Use of exit() function

Question

I want to know how and when can I use the exit() function like the program in my book:

#include

void main()
{
    int goals;
            


        

Answer 1

on unix like operating systems exit belongs to group of system calls. system calls are special calls which enable user code (your code) to call kernel code. so exit call makes some OS specific clean-up actions before returning control to OS, it terminates the program.

#include 

// example 1
int main(int argc, char *argv){
  exit(EXIT_SUCCESS);
}

// example 2
int main(int argc, char *argv){
  return 0;
}

Some compilers will give you the same opcode from both of these examples but some won't. For example opcode from first function will not include any kind of stack positioning opcode which will be included in the second example like for any other function. You could compile both examples and disassemble them and you will see the difference.

You can use exit from any part of your code and be sure that process terminates. Don't forget to include integer parameter.