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Software, system design and lessons from the road.
Red Hat: The Terminal and the Shell
A beginner's intro to the Linux terminal: read the prompt, move with pwd/ls/cd, get help from man and --help, speed up with Tab and history, meet bash and PATH.
- · 30 min readLinux
Red Hat: The Linux File System
The Linux directory tree from scratch: "everything is a file", the root and the FHS, file types, inodes, links, /proc, /dev/null, df, du and find.
#red-hat#linux#rhel#file-system#fhs#getting-started - · 32 min readJava
Java: Installing the JDK and Your First Hello, World!
Install JDK 25 on Windows, macOS and Linux, understand PATH, then write, compile and run your first Java program: javac, java, jshell and first errors.
#java#jdk#openjdk#installation#jshell#programming#getting-started - · 57 min readLinux
Red Hat: Installing RHEL Step by Step
Install RHEL 10 in a virtual machine with the free developer subscription: Red Hat account, ISO, VirtualBox, Anaconda step by step, registration, first update.
#red-hat#linux#rhel#rhel-10#installation#virtual-machine#virtualbox#getting-started - · 76 min readLinux
Red Hat: What Is Red Hat and How Does It Relate to Linux?
What are Red Hat and RHEL? Linux kernel vs distribution, package managers (rpm, dnf), the Fedora, CentOS Stream and RHEL family, and the subscription model.
#red-hat#linux#rhel#fedora#centos#package-manager#open-source#getting-started - · 23 min readJava
Java: A Journey into the Depths of the JVM
We open up every part of the JVM one by one, using everyday analogies: the class loader, memory areas, garbage collector, JIT, threads, JNI and the module system — all in plain language.
#java#jvm#jit#garbage-collection#classloader#programming - · 39 min readJava
Java: What Is Java and How Does It Work?
Starting Java from scratch: what is Java for, who made it? How does a program run, what are binary and bytecode, which layers live inside the JVM, and how do JIT and the garbage collector work?
#java#jvm#bytecode#jit#programming#getting-started - · 18 min readProgramming Basics
Algorithms: Dictionaries
What is a dictionary and how do you reach a piece of information by its name (its key) instead of its position? Learn key–value mapping, adding, updating, lookup and traversal — no code.
#dictionary#key-value#algorithm#programming-basics#data-structures#getting-started