[gentoo-user] Explenation about %-lines in fcrontab files

[gentoo-user] Explenation about %-lines in fcrontab files

[Grégoire Baron]

Hello,

I am not new in fcron but I have never used all its functionalities. In
fact, I only use &-lines in crontab which are like in Cron. However,
today, I need to use Fcron for executions like once all Friday between
10:00 and 13:00. So I read Fcrontab(5) again. And I thought %-lines are
what I needed. But, I didn't succeed in understanding how *ly, mid*ly
and *s keywords work. Maybe could you help me. Where could I find more
examples on those %-lines ?

What I have understood ?
    For instance for an execution all Friday between 10:00 and 13:00, I
would write:
       %hours * 10-12 * * Fri /what/I/want/to/do
    Is it right ?
    For *ly and mid*ly, I don't understand the difference between mid
and not mid. What are the differences between:
       %daily * 10-12 /what/I/want/to/do
       # an execution all days between 10:00 and 13:00 ?
    And:
       %nightly * 10-12 /what/I/want/to/do
       # an execution all nights between 10:00 and 13:00 ? So all days
between 10:00 and 13:00 ...
    Or between:
       %hourly 15-30 /what/I/want/to/do
       # an execution all hours between -:15 and -:30 ?
    And:
       %midhourly 15-30 /what/I/want/to/do
       # the same ?
    And what are the differences between weekly and midweekly, excepted
Fcron starts to "try" the execution Monday or Thursday ? ...

So can you explain me how work %-lines, or tell me where I could find a
documentation more explicit than Fcrontab(5) ;-) .

Regards,

Grégoire Baron



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Re: [gentoo-user] Explenation about %-lines in fcrontab files

[Régis Décamps]

On 10/15/06, Grégoire Baron <baronchon@n7mm.org> wrote:
> Hello,
>
> I am not new in fcron but I have never used all its functionalities. In
> fact, I only use &-lines in crontab which are like in Cron. However,
> today, I need to use Fcron for executions like once all Friday between
> 10:00 and 13:00. So I read Fcrontab(5) again. And I thought %-lines are
> what I needed. But, I didn't succeed in understanding how *ly, mid*ly
> and *s keywords work. Maybe could you help me. Where could I find more
> examples on those %-lines ?
>
> What I have understood ?
>     For instance for an execution all Friday between 10:00 and 13:00, I
> would write:
>        %hours * 10-12 * * Fri /what/I/want/to/do
>     Is it right ?

Yes, I think so.

>     And what are the differences between weekly and midweekly, excepted
> Fcron starts to "try" the execution Monday or Thursday ? ...

Fcron starts the command if is has not been executed in the period.
It's the same, except
weekly means mon-sun (or is it sun-mon?)
midweekly means thu-wed

Imagine you've just configured fcron on monday à 9:00 with
%weekly * 0-10 command1
%midweekly  * 0-10 command2

Both commands are executed immediately.
Tuesday, nothing happens.
Wednesday, nothing happens
Thursday, command2 is executed, but not command1.
Friday, nothing happens
Sat, nothing happens
Sun, nothing happens
Mon, command1 is exectued.

You can then understand all over mid* commands.


>     For *ly and mid*ly, I don't understand the difference between mid
> and not mid. What are the differences between:
>        %daily * 10-12 /what/I/want/to/do
>        # an execution all days between 10:00 and 13:00 ?
>     And:
>        %nightly * 10-12 /what/I/want/to/do
>        # an execution all nights between 10:00 and 13:00 ? So all days
> between 10:00 and 13:00 ...

By definition nightly=middaily.

But of course, if you indicate an hour which occurs only once in each
period, that won't change anything. There will be a difference for
%daily * 10-12,17-18 /what/I/want/to/do
%nightly * 10-12,17-18 /what/I/want/to/do

In practice, there will be a difference if you turn off the computer
for lunch time.

>     Or between:
>        %hourly 15-30 /what/I/want/to/do
>        # an execution all hours between -:15 and -:30 ?
>     And:
>        %midhourly 15-30 /what/I/want/to/do
>        # the same ?

idem, fcron needs a larger minute frame to have choices

>
> So can you explain me how work %-lines, or tell me where I could find a
> documentation more explicit than Fcrontab(5) ;-) .
>
I did'nt use more, either :-p
http://fcron.free.fr/doc/fr/fcrontab.5.html

Hope this helps,
-- 
Régis

http://regis.decamps.info/blog/

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Re: [gentoo-user] Explenation about %-lines in fcrontab files

[Grégoire Baron]

Ok, thanks

I think, for *s keywords I understood.
For *ly and mid*ly, I think I have some difficulties because I haven't 
concrete examples.

In fact, the difference between *ly and mid*ly keywords (between weekly 
and midweekly, for instance) is the beginning of the period and so when 
fcron start to try to execute the command. And in practice, we only can 
see that when we have several execution intervals for a same period, 
computer shutdown or 2 commands with "mid" and without "mid" (one with 
middaily and one with daily, for instance), aren't we ?

Thanks you very much for your help.
Sincerely,

Grégoire Baron

Régis Décamps a écrit :
> On 10/15/06, Grégoire Baron <baronchon@n7mm.org> wrote:
>> Hello,
>>
>> I am not new in fcron but I have never used all its functionalities. In
>> fact, I only use &-lines in crontab which are like in Cron. However,
>> today, I need to use Fcron for executions like once all Friday between
>> 10:00 and 13:00. So I read Fcrontab(5) again. And I thought %-lines are
>> what I needed. But, I didn't succeed in understanding how *ly, mid*ly
>> and *s keywords work. Maybe could you help me. Where could I find more
>> examples on those %-lines ?
>>
>> What I have understood ?
>>     For instance for an execution all Friday between 10:00 and 13:00, I
>> would write:
>>        %hours * 10-12 * * Fri /what/I/want/to/do
>>     Is it right ?
>
> Yes, I think so.
>
>>     And what are the differences between weekly and midweekly, excepted
>> Fcron starts to "try" the execution Monday or Thursday ? ...
>
> Fcron starts the command if is has not been executed in the period.
> It's the same, except
> weekly means mon-sun (or is it sun-mon?)
> midweekly means thu-wed
>
> Imagine you've just configured fcron on monday à 9:00 with
> %weekly * 0-10 command1
> %midweekly  * 0-10 command2
>
> Both commands are executed immediately.
> Tuesday, nothing happens.
> Wednesday, nothing happens
> Thursday, command2 is executed, but not command1.
> Friday, nothing happens
> Sat, nothing happens
> Sun, nothing happens
> Mon, command1 is exectued.
>
> You can then understand all over mid* commands.
>
>
>>     For *ly and mid*ly, I don't understand the difference between mid
>> and not mid. What are the differences between:
>>        %daily * 10-12 /what/I/want/to/do
>>        # an execution all days between 10:00 and 13:00 ?
>>     And:
>>        %nightly * 10-12 /what/I/want/to/do
>>        # an execution all nights between 10:00 and 13:00 ? So all days
>> between 10:00 and 13:00 ...
>
> By definition nightly=middaily.
>
> But of course, if you indicate an hour which occurs only once in each
> period, that won't change anything. There will be a difference for
> %daily * 10-12,17-18 /what/I/want/to/do
> %nightly * 10-12,17-18 /what/I/want/to/do
>
> In practice, there will be a difference if you turn off the computer
> for lunch time.
>
>>     Or between:
>>        %hourly 15-30 /what/I/want/to/do
>>        # an execution all hours between -:15 and -:30 ?
>>     And:
>>        %midhourly 15-30 /what/I/want/to/do
>>        # the same ?
>
> idem, fcron needs a larger minute frame to have choices
>
>>
>> So can you explain me how work %-lines, or tell me where I could find a
>> documentation more explicit than Fcrontab(5) ;-) .
>>
> I did'nt use more, either :-p
> http://fcron.free.fr/doc/fr/fcrontab.5.html
>
> Hope this helps,
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