Question

I know for malloc sbrk is the system call invoked ,Similarly What is the system cal invoked when i write to a malloed memory(heap memory)

int main

{

  /* 10 byte of heap memory allocated */
  char *ptr = malloc(5);


  ptr[0] = 10;  // **What is the system call invoked for 
                    writing into this heap memory** ?????


}

Answer 1

There are no system call involved in this case. Ask you compiler to generate assembly so that you can see that there is only some MOV instructions there. Or you can use a debugger to see the assembly