How to schedule a job using crontab
To schedule a job using crontab
Introduction
Cron is used to scheduling commands; it is a standard Unix utility. It helps to maintain the software environment and also known as job crons. Crons is a long-running process to schedule work at a fixed time and date. It is connected to the server to complete the task automatically and also a resourceful tool that helps to save time.
Installation Procedure
Checking the installed OS version
linuxhelp@linuxhelp:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 21.04
Release: 21.04
Codename: hirsute
Log in as a Root user by the following command
linuxhelp@linuxhelp:~$ sudo -s
[sudo] password for linuxhelp:
Editing the crontab file by the following command
root@linuxhelp:/home/linuxhelp# crontab -e
no crontab for root - using an empty one
Select an editor. To change later, run 'select-editor'.
1. /bin/nano <---- easiest
2. /usr/bin/vim.tiny
3. /bin/ed
Choose 1-3 [1]:
On Ubuntu based system it will ask for the editor for the first time to choose one or by default it uses the nano editor. Opened the Crontab file
Add the following lines, this will execute
10 14 * * * touch file
11 14 * * * mkdir folder
12 14 * * * cp file file1
Cron job scheduled
Changing directory by using following command
root@linuxhelp:/home/linuxhelp# cd /root/
Long listing the home directory to view the files created by crontab
root@linuxhelp:~# ls -la
total 40
drwx------ 6 root root 4096 Oct 6 13:54 .
drwxr-xr-x 20 root root 4096 Sep 8 16:50 ..
-rw------- 1 root root 627 Oct 6 13:47 .bash_history
-rw-r--r-- 1 root root 3106 Aug 15 2019 .bashrc
drwx------ 2 root root 4096 Apr 20 16:20 .cache
-rw-r--r-- 1 root root 0 Oct 6 13:52 file
-rw-r--r-- 1 root root 0 Oct 6 13:54 file1
drwxr-xr-x 2 root root 4096 Oct 6 13:53 folder
drwxr-xr-x 3 root root 4096 Oct 6 13:48 .local
-rw-r--r-- 1 root root 161 Sep 16 2020 .profile
-rw-r--r-- 1 root root 66 Oct 6 13:48 .selected_editor
drwxr-xr-x 3 root root 4096 Sep 8 17:00 snap
By this schedule a job using crontab comes to end