Edit a file with Vim:
1. vim <filename>
2. Press i
3. Make your changes
Saving in Vim:
1. Press ESC
2. Press :
3. Type w
Exit Vim:
1. Press ESC
2. Press :
3. Type q!
For the last couple of days I was having a weird issue with Firefox on Ubuntu, namely there was no sound.
After searching all over the Internet and trying different solutions I finally found one that worked and I wanted to share it with you in case you find yourself in the same situation.
Note: before running the following command, please make sure you have a backup of your data!
Run this command in a terminal:
rm ~/.config/pulse/*
And restart your computer.
You should now have a working sound in Firefox.
In Linux, everything is a file. Even running processes are represented as files. You will find all the running processes in /proc/, with a separate directory for each process id.
ps aux | grep [process name] # to get the process ID
cat /proc/[process ID]/environ | tr '\0' '\n'
What the above commands do, is:
tr stands for “translate”This is an interesting talk on various ways to optimize and deliver images on the web.
I’ve recently finished a great database course “Mastery with SQL” which I recommend to anyone interested in learning modern SQL as well as some specific PostgreSQL features.
It starts with the SQL fundamentals and builds up all the way to window functions, views and query performance optimizations.
Although it isn’t free, I’ve learned a lot from finishing this course and I consider it is well worth the money.
Together with Cosmin Seviciu, we built a JavaScript audio player library with visualizations.
Swave uses Web Audio APIs for visualizations, HTMLAudioElement for audio streaming and a Canvas element to draw the sound bars.
Live Demo: https://bogdan-cornianu.github.io/swave/examples/
Source code https://github.com/bogdan-cornianu/swave
NPM package https://www.npmjs.com/package/swave
If you ever wanted to make a video game, it is pretty easy nowadays having game engines and game development environments such as Unity 3D and Unreal Engine being free. There are also a lot of tutorials and documentation on how to use them.
When it comes to game design, there aren’t as many resources. In my opinion, one of the best book to learn about game design is “Level Up! The Guide to Great Video Game Design, 2nd Edition” by Scott Rogers.
Investigating why Ubuntu boots slowly can be difficult. There are a lot of things that can go wrong: a lingering service, a bad config file, a wrong disk uuid in fstab and others.
In my opinion the easiest way to start is by using “systemd-analyze” which is part of systemd.
Since version 15.04, Ubuntu has switched from upstart to systemd as the default system and service manager. Systemd is not something specific to Ubuntu, but rather an industry standard that other major distributions have adopted as well: Debian, Fedora and CentOS to name a few.
“systemd-analyze” gives us information about what programs are run on startup and how much time they need to start.
[Updated July 26, 2020]: Change swapfile permission; Set swapfile in /etc/fstab.
Swap is a special area on your computer, which the operating system can use as additional RAM.
Starting with Ubuntu 17.04, the swap partition was replaced by a swap file. The main advantage of the swap file is easy resizing.
Note: before running the following commands, please make sure you have a backup of your data!
In the following example, we’ll extend the swap space available in the /swapfile from 4 GB to 8 GB.
sudo swapoff -a
2. Resize the swap
sudo dd if=/dev/zero of=/swapfile bs=1G count=8
if = input file
of = output file
bs = block size
count = multiplier of blocks
sudo chmod 600 /swapfile
4. Make the file usable as swap
sudo mkswap /swapfile
5. Activate the swap file
sudo swapon /swapfile
6. Edit /etc/fstab and add the new swapfile if it isn’t already there
/swapfile none swap sw 0 0
7. Check the amount of swap available
grep SwapTotal /proc/meminfo
Together with Zoltán Szeredi at the 2017 HackTM edition we built a clone of the “Tanks” game. We used PhaserJS which is a great HTML5 game framework.
You can play the game online and also see the source code on Github:
https://github.com/hacktm2017BoZo/Tankr
