Short answer: These are reference-style books (not textbooks) with reliable, useful information related to parts of the course. Much of the information is available elsewhere for free, but the time you save by having these books in your hand is probably well worth the cost.
Full answer: This course touches on many topics, including those not covered in the texts and those covered in the text but covered equally well by free resources such as man pages and web pages. The lectures will not really follow the texts. Nonetheless, many students benefit from having a centralized hard-copy source of information. As reference books, the course texts should also prove useful in many parts of the CSE curriculum and even after you graduate. These are excellent books to have, even if they have little "unique" information.
A larger option: If you would like even more information about Linux, shells, emacs, etc. in your hands, "Linux in a Nutshell" published by O'Reilly has about 900 pages of useful stuff.