The value of this variable is an EXTFH shared library or DLL file name. You can use this variable to dynamically load an EXTFH library without relinking the ACUCOBOL-GT runtime. For example:

A_EXTFH_LIB libraryname.so

You can also use the following variables to specify library names for indexed, relative, and sequential files. 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.

A_EXTFH_IDX_LIB Specifies the EXTFH library to use for indexed files.
A_EXTFH_REL_LIB Specifies the EXTFH library to use for relative files.
A_EXTFH_SEQ_LIB Specifies the EXTFH library to use for sequential files.

You can specify these variables in the runtime configuration file or as operating system environment variables.

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 Loading DLLs with Configuration Variables.

See Working with an EXTFH Interface the topic for information on specifying EXTFH library and function names to use with the EXTFH interface.