Stride through the heap until segfault

x.c

// Linux only.
// gcc x.c  &&  ./a.out
//
// Example run on a 64-bit system:
//   0x56339fd78000 0x56339f74601a
//   0x56339fd78000 0x56339f74601b
//   0x56339fd78000 0x56339f74601c
//   0x56339fd78000 0x56339f74601d
//   0x56339fd78000 0x56339f74601e
//   ...
//   0x56339fd78000 0x56339f746ffc
//   0x56339fd78000 0x56339f746ffd
//   0x56339fd78000 0x56339f746ffe
//   0x56339fd78000 0x56339f746fff
//   0x56339fd78000 0x56339f747000
//   zsh: segmentation fault  ./a.out

#include<unistd.h>
#include<stdio.h>

char a = 0;
char end_of_data_segment = 0;

int main(void) {
  int* program_break = sbrk(0);
  char* curr = &end_of_data_segment;
  while (1) {
    printf("%p %p\n", program_break, curr);
    fflush(stdout);
    a = *curr;
    ++curr;
  }
  return 0;
}