mastercmp
if ((ftsp = fts_open(argv, fts_options, mastercmp)) == NULL)
static int mastercmp (const FTSENT *FTS_CONST *, const FTSENT *FTS_CONST *);
fts_open(argv, options, f_nosort ? NULL : mastercmp)) == NULL)
static int mastercmp(const FTSENT * const *, const FTSENT * const *);