buffer-overflow.c

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

#define BUFFER_SIZE 32


void signal_handler_seg_fault(int sig) {
    printf("Segmentation fault, accessing memory in page not mapped by process pid %d\n", getpid());
    exit(1);
}

int main()
{
    int a = 0;
    char buffer[BUFFER_SIZE];
    printf("Difference: %ld bytes\n", (char*)&a - buffer);
    signal(SIGSEGV, signal_handler_seg_fault);
    gets(buffer);
    printf("Data: %s\n", buffer);
    printf("Value of a: %d\n", a);
    return 0;
}