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#1 2012-02-12 13:22:30

stuvjordan
Member
Registered: 2011-08-09
Posts: 26

cron vs (anacron, cronie, fcron, etc.)

I'm confused about the relationship between crond -- the actual daemon that runs jobs from my various crontabs -- and the various cron programs anacron, cronie, fcron, etc.

Is it to correct to think of the latter programs as mediators between cron and the user -- like anacron manages the cron daemon on my behalf?  Or does anacron (or cronie or fcron or whatever) run scheduled jobs entirely independently of crond?

Mostly I'm just curious -- although it is a bit unsettling to be setting up cron jobs when I'm not really sure how all these entities relate.

Thanks!

Last edited by stuvjordan (2012-02-12 13:23:10)

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#2 2012-02-12 15:12:57

karol
Archivist
Registered: 2009-05-06
Posts: 25,440

Re: cron vs (anacron, cronie, fcron, etc.)

crond is the name of the cron daemon, it's provided by e.g. cronie and dcron.

Install cronie, check what anacron is - maybe it's just a think wrapper script.

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#3 2012-02-12 15:18:32

patroclo7
Member
From: Bassano del Grappa, ITALY
Registered: 2006-01-11
Posts: 915

Re: cron vs (anacron, cronie, fcron, etc.)

Dcron, cronie, fcron and vixie-cron are cron implementations. Dcron, cronie and vixie-cron (but not fcron) provide a crond daemon binary, but they implement it in their own way. Anacron was originally a standalone application which was meant to run cron jobs in systems not expected to be always on (thus the jobs are run when the system is actually on). An anacron binary with similar purposes has been included in cronie (which is a dcron derivative, but dcron does not include anacron-like functionalities). Fcron provides anacron-like functionalities thanks to the articulate syntax of its fcrontabs, thus it does need to include a separate anacron binary.


Mortuus in anima, curam gero cutis

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#4 2012-02-13 01:00:03

stuvjordan
Member
Registered: 2011-08-09
Posts: 26

Re: cron vs (anacron, cronie, fcron, etc.)

thanks y'all...I think I got it.

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#5 2012-02-13 03:34:02

Misfit138
Misfit Emeritus
From: USA
Registered: 2006-11-27
Posts: 4,189

Re: cron vs (anacron, cronie, fcron, etc.)

patroclo7 wrote:

Dcron, cronie, fcron and vixie-cron are cron implementations. Dcron, cronie and vixie-cron (but not fcron) provide a crond daemon binary, but they implement it in their own way. Anacron was originally a standalone application which was meant to run cron jobs in systems not expected to be always on (thus the jobs are run when the system is actually on). An anacron binary with similar purposes has been included in cronie (which is a dcron derivative, but dcron does not include anacron-like functionalities). Fcron provides anacron-like functionalities thanks to the articulate syntax of its fcrontabs, thus it does need to include a separate anacron binary.

Like sweet music!

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#6 2012-02-13 05:33:16

x33a
Forum Fellow
Registered: 2009-08-15
Posts: 4,587

Re: cron vs (anacron, cronie, fcron, etc.)

patroclo7 wrote:

An anacron binary with similar purposes has been included in cronie (which is a dcron derivative, but dcron does not include anacron-like functionalities).

dcron does provide anacron like functionality.

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#7 2012-02-13 09:32:07

karol
Archivist
Registered: 2009-05-06
Posts: 25,440

Re: cron vs (anacron, cronie, fcron, etc.)

x33a wrote:
patroclo7 wrote:

An anacron binary with similar purposes has been included in cronie (which is a dcron derivative, but dcron does not include anacron-like functionalities).

dcron does provide anacron like functionality.

Do you mean e.g. @daily ?

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#8 2012-02-13 09:46:53

x33a
Forum Fellow
Registered: 2009-08-15
Posts: 4,587

Re: cron vs (anacron, cronie, fcron, etc.)

@ karol

dcron runs sys-{hourly,daily,weekly,monthly} etc. So yes.

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#9 2012-02-13 10:58:25

patroclo7
Member
From: Bassano del Grappa, ITALY
Registered: 2006-01-11
Posts: 915

Re: cron vs (anacron, cronie, fcron, etc.)

@x33a
Yes, sorry for the mistake, I had used dcron for the last time in th 3.x series developed by Dillon, and this functionality was absent. It has been introduced by the new developer in 4.0, as far as I see not through an anacron-like binary but through an enrichment of the crontab syntax.

Last edited by patroclo7 (2012-02-13 11:00:09)


Mortuus in anima, curam gero cutis

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#10 2012-02-13 12:49:37

x33a
Forum Fellow
Registered: 2009-08-15
Posts: 4,587

Re: cron vs (anacron, cronie, fcron, etc.)

patroclo7 wrote:

@x33a
Yes, sorry for the mistake, I had used dcron for the last time in th 3.x series developed by Dillon, and this functionality was absent.

I thought you were referring to the current version, so that explains.

It has been introduced by the new developer in 4.0, as far as I see not through an anacron-like binary but through an enrichment of the crontab syntax.

Yes there is no bundling of an anacron binary, like i think cronie does.

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