Linux System AdminΒΆ
A user has a username, primary group and additional group.
/etc/passwd Contains one line for each user account. /etc/shadow Contains the password information in encrypted formatfor the system’s accounts and optional account aging information. /etc/group Defines the groups on the system. /etc/default/useradd This file contains a value for the default group, if none is specified by the useradd command. /etc/login.defs This file defines the site-specific configuration for the shadow password suite stored in /etc/shadow file.
Task | Format | Example - | |
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Add user to existing or new group | useradd -G <group> <user> |
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Add User to Primary Group | useradd -g <group> <user> |
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Add group | groupadd <group> |
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Set user password | passwd <user>`` |
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Add User to Existing Group as secondary group | usermod -a -G <group> <user> |
usermod -a -G <group> <user> |
Group can be a list of multiple groups |
Add User as Sudo:
su
visudo
Add the user uname
to the sudo group, this will permit them to sudo.:
usermod -a -G sudo uname
View Groups:
cat /etc/group
Get info on user:
id <username>