Representation of type and permissions
The first column of ls -l consists of 10 characters (possibly followed by a dot) and represent the entries' type and permissions.
Type
The first character represents the type of the entry listed.
The meaning of the first character is:
- | Regular file |
b | Block special file, typically (always?) found under /dev, for example /dev/sda or /dev/sr0 |
c | Character special file, typically (always?) found under /dev, for example /dev/tty0. |
d | Directory |
l | Symbolic link |
p | FIFO («pipe») |
s | Socket |
w | Whiteout |
Permission bits
The next nine characters define the permissions for the user (first three characters), the users of the group (next three characters) and «everyone else» (last three characters).
The meaning of the three characters is:
r | readable (always the first character) |
w | writable (always the second character) |
x | executable (always the third character) |
S | Entry is not executable, setuid (first group), setgid is set (second group) |
s | Same as S, but entry is executable |
T | Sticky bit is set, but not executable (only as last character of the last group) |
t | Same as T and is executable |
Dot
If the permission bits are followed by a dot (for example
-rwxr-x-r-x.), it indicates a file with a
SELinux context.
Sample script
The following script creates a few files and directories whose name corresponds to their permission bits. It then uses ls -l to display the permission bits:
function setMod {
touch b/f-$1
chmod $1 b/f-$1
mkdir b/d-$1
chmod $1 b/d-$1
}
rm -rf b
mkdir b
setMod 0000
setMod 0001
setMod 0002
setMod 0003
setMod 0004
setMod 0005
setMod 0006
setMod 0007
setMod 1700
setMod 2700
setMod 3700
setMod 4700
setMod 5700
setMod 6700
setMod 7700
setMod 1770
setMod 2770
setMod 3770
setMod 4770
setMod 5770
setMod 6770
setMod 7770
ls -l b | awk '{print $1 " " $9}'
# d---------. d-0000
# d--------x. d-0001
# d-------w-. d-0002
# d-------wx. d-0003
# d------r--. d-0004
# d------r-x. d-0005
# d------rw-. d-0006
# d------rwx. d-0007
# drwx-----T. d-1700
# drwxrwx--T. d-1770
# drwx--S---. d-2700
# drwxrws---. d-2770
# drwx--S--T. d-3700
# drwxrws--T. d-3770
# drws------. d-4700
# drwsrwx---. d-4770
# drws-----T. d-5700
# drwsrwx--T. d-5770
# drws--S---. d-6700
# drwsrws---. d-6770
# drws--S--T. d-7700
# drwsrws--T. d-7770
# ----------. f-0000
# ---------x. f-0001
# --------w-. f-0002
# --------wx. f-0003
# -------r--. f-0004
# -------r-x. f-0005
# -------rw-. f-0006
# -------rwx. f-0007
# -rwx------. f-1700
# -rwxrwx---. f-1770
# -rwx--S---. f-2700
# -rwxrws---. f-2770
# -rwx--S---. f-3700
# -rwxrws---. f-3770
# -rws------. f-4700
# -rwsrwx---. f-4770
# -rws------. f-5700
# -rwsrwx---. f-5770
# -rws--S---. f-6700
# -rwsrws---. f-6770
# -rws--S---. f-7700
# -rwsrws---. f-7770