Dave's Brain

Browse - programming tips - win32 simple use of createfile to open a file for writing

Date: 2009oct5
Platform: win32
Language: C/C++

Q.  How can I use CreateFile() to simply open a file for writing?

A.

inline HANDLE OpenForWrite(LPCTSTR szDest)
{
	HANDLE	h;

	h =  CreateFile(szDest // name of the file
		,GENERIC_WRITE // access mode
		,FILE_SHARE_WRITE // Share mode
		,NULL // Security
		,CREATE_ALWAYS	  // Creates a new file. If the file exists, the function overwrites the file and clears the existing attributes.
		,FILE_ATTRIBUTE_NORMAL // file attributes
		,NULL); // Template
	if (h == INVALID_HANDLE_VALUE) h = NULL;
	return h;
}

This is the the same as:

inline FILE *OpenForWriteStd(LPCSTR szDest)
{
	return fopen(szDest, "wb");
}

Except you get a different kind of handle.

void ExampleUse()
{
	LPCSTR	szDest = "c:\\myfile.txt";
	HANDLE	h;

	if ((h = OpenForWrite(szDest)) == NULL)
	{
		// ... Problem ...
		return;
	}

	// ... Write to the handle ...

	CloseHandle(h);
}

Add a comment

Sign in to add a comment