The IBM i Control Language, or CL, is the human interface to one of the most successful computing platforms ever. Mastery of this language is necessary to get the greatest benefit from the IBM i server. This book helps programmers and system administrators using IBM i get the most out of the platform by writing useful CL programs. This new edition has been updated for IBM i 7.3 and includes new built-in functions, new data types, and new support for SQL. Upon completion of the book, readers will be able to write and compile robust, production-grade programs in the IBM i Control Language, guided by a CL expert.