nxtfile
FILE *nxtfile(int, char **, char **, char *, int);
while ((inf = nxtfile(argc, argv, &fname, ohbuf, 0)) != NULL) {
while ((inf = nxtfile(argc, argv, &fname, ohbuf, 0)) != NULL) {
while ((inf = nxtfile(argc, argv, &fname, ohbuf, 0)) != NULL) {
if ((fbuf[j] = nxtfile(argc, argv, &fname, ohbuf, 1)) != NULL) {