Linux® Desk Reference, Second Edition

Introduction

The commands in this section are all used to tell the system to do something at (or until) a later time.

Proper use of these commands is the key to an efficiently run system. Throughout this book I have made suggestions about tasks that should be automated and run on a regular basis. These include, but are not limited to the following:

• system security checks (passwords, file access…)

• cleanup of temporary files (rm /tmp/*)

• updating system databases (updatedb)

• backups and archiving (tar, shar)

The following commands are included in this section:

at	Add a job to the scheduling queue.
atq	Display the contents of the scheduling queue.
atrm	Remove a job from the scheduling queue.
batch	Execute queue only when system resources permit.
crontab ...