Re: EPOCHREALTIME does not behave correctly before 1970

[Kerin Millar]

On Sun, 22 Aug 2021 16:13:28 -0400
Chet Ramey <chet.ramey@case.edu> wrote:

> On 8/21/21 1:28 AM, Emanuele Torre wrote:
> 
> > Bash Version: 5.1
> > Patch Level: 8
> > Release Status: release
> > 
> 
> > get_epochrealtime() casts tv.tv_sec (a time_t a.k.a. int) to unsigned
> > int causing EPOCHREALTIME to not behave correctly before the Unix Epoch.
> 
> The definition is seconds since the Unix epoch. It's not surprising that it
> doesn't pay attention to dates before that.

The problem with this statement is that EPOCHREALTIME is permitted to get it 
wrong, yet EPOCHSECONDS is permitted to get it right. The discrepancy certainly 
came as a surprise to me.

$ TZ=UTC faketime '1970-01-01' bash -c 'declare -p EPOCHSECONDS'
declare -- EPOCHSECONDS="0"

$ TZ=UTC faketime '1969-12-31' bash -c 'declare -p EPOCHSECONDS'
declare -- EPOCHSECONDS="-86400"

-- 
Kerin Millar