How to check if Directory already Exists in MFC(VC++)?

Question

How to check if Directory already Exists in MFC(VC++) ? I am using below code to get current application Path and there i am creating NDSLog folder so that all my Logfiles should place there , now i want to check the condition if NDSLog folder already exists dont create it .How to do that ?

Thanks.

char strPathName[_MAX_PATH];
    ::GetModuleFileName(NULL, strPathName, _MAX_PATH);

    // The following code will allow you to get the path.
    CString newPath(strPathName);
    int fpos = newPath.ReverseFind('\\');

    if (fpos != -1)
    newPath = newPath.Left(fpos+1);     
    newPath += "NDSLog\\" ;

    CreateDirectory(newPath,NULL); 

Answer 1

The simplest way to check if a file/directory exists is to use GetFileAttributes:

if (GetFileAttributes(newPath) == INVALID_FILE_ATTRIBUTES) {
  CreateDirectory(newPath,NULL);
}

Note that the function will return INVALID_FILE_ATTRIBUTES even if it fails due to some other reason, such as not having permissions to access the file, so you should check the return value of CreateDirectory to make sure that it succeeded.

Actually, you don't need to check whether the directory already exists; CreateDirectory will set an error code if the directory already exists:

if (!CreateDirectory(newPath,NULL)) {
  if (GetLastError() == ERROR_ALREADY_EXISTS) {
    // directory already exists
  } else {
    // creation failed due to some other reason
  }
}

Answer 2

How about PathIsDirectory()? In the original example, you can use PathRemoveFilespec() followed by PathCombine() to add a new filename/extension. In the unlikely case that your target is only Windows 8 or later, there are safer PathCch...() flavors of these functions.