Installation guide

login_directory
The absolute pathname of the directory where the
user account is located immediately after login. The
login program assigns this pathname to the
HOME environment variable. Users can change the
value of the HOME variable, but if a user changes
the value, then the home directory and the login
directory are two different directories. Create the
login directory after adding a user account to the
passwd file. Typically the user’s name is used as
the name of the login directory. Refer to the
chown
(1), mkdir(1), chmod(1), and chgrp(1)
reference pages for additional information on
creating a login directory.
login_shell
The absolute pathname of the program that starts
after the user logs in. Normally, a shell starts. If
you leave this field empty, the Bourne shell
/bin/sh starts. Refer to the sh
(1) reference page
for information on the Bourne shell. Users can
change their login shell by using the chsh
command. Refer to Section 9.3.3 and the chsh
(1)
reference page for more information.
9.1.2 The Group File
All users are members of at least one group. The group file identifies the
group name for a user. There are two primary reasons to group user
accounts:
• Several users work together on the same files and directories; grouping
these users together simplifies file and directory access.
• Only certain users are permitted access to system files or directories;
grouping them together simplifies the identification of privileged users.
The group file is used for the following purposes:
• To assign a name to a group identification number used in the passwd
file
• To allow users to be members of more than one group by adding the
user account to the corresponding group entries
Each entry in the group file is a single line that contains four fields. The
fields are separated by colons, and the last field ends with a new-line
character. The syntax of each entry and the meaning of each field is as
follows:
groupname: password: group_id: user1
[ user2,...,userN]
Administering User Accounts and Groups 9–3