[SOLVED] Re: How to subtract timestamp in elisp?

[stardiviner]

Dmitry Alexandrov <dag@gnui.org> writes:

> stardiviner <numbchild@gmail.com> wrote:
>> I hope a function can subtract two timestamps:
>>
>>     00:12:35 - 00:10:45 = 00:01:50
>>
>> Is there some hints or suggestion like function name or Emacs library or 
>> package?
>
>> Or Linux command is acceptable. I can write a function to execute shell 
>> command then parse the result.
>
> OMG!  Since when that started to require anything but arithmetics?
>
>       (defun timestamp-interval (a b)
>         (cl-flet* ((hms->s (h m s) (+ (* 3600 h)
>                                       (* 60 m)
>                                       s))
>                    (s->hms (s) (let* ((h (/ s 3600))
>                                       (s (% s 3600))
>                                       (m (/ s 60))
>                                       (s (% s 60)))
>                                  (list h m s)))
>                    (timestamp->s (string) (apply #'hms->s
>                                                  (mapcar #'string-to-number
>                                                          (split-string string 
> ":"))))
>                    (s->timestamp (s) (apply #'format "%s%02d:%02d:%02d"
>                                             (if (> 0 s) "-" "") (s->hms (abs 
> s)))))
>           (s->timestamp (- (timestamp->s a) (timestamp->s b)))))
>       
>       (timestamp-interval "00:12:35" "00:10:45")
>       ;; => "00:01:50"
>
> (Not tested.)
>

Dmitry:

This is really great. I thought to use `split-string` too to parse timestamp. My
thought was to use existing API if exist when I compose this email. But
implement a function to dealing with this is great too. Thanks for your help.
And of course Eli and Michael too.

> P. S. Sending mail ‘From: …@gmail.com’ right from your home machine is a best
> way to send it straight to junk folder. ;-) Use smtp.gmail.com.

I used to realized my email always go into Gmail junk, can't find out the
reason. I guess you just solved my long time issue. I'm using Emacs mu4e
package. I will Google how to use SMTP server in mu4e. Thanks again.

-- 
[ stardiviner ]
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