File mode syntax

File modes are described by a nine characters string that follows the same scheme as the ls shell command:

Position Character Meaning
1 - The file owner cannot read it.
r The file owner can read it.
2 - The file owner cannot write it.
w The file owner can write it.
3 - The file owner cannot execute it.
x The file owner can execute it.
S The file owner cannot execute it and the 'setuid' bit is set.
s The file owner can execute it and the 'setuid' bit is set.
4 - The file group cannot read it.
r The file group can read it.
5 - The file group cannot write it.
w The file group can write it.
6 - The file group cannot execute it.
x The file group can execute it.
S The file group cannot execute it and the 'setgid' bit is set.
s The file group can execute it and the 'setgid' bit is set.
7 - Other users cannot read the file.
r Other users can read the file.
8 - Other users cannot write the file.
w Other users can write the file.
9 - Other users cannot execute the file.
x Other users can execute the file.
T Other users cannot execute the file and the 'sticky' bit is set.
t Other users can execute the file and the 'sticky' bit is set.

See also