File size in standard way

CodingLover

Hi all, One of my application I used MFC(actually CFile) to find the file size in easy way. Now I thought to do it using standard C++. Here is my try.

size\_t file\_size;
ifstream in\_file;

    in\_file.open("C:\\\\temo\_file.txt", ios\_base::in);

if(in\_file.is\_open())
{
	file\_size = in\_file.seekg(-1, ios\_base::end).tellg();
	cout << file\_size;
}

My question is, this code gives misses one byte. Can you guys give me any reason for it. Thanks

I appreciate your help all the time... CodingLover :)

Doc Lobster

I guess with seekg you are looking for the position -1 from the end. Therefore you are missing the byte. Additionally look here: http://www.codeproject.com/KB/files/filesize.aspx[^] http://www.cplusplus.com/reference/iostream/istream/seekg.html[^]

CPallini

CodingLover wrote:

file_size = in_file.seekg(-1, ios_base::end).tellg();

should be

file_size = in_file.seekg(0, ios_base::end).tellg();

BTW you may also use GetFileSize [^]. :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

CodingLover

Thanks, so my attempt is not bad. :) Is that GetFileName is standard C++. I'm confusing with those.

I appreciate your help all the time... CodingLover :)

CodingLover

Thanks for links.

I appreciate your help all the time... CodingLover :)

CPallini

CodingLover wrote:

Is that GetFileName is standard C++. I'm confusing with those.

Nope. It is provided by Win32 API. If you just need to avoid MFC that's is fine, on the other hand, if you need to be stuck with C++ standard, then use ifstream. :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

CodingLover

Since I start to learn C++, confusing with this. Is that best way to work with standard C++? Sometimes I feel that use of MFC easy than standard C++, and other way too. Appreciate your explanation on it.

I appreciate your help all the time... CodingLover :)

CPallini

Using C++ standard you write code that will execute also on different platforms (for instance Linux). On the other hand, if you need to exploit Windows not-portable functionalities (like the GUI components1) the you have to use Win32 API or MFC. GUI development with MFC is usually simpler. :) (1) There are exceptions: for instance QT [^] is a framework that enable you to write portable GUI code.

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

CodingLover

Ok, as I said now I have mixture of them. If I want to learn standard C++ from where I should begin.

I appreciate your help all the time... CodingLover :)

CPallini

What about "The C++ Programming Language" [^] book of Stroustrup? :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

CodingLover

Thanks a lot. :)

I appreciate your help all the time... CodingLover :)