chown_and_chmod_examples
Table of Contents
CHOWN and CHMOD Examples
Change the owner of a file
# ls -lart tmpfile [ls is used to diplay the file/directory properties] -rw-r--r-- 1 himanshu family 0 2012-05-22 20:03 tmpfile # chown root tmpfile # ls -l tmpfile -rw-r--r-- 1 root family 0 2012-05-22 20:03 tmpfile
Change the group of a file
Through the chown command, the group (that a file belongs to) can also be changed. # ls -l tmpfile -rw-r--r-- 1 himanshu family 0 2012-05-22 20:03 tmpfile # chown :friends tmpfile # ls -l tmpfile -rw-r--r-- 1 himanshu friends 0 2012-05-22 20:03 tmpfile
Change both owner and the group
# ls -l tmpfile -rw-r--r-- 1 root family 0 2012-05-22 20:03 tmpfile # chown himanshu:friends tmpfile # ls -l tmpfile -rw-r--r-- 1 himanshu friends 0 2012-05-22 20:03 tmpfile
Change owner only if a file is owned by a particular user
Using chown “–from” flag, you can change the owner of a file, only if that file is already owned by a particular owner.
# ls -l tmpfile -rw-r--r-- 1 root friends 0 2012-05-22 20:03 tmpfile # chown --from=guest himanshu tmpfile # ls -l tmpfile -rw-r--r-- 1 root friends 0 2012-05-22 20:03 tmpfile # chown --from=root himanshu tmpfile # ls -l tmpfile -rw-r--r-- 1 himanshu friends 0 2012-05-22 20:03 tmpfile
- In the example above, we verified that the original owner/group of the file ‘tmpfile’ was root/friends.
- Next we used the ‘–from’ flag to change the owner to ‘himanshu’ but only if the existing owner is ‘guest’.
- Now, as the existing owner was not ‘guest’. So, the command failed to change the owner of the file.
- Next we tried to change the owner if the existing owner is ‘root’ (which was true) and this time command was successful and the owner was changed to ‘himanshu’.
Copy the owner/group settings from one file to another
This is possible by using the ‘–reference’ flag. # ls -l file -rwxr-xr-x 1 himanshu family 8968 2012-04-09 07:10 file # ls -l tmpfile -rw-r--r-- 1 root friends 0 2012-05-22 20:03 tmpfile # chown --reference=file tmpfile # ls -l tmpfile -rw-r--r-- 1 himanshu family 0 2012-05-22 20:03 tmpfile
In the above example, we first checked the owner/group of the reference-file ‘file’ and then checked the owner/group of the target-file ‘tmpfile’. Both were different. Then we used the chown command with the ‘–reference’ option to apply the owner/group settings from the reference file to the target file. The command was successful and the owner/group settings of ‘tmpfile’ were made similar to the ‘file’
List all the changes made by the chown command
Use the verbose option -v, which will display whether the ownership of the file was changed or retained as shown below. # chown -v -R guest:friends linux changed ownership of `linux/redhat/rh7' to guest:friends changed ownership of `linux/redhat' retained to guest:friends ownership of `linux/redhat_sym' retained as guest:friends ownership of `linux/ubuntu_sym' retained as guest:friends changed ownership of `linux/linuxKernel' to guest:friends changed ownership of `linux/ubuntu/ub10' to guest:friends ownership of `linux/ubuntu' retained as guest:friends ownership of `linux' retained as guest:friends
chown_and_chmod_examples.txt · Last modified: 2023/03/09 22:35 by 127.0.0.1