Adding and removing Permissions

Adding permissions

In order to change permissions of a file we can use specific options with the chmod command.

Important options

	Option	Examples
user	u+	u+w / u+rw / u+rwx
group	g+	g+w / g+rw / g+rwx
others	o+	o+w / o+rw / o+rwx

Example:

> ls -l
-r--rw----. 1 aaron family 49 Oct 27 14:41 family_dog.jpg

Here we can see aaron has only read permission, what if we want to change this to read and write permissions both, we will use it like this:

chmod u+w family_dog.jpg

and now if we do ls -l:

-rw-rw----. 1 aaron family 49 Oct 27 14:41 family_dog.jpg

Now we see user aaron has write permission to the file.

Removing permissions

Just as like in adding permissions we used u+ or g+ we will use u- or g-:

	Option	Examples
user	u-	u-w / u-rw / u-rwx
group	g-	g-w / g-rw / g-rwx
others	o-	o-w / o-rw / o-rwx

Example: Here we can see that we are removing write permission from the user:

chmod u-w family_dog.jpg

Now if we check by ls -l write permission is gone fromthe user:

-r--rw----. 1 aaron family 49 Oct 27 14:41 family_dog.jpg