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
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.
This command is intended to be used in a large system environment where
many accounts are updated at a single time.
The input file must be protected since it contains unencrypted passwords.