The DEBIAN_FRONTEND variable is an environment variable that controls the user interface used by the apt-get package manager on Ubuntu and Debian systems. It is used to specify the type of user interface that should be used when running apt-get commands. There are three main options for the DEBIAN_FRONTEND variable: noninteractive: This option tells apt-get … Read more

Firewalld is a firewall management tool for Linux systems that uses dynamic firewall rules. To enable logging for denied packets in Firewalld, you will need to make some changes to the Firewalld configuration. First, you need to set the log level to “debug” or “info”. You can do this by running the following command: sudo … Read more

In Linux, the net.ipv4.ip_nonlocal_bind sysctl variable controls whether or not a process can bind to an IP address that does not exist on the local system. By default, this variable is set to 0, which means that a process cannot bind to an IP address that does not exist on the local system. To allow … Read more

You can configure Vim to show line numbers by default on Linux by editing the Vim configuration file, .vimrc. Here are the steps to do this: Open a terminal window and navigate to your home directory by running the command cd ~. Check if the .vimrc file exist in your home directory using the command … Read more

The chsh command (short for “change shell”) allows you to change the default shell for a user in Linux. Here are the steps to change your default shell using chsh: Open a terminal window Run the command cat /etc/shells, this will list the available shells on your system, make sure the shell you want to … Read more

In Linux, you can use the iptables command to manage the firewall rules. To delete a prerouting rule, you can use the -D option, followed by the table, chain, and rule number. For example, to delete a prerouting rule in the nat table, in the PREROUTING chain, with a rule number of 2, you would … Read more

UFW (Uncomplicated Firewall) is a firewall management tool for Ubuntu 20.04 LTS. It is a command-line tool that makes it easy to configure and manage iptables, the Linux kernel’s built-in firewall. Here are the steps to configure the firewall with UFW on Ubuntu 20.04 LTS: Install UFW by running the following command: sudo apt install … Read more

To install phpredis on CentOS 8 / RHEL 8, you can use the following steps: First, make sure that your system is up to date by running the command sudo yum update. Install the PHP development tools and the Redis package by running the command sudo yum install php-devel redis. Next, you will need to … Read more

There are several ways to save terminal output to a file under Linux or Unix: Using the > operator: This operator redirects the output of a command to a file. For example, to save the output of the ls command to a file named “ls_output.txt”, you would use the following command: ls > ls_output.txt Using … Read more

To change the hostname on Ubuntu 20.04, you can use the hostnamectl command. Here are the steps to change the hostname on Ubuntu 20.04: Open a terminal window on your Ubuntu 20.04 system. Check the current hostname by running the following command: hostnamectl To change the hostname, use the following command, replacing “new_hostname” with the … Read more