About This Book
This book describes how to use the InterSystems Callin API, which offers an interface that you can use from within C or C++ programs to execute InterSystems IRIS™ commands and evaluate ObjectScript expressions.
In order to use this book, you should be reasonably familiar with your operating system, and have significant experience with C, C++, or another language that can use the C/C++ calling standard for your operating system.
This book is organized as follows:
The chapter “The Callin Interface” describes the Callin interface, which you can use from within C programs to execute InterSystems IRIS commands and evaluate ObjectScript expressions.
The chapter “Using the Callin Functions” provides a quick summary of the Callin functions (with links to the full description of each function) categorized according to the tasks they perform.
The chapter “Callin Function Reference” contains detailed descriptions of all InterSystems Callin functions, arranged in alphabetical order.
The Callin functions provide a very low-level programming interface. In many cases, you will be able to accomplish your objectives much more easily by using one of the standard InterSystems IRIS language bindings. For details, see the following sources:
The InterSystems Callout Gateway is a programming interface that allows you to create a shared library with functions that can be invoked from InterSystems IRIS. Callout code is usually written in C or C++, but can be written in any language that supports C/C++ calling conventions.