C++ Determine if a file is older than int hours

Question

I have an MFC application where I need to determine if a file's last write time is older than n hours.

I thought there was a method to get total seconds from either system or file time, but I ended up coding this method which works, but there might be a leaner method.

bool FileOlderThanHours(HANDLE hFile, int hours)
{
 FILETIME ftCreate, ftLastAccess, ftLastWrite;
 SYSTEMTIME stNow, stFile;
 GetSystemTime(&stNow); 
 if (!GetFileTime(hFile, &ftCreate, &ftLastAccess, &ftLastWrite))
 return false;
 if (!FileTimeToSystemTime(&ftLastWrite, &stFile))
 return false;
 COleDateTime oleNow(stNow.wYear, stNow.wMonth, stNow.wDay, stNow.wHour, 
 stNow.wMinute, stNow.wSecond);
 COleDateTime oleFile(stFile.wYear, stFile.wMonth, stFile.wDay, stFile.wHour, 
 stFile.wMinute, stFile.wSecond);
 COleDateTimeSpan timeDiff = oleNow - oleFile;
 double totHours = timeDiff.GetTotalHours();
 return (totHours > hours);
}

If someone knows a leaner way, please let me know, thanks.

• JDługosz: You seem to be missing the return type on the function.
• netcat: my bad--I copied this method from my class and omitted the type along with the ... ClassName:: prefix.
• user673679: Please don't edit or append code in the question after it has been reviewed. For details, see: codereview.meta.stackexchange.com/questions/1763/…
• Sᴀᴍ Onᴇᴌᴀ: In addition to what user673679 stated: incorporating feedback from answers goes against the Question + Answer style of Code Review. This is not a forum where you should keep the most updated version in your question. Please see What should I do when someone answers my question? as well as what you may and may not do after receiving answers.

Answer 1

In MFC, the CFile::GetStatus method lets you query the creation, modification or access time of a file.

Code to use it would look something like:

CTime getModificationTIme(const LPCTSTR filename)
/* Returns the last modification time of the requested file. The
 * filename must be a null-terminated wide string.
 */
{
 CFileStatus inputFileStatus;
 if (!CFile::GetStatus( filename, inputFileStatus )) {
 // Handle the error, perhaps by throwing an exception. E.g.,
 THROW((CException*) new CCustomException(filename));
 }
 return inputFileStatus.m_mtime;
}

In current versions of Windows, the filename is a null-terminated wide string. Future versions might un-deprecate the char* version to accept a UTF-8 filename.

Visual Studio 2017 and up support the standard library’s <filesystem> header, of which you can find an example of usage at cppreference.

One major difference between Windows and other systems is that, on Windows, the <filesystem> API uses wide strings to create a std::filesystem::path.

• netcat: Thanks! I implemented the CTime class into my method.
• Davislor: @netcat Glad it helped! Anyone who copies this later should be sure to notice, my error-handling code was just a dummy.