All users belong to one or more groups. Just as each file has a
specific owner, each file belongs to a particular group as well. The
group might be specific to the owner of the file, or may be a group
shared by all users. The ability to read, write or execute a file can
be assigned to a group; this is separate from the owner's rights. For
example, the owner of a file will be able to write to a document, while
other group members may only be able to read it.
To create a new group:
You may see a filter screen, depending upon the settings in
=>
. Either provide a filter, or select
Accept to bypass the filter.
Select Add at the bottom of the User
groups screen.
Enter a group name. You may also wish to specify members of the
group; you can do so in the Alternate members
field. The list of users should be space delimited, meaning that each
username must have a space between it and the next one. Leave the
Group name field blank, so that the system will
assign a Group ID (GID) to your new group. When
you're finished, select Accept and the group will
be created.
To delete a group:
Open => => =>
.
You may see a filter screen, depending upon the filter setting in
=>
. You can use the filter to
narrow your choice of groups by specifying a prefix.
With or without a prefix, select Accept at the
bottom of the screen.
On the User groups screen (see Figure 14-7), select the group you wish to
delete.
You'll be presented with the Group
specification screen (see Figure 14-8).
Select Del to delete the group.
Linuxconf will then prompt you to
confirm the deletion. Choose yes to delete
the group.
The group's files will still remain and their respective owners will
still have sole control over them. The group name will be replaced
with the deleted group's ID. The files may be assigned to a new group
by using the chgrp command. More information on
chgrp can be found by typing the command
info chgrp or man chgrp at the
shell prompt. If a new group is created and the deleted group's ID is
specified, then the new group will have access to the deleted group's
files. Linuxconf does not
recycle used group numbers or used user IDs, so it won't happen by
accident.
There are two ways to modify the list of users that belong to a group.
You can either update each user account itself, or you can update the
group definitions. In general, the fastest way is to update each of
the group definitions. If you're planning on changing more
information for each user than just the group information, then
updating each user account may be simpler.
We'll start by detailing the group definitions method.
Start Linuxconf by typing
linuxconf at the shell prompt.
Open => => =>
.
Depending on the filter settings in
=>
, you may see a filter screen.
Use the filter to narrow the list, or just select
Accept to bypass the filter.
Select the group you wish to modify. This will open the
Group specification screen (see Figure 14-8).
Add or remove each user from the Alternate
members field. Make sure that all of the usernames
are separated by a space character.
Select Accept at the bottom of the screen.
This will automatically update each user account with the group
showing up in the Supplementary groups field if
added or absent if removed.
Adding and removing groups can also be done by modifying each
individual user account:
Start Linuxconf by typing
linuxconf at the shell prompt.
Open => => =>
.
You may see a filter screen, depending on the settings in
=>
. Use the filter to narrow the
list or select Accept to bypass the filter.
On the User accounts screen (see Figure 14-4), select a user that you wish
to update. You will be presented with the User
information screen.
Add or remove the desired groups from the Supplementary
groups field. Each group should be separated by a
space.
Once you've made all the changes you'd like, select
Accept at the bottom of the screen.
This will automatically update the group definitions. Repeat the
process for each user.
