newusers reads a file of user name and cleartext password pairs and uses this information to update a group of existing users or to create new users. Each line is in the same format as the standard password file (see passwd(5)) with the following exceptions.
This field will be encrypted and used as the new value of the encrpted password.
This field will be ignored for shadow passwords if the user already exists.
This field may be the name of an existing group, in which case the named user will be added as a member. If a non-existent numerical group is given, a new group will be created having this number.
This field will be checked for existence as a directory and a new directory with the same name will be created if it does not already exist. The ownership of the directory will be set to be that of the user being created or updated.