ClrFF -- Remove files from the FastFile file caching subsystem

Syntax      ClrFF

Description In version 1.1 of the ORCA shell, ByteWorks introduced the FastFile
            high level file caching subsystem.  This system works by loading
            and managing disk images of files in memory for quicker access by
            compilers, linkers, and other tools that work with the FastFile
            system.  (See the appropropriate Orca/M documentation for details.)

            One side effect of the FastFile system is that memory is used to
            keep these file images in memory.  This means that less memory is
            available for use by the rest of the system.  This utility is used
            to remove these files from the FastFile system, and thence from
            memory, to free up memory for use by the remainder of the system.
            It does this by making FastFile calls to first determine which
            files are being maintained by the system, and then deleting these
            files from the system.  The disk copy of these files is NOT
            modified in any way.  The utility then searches for any purgeable
            memory blocks, and purges any that it finds.  Finally, it reports
            on memory usage statistics, such as amount of memory in use, amount
            of free memory, and total amount of memory installed.

Input       None.

Output      Standard output is used for all normal output.  This consists of
            the filenames of files discovered in and deleted from the FastFile
            system, purgeable memory blocks as they are discovered and purges,
            and the memory usage statistics

Diagnostics Error messages are written to diagnostic output.

Status      The following status codes may be returned to the shell:

            0   No errors.
            -1  An error occurred.

Options     None.

Known Problems.
            Once in a while, the FastFile system will get stuck when the last
            file in the system is deleted.  The file will not actually be
            deleted from the system.  Since the utility loops through the files
            in the cache until it receives a File-Not-Found error from the
            FastFile call, this could cause a non-terminating loop condition to
            occur.  If this happens, simply press the Command-. (period) key
            sequence to tell the utility to terminate the clearing process and
            continue on with the memory purge.
