User Account And Group Applications - Red Hat ENTERPRISE LINUX 3 - INTRODUCTION TO SYSTEM ADMINISTRATION Administration Manual

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Encrypted password — The encrypted password for the group. If set, non-members of the group
•
can join the group by typing the password for that group using the
of this field is , then no user is allowed to access the group using the
!
of is treated the same as a value of
!!
set before. If the value is null, only group members can log into the group.
Group administrators — Group members listed here (in a comma delimited list) can add or remove
•
group members using the
Group members — Group members listed here (in a comma delimited list) are regular,
•
non-administrative members of the group.
Here is an example line from
general:!!:shelley:juan,bob
This line shows that the
using the command. In addition,
newgrp
regular, non-administrative members.
Since editing these files manually raises the potential for syntax errors, it is recommended that the
applications provided with Red Hat Enterprise Linux for this purpose be used instead. The next section
reviews the primary tools for performing these tasks.

6.3.3. User Account and Group Applications

There are two basic types of applications that can be used when managing user accounts and groups
on Red Hat Enterprise Linux systems:
The graphical User Manager application
•
A suite of command line tools
•
For detailed instructions on using User Manager, see the chapter titled User and Group Configuration
in the Red Hat Enterprise Linux System Administration Guide.
While both the User Manager application and the command line utilities perform essentially the
same task, the command line tools have the advantage of being script-able and are therefore more
easily automated.
The following table describes some of the more common command line tools used to create and
manage user accounts and groups:
Application
/usr/sbin/useradd
/usr/sbin/userdel
/usr/sbin/usermod
passwd
Chapter 6. Managing User Accounts and Resource Access
— however, it also indicates that a password has never been
!
command.
gpasswd
/etc/gshadow
group has no password and does not allow non-members to join
general
shelley
Function
Adds user accounts. This tool is also used to specify primary and
secondary group membership.
Deletes user accounts.
Edits account attributes including some functions related to password
aging. For more fine-grained control, use the
is also used to specify primary and secondary group
usermod
membership.
Sets passwords. Although primarily used to change a user's password,
it also controls all aspects of password aging.
:
is a group administrator, and
command. If the value
newgrp
command. A value
newgrp
and
juan
command.
passwd
are
bob