S_ISDIR
#define S_ISDIR(m) ((m & 0170000) == 0040000) /* directory */
#define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
#define S_ISDIR(MODE) (((MODE) & S_IFMT) == S_IFDIR)
#define S_ISDIR(MODE) (((MODE) & _S_IFMT) == _S_IFDIR)
# define S_ISDIR(mode) (((mode) & (_S_IFMT)) == (_S_IFDIR))
#define S_ISDIR(a) (((a) & _S_IFMT) == _S_IFDIR)
#define S_ISDIR(a) (((a) & S_IFMT) == S_IFDIR)
#define S_ISDIR(a) (((a) & S_IFMT) == S_IFDIR)
#define S_ISDIR(a) (((a) & S_IFMT) == S_IFDIR)
#define S_ISDIR(a) (((a) & S_IFMT) == S_IFDIR)
#define S_ISDIR(a) (((a) & S_IFMT) == S_IFDIR)
#define S_ISDIR(m) (((m) & 0170000) == 0040000) /* directory */