他们有什么不为人知的?从ls
手册页:
The next three fields are three characters each: owner permissions, group
permissions, and other permissions. Each field has three character positions:
1. If r, the file is readable; if -, it is not readable.
2. If w, the file is writable; if -, it is not writable.
3. The first of the following that applies:
S If in the owner permissions, the file is not exe-
cutable and set-user-ID mode is set. If in the
group permissions, the file is not executable and
set-group-ID mode is set.
s If in the owner permissions, the file is exe-
cutable and set-user-ID mode is set. If in the
group permissions, the file is executable and set-
group-ID mode is set.
x The file is executable or the directory is search-
able.
- The file is neither readable, writable, exe-
cutable, nor set-user-ID nor set-group-ID mode,
nor sticky. (See below.)
These next two apply only to the third character in the last
group (other permissions).
T The sticky bit is set (mode 1000), but not execute
or search permission. (See chmod(1) or
sticky(8).)
t The sticky bit is set (mode 1000), and is search-
able or executable. (See chmod(1) or sticky(8).)