To change roger's password:
sudo passwd roger
and follow the prompts. There is no restriction on password length.
To add a new, ordinary user named roger with home directory /home/roger, password xyz, starting shell /bin/shell (this is normal) and in the group named users (this can be omitted):
sudo useradd -m roger -d /home/roger -p xyz -s /bin/bash -g users .
To remove the user roger and his home directory:
sudo userdel -r roger .
To see user names and primary groups:
sudo cat /etc/passwd .
To add the user roger to the sudo group:
sudo adduser roger sudo .
More information can be found at ahinc.
Your computer has a name, which can be seen every time you launch the terminal. To change it, enter the following into the terminal:
sudo old-name new-name .
If this doesn't work, then replace the old name with the new one in the files responsible for naming the computer: /etc/hostname and /etc/hosts.
To activate autologin for a user roger when lxdm is the display manager, open (as root) /etc/lxdm/default.conf, /etc/lxdm/lxdm.conf, /etc/xdg/lxdm/lxdm.conf and edit
# autologin= to autologin=roger.
To activate autologin when slim is the display manager, open (as root) /etc/slim.conf, change the lines
# default_user simone to default_user roger
# auto_login no to auto_login yes
To activate autologin when lightdm is the display manager, open (as root) /etc/lightdm/lightdm.conf, uncomment (delete "#") and change the appropriate lines in "session-wrapper" to:
autologin-user=roger,
autologin-user-timeout=0.
If not already present and if you have other users, you may wish to add (as root) in each of these cases an autologin group:
groupadd autologin.
Then add roger as a member:
adduser roger autologin.