welcome: please sign in

Upload page content

You can upload content for the page named below. If you change the page name, you can also upload content for another page. If the page name is empty, we derive the page name from the file name.

File to load page content from
Page name
Comment
First name of the author of the GNU Manifesto

Revision 5 as of 2007-11-14 03:53:40

Edit

MemberManual / UsingCron

This page describes the basic use of cron on HCoop systems.

TableOfContents

Prerequisites

It is very important that you read the [:MemberManual/RunningUnattendedCommands:Running Unattended Commands page] to understand the general idea of how to run unattended commands on Mire.

Making a cron configuration file

Cron needs a special configuration file to tell it how to operate. It is suggested that this file be called ~/.crontab, though it can have any name.

For an explanation of the format of this file, run:

man 5 crontab

Activating your cron configuration

Once you are satisfied with your setup, run the following command to activate your changes, assuming that your configuration file is called ~/.crontab:

crontab ~/.crontab

Examples

One convention for making scripts to run commands in their own PAG, as specified by the [:MemberManual/RunningUnattendedCommands:Running Unattended Commands page], is to create the ~/scripts directory, and place your scripts there. Then, make a cron configuration file that looks something like this.

PATH=/afs/hcoop.net/common/bin:/usr/local/bin:/usr/bin:/bin

09 0 * * 0   run-in-pagsh --fg ~/scripts/clean-mail
11 0 * * 0   run-in-pagsh --fg ~/scripts/remove-tmp
12 0 * * 0   run-in-pagsh --fg ~/scripts/weekly-comment-check
*/10 * * * * run-in-pagsh --fg ~/scripts/make-git-projects

The PATH line is needed so that you have access to run-in-pagsh. Make sure you don't try to reference any other environment variables like $HOME, because cron will not expand them properly.

The first cron command runs something 9 minutes after midnight (aka the "0th" hour), every day of the month, every month, provided that it is Sunday (aka the "0th" day of the week). In short: run something at 12:09 every Sunday.

The second and third command are similar.

The fourth command runs something every 10 minutes.