linux add user to root group code example

Example 1: add user to sudoers

usermod -aG sudo username

Example 2: add sudo user ubuntu

# add a user and set a password
adduser USERNAME

# add user to sudoers / sudo groupe with command below
usermod -aG sudo USERNAME

Example 3: linux add user to group

# Change the primary group a user is assigned to, note the -g here.
# When you use a lowercase g, you assign a primary group. When you 
# use an uppercase -G you assign a new secondary group.
usermod -g groupname username

Example 4: linux add user to group

# add user to additional group

usermod -G groupname username