XFD Files

The ACUCOBOL-GT compiler is capable of generating data dictionaries that store a map of COBOL record structures. These dictionaries are also called extended file descriptors (XFDs) because they're based on the standard COBOL file descriptors (FDs).

XFDs are used by Acu4GL to interface to database management systems and by AcuXML to interact with data in XML files. They are also used by alfred, Acucorp's record editor, and by AcuXDBC, Acucorp's database management system for Vision. In addition, they are used to help guide the mapping of international character sets between machines that use different underlying character codes.

The compiler creates an XFD for each indexed file in the compiled program when you specify the -Fx compile-time option. The -Fa option generates XFD files for all indexed, relative, and sequential files in the compiled program. Ordinarily, XFDs are generated in flat text file format. Use the -Fe option to generate XFD files in XML format instead. See File Options for details on these compiler options.

Acu4GL, AcuXDBC, and alfred can all read the XFD files in either format. XFDs are fully portable, and thus no recompilation is necessary if you change hardware.

The effects of all compile-time options, COPY REPLACING, and source-code control lines are reflected correctly in the XFDs.