Sun Certified System Administrator for Solaris 10 Study Guide Exams 310-XXX & 310-XXX

A user account on the Solaris system consists of several components such as a user login name, a user ID, a user password, and a home directory for the user. User accounts can be added, modified, and deleted by using the useradd, usermod, and userdel commands, respectively, or by using the Solaris Management Console (SMC) GUI tool. The admin tool from the previous versions is not available in Solaris 10.

Most of the information about user accounts lives in the file /etc/passwd, which also holds a placeholder for the password, and the encrypted password and other password information lives in the file /etc/shadow. Multiple users can be organized into a group, and the information about the groups live in the /etc/group file. The work environment for a user is created by the shell initialization files, which are executed when the user logs into the system. There are two kinds of initialization files: site initialization files, which are available to all the users and set up the global part of the environment, and user initialization files, which a user can change to customize the environment locally. During the login procedure, first the site initialization files are executed, followed by the user initialization files.

System security is an integral part of user management. We explore the system security aspect of the user administration in the next chapter.

Inside the Exam

Comprehend

• How the initialization files are created; they are copied from the /etc/skel directory into the user's home directory.

• The order in which the initialization files are executed: the site initialization files followed by the user initialization files as shown here:

  • C shell. /etc/.login, $HOME/.cshrc, $HOME/.login

  • Bourne shell./etc/profile, $HOME/.profile

  • Kornshell. /etc/profile, $HOME/.profile, $HOME/.kshrc

Look Out

• The passwd file does not contain the user password, but only a place holder: x. The encrypted password and other password information is stored in the /etc/shadow file.

• The usermod command contains the same options as the useradd command and is used mostly in the same way.

• A value of a variable set in the site initialization file will be overridden by the value set in the user initialization file.

Memorize

• The user name can be two to eight characters long.

• The numbers from 0 to 99 are used to specify UIDs for system accounts, and 100 to 60,000 for normal users. The largest UID can be 2³¹ -1.

• A user must be a member of one and only one primary group and may become a member of 15 secondary groups at maximum.

• The account information is stored in three files: /etc/passwd, /etc/shadow/, and /etc/group.

• The names of the initialization files for different shells, which are as follows:

  • C shell. /etc/.login, $HOME/.cshrc, $HOME/.login

  • Bourne shell. /etc/profile, $HOME/.profile

  • Korn shell. /etc/profile, $HOME/.profile, $HOME/.kshrc