Difference between revisions of "Mcron"

From Free Software Directory
Jump to: navigation, search
(added standard link)
Line 1: Line 1:
 
{{Entry
 
{{Entry
 
|Name=GNU mcron
 
|Name=GNU mcron
|Short description=Vixie cron replacement
+
|Short description=Vixie cron replacement.
 
|Full description=The mcron program represents a complete re-think of the cron concept originally found in the Berkeley and AT&T unices, and subsequently rationalized by Paul Vixie.  The original idea was to have a daemon that wakes up every minute, scans a set of files under a special directory, and determines from those files if any shell commands should be executed in this minute.
 
|Full description=The mcron program represents a complete re-think of the cron concept originally found in the Berkeley and AT&T unices, and subsequently rationalized by Paul Vixie.  The original idea was to have a daemon that wakes up every minute, scans a set of files under a special directory, and determines from those files if any shell commands should be executed in this minute.
  
Line 21: Line 21:
  
 
https://www.gnu.org/software/mcron/design.html
 
https://www.gnu.org/software/mcron/design.html
 +
 +
'''Selection from the [https://shop.fsf.org/ FSF shop]'''
 +
 +
[https://shop.fsf.org/books/free-freedom-20-richard-stallman Free as in Freedom 2.0, by Richard Stallman]
 +
 +
[https://shop.fsf.org/books-docs/introduction-command-line Introduction to the Command Line]
 +
 +
----
 +
----
 +
'''[https://www.gnu.org/help/help.html Helping the GNU Project and the Free Software Movement]'''
 +
----
 +
----
 +
 +
If you have corrections to this entry or questions about it, please contact: mailto:maintainers@gnu.org
 +
----
 
|Decommissioned or Obsolete=No
 
|Decommissioned or Obsolete=No
 
|Donate=https://my.fsf.org/donate/
 
|Donate=https://my.fsf.org/donate/
|Related projects=Cron,cronwrap,cronolog
+
|Related projects=gnustandards,Cron,cronwrap,cronolog
 
|Keywords=system administration,scheduling,scheme,cron,crontab,Vixie
 
|Keywords=system administration,scheduling,scheme,cron,crontab,Vixie
 
|Version identifier=1.1.1
 
|Version identifier=1.1.1
Line 30: Line 45:
 
|Version download=https://ftp.gnu.org/gnu/mcron/mcron-1.1.1.tar.gz
 
|Version download=https://ftp.gnu.org/gnu/mcron/mcron-1.1.1.tar.gz
 
|Last review by=Bendikker
 
|Last review by=Bendikker
|Last review date=2018/11/16
+
|Last review date=2019/01/05
 
|Submitted by=Database conversion
 
|Submitted by=Database conversion
 
|Submitted date=2011/04/01
 
|Submitted date=2011/04/01
Line 36: Line 51:
 
|Paid support=https://www.fsf.org/resources/service/
 
|Paid support=https://www.fsf.org/resources/service/
 
|Accepts cryptocurrency donations=Yes
 
|Accepts cryptocurrency donations=Yes
 +
|OpenPGP signature=https://ftp.gnu.org/gnu/mcron/mcron-1.1.1.tar.gz.sig
 
|Test entry=No
 
|Test entry=No
 
|Is GNU=Yes
 
|Is GNU=Yes
Line 59: Line 75:
 
{{Resource
 
{{Resource
 
|Resource audience=Savannah (Ref)
 
|Resource audience=Savannah (Ref)
|Resource URL=https://savannah.gnu.org/projects/mcron
+
|Resource URL=https://savannah.gnu.org/projects/mcron/
 
}}
 
}}
 
{{Resource
 
{{Resource
 
|Resource kind=VCS Repository Webview
 
|Resource kind=VCS Repository Webview
|Resource URL=https://git.savannah.gnu.org/cgit/mcron.git
+
|Resource URL=https://git.savannah.gnu.org/cgit/mcron.git/
 
}}
 
}}
 
{{Resource
 
{{Resource
 
|Resource kind=Mailing List
 
|Resource kind=Mailing List
|Resource URL=https://lists.gnu.org/mailman/listinfo/help-mcron
+
|Resource URL=https://lists.gnu.org/mailman/listinfo/help-mcron/
 
}}
 
}}
 
{{Resource
 
{{Resource
 
|Resource kind=Mailing List
 
|Resource kind=Mailing List
|Resource URL=https://lists.gnu.org/mailman/listinfo/bug-mcron
+
|Resource URL=https://lists.gnu.org/mailman/listinfo/bug-mcron/
 
}}
 
}}
 
{{Resource
 
{{Resource
Line 79: Line 95:
 
{{Resource
 
{{Resource
 
|Resource kind=Download
 
|Resource kind=Download
|Resource URL=https://ftp.gnu.org/gnu/mcron
+
|Resource URL=https://ftp.gnu.org/gnu/mcron/
 +
}}
 +
{{Resource
 +
|Resource kind=General
 +
|Resource URL=https://savannah.gnu.org/people/
 
}}
 
}}
 
{{Software category
 
{{Software category

Revision as of 02:57, 5 January 2019


[edit]

GNU mcron

https://www.gnu.org/software/mcron/
Vixie cron replacement.

The mcron program represents a complete re-think of the cron concept originally found in the Berkeley and AT&T unices, and subsequently rationalized by Paul Vixie. The original idea was to have a daemon that wakes up every minute, scans a set of files under a special directory, and determines from those files if any shell commands should be executed in this minute.

It'is a 100% Vixie cron replacement written in pure Guile. As well as accepting traditional crontabs, it also accepts configuration files written in Scheme for infinite flexibility in specifying when jobs should run (it could take the system load into account, for example).

The new idea is to read the required command instructions, work out which command needs to be executed next, and then sleep until the inferred time has arrived. On waking the commands are run, and the time of the next command is computed. Furthermore, the specifications are written in scheme, allowing at the same time simple command execution instructions and very much more flexible ones to be composed than the original Vixie format. This has several useful advantages over the original idea. (Changes to user crontabs are signalled directly to mcron by the crontab program; cron must still scan the /etc/crontab file once every minute, although use of this file is highly discouraged and this behaviour can be turned off).

  • Does not consume CPU resources when not needed. Many cron daemons only run jobs once an hour, or even just once a day.
  • Can easily allow for finer time-points to be specified, i.e. seconds. In principle this could be extended to microseconds, but this is not implemented.
  • Times can be more or less regular. For example, a job that runs every 17 hours can be specified, or a job that runs on the first Sunday of every month.
  • Times can be dynamic. Arbitrary Guile (scheme) code can be provided to compute the next time that a command needs to be run. This could, for example, take the system load into consideration.
  • Each user looks after his own files in his own directory. He can use more than one to break up complicated cron specifications.
  • Each user can run his own daemon. This removes the need for suid programs to manipulate the crontabs, and eliminates many security concerns that surround all existing cron programs.
  • The user can obtain an advance schedule of all the jobs that are due to run.





Licensing

License

Verified by

Verified on

Notes

Verified by

Genium

Verified on

13 March 2020




Leaders and contributors

Contact(s)Role
Adam Bilbrough Maintainer


Resources and communication

AudienceResource typeURI
SavannahVCS Repository Webviewhttps://git.savannah.gnu.org/cgit/mcron.git/
WikidataGeneralhttps://www.wikidata.org/wiki/Q76185633
Debian (Ref)Developerhttps://tracker.debian.org/pkg/mcron
Generalhttps://savannah.gnu.org/people/
Mailing Listhttps://lists.gnu.org/mailman/listinfo/gnu-system-discuss/
Mailing Listhttps://lists.gnu.org/mailman/listinfo/info-mcron/
Downloadhttps://ftp.gnu.org/gnu/mcron/
Mailing Listhttps://lists.gnu.org/mailman/listinfo/bug-mcron/
Savannah (Ref)Developerhttps://savannah.gnu.org/projects/mcron/
Mailing Listhttps://lists.gnu.org/mailman/listinfo/help-mcron/


Software prerequisites




Entry







"Debian (Ref)" is not in the list (General, Help, Bug Tracking, Support, Developer) of allowed values for the "Resource audience" property.


"Savannah (Ref)" is not in the list (General, Help, Bug Tracking, Support, Developer) of allowed values for the "Resource audience" property.



















Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the page “GNU Free Documentation License”.

The copyright and license notices on this page only apply to the text on this page. Any software or copyright-licenses or other similar notices described in this text has its own copyright notice and license, which can usually be found in the distribution or license text itself.