Watch each command run in a real-looking terminal, see what every part of it means, then try it yourself with practice tasks. From ls to kubectl.
The first three commands on any server: where am I, what's here, and how full is the disk.
grep, sed, awk and the pipeline tools that turn raw logs into answers.
grepSearch text for lines that match a patternBeginnersedStream editor: find and replace, delete and print linesIntermediateawkProcess text by columns: filter, sum, count and reportIntermediatecutCut columns or character ranges out of each lineBeginnersortSort lines: alphabetically, numerically, by columnBeginneruniqCollapse and count repeated adjacent linesBeginnertrTranslate, squeeze or delete charactersBeginnerpasteMerge lines of files side by side, or join lines into oneBeginnerteeCopy a stream to the screen and to files at onceBeginnerxargsBuild and run commands from standard inputIntermediate