2.1.3 File Permission Access Modes
File permission access modes consist of combinations of the following eleven modes:
Read mode
r
Write mode (mutually exclusive to
a
)
w
Append mode (mutually exclusive to
w
)
a
File locking mode
k
Discrete profile execute mode
px
Discrete profile execute mode—clean exec
Px
Unconstrained execute mode
ux
Unconstrained execute mode—clean exec
Ux
Inherit execute mode
ix
Allow
PROT_EXEC
with
mmap(2)
calls
m
Link mode
l
Read Mode (r)
Allows the program to have read access to the resource. Read access is required
for shell scripts and other interpreted content and determines if an executing process
can core dump or be attached to with
ptrace(2)
(
ptrace(2)
is used by utilities
like
strace(1)
,
ltrace(1)
, and
gdb(1)
).
Write Mode (w)
Allows the program to have write access to the resource. Files must have this per-
mission if they are to be unlinked (removed).
Append Mode (a)
Allows a program to write to the end of a file. In contrast to the
w
mode, the append
mode does not include the ability to overwrite data, to rename, or to remove a file.
Profile Components and Syntax
17
