Linux_Users

summary

/etc/passwd
/etc/shadow
/etc/groups
/etc/skel

id

useradd
usermod
userdel
passwd
chage

groupadd
groupmod -U anna,lisa -a students
groupdel
lid -g groupname

/etc/shadow contains the encrypted password

Create Users

• useradd: create user accounts

useradd --help
 
sudo useradd -u 1001 -g developers -G sudo,admin -d /custom/home -s /bin/bash -c "John Doe, developer" -m -k /etc/skel-custom -e 2024-12-31 -f 7 -p encryptedpassword -r -b /custom/base -N -Z "user_u" johndoe

encrypted_password

User default settings

• /etc/login.defs

• /etc/skel

• usermod: modify user accounts

limit user access

what_happens_after_password_locking

Groups

write about newgrp

• userdel: delete user accounts
• passwd: set passwords

unlock the password of a user