Tutorials Archive

Tutorials Archive - Page 6 of 32

How to View and Edit Large Files in Linux Using “less” and “sed”

Have you ever tried opening a large file of hundreds of MB or several GB in vi? It can take forever. And making edits is even longer. This is because vi loads the entire file into memory before displaying it to you. For large files, there are better and more efficient tools like “less” and “sed”. Here’s a tutorial on how to use them.

How to Hash a File in Linux and Verify it For Security

Here’s how to “hash” a file and compare it with what the sender of the file provides. This allows you to make sure that what you’re receiving is indeed what was sent. While MD5 has been shown to be insecure, we can use SHA256 instead.

How to Remove H1 Headings from the WordPress Editor Dropdown

Do you want to remove the “Heading 1” option entirely from your WordPress editor? It’s understandable because it can harm your SEO if you use it in the content and take away focus from the page title. This article shows you how to achieve this with screenshots and code.

How to Change File Permissions in Linux

Do you want to give individual users special access to certain files and directories in Linux? If so, you’ll know that it’s not straightforward. You either need to create separate groups, or change file owners. However, you can also use Access Control Lists (ACL) using a straightforward Linux command as shown in this tutorial!

How to Setup the Hostname and FQDN on CentOS / RHEL

The latest RedHat recommendations say that the hostname should be the same as the Fully Qualified Domain Name (FQDN). However, you can still have a separate domain name and FQDN if you want. Here’s how to set them up in a CentOS / RHEL distribution.

How to Start a VNC Gnome Session on Linux

This tutorial explains how to install GNOME on a remote server. Taken together with the first tutorial on installing VNC and obtaining the login credentials, this will allow you to have a complete and working GUI on your remote Linux server.

How to Install and Connect to a VNC Server on CentOS/RHEL

If you want to run a GUI on your Linux box and connect to it via a remote desktop client, you need to install VNC. Here’s a step by step tutorial with screenshots on how to set up the Tiger VNC server on CentOS/RHEL and how to configure it.

How to Prevent Email Spoofing Using SPF Records

SPF records are used to ensure that incoming mail is only sent from a list of approved servers and IP addresses. Here’s a quick explanation of SPF records, how to read them, and how to set them up.