permissions:
...
r Read bits.
s Set-user-ID and set-group-ID on execution bits.
t Sticky bit.
w Write bits.
x Execute/search bits.
X The execute/search bits if the file is a directory or any
of the execute/search bits are set in the original (unmodi-
fied) mode. Operations with the perm symbol `X' are only
meaningful in conjunction with the op symbol `+', and are
ignored in all other cases.
u User permission bits in the mode of the original file.
g Group permission bits in the mode of the original file.
o Other permission bits in the mode of the original file.
...
此外还有不同的 flags:
arch set the archived flag
opaque set the opaque flag (owner or superuser only)
nodump set the nodump flag (owner or superuser only)
sappnd set the system append-only flag (superuser only)
schg set the system immutable flag (superuser only)
uappnd set the user append-only flag (owner or superuser only)
uchg set the user immutable flag (owner or superuser only)
...
新发行的版本中还有 ACL 。。。 具体怎样还没了解。
