How To Install at on CentOS 8

at is Job spooling tools

Introduction

In this tutorial we learn how to install at on CentOS 8.

What is at

At and batch read commands from standard input or from a specified file. At allows you to specify that a command will be run at a particular time. Batch will execute commands when the system load levels drop to a particular level. Both commands use user’s shell. You should install the at package if you need a utility for time-oriented job control. Note need to be repeated at the same time every day/week, etc. you should use crontab instead.

We can use yum or dnf to install at on CentOS 8. In this tutorial we discuss both methods but you only need to choose one of method to install at.

Install at on CentOS 8 Using dnf

Update yum database with dnf using the following command.

sudo dnf makecache --refresh

The output should look something like this:

CentOS Linux 8 - AppStream                                       43 kB/s | 4.3 kB     00:00    
CentOS Linux 8 - BaseOS                                          65 kB/s | 3.9 kB     00:00    
CentOS Linux 8 - ContinuousRelease                               43 kB/s | 3.0 kB     00:00    
CentOS Linux 8 - Extras                                          23 kB/s | 1.5 kB     00:00    
CentOS Linux 8 - FastTrack                                       40 kB/s | 3.0 kB     00:00    
CentOS Linux 8 - HighAvailability                                36 kB/s | 3.9 kB     00:00    
CentOS Linux 8 - Plus                                            24 kB/s | 1.5 kB     00:00    
CentOS Linux 8 - PowerTools                                      50 kB/s | 4.3 kB     00:00    
Extra Packages for Enterprise Linux Modular 8 - x86_64           13 kB/s | 9.2 kB     00:00    
Extra Packages for Enterprise Linux 8 - x86_64                   24 kB/s | 8.5 kB     00:00    
Metadata cache created.

After updating yum database, We can install at using dnf by running the following command:

sudo dnf -y install at

Install at on CentOS 8 Using yum

Update yum database with yum using the following command.

sudo yum makecache --refresh

The output should look something like this:

CentOS Linux 8 - AppStream                                       43 kB/s | 4.3 kB     00:00    
CentOS Linux 8 - BaseOS                                          65 kB/s | 3.9 kB     00:00    
CentOS Linux 8 - ContinuousRelease                               43 kB/s | 3.0 kB     00:00    
CentOS Linux 8 - Extras                                          23 kB/s | 1.5 kB     00:00    
CentOS Linux 8 - FastTrack                                       40 kB/s | 3.0 kB     00:00    
CentOS Linux 8 - HighAvailability                                36 kB/s | 3.9 kB     00:00    
CentOS Linux 8 - Plus                                            24 kB/s | 1.5 kB     00:00    
CentOS Linux 8 - PowerTools                                      50 kB/s | 4.3 kB     00:00    
Extra Packages for Enterprise Linux Modular 8 - x86_64           13 kB/s | 9.2 kB     00:00    
Extra Packages for Enterprise Linux 8 - x86_64                   24 kB/s | 8.5 kB     00:00    
Metadata cache created.

After updating yum database, We can install at using yum by running the following command:

sudo yum -y install at

How To Uninstall at on CentOS 8

To uninstall only the at package we can use the following command:

sudo dnf remove at

at Package Contents on CentOS 8

/etc/at.deny
/etc/pam.d/atd
/etc/sysconfig/atd
/usr/bin/at
/usr/bin/atq
/usr/bin/atrm
/usr/bin/batch
/usr/lib/.build-id
/usr/lib/.build-id/5b
/usr/lib/.build-id/5b/62f43486550b03dd4fc8620421cdb5a191ddcf
/usr/lib/.build-id/83
/usr/lib/.build-id/83/49b3653cd2bee7e0d8c391862f7c0dd2de32c9
/usr/lib/systemd/system/atd.service
/usr/sbin/atd
/usr/sbin/atrun
/usr/share/doc/at
/usr/share/doc/at/ChangeLog
/usr/share/doc/at/README
/usr/share/doc/at/timespec
/usr/share/licenses/at
/usr/share/licenses/at/COPYING
/usr/share/licenses/at/Copyright
/usr/share/man/man1/at.1.gz
/usr/share/man/man1/atq.1.gz
/usr/share/man/man1/atrm.1.gz
/usr/share/man/man1/batch.1.gz
/usr/share/man/man5/at.allow.5.gz
/usr/share/man/man5/at.deny.5.gz
/usr/share/man/man8/atd.8.gz
/usr/share/man/man8/atrun.8.gz
/var/spool/at
/var/spool/at/.SEQ
/var/spool/at/spool

References

Summary

In this tutorial we learn how to install at on CentOS 8 using yum and dnf.