i think this includes if u start a bash set clock 1h to future and query after 1s , it may show not 0 or 1 second
On Tue, Aug 6, 2024, 18:26 Koichi Murase <myoga.mur...@gmail.com> wrote: > 2024年8月7日(水) 0:24 Bash-help via Bug reports for the GNU Bourne Again > SHell <bug-bash@gnu.org>: > > Reading the manual at > > <https://www.gnu.org/software/bash/manual/bash.html#Bash-Variables> > > regarding the SECONDS variable, it states that > > " [..] Assignment to this variable resets the count to the value > assigned, > > and the expanded value becomes the value assigned plus the number > > of seconds since the assignment. [..]" > > > > [...] > > > > As we sleep less than a full second the expanded value of SECONDS should > never be greater than 0 but it sometimes is. I guess this is because the > assignment might occur, say X.7 seconds and the expanded value will then > read (X+1).2 which would be rounded down to (X+1). > > I think the next sentence in the manual > > https://www.gnu.org/software/bash/manual/bash.html#Bash-Variables > > [...] The number of seconds at shell > > invocation and the current time are always determined by querying the > > system clock. [...] > > is supposed to imply that technically. It says "The number of seconds > at shell invocation", so the starting time point is considered to have > only the "second" resolution and doesn't have the subsecond > resolution. Then, when a value is assigned, the starting time point > would be updated to the number of "seconds" at the assignment. > > For example, when the assignment occurs at time X.7, the recorded time > becomes just X (with the fraction part being truncated). Then, the > value obtained from SECONDS is incremented when the clock becomes > (X+1).0. This is consistent with the observed behavior. > > However, I agree that this is implicit and ambiguous. A minimal > modification is probably something like > > diff --git a/doc/bash.1 b/doc/bash.1 > index 1f0a23d3..3ace21e9 100644 > --- a/doc/bash.1 > +++ b/doc/bash.1 > @@ -2091,7 +2091,7 @@ the value returned upon subsequent > references is > the number of seconds since the assignment plus the value assigned. > The number of seconds at shell invocation and the current time are always > -determined by querying the system clock. > +determined by querying the system clock at the resolution of a second. > If > .SM > .B SECONDS > diff --git a/doc/bashref.texi b/doc/bashref.texi > index 510b43f6..6ee0083b 100644 > --- a/doc/bashref.texi > +++ b/doc/bashref.texi > @@ -7038,7 +7038,7 @@ Assignment to this variable resets the count to > the value assigned, and the > expanded value becomes the value assigned plus the number of seconds > since the assignment. > The number of seconds at shell invocation and the current time are always > -determined by querying the system clock. > +determined by querying the system clock at the resolution of a second. > If @env{SECONDS} > is unset, it loses its special properties, > even if it is subsequently reset. > > -- > Koichi > >
