If the program opens an existing file or creates a new one, you can tell the runtime the file system to use with that file. The Vision file interface is used by default. You specify the file system with one of two configuration variables: DEFAULT_FILESYSTEM, or filename_HOST (syn. filename_FILESYSTEM). DEFAULT_FILESYSTEM specifies the default file system for all files (see the entry for DEFAULT_FILESYSTEM). filename_HOST specifies the file system for an individual file. For example,
assigns the specified data file to the named file system. Any file so assigned uses the designated file system and not the one specified by DEFAULT_FILESYSTEM. Filename must be the base name of the file and cannot include the path or the file extension (any part of the name that follows the first dot ("."). For example, to specify that data file IDX1.DAT be handled by the EXTFH interface, you would specify:
You must specify only the base name of the file in filename.
To specify that the data file DXML1.DAT be handled by the XML interface, you could specify:
Note that XML can be specified only with sequential files.