Files with a .rar extension are compressed archives, much like a .tar.gz or .zip file. It is one of many file compression formats that rose to popularity over the years, but requires its own utility to use.
Luke Reynolds
Find setuid binaries to perform Linux server hardening
The purpose of this tutorial is to find setuid binaries on Linux. It is very possible that your Linux server has more packages installed than you really need. To make it worse, those extra packages may contain a handful of binaries with setuid and setguid turned on.
Check domain name availability with bash and whois
If you’ve ever tried to come up with a catchy domain name, you know how annoying it can be to keep checking to see if a certain name is available. Fortunately, on Linux we can make the task a little easier on us by using the whois command. When a domain is available, the output from whois will let us know that it’s not able to find any information for that domain.
It’s easy enough then to put this functionality into a Bash script, which helps to automate checking lots of different TLDs (Top Level Domains, like .com, .net, .org, etc).
In this guide, we’ll show how to check domain name availability from the command line on Linux. Then, we’ll give you a simple Bash script that you can copy onto your own system and check for lots of domains at once. Read on to learn how.
In this tutorial you will learn:
- How to install whois on major Linux distros
- How to check for domain name availability with whois command
- Bash script for checking domain name availability
Extract user list from your Linux system
User management is an important part of Linux administration, so it’s essential to know about all the user accounts on a Linux system and how to disable user accounts, etc. In this guide, we’ll show you how to list the current users via command line and GUI. This will include a GNOME desktop environment as well as KDE.
In this tutorial you will learn:
- How to list users via command line
- How to list users on GNOME GUI
- How to list users on KDE GUI
Bash – Redirect both standard output and standard error to same file
The Bash shell is the most popular shell on Linux systems, and to use the shell efficiently, you need a little knowledge about Bash shell redirections. This is also an essential step in learning Bash scripting.
In this guide, we’ll show how to redirect standard output and standard error to the same file on the Bash shell command line. This will include several examples so you can pick the right method in any scenario.
In this tutorial you will learn:
- How to redirect standard output and standard error to same file
- How to redirect standard output and standard error to file and terminal
- How to redirect standard output and standard error to /dev/null
Configure Apache VirtualHost on Fedora
Apache web servers utilize the virtual host feature in order to host more than one website. If you have Apache installed on Fedora Linux and want to run multiple websites, this is the route you will have to take. But don’t worry, Apache makes it rather easy to setup and configure virtual hosts.
In this guide, we’ll go through the step by step instructions to configure Apache virtual hosts on Fedora.
In this tutorial you will learn:
- How to configure Apache virtual hosts on Fedora Linux
Backup permissions on Linux
If you’re worried about the file permissions on your Linux system being changed, it’s possible to back up the file permissions of a certain set of files or directories with the getfacl command. You can then restore file permissions en masse by using the setfacl command.
In this guide, we’ll show how to make a backup snapshot of file permissions, as well as how to restore the saved permissions.
In this tutorial you will learn:
- How to create a backup of file permissions
- How to restore a backup of file permissions
Show Bash script usage
Is it best practice to include usage in every Bash script that you create. This gives the user an idea of what options the script is expecting, so they can use it as intended. It also gives the script some error checking ability to make sure that the user has supplied arguments in the expected way.
How to remove www from url in htaccess
As you probably noticed a long time ago, online websites can be accessed either with or without their www. prefix. For example www.linuxconfig.org and linuxconfig.org.
What is DHCP and how to configure DHCP server in Linux
DHCP is a networking protocol used to assign IP addresses to networked devices. In this guide, we’ll introduce you to the protocol and explain how it works. You’ll also see how to implement a DHCP server on Linux systems, and configure it for your own network.
In this tutorial you will learn:
- What is DHCP?
- How to implement a DHCP server on major Linux distros
- How to configure DHCP on Linux
How to retrieve and change partition’s UUID Universally Unique Identifier on linux
Hard drive partitions on Linux systems rely on a UUID (universally unique identifier) for unique labels. This is basically a unique string of characters that the operating system will use to identify your hard disk partitions and other storage components.
You can see this for yourself by examining the /etc/fstab file on your own system.
$ grep UUID /etc/fstab
In this guide, we’ll go over several command line methods to retrieve the UUIDs of hard disk partitions. We’ll also show you how to generate UUIDs and change a partition’s UUID.
In this tutorial you will learn:
- How to retrieve, generate, and change the UUID of a partition