Linux User - Create New User, Change Password, Set Password Never Expired, Set Group to User, Remove User

Create new user "appcore" as System User and add to User Group :

$ sudo su

$ useradd -r -m -d /home/appcore -g db2iadm1 appcore

or you can do :

$ sudo adduser --system --group appcore

or

$ sudo adduser --system --group --home /home/appcore

Change password :

$ sudo su

$ passwd appcore

Check password expired :

$ sudo su

$ chage -l appcore

Set password never expired :

$ sudo su

$ chage -I -1 -m 0 -M 99999 -E -1 -W -1 appcore

Remove user and home directory :

$ sudo pkill -u username

$ sudo killall -u username

$ sudo deluser --remove-home username 

Source :

https://linuxize.com/post/how-to-create-users-in-linux-using-the-useradd-command/

https://www.shellhacks.com/linux-set-password-to-never-expire/

https://www.cyberciti.biz/faq/linux-set-change-password-how-to/

https://share.google/aimode/6WdhRDGDZ7OYYBRSN