How to Install Crontab in CentOS/RHEL

Linux crontab is similar to windows task schedulers. Crontab are very useful for routine tasks like scheduling system scanning, daily backups etc. To check  Crontab is installed or not, try to execute crontab -l command:

# crontab -l
-bash: crontab: command not found

The above error means Crontab is not installed yet, Use below command to install it on your server, this will install required dependencies also:

# yum install cronie
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base:
 * updates:
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package cronie.x86_64 0:1.4.4-12.el6 will be installed
--> Processing Dependency: dailyjobs for package: cronie-1.4.4-12.el6.x86_64
--> Running transaction check
---> Package cronie-anacron.x86_64 0:1.4.4-12.el6 will be installed
--> Processing Dependency: crontabs for package: cronie-anacron-1.4.4-12.el6.x86_64
--> Running transaction check
---> Package crontabs.noarch 0:1.10-33.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved                   
 Package                        Arch      Version           Repository     Size
 cronie                         x86_64    1.4.4-12.el6      base           73 k
Installing for dependencies:            
 cronie-anacron                 x86_64    1.4.4-12.el6      base           30 k
 crontabs                       noarch    1.10-33.el6       base           10 k
Transaction Summary                     
Install       3 Package(s)               
Total download size: 114 k                       
Installed size: 220 k                            
Is this ok [y/N]: y                              
Downloading Packages:                            
(1/3): cronie-1.4.4-12.el6.x86_64.rpm                         |  73 kB     00:00
(2/3): cronie-anacron-1.4.4-12.el6.x86_64.rpm                 |  30 kB     00:00
(3/3): crontabs-1.10-33.el6.noarch.rpm                        |  10 kB     00:00
Total                                                336 kB/s | 114 kB     00:00
Running rpm_check_debug                          
Running Transaction Test                         
Transaction Test Succeeded                       
Running Transaction                              
  Installing : cronie-1.4.4-12.el6.x86_64                   1/3
  Installing : crontabs-1.10-33.el6.noarch                  2/3
  Installing : cronie-anacron-1.4.4-12.el6.x86_64                           3/3
  Verifying  : crontabs-1.10-33.el6.noarch                                  1/3
  Verifying  : cronie-anacron-1.4.4-12.el6.x86_64                           2/3
  Verifying  : cronie-1.4.4-12.el6.x86_64                                   3/3
  cronie.x86_64 0:1.4.4-12.el6                   
Dependency Installed:                            
  cronie-anacron.x86_64 0:1.4.4-12.el6            crontabs.noarch 0:1.10-33.el6


As per your requirements to add a cron job use the :

# crontab -e

In filesystem crons are saved in file /var/spool/cron/

To list scheduled jobs for current user under Crontab ,we can use:

crontab -l

To view jobs scheduled under other user :

# crontab -u <username> -l