while ((ch = getopt(argc, argv, "benstuv")) != -1)
while ((ch = getopt(argc, argv, "benstuv")) != EOF)
main(argc, argv)	int argc;	char *argv[];{	extern int optind;	int ch;	setlocale(LC_ALL, "");	while ((ch = getopt(argc, argv, "benstuv")) != -1)		switch (ch) {		case 'b':			bflag = nflag = 1;	/* -b implies -n */			break;		case 'e':			eflag = vflag = 1;	/* -e implies -v */			break;		case 'n':			nflag = 1;			break;		case 's':			sflag = 1;			break;		case 't':			tflag = vflag = 1;	/* -t implies -v */			break;		case 'u':			setbuf(stdout, (char *)NULL);			break;		case 'v':			vflag = 1;			break;		default:			(void)fprintf(stderr,			    "usage: cat [-benstuv] [-] [file ...]\n");			exit(1);		}	argv += optind;	if (bflag || eflag || nflag || sflag || tflag || vflag)		cook_args(argv);	else		raw_args(argv);	if (fclose(stdout))		err(1, "stdout");	exit(rval);}