io_init()
void io_init()
io_init(){/* * Close the file descriptors if they are open.  The idea is that we * will be able to support a re-initialization if sent a SIGHUP. */	if(ttyfd>=0){		close(ttyfd);		ttyfd = -1;	}	if(sock>=0){		close(sock);		sock = -1;	}	if(udpsock>=0){		close(udpsock);		udpsock = -1;	}#ifdef USE_ICMP	if(icmpsock>=0){		close(icmpsock);		icmpsock = -1;	}#endif/* * The bzero is not strictly required - it simply zeros out the * address structure.  Since both to and from are static, they are * already clear. */	bzero( (char *)&to, sizeof(struct sockaddr) );	to.sin_family = AF_INET;	bzero( (char *)&from, sizeof(struct sockaddr) );	from.sin_family = AF_INET;	bzero( (char *)&udpbind, sizeof(struct sockaddr) );	udpbind.sin_family = AF_INET;}