User-Defined Functions

This chapter provides an overview of UDFs in C/C++.

• User Defined Functions in C/C++
  Sybase CEPallows you to write your own UDFs in C or C++ and call those functions from within CCL code.
• UDFs: Requirements and Example
  This section describes requirements for User-Defined Functions, including supported languages and implementation.
• UDFs: Packing and Unpacking Parameter Values
  In addition to writing the UDF that does the work that you want, you must also write code to pack and unpack values and to detect NULL values.
• UDFs: Example
  This section contains an example that creates a UDF that calculates the weighted average of 3 values.
• User-Defined Aggregate Functions in C/C++
  For an aggregate function, the user must have a place to store their data between invocations of the function.
• UDFs: XML Signatures
  This section describes the XML signature file and where to store it.
• UDFs: Interface Code
  This section introduces to the interface code function. Includes a description of the steps required to call the function.
• Compiling a UDF and Putting It in the Correct Directory
  This section provides the directory locations for the files on Windows and Unix-like operating systems.
• UDFs: Summary
  This section describes the functions and files you must create to call a UDF.