Re: 'withfile' function implementation

[Paul Smith]

On Mon, 2012-01-30 at 21:33 -0500, David Boyce wrote:
> On Mon, Jan 30, 2012 at 6:19 PM, Paul Smith <address@hidden> wrote:
> > Is there "something special" you would prefer beyond this?
> 
> Well ... it's more of a thought than an actual request or preference,
> but I'm suggesting that make might want to take positive steps in your
> last case (empty text argument, append to existing file) to force an
> update of the mod time. Reasons:

The problem, as I alluded to before, is that there's no way to get the
exact semantics of updating a file without actually updating the file.

In order to change the modtime on a file without changing the file you
have to use utime(), which sets the file to an explicit time... in
short, the time on the current system.

But modifying a file causes the timestamp to be set on the file by the
system where the file resides.

If the filesystem is local they're basically equivalent, but if the
filesystem is remote then you can easily get two different timestamps by
having the file updated in these two different ways.

Maybe this is not something we should worry about.  Certainly it's true
that touch(1) has the same problem.  I did need to make changes to the
regression tests, though, to take this potential issue into account.

-- 
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