_                    _
  ___ | |__   __ _ _______ | |_
 / _ \| '_ \ / _` |_  / _ \| __|
| (_) | | | | (_| |/ / (_) | |_
 \___/|_| |_|\__,_/___\___/ \__|

permissions — assign and modify file permissions.

Permission types can be an octal number or an symbols.

| |
None | 0 |
Execution | 1 | x
Write | 2 | w
Read | 4 | r
Permissions can be assigned by adding the octal values or assigning the symbols.

  • Write (2) + Read (4) = 6
  • w+r

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When a user creates a file or directory, it's assigned as the owner, and its main group is assigned as the owner group.

The permissions are displayed with the following format: owner, group owner, other groups, all users. Example:

$ whoami
user1
$ groups
users
$ ls -l
-rwxr-xr-- 1 user1 users .... file1
  • user1 is the owner and has permissions to read, write and execute.
  • The users corresponding to the group users have permissions to read and execute.
  • Users from other groups have permissions to read.
  • The corresponding octal value is 754.

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Users can modify permissions on files if they have write permissions.

Modifies the owner of a file or directory.

Modify user : chown username filename
Modify user and group : chown username:groupname filename
To modify recursively, use -R.

Changes the permissions on a file or directory as explained in Sx TYPES. To assign (=), add (+) or remove (-) permissions, the who symbols can be used for user (u), group (g) or other (o).

|
Octal assignment | chmod 755 file
Add write permissions for group | chmod g+w file
Assign read and write permissions to others | chmod o=rw file
Remove read permission to other groups and users | chmod o-r file
When using the octal value or assigning using =, the previous permissions are overwritten.

chgrp -R GROUP DIRECTORY

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user_management

- OpenBSD manpages: chmod(1) , chgrp(1) , chown(8)

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This document applies to: OpenBSD 7.8 , linux | Created:2026-03-26|Updated:2026-03-26|