file-ownership.md

file-ownership

Introduction

Linux files and directories always belong to a user and group. That is what we call ownership.
If this can be boring to new users, remember that this is a huge part of what makes Linux as secured as it is.

Check current ownership

Check ownership in the current directory:

ls -l

Example output:

ultimatebyte@game:~$ ls -l
total 32
drwxr-xr-x 5 ultimatebyte ultimatebyte 4096 Jan 29 22:26 lgsm
drwxr-xr-x 5 ultimatebyte ultimatebyte 4096 Jan 29 22:23 log
drwxr-xr-x 4 ultimatebyte ultimatebyte 4096 Jan 29 22:26 serverfiles
drwxr-xr-x 8 ultimatebyte ultimatebyte 4096 Jan 29 22:26 Steam
drwxr-xr-x 5 ultimatebyte ultimatebyte 4096 Jan 29 22:24 steamcmd
-rwxr-x--- 1 ultimatebyte ultimatebyte 5691 Jan 30 01:14 twserver

Syntax of the output is:

• d for directory or - for file
• user, then group, then others permissions
• number specifies the number of links or directories inside of a directory
• The user that owns the file, or directory
• The group that file or directory belongs to
• The size in bytes
• The date of last modification
• The name of the file

Check ownership from all files and hidden files of any directory

ls -al /path/to/file/or/dir

Sample output:

ultimatebyte@game:~$ ls -al /home/ultimatebyte
total 132
drwxr-xr-x 11 ultimatebyte ultimatebyte  4096 Feb  2 07:36 . # Ownership from the current given dir
drwxr-xr-x 22 root         root          4096 Feb  2 07:36 .. # Ownership from the parent dir
-rw-------  1 ultimatebyte ultimatebyte 49744 Feb 12 03:04 .bash_history
-rw-r--r--  1 ultimatebyte ultimatebyte   220 Apr 15  2016 .bash_logout
-rw-r--r--  1 ultimatebyte ultimatebyte  3515 Apr 15  2016 .bashrc
drwxr-xr-x  4 ultimatebyte ultimatebyte  4096 Jan 15 23:26 .config
drwxr-xr-x  5 ultimatebyte ultimatebyte  4096 Jan 29 22:26 lgsm
drwxr-xr-x  3 ultimatebyte ultimatebyte  4096 Jan 14 18:10 .local
drwxr-xr-x  5 ultimatebyte ultimatebyte  4096 Jan 29 22:23 log
-rw-------  1 ultimatebyte ultimatebyte  1005 Jan 30 01:14 .nano_history
-rw-r--r--  1 ultimatebyte ultimatebyte   675 Apr 15  2016 .profile
-rw-r--r--  1 ultimatebyte ultimatebyte    66 Sep  1 17:43 .selected_editor
drwxr-xr-x  4 ultimatebyte ultimatebyte  4096 Jan 29 22:26 serverfiles
drwxr-xr-x  3 ultimatebyte ultimatebyte  4096 Jan 15 01:40 .steam
drwxr-xr-x  8 ultimatebyte ultimatebyte  4096 Jan 29 22:26 Steam
drwxr-xr-x  5 ultimatebyte ultimatebyte  4096 Jan 29 22:24 steamcmd
-rwxr-x---  1 ultimatebyte ultimatebyte  5691 Jan 30 01:14 twserver
-rw-r--r--  1 ultimatebyte ultimatebyte    29 Jan 30 02:17 .tw-server.lock

All these commands require elevated privileges!

Change owner

Change owner from files or directories

Command

chown

As usual, chown --help will provide you with all available arguments

Single file syntax

chown newowner /path/to/file/or/directory

Recursive syntax (include sub files and directories)

chown -R newowner /path/to/directory

Example

chown -R myuser /home/myuser

Group ownership

Change group ownership on files or directories

Command

chgrp

As usual, chgrp --help will provide you with all available arguments

Single file syntax

chgrp newgroup /path/to/dir/or/file

Recursive syntax (include sub files and directories)

chgrp -R newgroup /path/to/dir/

User and group ownership

Change user and/or ownership for files and directories at the same time

Command

chown

As usual, chown --help will provide you with all available arguments

Single file command

chown user:group /path/to/dir/or/file

Recursive

chown -R user:group /path/to/dir

Example:

chown -R myuser:myuser /home/myuser