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

void handler(int)
{
    puts("I caught a segfault!");

    struct sigaction sa;
    sa.sa_handler = SIG_DFL;
    sigaction(SIGSEGV, &sa, NULL);
}

int main()
{
    struct sigaction sa;
    sa.sa_handler = handler;
    sigaction(SIGSEGV, &sa, NULL);

#pragma GCC diagnostic ignored "-Wnonnull"
    char* str = nullptr;
    memset(str, 0, 2);

    return 0;
}