gistfile1.cpp

static int sock;
	addrinfo *info;
	int Init(const char *addr,int port) {
		addrinfo hints, *res;
		memset(&hints,0,sizeof(addrinfo));
		hints.ai_family = AF_UNSPEC;
		hints.ai_socktype = SOCK_STREAM;
		hints.ai_flags = AI_PASSIVE;
		hints.ai_protocol = 0;
		hints.ai_canonname = NULL;
		hints.ai_addrlen = 0;
		hints.ai_addr = NULL;
		hints.ai_next = NULL;
		char buf[6];
		sprintf(buf,"%d",port);
		printf("%s:%s\n",addr,buf);
		int retv=getaddrinfo(addr,buf,&hints,&res);
		if(retv) {
			std::cout<<gai_strerror(retv);
			errno=EINVAL;
			return errno;
		}
		info=res;
		while(info) {
			if((sock=socket(info->ai_family,info->ai_socktype,info->ai_protocol))==-1) {
				printf("%s\n",strerror(errno));
				info=info->ai_next;
				continue;
			}
			if(bind(sock,info->ai_addr,info->ai_addrlen)) {
				printf("%s\n",strerror(errno));
				close(sock);
				info=info->ai_next;
				continue;
			}
			break;
		}
		if(!info) {
			errno=EINVAL;
			return errno;
		}
		freeaddrinfo(res);
		if(listen(sock,20)) {
			return errno;
		}
		return 0;
	}