Introduction

Cron & at

Automating Tasks

cron

  • environment variables
    • SHELL
    • PATH
    • MAILTO
    • HOME

anacron

  • called by cron hourly
  • mainly intended for use on laptops
  • environment variables
    • SHELL
    • PATH
    • MAILTO
    • HOME
    • RANDOM_DELAY: prevent system overloading
    • START_HOURS_RANGE: the time range of hours during the day when anacron can run scheduled jobs

One-Time Tasks

  • at
  • batch
    • /etc/sysconfig/atd
      • OPTS