Re: Is there a POSIX compliant way of turning a "HH:MM:SS" formatted string to seconds? ...

[Max Nikulin <manikulin@gmail.com>]

On 18/07/2025 05:52, Greg Wooledge wrote:
> On Thu, Jul 17, 2025 at 23:39:02 +0200, lbrtchx@tutamail.com wrote:
> > Video durations are formatted in youtube's .info.json files as "HH:MM:SS";

jq '.duration_string,.duration' m.info.json
"2:10:14"
7814

Taking into account earlier posts, I think that overall complexity of 
the problem is enough to switch from shell to a better programming 
language, e.g. python.

[...]
>                 s=${m#*:}  s=${s##+(0)}
[...]
> This is one way to tackle the problem.  It's *almost* POSIX compliant;
> the bashisms here are the local variables in the function, and the +(0)
> extended glob for removing multiple leading zeroes.

A mathematical trick may be used instead even if external processes like 
sed are considered as undesired overhead

for i in 0 09 008 59 080; do i1=1$i; i2=2$i; echo "$i = $((2*i1 - i2))"; 
done

0 = 0
09 = 9
008 = 8
59 = 59
080 = 80