Segmentation

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

void handler(int s)
{
    if (s == SIGBUS) printf("now got a bus error signal\n.");
    if (s == SIGSEGV) printf("now got a segmentation violation signal\n.");
    if (s == SIGILL) printf("now got an illegal instruction signal\n.");
    if (s == SIGPOLL) printf("now got a SIGPOLL signal\n.");
    exit(1);
}

int main(int argc, char** argv)
{
    int *p = NULL;
    signal(SIGBUS, handler);
    signal(SIGSEGV, handler);
    signal(SIGILL, handler);
    signal(SIGPOLL, handler);
    *p = 0;
    return 0;
}

now got a segmentation violation signal