Create multiple new user accounts on Linux, set passwords to match usernames, force password change at first login and add users to some-user-group.

create-users.sh

for username in foo bar baz qux
do
 /usr/sbin/useradd $username
 echo $username | passwd $username --stdin
 chage -d 0 $username
 /usr/sbin/usermod -a -G some-user-group $username
done