Linux beginners probably encounter problems like this: feel confused and puzzled facing multifarious tutorial books. Considering the quality level of books and the limited energy of individual, we all hope to be able to pick out the best ones. While, most often, we just got the opposite of what we want, or got half the results with twice the effort. Fortunately, The Linux Command Line (TLCL for short) came out. By reading it, we can go less detours and master more key knowledge.