Linux

A directory count changes with the definition behind it. Pipe ls into wc -l and a directory with nine visible files and two hidden ones reports thirteen, because plain ls does not print dot-prefixed entries. Every number quoted beside a command below comes from that tree. What You Need Before Piping Anything Every command here

speedtest-cli is the terminal answer every Linux admin reaches for when a link feels slow. Speedtest.net has started rejecting the tool’s plain-HTTP calls with an HTTP 403, and the flag that fixes it is worth knowing before the next outage. Each command below shows a fresh install: a pip install into a venv for the

Raspberry Pi Foundation does not support upgrading Raspberry Pi OS in place, so the supported answer is a clean flash. That trade is wrong when the Pi you are holding has a year of configured services on it. Here is the Bookworm to Trixie path end to end: the archive keyring that has to be

A port is only open when a process is listening on it. Here you will list every listening socket, see which process holds it, and check if it is reachable from outside. What “open port” actually means on Linux An open port is a port number with a process in LISTEN state on an IP

Secure boot on a Windows PC blocks any bootloader without a trusted signature, and that stops plenty of Linux installers cold. To disable secure boot and install Linux, you first open the UEFI firmware settings from Windows, then flip the toggle inside it. This guide covers both ways into firmware, the actual toggle for popular

You run rmdir on a folder you just created and it works, then you run the same command on a folder with a single file inside and get Directory not empty. That split is the whole design of directory removal in Linux, and once you see which tool guards against data loss and which one

The right-click Format option Windows puts on a USB drive has no Linux equivalent. Formatting a USB drive on Linux means naming a device node such as /dev/sdb1 and getting that name right, since the command that rewrites it asks for no confirmation and has no undo. Read the device table first, choose the filesystem

Ask an Ubuntu machine to list its services and the answer depends on the command you run. Four commands sound identical and answer four different questions, which is why the lists disagree and none of them says what starts at boot. I ran all four on Ubuntu 24.04.4 LTS and counted the output: 27 entries