The value of this variable is an EXTFH function name needed for the EXTFH interface. If you are using a library that contains an EXTFH function name other than cics_xfh, cobol_extfh, or EXTFH, you also need to set one or more of these variables to specify the function name:

A_EXTFH_FUNC Specifies a function to be used by all file types (indexed, relative, and sequential).
A_EXTFH_IDX_FUNC Specifies a function name to be used by indexed file types.
A_EXTFH_REL_FUNC Specifies a function name to be used by relative file types.
A_EXTFH_SEQ_FUNC Specifies a function name to be used by sequential file types.

For example, to specify a function name to use for all file types:

Or, to specify a different function for indexed, relative, and sequential files:

If the library is a DLL, you can specify both the name of the DLL and the calling convention to use. Any calling convention specified this way overrides the DLL_CONVENTION variable setting. For information about specifying DLLs and calling conventions, see the topic Loading DLLs with Configuration Variables, in A Guide to Interoperating with ACUCOBOL-GT.