# shadow The shadow 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.