[Info-vax] how to do a search for just today's info

[Paul Sture]

On 2015-01-28, rdpiccard at gmail.com <rdpiccard at gmail.com> wrote:
> On Wednesday, January 28, 2015 at 1:45:05 PM UTC-5, Stephen Hoffman wrote:
>> On 2015-01-28 17:59:51 +0000, pcoviello said:
>> 
>
> [snip]
>
>> 
>> OK.  If those assumptions of mine are correct, then this should get you 
>> close to where you want:
>> 
>> $ slashes = f$cvtime(,,"MONTH") + "/" + f$cvtime(,,"DAY") + "/" + 
>> f$extract(2,2,f$cvtime(,,"YEAR"))
>> $ show symbol slashes
>>   SLASHES = "01/28/15"
>> $
>> 
>> This probably used with something like the following command:
>> 
>> $ PIPE SEARCH sys$scratch:cconsole.tmp today | search sys$pipe 
>> "''slashes'" /output=sys$scratch:cconsole-today.tmp
>> 
>> If you're using a crappy font, that's a vertical bar in there, and then 
>> there's a double quote, and two single quotes, the symbolname slash, a 
>> single quote, and a double quote.
>> 
>> The quoting is used as DCL treats the slash as a special character.
>> 
>> #########
>> 
>
> [snip]
>
>
> A possible corner case:  if the command
>
> $ slashes = f$cvtime(,,"MONTH") + "/" + f$cvtime(,,"DAY") + "/" +
> f$extract(2,2,f$cvtime(,,"YEAR")) 
>
> is executed so as to span from before to after the stroke of midnight
> at the end of the last day of a month (or year), might it produce
> misleading results?  In other words, do each of the f$cvtime
> executions take the then-current time, or is the time when the first
> one executes used by all?

FWIW I usually put calls to get today's date (and time) at the beginning
of such a procedure, so that it's clear it's outside the processing loop.

Then if I need the current time in the context of a lengthy job, I'll
put that somewhere obvious.  Comments explaining why such code is in
that particular spot help greatly when you revisit the code later.

And as Hoff mentions, adding 5 or 10 minutes to batch jobs submitted for
tomorrow avoids problems where the execution queue's system has a
slightly different time than the submitting system.  I used to add
15 minutes in the days before we had NTP or similar mechanisms
available.

-- 
Of dates and times:
%S - Second as decimal number (00–61), allowing for up to two leap-seconds
(but POSIX-compliant implementations will ignore leap seconds)