File guides
Hands-on guides that cover File. Every command is run and verified on a live server before it is published.
GuideUnit Files and the systemd Model
Turn a bare script into a systemd service that survives a crash, then read the systemd unit files behind it: sections, systemctl cat and drop-ins.
GuideNavigating the Filesystem
Linux filesystem navigation with cd, ls and pwd on an Ubuntu 24.04 server. Move around the directory tree and learn to read what ls -la is telling you.
GuideFile-Based Secrets Done Right
Do file-based secrets right on a slice: a dedicated owner at mode 600, systemd LoadCredential kept out of the environment, and a tmpfs for runtime secrets.
GuideOwnership: chown and chgrp
Linux file ownership with chown sets which user and group a file belongs to. Change ownership on a live server and see why a service needs the right owner.
GuideThe SSH Config File, Jump Hosts and Multiplexing
Turn long commands into short aliases with the SSH config file, reach a private host through a bastion with ProxyJump, and reuse one connection.
GuideBuilding Your App's Image
Package a Node app into a small, non-root Docker image. Build it with a Dockerfile and learn why layer caching and COPY order decide rebuild speed.
GuideRead, Write and Execute Permissions
Linux file permissions rwx are the ten characters at the start of every ls -l line. Read them for user, group and other, and learn what execute means.
GuideWorking With Files and Directories
Create and move files on Linux with mkdir, cp, mv and rm. Practise on a real project tree so copying a config or cleaning up a release becomes muscle memory.
GuideViewing and Editing Files
View files on the Linux command line with cat, less, head and tail. Read configs and logs, and watch a log grow in real time while a problem is happening.
GuideMaking the Shell Your Own
Set up bash aliases and dotfiles on an Ubuntu 24.04 server. Add shortcuts for the commands you type most and make every future login start ready to go.