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.