Rahul Sahu

There are a few different ways to install Java on Ubuntu 20.04 LTS, but the most common way is to use the package manager. Here’s how you can do it: First, update your package lists by running the command “sudo apt update” Next, you can install the default OpenJDK package by running the command “sudo … Read more

ssh-agent is a program that allows you to store your private SSH keys in memory, so that you don’t have to enter the passphrase every time you use them. To use ssh-agent for authentication on Linux or Unix, you can follow these steps: Start by starting the ssh-agent program by running the following command: eval … Read more

You can create a Linux swap file by following these steps: First, check the available disk space by running the command “df -h”. This will show you the amount of free space available on your system. Decide on the size of the swap file. It’s recommended that the swap file size is at least twice … Read more

On CentOS and RHEL, you can check if the system needs a full reboot by checking the kernel version and the kernel release. A full reboot is required when the running kernel version and release are different from the latest installed kernel version and release. You can check the running kernel version and release by … Read more

To configure Amazon Web Services (AWS) Simple Email Service (SES) with the Postfix Mail Transfer Agent (MTA) on FreeBSD, you will need to follow these steps: Install the Postfix MTA by running the command “pkg install postfix”. Configure the Postfix MTA by editing the “/usr/local/etc/postfix/main.cf” file. Set the “myorigin” parameter to your domain name, set … Read more

To save iptables firewall rules permanently on Linux, you can use the iptables-save and iptables-restore commands. Start by saving your current iptables rules by running the following command: sudo iptables-save > /etc/iptables/iptables.rules This command will save the current iptables rules to a file named “iptables.rules” in the “/etc/iptables” directory. To make sure that the iptables … Read more

On Linux systems using systemd, you can use the “systemctl” command to view the status of a service. The basic syntax for the command is: systemctl status [service_name] For example, to check the status of the Apache web server, you can use the command: systemctl status httpd This command will return the current status of … Read more

Less is a command-line tool that allows you to view text files in a paginated manner. You can install it on CentOS, RHEL, and Fedora using the package manager. (https://www.fi-di.com/) To install less on CentOS or RHEL: Run the command “sudo yum install less” to install the less package. To install less on Fedora: Run … Read more

In Linux, you can write the output of a command to a file using the “>” operator. The basic syntax is: command > file For example, if you want to write the output of the ls command to a file named “list.txt”, you would run the following command: ls > list.txt This will create a … Read more

To set or change the Fully Qualified Domain Name (FQDN) on Ubuntu 20.04, you can follow these steps: Open the terminal by pressing “Ctrl + Alt + T” or by searching for “terminal” in the start menu. Run the command “sudo nano /etc/hostname” to open the hostname configuration file in nano text editor. Change the … Read more