C / C++ / MFC

4-May-09 9:32

jeron1 suggested a very good article, indeed.
Smile | :)

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[My articles]

Greg Mort4-May-09 9:42

4-May-09 9:42

I didn't I rated his post, however that is not my problem
(if you read my question) my issue is I need something such as BitConverter (in c#) in c/c++

CPallini4-May-09 9:52

4-May-09 9:52

Your question looks actually arising from a endianess problem; I doubt that a BitConverter-like class would be of any help.
Probably if you elaborate it a bit then we might properly appreciate your issue.
Smile | :)

Greg Mort4-May-09 9:57

4-May-09 9:57

CPallini wrote:
Your question looks actually arising from a endianess problem; I doubt that a BitConverter-like class would be of any help.
Probably if you elaborate it a bit then we might properly appreciate your issue.

? like the question suggests I have converted it from big endian to little, but as stated I cannot just read straight into a double now, i must first grab the data into a char[], convert from big to small, then what I am left with is a char[] filled with binary data.. i need to convert from binary data into a double,int,or float... I could write my own function that would use the mantissa and all that for the float, but I don't think it should be that much trouble and there has to be an easier way of doing it

David Crow4-May-09 10:02

David Crow

4-May-09 10:02

Greg Mort wrote:
...what I am left with is a char[] filled with binary data.. i need to convert from binary data into a double,int,or float...

Would a union work?

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Greg Mort4-May-09 10:08

4-May-09 10:08

I have seen a few implementations of unions with similar threads, I however seem not to be able to get it to work, then again I have never used unions before

CPallini4-May-09 10:24

4-May-09 10:24

Never heard about unions?
Smile | :)

Greg Mort4-May-09 10:49

4-May-09 10:49

you cant read can you?

CPallini4-May-09 21:01

4-May-09 21:01

Greg Mort wrote:
you cant read can you?

Yes, I'm able to (as a proof I can see a typo in your sentence... Roll eyes | :rolleyes:

).
Good luck with your reversed char[] and float.
Smile | :)

harold aptroot4-May-09 10:30

harold aptroot

4-May-09 10:30

This is C++, you don't even need a union, you could just type-pun it directly, from a char[] to a double* or float* or whatever you want. The union isn't any better with Unidefined Behaviour here, only one member of the union is required to have a value at any one time - so it's just as bad as pointer-wise type-punning. Both methods should work anyway.

Greg Mort4-May-09 11:02

4-May-09 11:02

Thank you, I just figured this out as well Smile | :)

[Message Deleted]

Greg Mort4-May-09 8:30

Re: why is 0x00,0x00,0x00,0x01 = 16777216 ? Should it not be = to 1?

4-May-09 8:30

[Message Deleted]

jeron14-May-09 9:05

jeron1

4-May-09 9:05

Looks like an endianess issue.

Re: why is 0x00,0x00,0x00,0x01 = 16777216 ? Should it not be = to 1?

Greg Mort4-May-09 9:10

Re: why is 0x00,0x00,0x00,0x01 = 16777216 ? Should it not be = to 1?

4-May-09 9:10

I agree, so how to I grab it from a file, reorder the data, and place the value in a double variable?

jeron14-May-09 9:15

jeron1

4-May-09 9:15

Maybe this[^] article will help.

Annoying error for me

CodingLover4-May-09 6:08

CodingLover

4-May-09 6:08

Please look at the following lines of code.

<br />
	PULONG count;<br />
	PLUID* sessions;<br />
<br />
	LsaEnumerateLogonSessions(count, sessions);<br />

I got the following error on that..

<br />
error C3861: 'LsaEnumerateLogonSessions': identifier not found, even with argument-dependent lookup<br />

Any idea why it's happen there in the code?

Thanks a lot

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

Re: Annoying error for me

I am BATMAN4-May-09 6:12

Re: Annoying error for me

4-May-09 6:12

Are you sure you're including the correct headers?

David Crow4-May-09 7:59

David Crow

4-May-09 7:59

CodingLover wrote:
Any idea why it's happen there in the code?

Are you including Ntsecapi.h?

Convert a in_addr to an IPAddr

I am BATMAN4-May-09 5:30

4-May-09 5:30

In my code I'm trying to call SendARP to get the MAC address of a computer on the local network. I have their IP address in the in_addr data format, but SendARP takes it as an IPAddr.

I looked on MSDN and they don't offer any explicit ways to convert between the two and google searches so far have not proven fruitful.

Anyone done this before?

led mike4-May-09 7:24

led mike

4-May-09 7:24

I am BATMAN wrote:
In my code I'm trying to call SendARP to get the MAC address of a computer on the local network. I have their IP address in the in_addr data format, but SendARP takes it as an IPAddr.

I looked on MSDN and they don't offer any explicit ways to convert between the two and google searches so far have not proven fruitful.

Anyone done this before?

Have you looked at the two definitions? IPAddr and in_addr?

I am BATMAN4-May-09 11:05

4-May-09 11:05

yes, that was sort of vague...are you talking about how it says you can cast an IPAddr to an in_addr? I tried casting the other direction (in_addr to IPAddr) but it throws errors.

Forgive me, this is basically the beginning of my windows C++ programming, up until now it's all been command line linux code. Is there a special way to cast with the win API or something?

led mike4-May-09 11:22

led mike

4-May-09 11:22

I am BATMAN wrote:
Forgive me, this is basically the beginning of my windows C++ programming, up until now it's all been command line linux code. Is there a special way to cast with the win API or something?

Then you need to study beginners material of the language since you need to understand types, structures and unions as well as many, many other things. Trying to explain them to you in a forum is not appropriate.

typedef struct in_addr {
        union {
                struct { UCHAR s_b1,s_b2,s_b3,s_b4; } S_un_b;
                struct { USHORT s_w1,s_w2; } S_un_w;
                ULONG S_addr;
        } S_un;

The S_addr member of the union is the same type as IPAddr.

//
// IP type definitions.
//
typedef ULONG IPAddr;       // An IP address.

I am BATMAN4-May-09 11:20