This professional-grade textbook, 'An Introduction to ANSI C on UNIX' by Paul S. Wang, offers a comprehensive guide for learning C programming within the UNIX environment. Ideal for university students, adult learners, and professionals seeking to enhance their skills in computer science, programming, and operating systems. The book covers fundamental concepts of ANSI C, UNIX system basics, data structures, pointers, error handling, and multiprocessing. Features a clear, structured approach with practical examples and exercises to reinforce learning. This edition is a valuable resource for anyone looking to master C programming on UNIX.