The ALCSA Training #1: Access a shell prompt and issue commands with correct syntax

In computing, a shell is a program that gives broad and direct access to the operating system on which it runs. The term shell refers to how it is a relatively thin layer around the operating system. The Arch Linux default shell is called bash. Other popular shells in the Arch community are zsh and fish.

6 hours ago

The ALCSA Training Objectives

What is the ALCSA Training?

Understand and use essential tools

Access a shell prompt and issue commands with correct syntax
Use input-output redirection (>, >>, |, 2>, etc.)
Use grep and regular expressions to analyze text
Access remote systems using SSH
Log in and switch users in multi-user targets
Archive, compress, unpack, and uncompress files using tar, gzip, and bzip2
Create and edit text files
Create, delete, copy, and move files and directories
Create hard and soft links
List, set, and change standard ugo/rwx permissions
Locate, read, and use system documentation including man, info, and files in /usr/share/doc

16 hours ago

The Unofficial Arch Linux Certified System Administrator (ALCSA) Training

The ALCSA Training Objectives

I discovered I'm allergic to pollen in my mid-twenties. For years, as summer came along, I'd experience a slight itchiness in my eyes, nose, ears and throat. However, my symptoms were minor and the onset gradual, so I didn't realize I was sick. I thought everyone felt the same way in summer. One day, out of nowhere, it dawned on me - I might be allergic. I tried an antihistamine. Suddenly, my symptoms were alleviated and the world felt crisper and clearer.

2026-06-11

Back in Scrubs

Last week, I returned to my mandatory clinical internship at Karolinska University Hospital, after a wonderful seven month stint as stay-at-home dad. First stop - the emergency department.

I got curious and managed to find statistics on number of visits by diagnosis groups at the ED. I whipped up a plot and ran it through Claude Code for polish:

2026-05-06

I've been on the lookout for a way to maintain my coding skills and simultaneously apply my maths knowledge. I found it!

projecteuler.net

Project Euler provides mathematical problems that require a computer and programming to be solved. For example, in order to even register for the site, one must solve the following problem:

A number is a perfect square, or a square number, if it is the square of a positive integer.
For example, 25 is a square number because 5^2=5 \times 5=25; it is also an odd square.
The first 5 square numbers are: 1,4,9,16,25, and the sum of the odd squares is 1+9+25=35.
Among the first 290 thousand square numbers, what is the sum of all the odd squares?

2026-03-23

The Python Ternary Operator

My most recent Python dicovery is the ternary operator.

The ternary operator returns one of two values, based on the truthiness of a Boolean expression.

value_if_true if boolean_expression else value_if_false

Here's an example without the ternary operator, using an if-statement.

def odd_or_even(x):
    if x % 2:
        return "Odd"
    else:
        return "Even"

Here's the same function, using the ternary operator.