Re: SECONDS=0 does not reset SECONDS, or I'm missing something

[Mike Jonkmans]

On Thu, Jun 04, 2020 at 02:34:35PM -0400, Chet Ramey wrote:
> Yes, SECONDS is in seconds granularity, whether that is seconds since the
> epoch or seconds since an assignment to it, as you quoted below. There's
> no expectation of subsecond granularity -- it's just whatever the system
> tells the shell the current number of seconds is.
> 
> The next version will use the number of seconds returned from gettimeofday,
> but there's still nothing in there that attempts to round it up or down
> depending on tv_usec.

Hi Chet,

Instead of gettimeofday, you might want to use 
clock_gettime(CLOCK_MONOTONIC,..).

The problem with gettimeofday is described here:
https://blog.habets.se/2010/09/gettimeofday-should-never-be-used-to-measure-time.html

TL;DR gettimeofday may be inaccurate in combination with NTP.

Regards, Mike

-- 
Mike Jonkmans <bashbug@jonkmans.nl>