Mapper File Structure

Before you can use the External File Mapper, you must create an ordinary text file (use a text editor such as Notepad to do this) and call that text file mfextmap.dat.

Each line in this file contains a filename assignment and takes the following form:

assigned-name physical-name

where the parameters are:

assigned-name
The assigned filename used in your program.
physical-name
The actual name of the physical file, including the pathname.

In this file:

You can alter the contents of the mapper file during the execution of your program. The mapping information in the current version of the mapper file is always used.