$ curl cheat.sh/
 cheat:usermod 
# Add user to sudo group
sudo usermod -aG sudo <username>

 tldr:usermod 
# usermod
# Modifies a user account.
# See also: `users`, `useradd`, `userdel`.
# More information: <https://manned.org/usermod>.

# Change a username:
sudo usermod --login new_username username

# Change a user id:
sudo usermod --uid id username

# Change a user shell:
sudo usermod --shell path/to/shell username

# Add a user to supplementary groups (mind the lack of whitespace):
sudo usermod --append --groups group1,group2,... username

# Change a user home directory:
sudo usermod --move-home --home path/to/new_home username

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