F_OK(readable): 0
errno: 0
R_OK(readable): 0
errno: 0
X_OK(readable): -1
errno: 13
W_OK(readable): -1
errno: 13

F_OK(writeable): 0
errno: 0
R_OK(writeable): -1
errno: 13
X_OK(writeable): -1
errno: 13
W_OK(writeable): 0
errno: 0

F_OK(allaccess): 0
errno: 0
R_OK(allaccess): 0
errno: 0
X_OK(allaccess): 0
errno: 0
W_OK(allaccess): 0
errno: 0

F_OK(forbidden): 0
errno: 0
R_OK(forbidden): -1
errno: 13
X_OK(forbidden): -1
errno: 13
W_OK(forbidden): -1
errno: 13

F_OK(nonexistent): -1
errno: 2
R_OK(nonexistent): -1
errno: 2
X_OK(nonexistent): -1
errno: 2
W_OK(nonexistent): -1
errno: 2