How to Use a Recursive Chown on Linux

A recursive chown is a command that allows you to change the ownership of a directory and all of its subdirectories and files. This can be useful when you want to transfer ownership of a large number of files or directories to a different user or group.

Here is the basic syntax for using a recursive chown:

chown -R user:group directory

The -R flag specifies that the chown command should be applied recursively to all subdirectories and files. The user and group arguments specify the user and group that you want to assign as the new owner of the directory and its contents. The directory argument is the path to the directory whose ownership you want to change.

For example, to change the ownership of the /home/user/documents directory and all of its contents to the user bob and the group admins, you would use the following command:

chown -R bob:admins /home/user/documents

You can also use the chown command to change the ownership of a single file by specifying the file’s path instead of a directory path.

There are a few benefits to using a recursive chown:

• It allows you to quickly and easily change the ownership of a large number of files and directories.
• It can be useful when transferring ownership of files and directories to a different user or group.

There are also some risks to consider when using a recursive chown:

• If you accidentally specify the wrong user or group, you could end up changing the ownership of files and directories to the wrong person.
• If you use the chown command on system files or directories, you could cause issues with your operating system. It is generally best to avoid changing the ownership of system files unless you are an experienced user and know what you are doing.

recursive chown examples

To change the ownership of all files and directories in the /var/www/html directory to the user www-data and the group www-data, you would use the following command:

chown -R www-data:www-data /var/www/html

To change the ownership of all files and directories in the /home/user directory to the user user and the group users, you would use the following command:

chown -R user:users /home/user

To change the ownership of all files and directories in the current directory to the user bob and the group developers, you would use the following command:

chown -R bob:developers .

To change the ownership of a single file, such as /etc/hosts, to the user root and the group root, you would use the following command:

chown root:root /etc/hosts

You can use the find command in combination with the chown command to change the ownership of files and directories that meet certain criteria.

Here are a few examples of using chown with the find command. To change the ownership of all files in the current directory and its subdirectories that have the .txt extension to the user bob and the group users, you would use the following command:

find . -type f -name "*.txt" -exec chown bob:users {} \;

The find command will search for all files (-type f) with the .txt extension (-name "*.txt") and execute the chown command on each file it finds (-exec chown bob:users {} \;).

To change the ownership of all directories in the /var/www/html directory and its subdirectories to the user www-data and the group www-data, you would use the following command:

find /var/www/html -type d -exec chown www-data:www-data {} \;

The find command will search for all directories (-type d) in the /var/www/html directory and its subdirectories and execute the chown command on each directory it finds. To change the ownership of all files in the /home/user directory that are larger than 100MB to the user user and the group users, you would use the following command:

find /home/user -type f -size +100M -exec chown user:users {} \;

The find command will search for all files (-type f) in the /home/user directory that are larger than 100MB (-size +100M) and execute the chown command on each file it finds.

As always, be sure to use caution when modifying file ownership, as incorrect usage can cause issues with your operating system. Before running any commands you should test them safely where possible. For example, you could test the process on the virtual machine.

Final Thoughts

In summary, a recursive chown is a useful command that allows you to change the ownership of a directory and all of its contents to a different user or group. Just be sure to use it carefully and only on files and directories that you have the proper permissions to modify.