Chapter 7
user info stored in 2 config files
- /etc/default/useradd ;text file read by all users, shell, skel, groups /etc/login.defs(also read by all users; default PATH settings, passwd changes, UID and GID ranges
configuration files, user database
- /etc/passwd - /etc/shadow
/etc/passwd, fields
Username (lower-case reccomended), password (encrypted), user identifier(UID), Group identifier (GID), GECOS, Home directory, Shell
/etc/group file
config file that stores group info, can be read by all, includes group name, password group identifier, list of members
/etc/shadow
configuration file containing passwords and password expiration information for all User Accounts. Can only be read by the root user.
/etc/passwd
contains user account information; ea. entry has 7 fields separated by colons; everyone has permission to view this file's contents (world-readable)
yast2 users
modify users with YaST, can add/change user data, detials, password settings, plug-ins
Authentication
the process of verifying someone's identity by checking his or her username and password against a central user database.
'usermod' command
use to change user account info - only done by root user
'groupadd' command
use to create a group account
'userdel' command
use to delete user accounts and remove all entries from user database files (/etc/passwd and /etc/shadow
'chage' command
use to list and modify password info for user accts, add'l privileges for root user
'groupmod' command
use to modify existing groups
/etc/shadow, fields
username, encrypted password, last password change, minimum (b4 passwd changed), expiration, warning, disabled, disabled date, reserved