crond (timing task scheduling) of linux

crond timing task scheduling

    Set timing tasks through crontab

1.1 Overview

• Task scheduling : refers to a specific command or program executed by the system at a certain time.
• Task scheduling classification :
      1. System work : Some important tasks must be performed round- robin . Such as virus scanning, etc.
      2. Individual user work : Individual users may wish to execute certain programs, such as backup of mysql database

1.2 Basic syntax

• crontab [options]
• -e : edit crontab timing tasks
• -l : query crontab tasks
• -r : delete all crontab tasks of the current user

1.3 Quick start

• Set up personal task scheduling, execute the following code
      crontab -e
• Input task to schedule file
      */1 * * * * ls -l /etc/ > /tmp/to.txt

1.4 Parameter details

Format description Examples

of parameter analysis for each *