Subj : Remote - Local Time synchro
To   : Gerald Miller
From : Jasen Betts
Date : Sun Jul 21 2002 09:11 am

Hi Gerald.

19-Jul-02 16:30:48, Gerald Miller wrote to Jasen Betts


 GM> Hello Jasen,

 GM> On Friday July 19 2002 at 07:43, Jasen Betts [3:640/531.42] wrote
 GM> to Gerald Miller, about:  Remote - Local Time synchro

 GM>>> Remote Time is: [61205] 17:00:05 LOCAL Time is: [61230] 17:00:30
 GM>>> The Remote site is SLOWER by:         00:00:25 Action is:  -
 GM>>> (subtraction) of:         00:00:25 from current LOCAL time... Do
 GM>>> you wish to make an adjustment?

 GM>>> Now, I have to decide how the adjustments are to be made and if
 GM>>> I should let an "X" number of seconds #_slide_by_# before any
 GM>>> notification of adjustments.....  ??? Suggestions ???

 JB>> I'd just put a message in the log file and change the system time
 JB>> (unless the mailer event was less than the time taken)

 GM> I #think# that is the method that FrontDoor uses to synch systems
 GM> and it's unavailable to me....  When the event is running (making
 GM> the connection, the "handshake", the file exchanges...) the log
 GM> file is locked (in use) by 'Frodo'.....  :))

Just pretend that it happened during the event.

 JB>> Still a delay of 5 seconds isn't going to be a big problem
 JB>> either. you may want to ignore differences of greater than a
 JB>> certain amount (if the remote end sets their clock wrong....)

 GM> If I am within fifteen seconds (either way) of my Host, then the
 GM> time is acceptable.

 JB>> if you want you could use inkey to delay and if the use doesn't
 JB>> say no include the inkey delay could be the synchronisation
 JB>> delay.

 GM> This sounds appealing...  Would you provide an example?

assuming %localtime and %remotetime are the times read from the logfile.

  set correction =  %@eval[(%@maketime[%remotetime]-%@time[%localtime] %+
                    +43200 ) %% 86400 - 43200 ]]

 :: %correction is the time difference seconds,
 ::    and is negative if your computer is fast.

 iff %correction lt -1
  set z=
  inkey /w%@eval[%correction *-1] Correcting time: "c" to cancel /KC %%z
  if "%z" ne "c" time %@maketime[%@eval[(%@time[%_time]+%correction)%%86400]]
  set z=
 elseiff %correction gt i
   :: correct time forwards - no waiting
   time %@maketime[%@eval[(%@time[%_time]+%correction)%%86400]]
 endiff

 JB>> most times you'll probably only have to adjust by a few seconds
 JB>> (if you only get 1 second difference probably you should ignore
 JB>> it because it could really be less than one second)

 GM> It's a math problem......

yes, a rounding error.

 GM> This doesn't work, yet I can't see where my error is....

it looks to me like you're trying too hard.
/---* (ZZZ)

 GM>   case y
 GM>       unset /q reply %+ (
 GM>       iff "%act"==" + (addition)" then %+

why not always use addition, 4dos understands negative numbers.

 GM>         set today=%@eval[%@date[%_date]*86400 + %@time[%_time]]
 GM>         set now=%@eval[%today + %@time[%amount]]
 GM>         set newtime=%@maketime[%@eval[%now %% 86400]]
 GM>           time %newtime
 GM>         echo              Revised time is:  %_time

 GM> This doesn't work, yet I can't see where my error is....

time sets the time to a few milliseconds before the time you ask for.
could that be the problem? OTOH %act or %amount could have the wrong value...

  GM> -!- GoldED+/386 v1.1.5-20617
 GM>  - Origin: As the Iron Curtain rusts. (1:342/512)

 -=> Bye <=-

*---/




 -=> Bye <=-

---
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 * Origin: Baddog BBS (1:218/903)

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