Getting Started with cron timer execution tools under Linux

Cron is a regular execution tool under Linux that can run jobs without human intervention. Because Cron is a built-in service for Linux, it does not automatically get up and you can start and close this service in the following ways:

/sbin/service crond Start//boot service

/sbin/service Crond Stop//Off service

/sbin/service crond Restart//Restart service

/sbin/service Crond Reload//Reload Configuration

You can also start this service automatically when the system is started:

At the end of the/etc/rc.d/rc.local script, add:

/sbin/service Crond Start

Now that the Cron service is in the process, we can use this service, and the Cron service provides the following interfaces for everyone to use:

1. Edit directly with crontab command

The Cron service provides the crontab command to set the Cron service, and here are some of the parameters and instructions for this command:

Crontab-u//Set a user's Cron service, which is required by the general root user when executing this command

CRONTAB-L//list details of a user's cron service

Crontab-r//Remove cron service for no users

CRONTAB-E//Edit a user's cron service

For example, root view your cron settings: Crontab-u root-l

Again for example, Root wants to delete Fred's cron settings: Crontab-u fred-r

When editing a cron service, there are some formatting and conventions for editing the content, input: Crontab-u root-e

into the vi editing mode, the contents of the edit must conform to the following format: */1 * * * * ls >>/tmp/ls.txt