I have a question about FILE_ATTRIBUTE_TEMPORARY marked files.
First of all, here is what I want to do:
I have a DLL, that takes a Filename, and opens that file internally and reads from it. I do not know how this file is handled inside.
The file I want to give to that DLL will be created by my process. It must be a temporary file and its data must be held only in RAM and must not be accessed by other processes. So I use the Win32 function CreateFile() with the FILE_ATTRIBUTE_TEMPORARY and the FILE_FLAG_DELETE_ON_CLOSE. This so far works, fine.
I have a tes code where I test if the file can be accessed a second time, while still opened. Here it is:
HANDLE WINHandle = CreateFile("TempFileWIN.txt", (GENERIC_WRITE | GENERIC_READ) ,(FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE), 0, CREATE_ALWAYS, (FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE), 0);
ifstream ifs("TempFileWIN.txt", (ios::in | ios::trunc));
if(ifs.is_open())
{
cout << "Success!" << endl;
}
else if(ifs.fail())
{
cout << "Failed!" << endl;
}
I am using the fstream to test if the file could be opened with a stream. That code up there doesn't work. The output is "Failed!". I know, that the file could be opened with the CreateFile a second time. I checked that out. But want to know if it is possible to open the file by an external DLL that works with (e.g.) a fstream.
I hope you can help me with this matter. Best regards.
Edit: Maybe a better question is how I can lock a file to my process and ensure, that it can never be accessed by an other process (even if my process is killed). The file must be openable with C++ fstream object.
