Change folder permissions and ownership
I would like the user to have full rights on this folder (as well as all sub-directories and files in it):
currently owned by root. I have found numerous posts (in this forum and elsewhere) on how to do this for files but I can’t find a way to do it for whole folders.
9 Answers 9
Use chown to change ownership and chmod to change rights.
As Paweł Karpiński said, use the -R option to apply the rights for all files inside of a directory too.
Note that both these commands just work for directories too. The -R option makes them also change the permissions for all files and directories inside of the directory.
sudo chown -R username:group directory will change ownership (both user and group) of all files and directories inside of directory and directory itself.
sudo chown username:group directory will only change the permission of the folder directory but will leave the files and folders inside the directory alone.
As enzotib mentioned, you need to use sudo to change the ownership from root to yourself.
Note that if you use chown : (Note the left-out group), it will use the default group for that user.
If you want to change only the group, you can use:
BEWARE of recursively taking ownership of ANY directory. Think before you leap. Don’t be chown copypastin’ from the internet, kids. Just because you want to install a node package and it won’t let you, don’t sudo chown -R just because the fist hit from googling the error message says to. Reckless sudo chown -R -ing can kill your OS.
It needs to be said that using the -R option only applies to files and folders that exist in the directory already. It does NOT apply to future creations. For example, if you create another folder or file as root within the folder you’ve already changed permissions on, you will have the same experiences you’re having now until you chmod\chown them again.
Make the current user own everything inside the folder (and the folder itself):
very helpful for newbies (like me) when don’t know what to type in ‘usergroup’ for sudo chown
If you prefer, this can be done with a GUI as well. You will need to open Nautilus as root to do so. Press Alt + F2 to access the «Run Applications» dialog and enter gksu nautilus
Next, browse to and right click on the folder you would like to modify. Then, select «Properties» from the context menu. You can now select the user or group that you would like to be the «Owner» of the folder as well as the permissions you would like to grant them. Finally, press «Apply Permissions to Enclosed Files» to apply the changes recursively.
Though it seems this does not always work for some operations in a deep folder tree. If it does not work use the appropriate terminal command.
File Permissions in Linux / Unix: How to Read, Write & Change?
Linux is a clone of UNIX, the multi-user operating system which can be accessed by many users simultaneously. Linux can also be used in mainframes and servers without any modifications. But this raises security concerns as an unsolicited or malign user can corrupt, change or remove crucial data. For effective security, Linux divides authorization into 2 levels.
The concept of Linux File permission and ownership is crucial in Linux. Here, we will explain Linux permissions and ownership and will discuss both of them. Let us start with the Ownership.
Click here if the video is not accessible
Linux File Ownership
Every file and directory on your Unix/Linux system is assigned 3 types of owner, given below.
User
A user is the owner of the file. By default, the person who created a file becomes its owner. Hence, a user is also sometimes called an owner.
Group
A user- group can contain multiple users. All users belonging to a group will have the same Linux group permissions access to the file. Suppose you have a project where a number of people require access to a file. Instead of manually assigning permissions to each user, you could add all users to a group, and assign group permission to file such that only this group members and no one else can read or modify the files.
Other
Any other user who has access to a file. This person has neither created the file, nor he belongs to a usergroup who could own the file. Practically, it means everybody else. Hence, when you set the permission for others, it is also referred as set permissions for the world.
Now, the big question arises how does Linux distinguish between these three user types so that a user ‘A’ cannot affect a file which contains some other user ‘B’s’ vital information/data. It is like you do not want your colleague, who works on your Linux computer, to view your images. This is where Permissions set in, and they define user behavior.
Let us understand the Permission system on Linux.
Linux File Permissions
Every file and directory in your UNIX/Linux system has following 3 permissions defined for all the 3 owners discussed above.
- Read: This permission give you the authority to open and read a file. Read permission on a directory gives you the ability to lists its content.
- Write: The write permission gives you the authority to modify the contents of a file. The write permission on a directory gives you the authority to add, remove and rename files stored in the directory. Consider a scenario where you have to write permission on file but do not have write permission on the directory where the file is stored. You will be able to modify the file contents. But you will not be able to rename, move or remove the file from the directory.
- Execute: In Windows, an executable program usually has an extension “.exe” and which you can easily run. In Unix/Linux, you cannot run a program unless the execute permission is set. If the execute permission is not set, you might still be able to see/modify the program code(provided read & write permissions are set), but not run it.
Let’s see file permissions in Linux with examples:
ls – l on terminal gives
Here, we have highlighted ‘-rw-rw-r–‘and this weird looking code is the one that tells us about the Unix permissions given to the owner, user group and the world.
Here, the first ‘–‘ implies that we have selected a file.p>
Else, if it were a directory, d would have been shown.
The characters are pretty easy to remember.
r = read permission
w = write permission
x = execute permission
– = no permission
Let us look at it this way.
The first part of the code is ‘rw-‘. This suggests that the owner ‘Home’ can:
- Read the file
- Write or edit the file
- He cannot execute the file since the execute bit is set to ‘-‘.
By design, many Linux distributions like Fedora, CentOS, Ubuntu, etc. will add users to a group of the same group name as the user name. Thus, a user ‘tom’ is added to a group named ‘tom’.
The second part is ‘rw-‘. It for the user group ‘Home’ and group-members can:
The third part is for the world which means any user. It says ‘r–‘. This means the user can only:
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Changing file/directory permissions in Linux Using ‘chmod’ command
Say you do not want your colleague to see your personal images. This can be achieved by changing file permissions.
We can use the ‘chmod’ command which stands for ‘change mode’. Using the command, we can set permissions (read, write, execute) on a file/directory for the owner, group and the world.
chmod permissions filename
There are 2 ways to use the command –
Absolute(Numeric) Mode in Linux
In this mode, file permissions are not represented as characters but a three-digit octal number.
The table below gives numbers for all for permissions types.
| Number | Permission Type | Symbol |
|---|---|---|
| 0 | No Permission | — |
| 1 | Execute | –x |
| 2 | Write | -w- |
| 3 | Execute + Write | -wx |
| 4 | Read | r– |
| 5 | Read + Execute | r-x |
| 6 | Read +Write | rw- |
| 7 | Read + Write +Execute | rwx |
Let’s see the chmod permissions command in action.
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In the above-given terminal window, we have changed the permissions of the file ‘sample to ‘764’.
.png)
‘764’ absolute code says the following:
- Owner can read, write and execute
- Usergroup can read and write
- World can only read
This is shown as ‘-rwxrw-r–
This is how you can change user permissions in Linux on file by assigning an absolute number.
Symbolic Mode in Linux
In the Absolute mode, you change permissions for all 3 owners. In the symbolic mode, you can modify permissions of a specific owner. It makes use of mathematical symbols to modify the Unix file permissions.
Adds a permission to a file or directory
Sets the permission and overrides the permissions set earlier.
The various owners are represented as –