question on C program

[tekkiram]

Hi,

void my_func();
main() {
int i = 5;
my_funct(); /*- The definition of my_funct has to change the value of I*/
printf("%d",i);
}

void my_funct(void) {
...
}

Please let me know how to do that?
That is, my_funct body has to be written in such a way that it makes changes in the var i.

[rob90]

You ought to pass the i variable as a reference parameter, so my_funct() should be my_funct(int* i) and then you can access that variable by dereferencing it with the * operator

[tekkiram]

Thanks for your reply,

I knew it already,

But here my_func is intentionally written as void function which has no arguments.

It is an interview question.

Experts, pl give a solution.

[rags_to_riches]

Why should we give you a solution to an interview question??? The idea of an interview question is to get an idea of what you know prior to hiring you...if you don't know how to pass by reference in C, and the job requires it, you should not be hired.

[tekkiram]

Why should we give you a solution to an interview question??? The idea of an interview question is to get an idea of what you know prior to hiring you...if you don't know how to pass by reference in C, and the job requires it, you should not be hired.

I told it clearly, this problem not at all related to pass by reference,

my_func has no arguments. It is something related to stack smashing, from my_func stack, we need to find main function stack starting address, from there we need to find address of i, then modifying that value,

I found this qn will be very useful others also,

Anyway thanks for your complement, pl dont consider my CV in your high tech corporate.

What is wrong in asking clarification, this is a forum. Please read the post then reply.

[nonpuz]

That seems a bit complex for a interview question? How are you going to do that on paper without knowing the address to start at?

[Fordy]

>> related to stack smashing

Sorry, but this sails a little to close against the rules we have about the discussion of hacking (C Board - Announcements in Forum : C Programming)

If you disagree please feel free to PM me.