on the primary group the user belongs to when creating the object. When you create
a new le or directory, initial access permissions for this object are set according to
a predened scheme. For further details refer to Section 17.5, “File Access Permis-
sions” (page 200).
As the owner of a le or directory (and, of course, as root), you can change the access
permissions to this object.
To change object attributes like access permissions of a le or folder, use the chmod
command followed by the following parameters:
• the users for which to change the permissions,
• the type of access permission you want to remove, set or add and
• the les or folders for which you want to change permissions separated by
spaces.
The users for which you can change le access permissions fall into the following
categories: the owner of the le (user, u), the group that own the le (group, g) and
the other users (others, o). You can add, remove or set one or more of the following
permissions: read, write or execute.
As root, you can also change the ownership of a le: with the command chown
(change owner) you can transfer ownership to a new user.
17.5.3.1 Examples for Changing Access Permissions and Ownership
The following example shows the output of an ls -l command in a shell.
Example 17.2: Access Permissions For Files and Folders
-rw-r----- 1 tux users 0 2006-06-23 16:08 checklist.txt
-rw-r--r-- 1 tux users 53279 2006-06-21 13:16 gnome_quick.xml
-rw-rw---- 1 tux users 0 2006-06-23 16:08 index.htm
-rw-r--r-- 1 tux users 70733 2006-06-21 09:35 kde-start.xml
-rw-r--r-- 1 tux users 47896 2006-06-21 09:46 kde_quick.xml
drwxr-xr-x 2 tux users 48 2006-06-23 16:09 local
-r-xr-xr-x 1 tux users 624398 2006-06-23 15:43 tux.jpg
In the example above, user tux owns the le kde-start.xml and has read and write
access to the le but cannot execute it. The users group can read the le but cannot
write or execute it. The same holds true for the other users as shown by the third
block of characters.
Procedure 17.4: Changing Access Permissions
Suppose you are tux and want to modify the access permissions to your les:
1
If you want to grant the users group also write access to kde-start.xml, enter
chmod g+w kde-start.xml
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