Category Archives: Casual tech

See where is the space used in your Android phone from Ubuntu Terminal

So, you may have your Android phone full and you don’t know where the space is.

You may have tried Apps for Android but none shows the information in the detail you would like. Linux to the rescue.

First of all you need a cable able to transfer Data. It is a cable that will be connected to your computer, normally with an USB 3.0 cable and to your smartphone, normally with USB-C.

Sometimes phone’s connectors are dirty and don’t allow a stable connection. Your connections should allow a stable connection, otherwise the connection will be interrupted in the middle.

Once you connect the Android smartphone to the computer, unlock the phone and authorize the data connection.

You’ll see that your computer recognizes the phone:

Open the terminal and enter this directory:

cd /run/user/1000/gvfs/

Here you will see your device and the name is very evident.

The usual is to have just one device listed, but if you had several Android devices attached you may want to query first, in order to identify it.

The Android devices use a protocol named Media Transfer Protocol (MTP) when connecting to the USB port, and that’s different on the typical way to access the USB port.

usb-devices  | grep "Manufacturer=" -B 3

Run this command to see all the devices connected to the USB.

You may see Manufacturer=SAMSUNG or Manufacturer=OnePlus etc…

The information returned will allow you to identify your device in /run/user/1000/gvfs/

You may get different type of outputs, but if you get:

T:  Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 13 Spd=480 MxCh= 0

your device can be accessed inside:

cd mtp\:host\=%5Busb%3A002%2C013%5D/

There you’ll see Card and Phone.

You can enter the Phone internal storage or the SD Card storage directory:

cd Phone

To see how the space is distributed nicely I recommend you to use the program ncdu if you don’t have you can install it with:

sudo apt install ncdu

Then run ncdu:

ncdu

It will calculate the space…

… and let you know, sorted from more to less, and will allow you to browse the sub-directories with the keyboard arrow keys and enter to get major clarity.

For example, in my case I saw 8.5 GB in the folder Movies on the phone, where I didn’t download any movie, so I checked.

I entered inside by pressing Enter:

So Instagram App was keeping a copy all the videos I uploaded, in total 8.5 GB of my Phone’s space and never releasing them!.

Example for the SD card, where the usage was as expected:

Solving problems when updating to GNS3 last version, running with VirtualBox

Last Updated: 2022-01-19 12:05 Irish Time

So here I explain how to solve a problem that was happening to a friend.

He uses GNS3 for the university, and after installing the latest version, which in this case is 2.2.29, it stopped working.

He had it configured to use the local Server and VirtualBox in Windows 10.

The first thing to check and to fix is the Ip address for Host Only.

If you use Linux or Mac, only certain Ip ranges can be used, or you’ll have to edit a config file inside /etc/vbox

So the first thing is to set an Ip Address in VirtualBox VM that will make you worry free.

So start VirtualBox VM directly, and when the VM boots, use the text menu application to Configure to a valid Ip from the range defined for Host Only.

You can check this in VirtualBox in File > Host Network Manager

In my initial test I picket this Ip for the VM:

192.168.56.100

But using 192.168.56.100 can bring problems as the default DHCP Server is defined with this Ip, so I switched to:

192.168.56.10

Press CTRL + X to save and exit.

The VM will reboot automatically. Wait until it has booted and ping 192.168.56.10 from the Command Prompt.

Now, open a Windows Command Prompt or a Linux/Mac Terminal in you computer and ping the Ip:

You should also be able to see the web interface going to:

http://192.168.56.10

If it works then power off the VM, as we will start it automatically when running GNS3 main program (not from VirtualBox).

Now launch GNS3 program. Wait 30 seconds until it initializes and go to Edit > Preferences

Make sure you have the configuration like this:

Pay special attention to the Port for the GNS3 VM.

It seems like the main problem of my friend was that he was using a previous version, and he updated, and the settings from the previous version were kept. In his previous version he had configured the port 3080, but the new GNS 3 Server version 2.2.29 in the VM was using port 80, as you saw in my previous screenshots. So GNS3 was unable to connect to the VM.

After fixing this, restart GNS3, stop the VM if was not automatically stopped, and start GNS3 again.

After one minute approx connecting, you’ll see it working fine.

Have a cheap Ubuntu in your Windows or Mac with Docker

I had this idea after one my Python and Linux students with two laptops, a Mac OS X and a Windows one explained me that the Mac OS X is often taken by their daughters, and that the Windows 10 laptop has not enough memory to run PyCharm and Virtual Box fluently. She wanted to have a Linux VM to practice Linux, and do the Bash exercises.

So this article explains how to create a Ubuntu 20.04 LTS Docker Container, and execute a shell were you can practice Linux, Ubuntu, Bash, and you can use it to run Python, Apache, PHP, MySQL… as well, if you want.

You need to install Docker for Windows of for Mac:

Docker for Windows is very handy and visual

Just pay attention to your type of processor: Mac with Intel chip or Mac with apple chip.

The first thing is to create the Dockerfile.

FROM ubuntu:20.04

MAINTAINER Carles Mateo

ARG DEBIAN_FRONTEND=noninteractive

RUN apt update && \
    apt install -y vim python3-pip &&  \
    apt install -y net-tools mc htop less strace zip gzip lynx && \
    pip3 install pytest && \
    apt-get clean

RUN echo "#!/bin/bash\nwhile [ true ]; do sleep 60; done" > /root/loop.sh; chmod +x /root/loop.sh

CMD ["/root/loop.sh"]

So basically the file named Dockerfile contains all the blueprints for our Docker Container to be created.

You see that I all the installs and clean ups in one single line. That’s because Docker generates a layer of virtual disk per each line in the Dockerfile. The layers are persistent, so even if in the next line we delete the temporary files, the space used will not be recovered.

You see also that I generate a Bash file with an infinite loop that sleeps 60 seconds each loop and save it as /root/loop.sh This is the file that later is called with CMD, so basically when the Container is created will execute this infinite loop. Basically we give to the Container a non ending task to prevent it from running, and exiting.

Now that you have the Dockerfile is time to build the Container.

For Mac open a terminal and type this command inside the directory where you have the Dockerfile file:

sudo docker build -t cheap_ubuntu .

I called the image cheap_ubuntu but you can set the name that you prefer.

For Windows 10 open a Command Prompt with Administrative rights and then change directory (cd) to the one that has your Dockerfile file.

docker.exe build -t cheap_ubuntu .

Image being built… (some data has been covered in white)

Now that you have the image built, you can create a Container based on it.

For Mac:

sudo docker run -d --name cheap_ubuntu cheap_ubuntu

For Windows (you can use docker.exe or just docker):

docker.exe run -d --name cheap_ubuntu cheap_ubuntu

Now you have Container named cheap_ubuntu based on the image cheap_ubuntu.

It’s time to execute an interactive shell and be able to play:

sudo docker exec -it cheap_ubuntu /bin/bash

For Windows:

docker.exe exec -it cheap_ubuntu /bin/bash

Now you have an interactive shell, as root, to your cheap_ubuntu Ubuntu 20.04 LTS Container.

You’ll not be able to run the graphical interface, but you have a complete Ubuntu to learn to program in Bash and to use Linux from Command Line.

You will exit the interactive Bash session in the container with:

exit

If you want to stop the Container:

sudo docker stop cheap_ubuntu

Or for Windows:

docker.exe stop cheap_ubuntu

If you want to see what Containers are running do:

sudo docker ps

Raspberry Pi: Solving the problem GPIO.setup(self.number, GPIO.IN, self.GPIO_PULL_UPS[self._pull]) RuntimeError: Not running on a RPi! in Ubuntu 20.04LTS

So you are trying to program the Raspberry expansion PINS in Python, for example for this 3D LED Christmas Tree, and you’re getting the error:

GPIO.setup(self.number, GPIO.IN, self.GPIO_PULL_UPS[self._pull])
RuntimeError: Not running on a RPi!

I’m running this on Ubuntu 20.04LTS with a Raspberry 4.

The first thing:

Make sure you have an official Raspberry Pi charger.

Or at least, make sure your USB charger provides enough intensity to power the Raspberry and the LEDs.

The LED power comes from the motherboard and if Raspberry Pi has not enough energy this is not going to work.

My colleague Michela had her tree not working because of the charger was not able to provide enough energy. When she ordered a new charger, it worked like a charm.

Install the base Software

In order to communicate with General Purpose Input Output ports (GPIO) you need to install this Software:

sudo apt install python3-pip python3-gpiozero
sudo pip3 install giozero

In order to run the 3D LED Christmas Tree code samples

sudo pip3 install colorzero
sudo pip3 install rpi.gpio --upgrade

Reboot

It may be not required in some cases.

Download the Source code

https://github.com/ThePiHut/rgbxmastree#rgbxmastree

Run the samples as root

I saw many people stuck, in the forums, because of that.

To work with the LEDs you need to run the samples as root.

Some code examples

To provide a bit of “the whole package” here are some simple examples.

Turn to red the LED’s one by one

from tree import RGBXmasTree
from time import sleep

o_tree = RGBXmasTree()

for o_pixel in o_tree:
    o_pixel.color = (1, 0, 0)
    sleep(0.1)

Turn to a different color, sleep, and again

from tree import RGBXmasTree
from time import sleep

o_tree = RGBXmasTree()

a_t_colors = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]

for t_color in a_t_colors:
    o_tree.color = t_color
    sleep(1)

Turn off the lights

from tree import RGBXmasTree

o_tree = RGBXmasTree()

o_tree.color = (0, 0, 0)

Where I used it?

I used it in my Open Source monitor Software CTOP.py in order to show the plugins/extensions capability of it. :)

Programs I use for Windows in my Workstations

I love Linux and Linux tools and I’m a big fan of it, using it for Servers since 1995.

However some companies use Windows for the Workstations, and that’s not necessarily bad.

So I describe here the tools I use to maximize productivity.

Antivirus

That really depends on my employers. I’ve my opinion about several of them.

Apache Directory Studio

For working with LDAP.

BalenaEtcher

To flash images to USB and external drives. https://www.balena.io/etcher/

I also use Rufus https://rufus.ie/

Chrome

Debut
This is a Commercial Software to capture video. I record bugs, tutorials, internal web training sessions…

Docker Desktop for Windows

But not in the laptops cause the hyper-v may conflict with the BitLocker drive encryption and may cause the entire drive to be lost.

However as much as possible, I will do everything in Linux Workstations and Servers.

(CRLF problems in Docker Linux are horrible)

Editplus

Very powerful for doing replacement over large CSV files.

Firefox

Filezilla

GIMP

HeidiSQL

Free Database Manager for MariaDB, MySQL, SQLite, PostgreSQL and Microsoft SQL.

Is compatible with Wine, so you can use it on Linux.

LastPass (for Teams)

With Chrome’s plugin.

LibreOffice

MobaXTerm

With zmodem, sftp, SSH, tunnel….

MyDebugger

A MySQL debugger. Specially useful for Stored Procedures.

Is compatible with Wine, so you can use it on Linux.

OBS

https://obsproject.com/ is a screen recorder Software, for Linux, Mac Os X and Windows.

One Note

OpenVPN

Opera

Specially useful the option of using a VPN.

Project (Microsoft Project)

PuTTy

PyCharm, PHPStorm, CLion from JetBrains

Python

Radmin

A powerful Server Remote Control for Windows, much more stable than VNC.

Remote Desktop Connection

Rufus – https://rufus.ie

To toast ISOs to USB.

Slack

Toad for Oracle

Videopad

Video editor

VirtualBox
Yes, I always have a Linux VM.

Visio

For the Diagrams.

VLC

Video player

VMWare Player

VNC

Normally RealVNC.

WinRAR

Zoom

Some advice for WFH (Working From Home, especially under the covid lock down)

Last updated: 2022-08-03

I wrote this article at the beginning of the lock-down during the pandemic in 2020, to help others to adapt healthy.

Those are crazy times in which is difficult to handle working from home, doing the lock down…

But very nice times in which other people help others. Doctors and sanitary personnel fight in first line, truck drivers and supermarket staff are doing extra hours to provide to the society, investigators are working hard to get a vaccine…

Is beautiful that so many people are helping and contributing to the society.

I want to provide my humble experience on working remotely, from many years working remotely, so you avoid going bananas. Is very easy get depressed, anxious… So here is my advice.

Stick to a routine
Respect the working times, like if you was going to the office.
Dress yourself like a normal day in the office. Don’t be all day in pajamas or sport wear. Switch to sports wear when you finish your daily work at 6PM, if you want, but not before.
If you talk via Slack, myself always keep the video turned on, as is a way to force myself into dressing and taking care of my look.
I take a shower, dress like an Engineer at work, I have my break for breakfast and for lunch, and when I finish work I study 30 minutes and do exercise 30 minutes or more. Then I take another shower and I consider myself free.
Note: The only exception I do to the dressing is in the shoes. I don’t wear any shoes, as my feet really enjoy walking freely over the parket.
Take care of yourself
Shave, cut your nails… be polite. The same way you would if you had to go to the office.
Stick to the working clock
As said in the stick to a routine advice, work your time, from 9AM to 6PM, and don’t get lost. The week ends are week ends, don’t work to free your mind.
For the week ends I have my side projects, like writing books.
Walk
If you can, walk an enjoy nature as much as you can. This clears the mind and keeps your mental health wellness.
Do exercise
May be walking, but if you have a home bicycle, use it.
Try to set a goal, like 15 minutes of bicycle daily, and grow from there, of keep it like that. But doing even 15 minutes of cardio every day will be highly beneficial for your mind and body.
You may find it easy to do if you play videogames while cycling, or watch Netflix.
Stretch
After doing exercise stretch your muscles.
See the light
As much as you can, see the sun light. Try to do walks too and see nature.
Daylight and nature are amazingly good for your mental health and morale.
Study/Learn new things
I keep this as part of my routine. I study every day in Linux Academy or read a book at least half an hour. I’ve done this for years.
Keep you hydrated
Drink lots of water.
I said water, not sugar drinks or carbonated ones, which are very unhealthy.
Do your breaks
After each 1 hour of work try to walk a bit in the house, to focus your view in distant points to relax your ocular muscles.
Ergonomics and light
Try to have a correct light in the working are, a comfortable chair, the right height for the keyboard and for the monitor, so your neck doesn’t hurt and your hands neither.
Do like in the office: discipline
In the office you don’t drink, you don’t smoke at your desk.
So do the same. If you want to smoke one cigar after 2 hours of work, Ok, but don’t loss yourself in self-indulgence. Set strict rules respect alcohol if you love beer:
No alcohol during working hours.
Years ago I was CTO of a company with Team in half the world and I had a Team in Belarus. The Team Lead would be drunk in the sofa at business hours and start talking common words. If you have weak points, you don’t want to lose yourself. Be disciplined.
Set boundaries with your family and pets
If you want to close the door of the room you work, your cat is not gonna die.
It is used to be alone when you’re are in the office.
So if it’s excessively demanding and wants you to pet him, or jumps over your laptop’s keyword while you are typing commands as root, set boundaries. Close the door. He can take it.
Also for the kids, the wife, the mother.
Please, do not disturb me while I’m working. We will play after.
During covid-19 lockdown, do videoconference
Do videoconference with your family and friends.
You can use Slack, Skype, Zoom, Whatsapp, Facebook Messenger…
I schedule a daily whatsapp video conf with my family, and a weekly with my cool friend Alex :)
Socialize.
When the lockdown is over, try as much to socialize, or at least to see friendly faces irl. If you can’t because you’re an expat, go to the coffee and to the commercial center to see faces, for the sake of your mental health. If the law and common sense allow it, try to go to a gym to get back to be fit and healthy.
Despite your beliefs about vaccines, take fruits, and vegetables.
You are certainly exiting less home, so your intake of sun is also reduced.
Myself I take vitamin supplements.
Be very patient with your colleagues and Team members
We are all humans and each one has its own situation.
Some people may feel depressed, alone, others may have problems with the partners or the parents of her/him living with them.
Other may have a cat trolling all the time stopping the work.
Others may have hyperactive children, or just having a poor chair, poor desk, and having only the laptop and no external monitor.
Others may have the family far, in another country, and suffer for them.
Be patient and understanding. Be Human.
Have a good Internet connection and use Ethernet cable, not Wifi if possible
I have 360 Mbit at home with Virgin and I connect the laptops with Ethernet Gigabit cables. That brings me the best and most stable connection.
In case of emergency I can do tethering with the phone (share the connection using the phone as Wifi Hotspot)
Use cable headsets, not Bluetooth if possible, and use the microphone from the headset not the one from the laptop
The Bluetooth can be very useful to allow you to move around during audio calls, but some times they provide a poor signal and the sound is lost or may sound metallic or they perform poorly when they have few battery, or they can let you down.
Using the microphone embedded in the laptop sends echo to your partners, many times.
If you don’t use headphones the sound coming from the speakers can couple with the microphone and make it very uncomfortable to your partners talking in a video conference, as they will hear themselves with echo.
If you use Bluetooth, I recommend to have cable headsets at least as backup in case the Bluetooth runs out of battery.
Use a camera with cover or add a plastic cover that slides to your webcam.
It is good to have a physical barrier to prevent your camera turning on and you not knowing, and to get used to block the camera after you used.
Have spare Hardware and cables
In this time of lockdown, is good to have spare cables and adapters for everything. Just in case they die.
If you can have a spare monitor, and spare laptops this is great too.
I have 3 laptops, plus one tower, plus several raspberry pis, plus the tablet, plus my working laptop. If one dies, I can use the others.
I always have all kind of Hardware and cables as spare (Gigabit switches, power adapters, international adapters, Ethernet cables, USB cables, headphones…). Even if I can buy in Amazon nothing can stop me.
One day we had an incident with Virgin, which affected all Ireland.
I was out as the Fiber was not working and the phone was with Virgin too, but I have two additional SIM cards and spare phones, from vodaphone and Tesco mobile.
So I’m well protected. :)
As per the comment of Jordi Soler, I update the list of gadgets, mentioning my Hp Laserjet Color Printer, very handy to print document that I have to sign and then scan and sending back by email, and the UPS.
The UPS is cool, as if electricity goes down I don’t loss Fiber Internet.
Imagine, a router connected to the UPS can last hours! however is very infrequent that in Ireland we loss electricity. And the issues I experienced in 3 years were quickly resolved (unlike Barcelona where once more than 300,000 people were 3 days without electricity).
Keep doing backups
If talking about job things, you can upload to Corporate Google Drive or Microsoft One Drive.
Do exercise regularly
I bought a static bicycle and a pair of weights, nintendo boxing games, so I keep fit.
Sitting all the day and not doing any exercise in not made for humans and is bad for your health.
Play videogames
Playing videogames can keep your amused and distracted, with a goal you do to relax.
Have fun.
Play Quizz style games online, with your friends/university/work mates
Playing Questions/Answers games with other people can be a great source of fun.
Recently I played with my friends at work at jackbox.tv , coordinating through Zoom, and it was really fun.
I also play in the Quizz that was being performed at my local pub every week, and when the lockdown closed the pubs, they moved to Internet. It is great to see some of the people I was seeing at the pub, and revive these moment, even from home, virtually.
Check your health
Take that blood analysis, the breast yearly revision, or whatever test you should do regularly. Performing a blood analysis is particularly a good idea. Most people got weight with the lockdown, and the lack of activity can have had an adverse effect in your health. I recommend you to take a blood analysis to make sure all is good with your health.
Deciding to take a proactive blood analysis saved my life.
It is a good moment to go to the university
Pick your dream’s degree, that you can do remotely, and before you can realize you’ll have your degree and a bunch of nice good friends. :)
Specially if you are older than 40/45 years, many universities will grant you access with your motivation letter.
I recommend you evening degrees designed for people that work.
They will be helpful and understanding, flexible, and provide workloads more reasonable for people with families and work.
Also some countries subsidize certain degrees, for example in IT, as they want workers to be digital capable.
My friend Nico C. de F. provided a super useful tip:
When in a call say only nice things (if you talk to another person, if you pick the phone…) always assume you’re not muted.
And that’s super true! How many times we have heard or seen something that the other person regretted sharing. Even if you muted your Zoom call, it could happen that it gets unmuted (like pressing ALT A).
Keep liquids far from your hardware
It is very easy to poor a cup or glass full of liquid over your laptop or keyboard

Security risks

One of the problems with the laptops and battery-power devices in general is that if we have them connected to the energy line all the time, never using the battery, the battery just loses effectiveness and dies.

But some batteries can also explode.

As we are working all day at home now, our laptops are connected 100% of the time.

In my case one of the equipment I use is a Dell Laptop and the battery started to swallow and to bring the touchpad up. As the temperature of the laptop internally increased by the battery being hot as it swallows, you may notice the internal fan doing extra hours, running almost all the time, a high temperature on the chassis. High temperatures can lead to laptop malfunction like hang or reboot.

In extreme cases the battery can explode, so you should replace it if it is swallowing.

So I recommend you from time to time to unplug the power cable and run the laptop on battery until it almost completely depletes, or at leas for a couple hours before plugging the power cable again.

In another order of things I recommend you not to do drugs. Drugs affect your brain, and is hard enough to be isolated in lock down, to add chemicals messing with your neurons.

Lesson 0, learning to code in Python for non programmers

Please note: Even if I tried to make it easy, probably there are too many concepts for a non-programmer. Will try to deliver more basic previous knowledge and foundations, so people with zero knowledge don’t feel overwhelmed.

Start by installing Python 3.8 or 3.9 in your computer, and the IDE PyCharm. Install also Git, and create an account in GitLab so you can share code with other people and understand how Git works.

Here you can read the basic steps for setup PyCharm and GitLab.

Ok, so you can take a look at my video, and hopefully it makes spark your motivation to learn by yourself. :)

I’ve been asked why I used print(“”) instead of print().

Is a good question. The reason is, when we programmed in Python 2.x the native way was to print without parenthesis, like:

print "Hello World!"

Python 3.x was incompatible with that and requires to use parenthesis, like:

print("Hello World!")

Fortunately Python 2.x accepts also to print using parenthesis. In order to have compatibility within Python 2.x and Python 3.x or for future compatibility we were using always print(“Whatever”) in Python2.

However, there is one difference.

If you user print() or print(“”) in Python3 that will generate an empty line.

In Python 2 print(“”) will generate too an empty line, nevertheless print() in Python2 will print two parenthesis. We don’t want that.

This is illustrated in this screenshot:

So all the people that are at home, closed down for coronavirus, you have a chance now to start learning Python and from there get a live as programmer.

You can download the code for this lesson 0, from:

https://gitlab.com/carles.mateo/teach-unit-testing/-/blob/master/lesson0/tree.py

Capturing data from keyboard

In order to be able to do more samples, and then being a bit interesting an dynamic, I will introduce here how to get data inputted by the Keyboard.

print("Please enter your name:")
s_name = input()

This will add whatever we type, without the final Enter, to the String variable s_name.

Capturing numbers from Keyboard

How we do to capture a number, like how old are you, in years?.

The same way, and then we convert this to an Integer value. An Integer is a data type which is basically a number, not decimal. Like: 1, 2, 7, 1000 o -5.

print("Please enter your name:")
s_name = input()

print("Please enter your age:")
s_age = input()
# With int() we convert a String to an Integer, as long as it is possible.
# Wit str() we convert a Integer to a String, as long as it is possible.
i_age = int(s_age)

If you enter a number incorrectly and so that cannot be converted, you will get an Exception Error. That is something that happened in a way that was not expected. These error can be trapped, and we will see this later, in the future.

You know:

How to capture data from the keyboard with input()
How to convert data entered as String to Integer with int()
How to sum two numbers, like 2 + 3
How to subtract two numbers, like 2 – 3
How to multiply, like 2 * 3

So know, you should be able to solve a basic arithmetic exercise in Hacker Rank:

https://www.hackerrank.com/challenges/python-arithmetic-operators/problem

More sources with explanations

I’m teaching Unit Testing, Refactors, Quality Code and moving from Procedural to OOP to some colleagues, you can find source code for our classes here (please, be aware that there are some error made on purpose to show why and why not do things and hot to apply proper unit testing)

https://gitlab.com/carles.mateo/teach-unit-testing/-/tree/master

More resources

There are many free useful resources to learn Python:

A free course from Google in ~~several languages~~ English
- https://developers.google.com/edu/python
Hackerrank has exercicis and you can test, and teach you, and give you point for each exercise that you do well.
- https://www.hackerrank.com/domains/python

Making responsive WordPress Theme Twenty Twelve to support greater resolutions

This is the first article I write about FrontEnd in here, as this is very casual and trivial, and I wanted to specialize the blog in Extreme IT, going deep into knowledge and difficult questions. And in any case, more for BackEnd, Engineering, and Hardware and Operations.

But as it is something useful and myself didn’t found an answer when I googled it, I think is no bad to share it here. Nevertheless I’ll not make it appear in the front page to be loyal to my essence.

So I like Twenty Twelve WP Theme. It’s clear, that’s what I expect from a blog from an Engineer: easy to read. Maybe is to Spartan, but that’s grant.

The instructions to do like me:

Make a copy of your original Twenty Twelve Theme in another directory, at the same level
Edit the file /var/www/blog.carlesmateo.com/wp-content/themes/2021-blog-carlesmateo-com/style.css
Add a new section like this

So I defined a new @media screen with min-width of 1800px.

Why 1800px and not 1920px like Full Hd?. Because Ubuntu use some width for the lateral bar.

Then over body .site section I set a max-width: 1800px that will do the trick for some browsers, and the rem value that will do the trick for Chrome.

Now the main section of the block can be correctly displayed using most of the space available.

Media Player in my Raspberry Pi 4

Just installed a media player in my Raspberry Pi 4

So I mentioned it was one of my pending tasks, to do while I’m confined here, at home, to help the Irish government to stop the quick spread of the coronavirus.

I’m happy that the situation in Ireland has stabilized, unlikely in Spain, where that historical lack of discipline and selfishness and super ego to believe Madrid the capital of the world, and so deciding not to close it for quarantine, will cause a lot of pain. I hope the closing of frontiers in Catalonia works.

Well, what I do you’re probably asking yourself, so I installed LibreELEC https://libreelec.tv/.

They have a very nice SD image writer for Linux, Mac and Windows, that will install the proper image on the micro-SD for your ARM device.

This Raspberry Pi 4 comes with Wifi integrated and a Gigabit Ethernet network port.

When I was in Barcelona, I had Kodi with Raspberry pi 2 and version 3.

This model v. 4 is much more cooler. I bought the 4GB version, and has 2xHDMI 4K.

So it is great to connect to any modern TV.

In Barcelona, I have Linux tower as NFS Server sharing my files with the Pi. Work good, even for the 100Mbit NIC of the version 3, but at that time I was only playing Full HD as the Pi didn’t supported greater resolution, and I only had that resolution on my displays too.

For now, I’m going to explore how is reading from a USB 3.0. Let’s see if it’s able to play smoothly.

The cool thing also is that I have SSH access, and so I can use the Pi for many more things. :)

I have my first update, I noticed that copying to that USB was not the best for me, as I tried to copy a .MKV file of 4.9GB and I encountered the limit of 4GB of FAT32. I could format the USB as ext4, but what I did is, SSH into the box, I see that I have two partitions on the SD for booting the Pi, the second one is a ext4 called storage. So I copied to the SD, through the network, using sftp the file I wanted.

The Gigabit connection was fast, but when the buffer fulled it started to show the real speed of the SD which is 15MB/s for writing.

Ext4 has no problem in holding a file 4.9GB so I’m watching my movie now. Will think about setting a NFS for the Pi as it will be very convenient. :)

I have an external, remote, keyboard logitech, but it happens that LibreELEC recognizes my Sony command, from the television. I don’t need the keyboard/mouse. Nice.

Here you can see my Raspberry Pi 4, connected to TV, in “combat mode”, naked, as PoC, before setting in its definitive place behind the TV.

Playing from the external USB 3.0 stick was also fluid, allowing 4K perfectly.

The only problem I has was when I was pushing movies to the USB through the network, and playing at the same time from the SD. It seems like the Raspberry reached its limits doing this and playing stuck frequently.

A handy trick command line to get the usages of our Python Methods in the code

We all use powerful code analysis tool, but sometimes you’re presented with a problem and you have just… the terminal.

This Bash code is handy.

grep "def " /home/carles/code/gitlab/cloud/terraform/src/scale/lib/iscsi.py | tr "()" "  " | awk '{ print $2; }' |  grep -v "__init" | sort > ./function_names_iscsi.txt

So this basically will get all the methods (“def ” whatever), strip the parenthesis with tr, and get the second column with awk, so basically the method name, sort it and write it to the file.

Then I will cd to the src directory and execute the seconds part:

cd /home/carles/code/gitlab/cloud/terraform/src/
for fname in $(cat ~/function_names_iscsi.txt); do printf "%s: %s\n" "$fname" "$(grep -r $fname *|grep -v 'def ' -c)"; done > ~/functions_being_used.txt

That will produce a nice list with the number of times of the method being called, in the form of:

method_name: occurrences

That’s the equivalent to doing Find Usages is PyCharm.

It’s easy to identify dead code then, with method_name: 0.

You can also run this to your Jenkins to warn when there is Dead Code in your repository.