| HFILE OpenFile(lpszFileName, lpOpenBuff, fuMode) | |||||
| LPCSTR lpszFileName; | /* address of filename | */ | |||
| OFSTRUCT FAR* lpOpenBuff; | /* address of buffer for file information | */ | |||
| UINT fuMode; | /* action and attributes, */ | ||||
The OpenFile function creates, opens, reopens, or deletes a file.
lpszFileName
Points to a null-terminated string that names the file to be opened. The string must consist of characters from the Windows character set and cannot contain wildcards.
lpOpenBuff
Points to the OFSTRUCT structure that will receive information about the file when the file is first opened. The structure can be used in subsequent calls to the OpenFile function to refer to the open file. The OFSTRUCT structure has the following form:
typedef struct tagOFSTRUCT { /* of */
BYTE cBytes;
BYTE fFixedDisk;
UINT nErrCode;
BYTE reserved[4];
BYTE szPathName[128];
} OFSTRUCT;The szPathName member of OFSTRUCT contains characters from the OEM character set.
For a full description of this structure, see the Microsoft Windows Programmer's Reference, Volume 3.
fuMode
Specifies the action to take and the attributes for the file. This parameter can be a combination of the following values:
| Value | Meaning |
| OF_CANCEL | Adds a Cancel button to the OF_PROMPT dialog box. Pressing the Cancel button directs OpenFile to return a file-not-found error message. |
| OF_CREATE | Creates a new file. If the file already exists, it is truncated to zero length. |
| OF_DELETE | Deletes the file. |
| OF_EXIST | Opens the file, and then closes it. This value is used to test for file existence. Using this value does not change the file date. |
| OF_PARSE | Fills the OFSTRUCT structure but carries out no other action. |
| OF_PROMPT | Displays a dialog box if the requested file does not exist. The dialog box informs the user that Windows cannot find the file and prompts the user to insert the file in drive A. |
| OF_READ | Opens the file for reading only. |
| OF_READWRITE | Opens the file for reading and writing. |
| OF_REOPEN | Opens the file using information in the reopen buffer. |
| OF_SEARCH | Windows searches in directories even when the file name includes a full path. |
| OF_SHARE_COMPAT | Opens the file with compatibility mode, allowing any program on a given machine to open the file any number of times. OpenFile fails if the file has been opened with any of the other sharing modes. |
| OF_SHARE_DENY_NONE | Opens the file without denying other programs read or write access to the file. OpenFile fails if the file has been opened in compatibility mode by any other program. |
| OF_SHARE_DENY_READ | Opens the file and denies other programs read access to the file. OpenFile fails if the file has been opened in compatibility mode or for read access by any other program. |
| OF_SHARE_DENY_WRITE | Opens the file and denies other programs write access to the file. OpenFile fails if the file has been opened in compatibility or for write access by any other program. |
| OF_SHARE_EXCLUSIVE | Opens the file with exclusive mode, denying other programs both read and write access to the file. OpenFile fails if the file has been opened in any other mode for read or write access, even by the current program. |
| OF_VERIFY | Compares the time and date in the OF_STRUCT with the time and date of the specified file. The function returns HFILE_ERROR if the dates and times do not agree. |
| OF_WRITE | Opens the file for writing only. |
The return value is an MS-DOS file handle if the function is successful. (This handle is not necessarily valid; for example, if the fuMode parameter is OF_EXIST, the handle does not identify an open file, and if the fuMode parameter is OF_DELETE, the handle is invalid.) The return value is HFILE_ERROR if an error occurs.
If the lpszFileName parameter specifies a filename and extension only (or if the OF_SEARCH flag is specified), the OpenFile function searches for a matching file in the following directories (in this order):
1.The current directory.
2.The Windows directory (the directory containing WIN.COM), whose path the GetWindowsDirectory function retrieves.
3.The Windows system directory (the directory containing such system files as GDI.EXE), whose path the GetSystemDirectory function retrieves.
4.The directory containing the executable file for the current task; the GetModuleFileName function obtains the path of this directory.
5.The directories listed in the PATH environment variable.
6.The list of directories mapped in a network.
To close the file after use, the application should call the _lclose function.