Problem hex string to char * ..

[Fuji22]

I want to transform hex string I type in Edit Box (MFC) to a char *

like...

aa bb cc dd ee ff 03 f8 d3 fe

typed that in Edit Box and when I press convert button

It should make that into char array well yah char * same thing.

This is what I got so far but for some reason yes it compiles great but when I press convert it crashes

char strData[255] = {0};//held from Edit Box.
char * intercept = NULL;



LRESULT res;

res = SendMessage(GetDlgItem(hDlg,IDC_EDIT),WM_GETTEXTLENGTH,0,0);
if(((int)res == 0 || (int)res > 999))// we want text but not bigger than limit.
{
return 0;
}
SendMessage(GetDlgItem(hDlg,IDC_EDIT),WM_GETTEXT,sizeof(strData),(LPARAM)strData);

char* temp=strdup(strData);

//Convert a hexyString to a hex character and put in array
for(int i = 0; i < res; i++)
intercept[i] = strtoul(temp, &temp, 0x10);
delete[] temp;
temp = 0;




yah.. thats about it

well I know I ain't that smart to figure this out so if anyone could help I'd really like that

[Pravin Kumar]

Will this FAQ Integer to string and vice-verca for any base be of any help?

[hoxsiew]

'intercept[i]' looks like you are dereferencing a NULL pointer.

[Skizmo]

You are using MFC, so why are you messing around with SendMessage, GetDlgItem and char pointers ?

[ahoodin]

Good point Skizmo! You can always easily use DDE by creating your dialogs with the classwizard. Or alternatively you can "cheat" by:

         char ctxt[8]="Hello\0";
         CString svtxt;
         GetDlgItem(IDC_EDIT1)->SetWindowText(ctxt);
	 GetDlgItem(IDC_EDIT1)->GetWindowText(svtxt);

[Fuji22]

nope that Integer to string and vice-verca for any base had no help what so ever..

anyways yah its not really MFC im just using Resource editor from Visual C++ 6.0 but its really Win32 dialogs but thats not the problem

[ahoodin]

I want to transform hex string I type in Edit Box (MFC) to a char *

Oh thanks for letting us know in advance!

[ahoodin]

Can I ask what products you are using to accomplish your goals?

[Fuji22]

I also got this done by myself a little problem with arrays now.. If I'd make a array like 5000 (guess size) then at the end It must be the same size as the hex value of ascii string. But okay here is my current code.

					res = SendMessage(GetDlgItem(hDlg,IDC_EDIT),WM_GETTEXTLENGTH,0,0);
					if(((int)res == 0 || (int)res > 9999))// we want text but not bigger than limit.
					{
						return 0;
					}
				//	SendMessage(GetDlgItem(hDlg,IDC_EDIT),WM_GETTEXT,sizeof(strData),(LPARAM)strData);
					SendMessage(GetDlgItem(hDlg,IDC_EDIT),WM_GETTEXT,res,(LPARAM)strData);

					for(int ac = 0; ac <= sizeof(strData); ac++)
						printf("strData [%d] = %d\n", ac, strData[ac]);

					printf("\n");



					char temp[(res/2)+sizeof(char)] = {0}; //allocate temp array <- the hell this giving me a array for error C2466: cannot allocate an array of constant size 0

					char *p = strtok(strData, " ");  //split hex characters by space
					int curPos = 0;

					while(p != NULL)  //if pointer is not NULL
					{ 
					  temp[curPos]=(char)strtoul(p, NULL, 0x10); 
					  p = strtok(NULL, " "); 
					  curPos++;
					} 


//					char* temp=strdup(strData);


					for(int ab = 0; ab <= (res / 2)-1; ab++)
						printf("temp [%d] = %d\n", ab, temp[ab]);

					printf("\n");

[ahoodin]

Please use code tags when posting. Edit your post. Right above the words LastPost in your editor there is a white button marked code tags. Select all the text in your post that is code and click "Code" please.

Lack of Code Tags leads to practically un-readable and ugly postings.

Thank you.

Also Which OS/Windows version? Compiler? etc? Thanks.

[hoxsiew]

USE CODE TAGS!

	char temp[(res/2)+sizeof(char)] = {0}; //allocate temp array <- the hell this giving me a array for error C2466: cannot allocate an array of constant size 0

You cannot declare an array that way. The array size must be constant at compile time. res is a variable. If the size varies, you'll need to dynamically allocate the array at runtime.

[Fuji22]

error C2057: expected constant expression
error C2466: cannot allocate an array of constant size 0

for

const int size = (res/2)+1;
char temp[size] = {0}; //allocate temp array

I don't believe the compiler is this stupid.

[ahoodin]

Ou Contraire:

char temp[size] = {0}; //allocate temp array

Should be:

char* ptemp = new char[size]; //allocate temp array

//after you use it
delete [] ptemp;

now to access an element dereference by:

*(ptemp+ addr) = 'a';

or

ptemp[addr] = 'a';

You have alot of learning to do my young Padwan. And apparently the compiler is all over it. Whichever compiler you are using.

[Fuji22]

but why must I use pointers for such similar operations. I already mastered Java but I can't find the power in java aka dll injection so thats why I switched to C.

if char blahlbah[30] works I dont get it.. aint pointers for functions and such so it will be less overhead on functions

so Dynamic Allocation of arrays can't be done without pointers? wow.. why doesn't someone just make a new langauge thats just as powerful but without the hassle lol.

[hoxsiew]

but why must I use pointers for such similar operations. I already mastered Java but I can't find the power in java aka dll injection so thats why I switched to C.

if char blahlbah[30] works I dont get it.. aint pointers for functions and such so it will be less overhead on functions

The compiler allocates space for that array at compile time. The compiler knows what 30 means. It means allocate 30 units for this thing; save it in the executable. If you have a variable, the compiler has no idea what it will be when the program runs later after it is compiled.

so Dynamic Allocation of arrays can't be done without pointers? wow.. why doesn't someone just make a new langauge thats just as powerful but without the hassle lol.

Pretty much every language since C was an attempt to do just that.