Preguntas Frecuentes - FAQ

 "You have new mail" message in Linux

When logging into your Ubuntu or Debian server, you might be greeted with the message You have...

 5 Ways to Send Email From Linux Command Line

We all know the importance of emails these days for information transfer. There are many free...

 Basic Linux commands for Beginners

What Is Linux? Linux is an operating system's kernel. You might have heard of UNIX. Well,...

 Compress and Extract Files Using the tar Command on Linux

The tar command on Linux is often used to create .tar.gz or .tgz archive files, also called...

 Configure Networking on Ubuntu

During the installation of Ubuntu on your server an IP address was most likely obtained...

 Configure Postfix Send Mail Using an External SMTP Server

Introduction Postfix is one of the most popular open-source Mail Transfer Agent (MTA) which...

 Configure Postfix to Send Mail Using Gmail and Google Apps on Debian or Ubuntu

Postfix is a Mail Transfer Agent (MTA) that can act as an SMTP server or client to send or...

 Debian 10 set up WireGuard VPN server

How do I install and set up WireGuard VPN server on a Debian 10 Linux server? How can I configure...

 Debian 9 – How to upgrade to python 3.9

This post relates specifically to python version 3.9.0. Although the generic commands should also...

 E: Unable to locate package npm

When I try to install npm with sudo apt-get install npm, I got following error: E: Unable to...

 Enable snaps on Debian and install certbot-dns-cloudflare

Snaps are applications packaged with all their dependencies to run on all popular Linux...

 Find Files in Linux, Using the Command Line

find is a command for recursively filtering objects in the file system based on a simple...

 How To Create a SSL Certificate on Apache for Debian

Introduction This tutorial walks you through the setup and configuration of an Apache server...

 How To Install Node.js on a CentOS server

Node.js is a Javascript platform for server-side programming. It allows users to easily create...

 How To Install PHP 8 on Debian 11

PHP is a popular server-side scripting language. This guide explains how to install PHP 8 on...

 How To Install the Apache Web Server on Debian 10

Introduction The Apache HTTP server is the most widely-used web server in the world. It...

 How do you install Node.JS on CentOS?

su - yum install gcc-c++ openssl-devel cd /usr/local/src wget...

 How to Add and Delete Users on Debian

Debian, as well as all other Linux distributions is a multi-user operating system. Each user can...

 How to Change hostname in Linux

As a System Admin, one must be aware of changing the hostname. If you have entered the wrong...

 How to Enable and Disable Root User Account

As a new linux user, you may wonder how to log in to your system as a root user or what is the...

 How to Get Help With a Command from the Linux Terminal

Whether you’re an inexperienced terminal user or a grizzled veteran, you won’t always know the...

 How to Install & Configure Sendmail on Debian 9 (Stretch)

Sendmail is a MTA (Mail Transfer Agent) server used for transferring e-mail from between...

 How to Install Icecast Audio Streaming Server

Icecast is an open-source audio/video streaming server that can be used to create your Internet...

 How to Install JSON Support on CentOS

Here’s a way to add JSON support for PHP on your CentOS server. yum install php-pear php-devel...

 How to Install PHP 8.0 in Ubuntu 20.04

PHP is a general-purpose, server-side scripting language that can be used to create dynamic web...

 How to Install Python 3.7 on Debian 9

Python is one of the most popular programming languages in the world. With its simple and easy to...

 How to Install Sendmail on Debian

Sendmail is a MTA (Mail Transfer Agent) server used for transferring email from between different...

 How to Install TeamViewer on Debian 10

TeamViewer is a cross-platform application that can be used for remote control, desktop...

 How to Install and Setup Sendmail on Debian

How to install and configure Sendmail on Debian for sending emails using a email server which...

 How to Install and Use Composer on Debian

Composer is a popular dependency management tool for PHP, created mainly to facilitate...

 How to Restart Network Interface in Linux

How do I restart the network interface under Linux operating systems after making changes to IP...

 How to Secure and Harden Cloud/VPS VM

Securing OS is as important as your website, web applications, online business. You may be...

 How to Send an Email via Gmail SMTP Server using PHP

Introduction In this tutorial, you will learn how to send email in PHP using PHPMailer library...

 How to Set Up a Mac for Your Kids

Providing children with access to a computer and the internet is increasingly important, but so...

 How to Test Sendmail from Linux Command Line

Introduction Linux by default comes with a mail command which can be used to sendmail from...

 How to Upgrade from Debian 10 to Debian 11

For those wishing to upgrade from Debian 10 Buster to Debian 11 Bullseye, the process is very...

 How to Use the tail Command on Linux

The Linux tail command displays data from the end of a file. It can even display updates that are...

 How to change the directory colors for the command LS

bash is a Unix shell written for the GNU Project. Its name is an acronym for Bourne-again shell,...

 How to change the ssh port on Linux

To Change the SSH Port for Linux Server Connect to your server via SSH Switch to the root...

 How to compile and install CMake on Linux

CMake is a cross-platform, open-source build system. CMake is a family of tools designed to...

 How to create ES and RS keys

These methods allow you to pass your public key to someone verifying your tokens, without giving...

 How to create an archive with Linux

Create a tar backup: How the archiving works The archiving program tar is based on an...

 How to enable allow_url_fopen thorugh WHM panel

PHP is a scripting language used by developers to build websites. ‘url_fopen’ refers to a PHP...

 How to fix resolv.conf on Ubuntu or Debian

If you are having wget: unable to resolve host address issues with your Ubuntu machine, you are...

 How to forcefully renew Let’s Encrypt certificate

How do I forcefully renew the Letsencrypt certificate on an Ubuntu, Debian, CentOS, RHEL, Fedora,...

 How to install tDOM package in my linux machine

COMPILING tDOM Depending on your platform (unix/mac or win), go to the corresponding directory...

 How to manage MySQL databases and users from the command line

This article describes how to do common MySQL database administration tasks from the command line...

 How to remove hidden files in Linux

I am a new Linux sysadmin and Ubuntu Linux user. How can I remove hidden files in Linux? How do I...

 How to set a DNS A record?

The "A" stands for "address" and this is the most fundamental type of DNS record: it indicates...

 How to uninstall python completely and install again

Python is a general-purpose, high-level, object-oriented, interactive, and interpreted...

 Install Let's Encrypt to Create SSL Certificates

Let’s Encrypt is an SSL certificate authority managed by the Internet Security Research Group...

 Install updated version of Python on centOS

1. Update System, installing wget and dependencies sudo yum -y updatesudo yum -y install...

 Installing a custom version of curl

Overview curl is installed on all SiSrv servers by default; however, you may want to install a...

 Linux file permissions

How to change directory permissions in Linux To change directory permissions in...

 Move A Folder In Linux Using mv Command

How do I move a folder in BSD/Linux/Apple OX or Unix operating system using bash command line...

 MySQL and MariaDB with unmet dependencies

I could not uninstalled mysql-server because there are unmet dependencies after uninstalling...

 Nginx restore real IP address when behind a reverse proxy

My Nginx web server is behind a reverse proxy server. How do I restore the original and real IP...

 SSH Commands - Linux SSH Commands

Navigating in UNIX pwd Shows the full path of the current directory ls Lists all...

 Setting up an SMTP Server on Linux

The Four Horsemen of Linux Mail Transfer: Exim, Postfix, Sendmail, and Qmail Considering how...

 Start / Stop and Restart Apache 2 Web Server Command

How do I restart an Apache 2 Web Server under a Debian / Ubuntu / CentOS / RHEL / Fedora Linux...

 Static IP vs. Dynamic IP Address

A static IP address is one that remains fixed and never changes. The PC always sees the same...

 Su Command in Linux (Switch User)

The su (short for substitute or switch user) utility allows you to run commands with the...

 This must be accepted explicitly before updates for this repository can be applied

When I run apt-get update on my ubuntu/debian I receive the following error: Ubuntu: E:...

 UnrealIRCd User and Oper commands

Below you can see all the available commands on UnrealIRCd and which module provides...

 Unzip and Untar Those tar.gz or tar.bz2 Files

If you are new to the world of Linux, you probably unzip your tar.gz files first, and then...

 Update, configure and compile TCL version

If you have TCL version issue and need to upgrade, first check your version: list tcl tcl-devel...

 Upgrade OpenSSL to support TLS 1.2

OpenSSL is an open-source toolkit for Transport Layer Security (TLS) and Secure Sockets Layer...

 Using WeeChat for Internet Relay Chat

WeeChat is a multi-platform, terminal-based Internet Relay Chat (IRC) client written in C....

 rSync Command in Linux

Rsync (Remote Sync) is the most commonly used command for copying and synchronizing files and...

 How To Install screenFetch in Linux

If you've browsed Linux groups on social media, you've probably seen a lot of screenshots that...