This post will contain a list of common unix commands for user management that I didn't use that often, but that are pretty common for others. And just to prevent me from searching again in the web I will collect them here for myself.
These are commands for creating users and adding users to groups. Please make sure to run the command adduser, passwd and deluser with super-user permissions. On Ubuntu for example with sudo if you are not the root user.
The following command will create a new USER.
adduser USER Adding user `USER' ... Adding new group `USER' (1001) ... Adding new user `USER' (1001) with group `USER' ... Creating home directory `/home/USER' ... Copying files from `/etc/skel' ... Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully Changing the user information for USER Enter the new value, or press ENTER for the default Full Name : Room Number : Work Phone : Home Phone : Other : Is the information correct? [Y/n]
This command will add an existing USER to an existing GROUP.
adduser USER GROUP Adding user `USER' to group `GROUP' ... Adding user USER to group GROUP Done.
This command will update the password of an existing USER.
passwd USER Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully
The following command will delete user USER.
deluser USER Removing user `USER' ... Warning: group `USER' has no more members. Done.