To use different EXTFH libraries for indexed, relative, and sequential files, you can set the file names or paths of the libraries in one or more of the following variables:
The ACUCOBOL-GT runtime uses A_EXTFH_LIB as the default EXTFH library for all three file types. If one or more of these three variables is also set, the runtime uses its value instead of A_EXTFH_LIB for the corresponding file type.
Remember that when you use configuration variables to identify the library names and specify file names instead of absolute paths, the operating system must be able to find the files in the locations it normally searches for shared libraries. You may need to set the correct search path environment variable, such as LIBPATH on AIX.
All the configuration variables that allow you to specify an EXTFH library name also allow you to specify the calling convention for a particular DLL and thereby override the setting of the DLL_CONVENTION runtime configuration variable. For more information, see DLL_CONVENTION.