Getting value from an address.

[metodski]

I have a question. How should i go about getting a value from an address ? In my case i have a health address and i want to get the value so i can use it for comparison with some other value. Is there any way to do that ?

[black0utCpp]

Do you know CheatEngine excellent Software !

[5769854332]

there are ways to do this, of course.
If you use C/C++ you could do inline asm (there may be mistakes, because im new to all this):


in intel syntax it would be something like this:

 Spoiler

DWORD my_addr=0x403000;  //the address where the data is stored
DWORD my_var;   //the varaiable to store the data

__asm("mov eax, my_addr");
__asm("mov my_var, DWORD PTR DS:[eax]");

in AT&T:

 Spoiler

DWORD my_addr=0x403000;  //the address where the data is stored
DWORD my_var;   //the varaiable to store the data

__asm("movl _my_addr,%eax");
__asm("movl (%eax), _my_var");
//as far as I know, my_var and my_addr must be [I]global[/I] variables

or use pointers:

 Spoiler

PHP Code:

#include <iostream>
using namespace std;

int main() {

int* ptr=(int*) 0x403000;

cout <<"address is: " << ptr << endl;
cout << "value is: " << *ptr << endl;
} 


you can also use memcpy, of course.

 Spoiler

PHP Code:

#include <iostream>
#include <strings.h>

using namespace std;
int main() {

char buf[10];
int my_size=4; //=> 4 bytes
const void* my_addr= (const void*) 0x403000;

memcpy(buf, my_addr, my_size);

cout << "my Value: " << buf;
} 


[metodski]

Thanks but all of those give me some access violation .

Unhandled exception at 0x5254cac4 (msvcr100d.dll) in Trainer.exe: 0xC0000005: Access violation reading location 0x03c870a0.

[5769854332]

well, the above methods only work, if you read or write to memory of your own process (i should have mentioned that earlier, sry).

If you want to read or write memory of another process, then -in order to prevent access violations- you need ReadProcessMemory() and WriteProcessMemory(). Use Google, then you will find many example programs that use those functions.