Function libraries in DataStage
You can define your own functions to use in derivations by creating a function library asset. You can access those functions from the expression editor under the User-defined functions category.
Create a function library asset
To create a function library asset, click New asset +, click DataStage component, and select Function library. Compile the C or C++ file that contains your functions into an object file, then convert the object file into a .so file. Upload the .so file, then give your function library a name and description.
The functions in your .so file are automatically parsed into the asset, but you must manually configure the return type for each function. You can also add a description of each function or edit the argument names. After you have edited and saved your asset, the User-defined functions category is available for use wherever you define a derivation.