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

void sigcatcher(int sig)
{
    fprintf(stderr, "The sigcatcher caught signal %d\n", sig);
    pthread_exit(0);
}

void *sig_thread(void *p)
{
    sigset_t sigs_to_catch;

    /* Unblock SIGINT */
    sigemptyset(&sigs_to_catch);
    sigaddset(&sigs_to_catch, SIGINT);
    pthread_sigmask(SIG_UNBLOCK, &sigs_to_catch, NULL);

    fprintf(stderr, "sent a SIGINT (ctrl-C) to this process(%d)\n", getpid());
    sleep(60);

    return (NULL);
}

extern int main(void)
{
    pthread_t thread;
    sigset_t sigs_to_block;
    struct sigaction action;

    /* Block all signals */
    sigfillset(&sigs_to_block);
    pthread_sigmask(SIG_BLOCK, &sigs_to_block, NULL);
    /* Set a signal handler */
    action.sa_handler = sigcatcher;
    action.sa_flags = 0;
    sigaction(SIGINT, &action, NULL);

    pthread_create(&thread, NULL, sig_thread, NULL);

    /* wait until thread is finished */
    pthread_join(thread, NULL);

    return 0;
}