#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>

#include <signal.h>

void handler(int sig, siginfo_t *extra, void *cruft) {
	if (sig == SIGIO) {
		fprintf(stderr,"signal: %d errno: %d fd: %d\n",extra->si_signo,extra->si_errno,extra->si_fd);
	} 
}

int main(void)
{
int fd;
int insock;
int on = 1;
socklen_t addrlen;
struct sigaction sa;
struct sockaddr_in addr_in;
struct sockaddr_in addr_other;

sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
sa.sa_sigaction = handler; 
sa.sa_flags = SA_SIGINFO;
sigaction(SIGIO, &sa, NULL);

addr_in.sin_family = AF_INET;
addr_in.sin_port = htons(9753);
addr_in.sin_addr.s_addr = htonl(INADDR_ANY);

insock = socket(PF_INET,SOCK_STREAM,0);
setsockopt(insock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
bind(insock, (struct sockaddr *) &addr_in, sizeof(addr_in));
listen(insock, 1);
if ((fd = accept(insock,(struct sockaddr *) &addr_other, &addrlen)) == -1) {perror("fault");} 
fprintf(stderr,"fd is %d\n",fd);
if (fcntl(fd, F_SETFL, fcntl (fd,F_GETFL) | O_NONBLOCK | O_ASYNC) == 1) {perror("fault");}
if (fcntl(fd,F_SETOWN,getpid()) == -1) {perror("fault");}
fprintf(stderr,"accepted connection\n");

do {
} while(1);

}