Int_64 - 64 bit question

[Alex]

Hi,

I am a little confused as to how numbers are represented as 64 bit
integers.

I have a file that is 2GB in size.

I call __stati64 and from the st_size attribute, I see that the size
is returned as:

High - 0
Low - 2147483648

I know that high and low are unsigned and can be a maximum of 2**32
(ie. 4,294,967,296 bytes 4Gb)

So my question is, how is a 5Gb file represented in st_size??

Would it be:
High - 1
Low - 1073741824

My hardrive on my laptop is not big enough to test this and I cannot
find an answer on the web.

[Victor Bazarov]

Re: Int_64 - 64 bit question

Alex wrote:[color=blue]
> I am a little confused as to how numbers are represented as 64 bit
> integers.[/color]

What do you think is the difference between those and 32-bit ones or
16-bit ones? None, AFA C++ is concerned.
[color=blue]
> I have a file that is 2GB in size.
>
> I call __stati64 and from the st_size attribute, I see that the size
> is returned as:
>
> High - 0
> Low - 2147483648[/color]

What's __stati64? It's not a standard function. What does it return?
What's "High" and "Low"? Some 32-bit parts of a struct?
[color=blue]
> I know that high and low are unsigned and can be a maximum of 2**32
> (ie. 4,294,967,296 bytes 4Gb)[/color]

If they are 32-bit unsigned integers, then the maximum is (2**32 - 1),
actually. That's 4,294,967,295.
[color=blue]
>
> So my question is, how is a 5Gb file represented in st_size??
>
> Would it be:
> High - 1
> Low - 1073741824[/color]

_Assuming_ that 'High' and 'Low' are of type "unsigned long", then, yes,
_probably_.
[color=blue]
> My hardrive on my laptop is not big enough to test this and I cannot
> find an answer on the web.[/color]

Try the FM for your compiler. You know, the second part of RTFM...

V