chmod 000
chmod 000 is ---------.
What 000 grants
| Who | Digit | Permissions | Adds up as |
|---|---|---|---|
| Owner | 0 | no access | 0 |
| Group | 0 | no access | 0 |
| Others | 0 | no access | 0 |
When 000 is the right answer
No access for anyone, including the owner. The owner can still change the permissions back, because that right comes from ownership rather than from the permission bits — which is the detail that surprises people the first time they try it.
The command
chmod 000 filename
chmod -R 000 directory/Note that nobody has the execute bit here, so this value cannot be used on a directory that anyone needs to enter. On a directory, execute grants traversal rather than the right to run something.
How it is written elsewhere
| Octal | 000 |
| Symbolic | --------- |
As a file in ls -l | ---------- |
As a directory in ls -l | d--------- |
| Binary | 000 000 000 |
| World-writable | No |
Frequently asked questions
What does chmod 000 mean?
It sets owner to no access, group to no access, others to no access. In symbolic notation that is ---------.
How do I apply 000?
Run chmod 000 filename. Add -R to apply it to a directory and everything inside, though be careful: a recursive numeric chmod marks every file the same way, which is rarely correct for a mixed tree of files and directories.
Is 000 safe?
It grants no write access outside the owner, so it is a reasonable setting as long as the owner is the account you intend.
What is 000 in symbolic notation?
---------. Written as ls -l shows it, with a leading file-type character, an ordinary file would appear as ---------- and a directory as d---------.