The Unix Programming Environment and A User Guide to the Unix System and The Unix Programming Environment are two books published by Prentice-Hall and McGraw-Hill in 1983. Authored by Brian Kernighan, Rob Pike, Rebecca Thomas, and Jean Yates, these guides provide a comprehensive introduction to Unix systems. The first edition of the books, presented in paperback format and totaling 357 and 508 pages, offer detailed insights into Unix programming and system usage. With a focus on the Unix subject area, these books serve as valuable resources for those looking to deepen their understanding of Unix systems and programming.