BYTE, char data corruption

**dwks** · 11-12-2005

Originally Posted by Denethor2000

error C2440: 'initializing' : cannot convert from 'unsigned char [300]' to 'unsigned char'

What's _Buffer? According to the error, it's an 'unsigned char'.

**Harbinger** · 11-12-2005

> input Line = { GetCurrentProcessId(), Address, Length, _Buffer };
You can't assign arrays - use memcpy()

Having BYTE *bytes; in your struct would work, but that wouldn't be making a copy of the buffer.

**Denethor2000** · 11-12-2005

Originally Posted by dwks

What's _Buffer? According to the error, it's an 'unsigned char'.

Yeah, I edited that in a minute later, sorry about that.

It's a BYTE array.

Code:

BYTE _Buffer[300];

**Ancient Dragon** · 11-12-2005

Code:

input Line = { GetCurrentProcessId(), Address, Length, _Buffer };

What the hell is the above? what are those curly-braces doing there? First calls GetCurrentProcessID() and assigns the return value to Line (which is wrong because Input is not a DWORD). but what's the purpose of Address, Length, and _Buffer in that line?

**Denethor2000** · 11-12-2005

Originally Posted by Ancient Dragon

Code:

input Line = { GetCurrentProcessId(), Address, Length, _Buffer };

What the hell is the above? what are those curly-braces doing there? First calls GetCurrentProcessID() and assigns the return value to Line (which is probably wrong if Input is not a DWORD). but what's the purpose of Address, Length, and _Buffer in that line?

It's a struct. Which I included in the same post.

It gets passed to a driver with DeviceIoControl. Which has nothing to do with my problem.

**dwks** · 11-12-2005

Probably to initialize the remaining members of the structure.

Code:

struct s {
    int x;
    float f;
};

s one;
s two = {1};
s three = {1, 2.0};

[edit]You beat me to it.[/edit]

**dwks** · 11-12-2005

Which has nothing to do with my problem.

It might, depending on what _Buffer is. It's [300], right?

**Ancient Dragon** · 11-12-2005

Originally Posted by Denethor2000

It's a struct. Which I included in the same post..

Yes, I reread your previous post and found that out. You can't assign members of a struct like that -- each member requires its own assign statement.

Code:

Line.processid = GetProcessID();
Line.address = Address;
Line.bytestowrite = Length;
// The next line may not work if sizeof(Line.bytes) > siezof(_Buffer)
memcpy(Line.bytes,_Buffer,sizeof(Line.bytes));

**dwks** · 11-12-2005

You can too assign a struct like that. How about you re-read my post:

Originally Posted by dwks

Code:

struct s {
    int x;
    float f;
};

s one;
s two = {1};
s three = {1, 2.0};

**dwks** · 11-12-2005

And what's siezof?

**Ancient Dragon** · 11-12-2005

Originally Posted by dwks

You can too assign a struct like that. How about you re-read my post:

That obscure trick won't work with his struct because it contains character arrays which cannot be copied like that.

**dwks** · 11-12-2005

That obscure trick

I use it all the time.

won't work with his struct because it contains character arrays

Yes, you're right. (It does work for char*, not for char[].) But

but what's the purpose of Address, Length, and _Buffer in that line?

Address and Length are valid.

**Ancient Dragon** · 11-12-2005

Originally Posted by dwks

I use it all the time.

You are one of a very select few who do. I've never see that before in over 20 years.

Originally Posted by dwks

Yes, you're right. (It does work for char*, not for char[].)

well, it really does not work for char* either -- unless all you want copied is the address and not the object to which it points.

**dwks** · 11-12-2005

You are one of a very select few who do. I've never see that before in over 20 years.

What? Really? That's amazing.

well, it really does work for char* either -- unless all you want copied is the address and not the object to which it points.

It does work?

Oh, you mean doesn't. It does work, because all I want copied is the address.

**Thantos** · 11-12-2005

technically you aren't doing assignment. You are doing initalization.

Denethor2000 instead of rationing out your limitations to us how about you give us all the info in the beginning?

A BYTE is nothing more then a fancy unsigned char.

Changing both types to char[300] is accepted, but "corrupts" it.

how does it corrupt it?