Mcron

Introduction to Mcron

The GNU package mcron (Mellor's cron) is a 100% compatible replacement for Vixie cron. It is written in pure Guile, and allows configuration files to be written in scheme (as well as Vixie's original format) for infinite flexibility in specifying when jobs should be run. Mcron was written by Dale Mellor (see his personal web pages).

Mcron was proposed to the FSF (2003-07-11) as a component of the GNU system, and accepted on 2003-12-02. Version 1.0.1 was the first release of mcron as a GNU package homed at gnu.org.

A copy of a white paper describes the motivation and initial design concepts of mcron.

The manual describes how the realized incarnation of mcron works, and explains how its functionality can be incorporated into other projects. This is distributed in all the releases, and the latest one can be perused online by clicking the link above.

Releases of Mcron

1.0.3 --- DOWNLOAD

This release has come about mainly due to a suggested patch from Sergey Poznyakoff - very many thanks.

• Updated for guile 1.8 (it will not work with guile 1.6.x).
• A bug in the parsing of Vixie-style input files has been fixed.
• Daylight savings time shifts are now taken into account properly.
• When a user writes an invalid crontab (Vixie personality), they are given a chance to change it (Vixie cron and the previous mcron would simply have thrown the whole lot into oblivion).
• Numerous improvements have been made in the coding.
• The manual has been updated to properly specify the GFDL, and suggestions made by Karl Berry have been taken on board.

1.0.2

• Mcron can now be installed and run by a user without root privileges (but the full Vixie compatibility will be missing).
• Full anachronistic behaviour (the ability for mcron to reboot after a system shutdown and continue to schedule jobs) is not implemented. However, the behaviour of mcron after a laptop computer comes out of sleep mode has been tidied up; jobs which have been missed one or more times during the sleep period will be run exactly once on restart, and all other jobs will be unaffected. Huge and rosy thanks to David D. Smith for suggesting this, and other improvements in the code.
• The manual has been updated, including corrections in the esoteric examples section.

1.0.1

Upgraded all auxiliary and documentation files to reflect the fact that the package is now homed at gnu.org. Mailing lists, etc, have been set up and are now running.

1.0.0

Upgraded all auxiliary and documentation files to reflect the fact that we are now a GNU package, and this is version 1.

0.99.4

Two package configuration additions have been made in light of the review made by the GNU organization (thanks to Karl Berry for these suggestions):

• the configure script now checks that a suitably modern Guile package is installed on the system,
• the configure script provides options for placing the spool directories in non-standard places, as seems to have been the practice in most installations of Vixie-ish crons.

Due to the disruption to service, this version is neither tagged in CVS nor released to the masses.

0.99.3

The code is now broken out into modules which can be used in other programs (the API is fully documented in the manual).

0.99.2

100% Vixie compatibility is now achieved. The code is fully functional and production quality, but still hasn't had any testing done.

0.99.1

The code base is currently functionally complete and written to production quality. Unfortunately the current incarnation of Guile is unable to support it fully. As this will take some time for me to sort out, I have made an interim release 0.99.1 which only has the mcron personality active by default. There are two main reasons why I have released this now.

1. The world deserves mcron, even without the Vixie compatibility.
2. Maybe someone who knows the Guile innards better than me will look into the problem (I don't want to harass the Guile team directly - they're making good, steady progress as it is).

Administration of Mcron

This package is being distributed through the holes http://www.gnu.org/software/mcron (this page) and ftp://ftp.gnu.org/pub/gnu/mcron. Mailing lists are now established, and are bug-mcron@gnu.org for reporting problems with the package; help-mcron@gnu.org for requesting help from the community (including the author of the package) in using mcron and for suggesting and requesting new features; and info-mcron@gnu.org will disseminate items of news as they happen regarding the package.

For more information on the development of mcron and to see the CVS tree please visit mcron's Savannah page.