The rsync command’s roots go back to 1996 – though not nearly as far back as some of the other Linux commands like awk. It was designed to efficiently sync files between two locations. At the time, the technology it used – the delta transfer algorithm – was a new one, but it has since […]
Awk Command: Everything You Need To Know
As with so many Linux tools, the awk command was developed in Bell Labs in the 1970s. It was named after its creators – Alfred Aho, Peter Weinberger, and Brian Kernighan, whose last names’ letters form “AWK”. Awk is a tool for manipulating strings. It can take a text file as an input, read its […]
How to Add Users to Sudoers in Debian
Many commands in Debian require elevated privileges. Something as simple as updating the system with: apt update Generates the following message: As you can see, you get a “permission denied” message. This is because the command can only be executed by users using a special qualifier – sudo. The “sudo” command allows you to run […]
How To Use the Bash Source Command And Why
The “source” command in bash is used to execute a script in the current shell instead of a separate one. This simple difference has a wide variety of implications as I’ll describe below. Regular users of Linux are most familiar with the source command because they use it to reload configuration changes in the bash […]
How to Use SCP: Transfer Files from Local to Remote
While SSH is a way to log into a remote server from your local machine, it’s not a way to transfer a file from your local computer to the remote server. An SSH session works within the context of the remote server’s file system, and it doesn’t have any access to the files on your […]
How to Use Bash Sleep and Why
The “sleep” command in the bash terminal is a way to pause the execution of a script. We commonly use it to illustrate the concepts of processes to beginners, but beyond mere demonstrations, it’s quite useful for a variety of applications. In this article, I’ll show you what the sleep command does, how to use […]
What a “502 Bad Gateway” Error Means for NGINX
Every now and then, when you browse the web, you see an error message that says “502 Bad Gateway” like this: It’s a rather cryptic message, and if this is something you encounter as a user, there’s nothing you can do other than move along and try again later. But if you’re a website administrator, […]
How to Use the Nohup Command in Linux
The nohup command in Linux, allows the user to run a command without worrying that it’ll get interrupted. Normally, long-running processes that you initiate via SSH not only prevent further input but they can also be shut down when the user logs out. The nohup command prevents this, and allows the command to keep running, […]
How To Install Pip And What You Need To Know
Earlier, I’d written about how to use Python to change directories. You can see from that, that Python is a very user-friendly language and you can already do much with it out of the box. For example, in the linked article, I used the standard library function called “os”, which is included with python, so […]
How to Merge a Git Branch to Master
In an earlier article, I showed you how to use git fetch, why it’s different from “git pull”, and under which circumstances it makes sense to use “fetch” instead of pull. With that background, we will now look at how to merge a git branch into the master branch. This operation is at the heart […]
