useradd

To create a user, run

useradd -m -s /bin/bash USERNAME

-m = create home directory.
-s = specify location of shell.

To create a user with custom home directory, use

useradd -d /var/www -s /bin/bash USERNAME

Create User with Specific User id

Create the user “serverok” with uid 4223, run

useradd -u 4223 serverok

Create User to Run System Service

-r option select gid/uid for running system service.

groupadd -r prometheus
useradd -r -g prometheus -s /sbin/nologin -d /usr/hostonnet/prometheus/ -c "prometheus Daemons" prometheus

Related commands

Create, delete, and modify local user accounts

Add: useradd
Delete: userdel
Modify: usermod

Create, delete and modify local groups and group memberships

Add: groupadd
Delete: groupdel
Modify: groupmod

To add a user to sudo/wheel group, see usermod