Each person who uses a Solaris system is given a user account. The user account uniquely identifies the person; this allows the system administrator to tailor each user's working environment.
Account information is stored in the password file (/etc/passwd). Encrypted passwords and password aging information are stored in the shadow file (/etc/shadow). Group memberships are defined in the group file (/etc/group).
The user known as root has all system privileges. The attribute that gives root its power is its user number 0.
The system administrator uses the Admintool program to create, modify, and remove user accounts and groups. The useradd, usermod, userdel, groupadd, groupmod, and groupdel commands are command-line tools used to manage users and groups.
The system administrator has a choice of shells to choose from when setting up each new user. The various shells employ systemwide and per-user initialization files in order to customize each user's environment. The shells used in Solaris are the Bourne Shell, the C-Shell, and the Korn Shell. Restricted shells are available in instances where users need restricted capabilities.
There are a variety of commands available to see which other users are logged into the system or other systems on the network. They are who, rwho, rusers, and finger.
The user account is the sole means for associating an individual to a system. A system administrator creates a username for an individual. This username is a name that he uses to identify himself to the system. The administrator also assigns a secret password to the user account.
To use a system, the user must first log in with his or her userid and, later, the associated password as requested by the system. When the system is satisfied that the user has furnished the correct userid and password, the system admits the user.
The -l and -n options to the ls command list user/group names or user/group numbers, respectively. The find command can be used to find files owned by specific users or groups.
Users can change their password with the passwd command. The system will enforce password complexity policies, such as the length of the password and the number and type of characters in the password. These policies are not checked when root changes a user's password.