fts_open
fts = fts_open(paths, FTS_LOGICAL | FTS_NOCHDIR, NULL);
f = fts_open((char * const *)argv, FTS_PHYSICAL | FTS_NOCHDIR,
FTS *fts_open(char * const *, int,
fts = fts_open(root, FTS_LOGICAL | FTS_NOCHDIR, NULL);