https://sourceforge.net/projects/gnucobol/files/
I read this:
** file handling: include support for a callable EXTFH interface also provided
by several compilers including Micro Focus
This allows users to insert an external file handler while retaining
all of the normal COBOL I/O functions with a possible callback to libcob.
To have the compiled program call `yourfh()` for file I/O use:
`cobc -fcallfh=yourfh`
In turn `yourfh()` may call `EXTFH()` to use I/O functions from GnuCOBOL.
The external file handler can also be directly invoked from COBOL, too,
using `CALL "EXTFH"`.
** Note: Not each flag contained in the FCD3 is handled already **
Here are my questions:
1. Does yourfh() accept a single argument which is a FCD3 structure pointer?
2. Is there any other documentation on this? Google is not very helpful as it is returning answers for other cobol compilers.
3. Is there a list of the fields/flags that are not handled?