The shadow-utils package includes the necessary programs for
converting UNIX password files to the shadow password format, plus
programs for managing user and group accounts. The pwconv command
converts passwords to the shadow password format. The pwunconv command
unconverts shadow passwords and generates an npasswd file (a standard
UNIX password file). The pwck command checks the integrity of password
and shadow files. The lastlog command prints out the last login times
for all users. The useradd, userdel, and usermod commands are used for
managing user accounts. The groupadd, groupdel, and groupmod commands
are used for managing group accounts.