User Administration

Types of Users

1) root user -> group id(gid) and user id(uid) is always 0(zero)

2) system users -> gid and uid is from 1-499

3) normal users -> above 500 upto 60,000

user information files are stored in

#cat /etc/passwd

#cat /etc/shadow

#useradd -d (home) -c (comments) -s (shell) -u (uid) -g (gid) -G (secondary uid) -p ("encrypted passwd") username

eg:

#useradd -d /home/user1 -c "a special user" -s /bin/csh -u 500 -g 500 -p "passwd" user1

to encrypt the password before entering

#grub-md5-crypt

User modification:

#usermod username

User Delete:

#userdel username

#userdel -r username with this the content of the password file and home directories are delected