BYTE array size

I have a BYTE array -
BYTE const* pbBinary

I would like to know how many bytes in that byte array

but if I do - sizeof(* pbBinary); - then I got 1
but if I do - sizeof( pbBinary); - then I got 4

I am sure the array has hundreds of bytes

how can I do that?

======================

BYTE const* pbBinary = &bytes[0];
int size = sizeof( pbBinary);

re: BYTE array size

"Chunekit Pong" <worlman385@yahoo.comwrote in message news:f54ai4l6o3hdj8k2j0as78nhm0166ndt4r@4ax.com...You don't have a BYTE array, you have a pointer to BYTE.
(What is a BYTE?)
Without other information you can't.

re: BYTE array size

On Nov 20, 8:27*am, Chunekit Pong <worlman...@yahoo.comwrote:pbBinary is just a pointer.. it does not store the information about
number of bytes/elements it points to
if you care about the size of an "array", use std::vector<instead.
m.

re: BYTE array size

On Thu, 20 Nov 2008 08:46:12 +0100, "Fred Zwarts" <F.Zwarts@KVI.nl>
wrote:
The whole code is like this - the purpose is to convert binary file
into a Base64 string
=================
typedef unsigned char BYTE;
std::ifstream file1("c:/test2.png");

// read from test2.png into BYTE array
std::vector<BYTEbytes(
(std::istreambuf_iterator<char>(file1))
, (std::istreambuf_iterator<char>())
);
if(bytes.empty())
; // no bytes have been read

BYTE const* pbBinary = &bytes[0];
int size = sizeof(pbBinary);

unsigned long ulEncLen = 0;
char *pEncOut = NULL;

BOOL fRet = ::CryptBinaryToString( pbBinary, size,
CRYPT_STRING_BASE64, pEncOut, &ulEncLen );
====================
BOOL WINAPI CryptBinaryToString(
__in const BYTE *pbBinary,
__in DWORD cbBinary,
__in DWORD dwFlags,
__out_opt LPTSTR pszString,
__inout DWORD *pcchString
);

re: BYTE array size

"Chunekit Pong" <worlman385@yahoo.comwrote in message news:ok7ai4hn1aifrcput99okpvvoricqu7qsa@4ax.com...bytes.size () gives you the size of the vector.

re: BYTE array size

On Nov 20, 9:25*am, Chunekit Pong <worlman...@yahoo.comwrote:You cannot get the size of an array, by doing sizeof on a pointer to
an external array. Only if the pointer is in fact declared as a
statically dimensioned array (eg. BYTE pbBinary[10]) you can get the
size of the array by doing sizeof(pbBinary). In your case you are in
the same scope, but still pbBinary is considered as a pointer to a
dynamically allocated or external array. Note that sizeof is
calculated compile time, and when you declare a pointer to an array,
the compiler CANNOT know what the size of the array will be to what
the pointer will point at runtime.

re: BYTE array size

Chunekit Pong wrote:
Well, *pbBinary is a BYTE, so you get the size of a BYTE.
pbBinary is a pointer to const BYTE, so you get the size of a pointer to
const BYTE.
You can't, unless the array contains some end marker that you can use to find
out.

re: BYTE array size

On Nov 20, 12:47 pm, Tonni Tielens <tonnitiel...@gmail.comwrote:I know what you mean, but you really should say that you can't
get the size of an array given a pointer to its first element.
(Pointers to arrays, i.e. BYTE (*p)[ 200 ], exist, and in such
cases, sizeof( *p ) would be useful. But they aren't very
idiomatic.)
If something is declared as an array, it's not a pointer.

--
James Kanze (GABI Software) email:james.kanze@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientierter Datenverarbeitung
9 place Sémard, 78210 St.-Cyr-l'École, France, +33 (0)1 30 23 00 34

re: BYTE array size

On Nov 20, 8:27 am, Chunekit Pong <worlman...@yahoo.comwrote:Ask whoever created the array to tell you. Once the array has
been converted to a pointer to the first element, all
information concerning the size has been lost.

A better solution might be to use std::vector.

--
James Kanze (GABI Software) email:james.kanze@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientierter Datenverarbeitung
9 place Sémard, 78210 St.-Cyr-l'École, France, +33 (0)1 30 23 00 34

re: BYTE array size

On Nov 20, 10:25*am, Chunekit Pong <worlman...@yahoo.comwrote:The previous posters have explained the problem. A possible fix to
your program:

Instead of:
int size = sizeof(pbBinary);
Try:
int size = bytes.size();

re: BYTE array size

Chunekit Pong <worlman385@yahoo.comwrote in
news:ok7ai4hn1aifrcput99okpvvoricqu7qsa@4ax.com:
Why bother to make pbBinary and size ?

Why not:

BOOL fRet = ::CryptBinaryToString(&bytes[0], bytes.size(),
CRYPT__STRING_BASE64, pEncOut, &ulEncLen);

?