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

[stardiviner <numbchild@gmail.com>]

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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