Book Image

Linux Shell Scripting Essentials

By : Sinny Kumari, Khem Raj
Book Image

Linux Shell Scripting Essentials

By: Sinny Kumari, Khem Raj

Overview of this book

Table of Contents (15 chapters)
Linux Shell Scripting Essentials
About the Author
About the Reviewers

Managing the crontab entry

We don't add or modify an entry of a crontab directly. It is done by using the crontab command that allows you to add, modify, and list crontab entries. Each user can have their own crontab where they can add, delete, or modify tasks. By default, it is enabled for all users, but if a system administrator wants to restrict some of the users, he or she can add that user in the /etc/cron.deny file.

The syntax of using the crontab command is as follows:

crontab [-u user] file
crontab [-u user] [option]

The options of the crontab are explained in the following table:



-u user

Appends the name of the user whose crontab is to be modified


Displays the current crontab on stdout


Edit the current crontab using an editor specified by the EDITOR env


Remove the current crontab


Interactive removal of the current crontab when used with the -r option

Listing crontab entries

To list the crontab entries, we use the -l option for...