openFile

OpenFile is a legacy Windows API function historically used to open files with DOS-style file access semantics. It was designed to provide compatibility with 16-bit DOS applications by returning a handle that could be used with the low-level, DOS-era I/O facilities. The function relies on a structure called OFSTRUCT to convey status information about the file and to receive details such as the file path and access outcomes.

The typical usage involves calling OpenFile with three parameters: the file name, a pointer to an OFSTRUCT buffer, and a style flag that specifies the desired access mode and creation behavior. The style flags indicate whether the file should be opened for reading, writing, or both, and may include options related to creation or existence checks. On success, OpenFile returns an HFILE handle; on failure, it returns HFILE_ERROR. The returned handle is intended for use with the older DOS-like I/O routines rather than modern Win32 file I/O.

OpenFile is part of the Windows API but is considered obsolete. It predates the Windows CreateFile function and the broader Win32 I/O model, and it is largely superseded by CreateFile for new development. In modern applications, OpenFile is typically used only for maintaining compatibility with older software or libraries that rely on 16-bit file semantics. For contemporary programming, CreateFile and higher-level interfaces provide more flexible and robust file handling.

See also: CreateFile, OFSTRUCT, HFILE, HFILE_ERROR.