file-ownership

Last updated 6 months ago
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 secure 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
ftp-scp
firewalls