Command guides
Hands-on guides that cover Command. Every command is run and verified on a live server before it is published.
GuideThe Shell and Your First Commands
Learn Linux command line basics on a live Ubuntu 24.04 server. Run whoami, pwd, uname and id to see who you are and where you are before you change anything.
GuideInterfaces and the ip Command
Use the linux ip command on an Ubuntu 24.04 server to see an interface, its IP address, and the route your traffic takes to leave the machine.
GuidePorts and Sockets With ss
Use the linux ss command to see which ports are open on a server, which process owns each one, and whether it listens to the world or just localhost.
Guidechmod: Symbolic and Octal
The chmod command Linux uses edits permission bits two ways. Add execute to a script with symbolic mode, then lock a secrets file to 640 with octal mode.
Guidedpkg and .deb Files
The dpkg command Linux runs under apt: list an installed package, see the files it placed, and map a file back to its package.
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.
GuideText Processing With sed
Use the linux sed command on Ubuntu 24.04 to find and replace text as it streams past, editing a log from a script without opening an editor.
GuideText Processing With awk
Use the linux awk command on Ubuntu 24.04 to read text as columns: pull specific fields from a log or CSV and add them up into the numbers you need.