chown command in Linux

Syntax

The basic syntax of the chown command: 

chown [options] new-owner File/Directory

 

The new-owner argument describes the new user or group of the file or directory, and the file/directory specifies the file in which you want the ownership to be changed.

Options of the chown command in linux

Commonly used options in the chown command to customise its behaviour include:

• -R: It recursively changes the ownership of a file/directory and all its contents. 
  For example, to change ranDir ownership and its content to the user Dhruv, we will run the following command:
   

chown -R Dhruv ranDir

 

• -h: It allows you to directly change the ownership of a symbolic link instead of modifying the file it refers to. When we use chown on a symbolic link, it changes the ownership of the file that the link points to, not the link itself. But the -h option allows us to change the link ownership. 
  For example
   

chown -h dhruv Mylink

The above command will change the ownership of the symbolic link Mylink to user dhruv.

• -v (Verbose): It operates in verbose mode. This means it displays detailed information about the changes made, showing each file or directory affected by the ownership modification. 
  For example

chown -v newowner:newgroup Ninja.txt

• c(Changes): It is used to report only when a change is made. It is similar to verbose mode but provides condensed information, showing output only for files or directories where ownership modifications occurred.
  For example

chown -c newowner:newgroup Ninja1.txt Ninja2.txt

 

• --reference=file: It copies another file's ownership to the specified file. For example, if we want the file Ninja1.txt to have the same owner and group as the file Ninja2.txt, run the following command:
   

chown --reference=Ninja1.txt Ninja2.txt

File Permission Types

Three sets of permission types through which permission of file manages are: 

• User: file permission which applies to the user who owns the file. 
   
• group: file permission which applies to the group that owns the file or directory.
   
• other: file permission which applies to all other users on the system.

List the UID, GID, and Groups

Let's see some commands to display UID, GID and Groups in the Linux System.

using groups command

For listing all the existing groups in the Linux system, the groups command is used:

Output:

using id command

For listing all the UID and GID of their existing user or groups, the id command is used:

Output:

Ownership and Permissions in Linux

File ownership and permission in Linux play an important role in providing access control. File ownership means the users or group allowed to access the file/directory, while permission is for the access to read, write, and execute by a user or group in the file/directory.

In Linux, Every file has its owner or group. The owner is the one who created the file or directory, and the group is a common set of users who shares the common permissions to access the file. Ownership and permissions go hand in hand to determine who can access and modify the file or directory. 

Types of ownership and permissions in Linux

 There are 3 types of permissions that we should know:
 

1. read: it allows the user to view all the contents available in the file.
    
2. write: it allows the user to modify the contents available in the file.
    
3. execute: it allows the user to run the contents of a file like a program.
    

chown command in linux allows us to control the file permissions and manage its ownership in Linux. Using the chown command we can specify the files or directories to the user or group to which we want to give permissions and ownership. Also combined with other commands, the chown command can be used to manage file permissions and access control.

Managing file permissions and access control

Let's see with the help of commands, how to manage files, permissions and access control.

Providing Access 

We can provide access to the file to a group of users by using the below commands:

chown :my_group ninjaFile

 

Now, use the chmod command to set up permissions like this:

chmod g+rwx ninjaFile

 

This above command gives read, write and execute permission for the file.

Transferring Ownership

Let's see, how we can transfer the file ownership from one user to another user by performing the below commands:

chown ninja2 myCpp.txt

 

Now, use the chmod command to give permissions to the new user, i.e. ninja2

chmod u+rw myCpp.txt

 

This above command gives read and writes permission to the ninja2 user.

Frequently Asked Questions

What is chown R in Linux?

In Linux, the -R option with the chown command stands for "recursive." When you use chown -R, it recursively changes the ownership of a directory and its contents.

Can we use chown command in linux to change file permissions?

The chown command is to change file ownership only; we could not change the file permission using it. For changing file permission, we need to use chmod command, and you can refer to the above examples to know more.

Common applications for chown command in Linux?

Some common applications of chown include it is used to transfer ownership of files or directories between different users and changing the ownership of files and directories. It is also used to provide access to a file or directories to specific users or groups.

Are any precautions to be taken while using chown command in Linux?

Yes, it's important when using the chown command not to change the file ownership or give access to a user or group by accident, as it can lead to problems. Also, always check the command for any mistake in the naming of the file or group; otherwise, your privacy will be at stake.

Conclusion

This article has covered the syntax and options of the chown command. We've discussed examples, the importance of file ownership and permissions in Linux, and how access control to files and directories works.

I hope you enjoyed reading this article. Here are some more related articles:

• Linux Operating System 
• Linux - Commands List 
• file management commands
• Types of Unix Operating System 
• wget command in linux
   

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