printing an address with Write function

[TuRu87]

Hello,

So I'm trying to create a malloc function and want to print some addresses to check on them and be able to visualize a little what's going on but I can't use printf cause it messes around my process's heap which I don't want.
I was wondering how I could use the write function to print an address recovered from a pointer.
Thanks

[JosAH]

Why does printf("%p", your_pointer) mess around in the heap?

kind regards,

Jos

[TuRu87]

because it uses the malloc from the standard library. In fact when I execute the following code:

printf("%p\n", sbrk(0));
printf("%p\n", sbrk(0));

I get:

0x804979c
0x804c000

Which means that when the 1st printf is executed the 'break' indicating the end of the heap is moved (I think).

[JosAH]

What happens if you first execute "free(malloc(4096))" first?

kind regards,

Jos

[donbock]

because it uses the malloc from the standard library. In fact when I execute the following code:

printf("%p\n", sbrk(0));
printf("%p\n", sbrk(0));

I get:

0x804979c
0x804c000

Which means that when the 1st printf is executed the 'break' indicating the end of the heap is moved (I think).

What sort of behavior caused you to instrument your code like this?