A serious Question new

I have Perl books. The books I was asking was about in the above thread was for System Programming. Sorry for not making it clear.

I recently bought the book "Unix the textbook" for that clbutt that got cancelled. The reviews on the book at amazon is good and so I am keeping it. Is that enough for now or should I get another book? The book "Understanding UNIX-LINUX Programming: A Guide to Theory and Practice (Paperback) by Bruce Molay (0130083968 )" was used at another campus of the same school (which also is not getting enough people to offer the clbutt. This book got five stars but it's 2002 Ed. Any opinion on this book?

A nearby University uses "Interprocess Communications in Linux: The Nooks and Crannies (Paperback)by John Shapley Gray (ISBN: 0130460427 )" - it got 4 stars - along with "The C programming by Kernighan and Richie. I have the 2nd book.

My concerns is some books are textbooks designed for clbutt room. So I'd like advice which book should I get or is the one I already have "Unix the textbook, 2nd Ed, by Sarwar " enough?

I know basic commands in Unix but haven't done much in Linux. I am working on getting a Linux box.

Thank you all.