OpenFile

Syntax

int OpenFile(lpFileName,lpReOpenBuff,wStyle)

This function creates, opens, reopens, or deletes a file.

Parameter Type/Description  

lpFileName LPSTR Points to a null-terminated character string that names the file to be opened. The string must consist of characters from the ANSI character set.  
lpReOpenBuff LPOFSTRUCT Points to the OFSTRUCT data structure that is to 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 szPathName field of this data structure contains characters from the OEM character set.  
wStyle WORD Specifies the action to take. These styles can be combined by using the bitwise OR operator:  
  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 Directs OpenFile to create 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. Used to test for file existence.
  OF_PARSE Fills the OFSTRUCT data 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 re-open buffer.
Parameter Type/Description  

  Value Meaning
  OF_SHARE_COMPAT Opens the file with compatibility mode, allowing any process 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 processes read or write access to the file. OpenFile fails if the file has been opened in compatibility mode by any other process.
  OF_SHARE_DENY_READ Opens the file and denies other processes read access to the file. OpenFile fails if the file has been opened in compatibility mode or for read access by any other process.
  OF_SHARE_DENY_WRITE Opens the file and denies other processes write access to the file. OpenFile fails if the file has been opened in compatibility or for write access by any other process.
  OF_SHARE_EXCLUSIVE Opens the file with exclusive mode, denying other processes 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 process.
Parameter Type/Description  

  Value Meaning
  OF_VERIFY Verifies that the date and time of the file are the same as when it was previously opened. Useful as an extra check for read-only files.
  OF_WRITE Opens the file for writing only.

Return Value

The return value specifies a DOS file handle if the function is successful. Otherwise,
it is –1.

Comments

If the lpFileName parameter specifies a filename and extension only, this function searches for a matching file in the following directories:

1.The current directory.

2.The Windows directory (the directory containing WIN.COM); the GetWindowsDirectory function obtains the pathname of this directory.

3.The Windows system directory (the directory containing such system files as KERNEL.EXE); the GetSystemDirectory function obtains the pathname of this directory.

4.Any of the directories listed in the PATH environment variable.

5.Any directory in the list of directories mapped in a network.

Windows searches the directories in the listed order.

The lpFileName parameter cannot contain wildcard characters.

To close the file after use, the application should call the _lclose function.