File permissions·165
165
--xrw-r-x
---xrw-r-x

chmod 165 — the --xrw-r-x permission

165 is --xrw-r-x. The owner gets x, and everyone else gets rx.

Who can do what

Three rows for owner, group and others; three columns for read, write and execute. On a folder that last one means the right to go inside.

ReadWriteExecute
Owner1··
Group6·
Others5·

On a folder the execute bit means going inside. With read but no execute you can list the names yet open nothing in it.

Symbolic
--xrw-r-x
ls -l (file)
---xrw-r-x
ls -l (directory)
d--xrw-r-x
chmod symbolic form
chmod u=x,g=rw,o=rx
Command
chmod 165 <file>
Binary
001110101
Decimal
117
umask (directory)
612
umask (file)
Not reachable — new files never start with the execute bit

One digit away

How to read this

  • Read is 4, write 2, execute 1; add them for one digit. 7 is 4+2+1, 5 is 4+1.
  • The digits are owner, group, others, left to right.
  • umask is what gets taken away: from 777 for directories, from 666 for files.
  • Special bits (setuid 4000, setgid 2000, sticky 1000) add a fourth digit in front — /tmp is 1777.

Frequently asked questions

Q. What does chmod 165 mean?

It is --xrw-r-x. ls -l shows a file as ---xrw-r-x and a directory as d--xrw-r-x.

Q. How is 165 written in rwx form?

It is the same as chmod u=x,g=rw,o=rx.

Q. What can other people do with 165?

They get r-x.

Q. Which umask produces 165?

612 for directories. For files it cannot be reached by umask alone, since new files never carry the execute bit.