This new edition of the bestselling i5 application programming interface (API) book includes powerful new APIs and updated code to give programmers a working knowledge of the APIs available under i5/OS. Using real business-world examples, this book explains APIs that serve webpages, list APIs, APIs that work with user spaces, dynamic index APIs, APIs that retrieve system values, job information and job queue information APIs, APIs that work with data queues, APIs for error handling and message handling, and spool file APIs, among many others. Completely revised and including eight new chapters, changes that have occurred in the API itself as well as the RPG code are described, reflecting modern coding style and newer standards. Exit point concepts, the Integrated File System (IFS), TCP/IP, date and time APIs, cryptographic services, and vining are all covered, making this singular resource more helpful than ever.