Accessing Files

The first time a file function accesses a volume and whenever a diskette is placed in a floppy-disk drive, the operating system examines the volume to determine its file system. Thereafter, the operating system manages all I/O to that volume through the device driver supporting the file system.

The file I/O functions enable applications to access files regardless of the underlying file system. However, capabilities may vary depending on the file system and/or operating system in use. For example, the CreateFile function includes a security parameter that provides no security benefits for files not residing on an NTFS volume.

The file I/O functions that create, open, and delete files and directories identify them by their names. These functions store or search for the file or directory in the current directory on the current disk drive, unless the name explicitly specifies a path to a different directory, disk drive, or both.