if (!force && isatty(ofd)) {
if (method != M_COMPRESS && !force && isatty(ofd)) {
compress(in, out, method, bits)	const char *in;	const char *out;	register struct compressor *method;	int bits;{	register int ifd;	int ofd;	register void *cookie;	register size_t nr;	u_char buf[Z_BUFSIZE];	int error;	error = 0;	cookie  = NULL;	if ((ofd = open(out, O_WRONLY|O_CREAT, S_IWUSR)) < 0) {		if (verbose >= 0)			warn("%s", out);		return -1;	}	if (!force && isatty(ofd)) {		if (verbose >= 0)			warnx("%s: won't write compressed data to terminal",			      out);		return -1;	}	if ((ifd = open(in, O_RDONLY)) >= 0 &&	    (cookie = (*method->open)(ofd, "w", bits)) != NULL) {		while ((nr = read(ifd, buf, sizeof(buf))) > 0)			if ((method->write)(cookie, buf, nr) != nr) {				if (verbose >= 0)					warn("%s", out);				error++;				break;			}	}	if (ifd < 0 || close(ifd) || nr < 0) {		if (!error && verbose >= 0)			warn("%s", in);		error++;	}	if (cookie == NULL || (method->close)(cookie)) {		if (!error && verbose >= 0)			warn("%s", out);		error++;		(void) close(ofd);	}	return error? -1 : 0;}