#include <sys/signalfd.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>

#define handle_error(msg)				\
  do { perror(msg); exit(EXIT_FAILURE); } while (0)

/*
  Code taken from signalfd(2) man page and slightly modified.
 */

int
main(int argc, char *argv[])
{
  sigset_t mask;
  int sfd;
  struct signalfd_siginfo fdsi;
  ssize_t s;
  
  sigemptyset(&mask);
  sigaddset(&mask, SIGINT);
  sigaddset(&mask, SIGQUIT);
  sigaddset(&mask, SIGPIPE);
  sigaddset(&mask, SIGSYS);
  sigaddset(&mask, SIGIO);
  sigaddset(&mask, SIGURG);
  sigaddset(&mask, SIGTERM);
  sigaddset(&mask, SIGUSR1);
  sigaddset(&mask, SIGUSR2);
  
  /* Block signals so that they aren't handled
     according to their default dispositions */
  
  if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
    handle_error("sigprocmask");
  
  sfd = signalfd(-1, &mask, 0);
  if (sfd == -1)
    handle_error("signalfd");
  
  for (;;) {
    s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));
    if (s != sizeof(struct signalfd_siginfo))
      handle_error("read");
    
    switch(fdsi.ssi_signo)
      {
      case SIGINT:
	printf("Got SIGINT\n");
	break;
      case SIGQUIT:
	printf("Got SIGQUIT\n");
	break;
      case SIGPIPE:
	printf("Got SIGPIPE\n");
	break;
      case SIGSYS:
	printf("Got SIGSYS\n");
	break;
      case SIGIO:
	printf("Got SIGIO\n");
	break;
      case SIGURG:
	printf("Got SIGURG\n");
	break;
      case SIGTERM:
	printf("Got SIGTERM\n");
	break;
      case SIGUSR1:
	printf("Got SIGUSR1\n");
	break;
      case SIGUSR2:
	printf("Got SIGUSR2\n");
	break;
      default:
	printf("Got unexpected signal!?\n");
	break;
      }
  }
}