stat() to double-check).
Not "double check" -- nearly every time stat will show that there is no need.
> Use of stat()
*every* time
> would ensure that *no* further writes were done after the file has been
> mv-ed (apart from anything that is actually in progress at the time of the
> mv).
well, could be "stat", then "mv", then "write", but yes -- unlikley.
