gpasswd 1 User Commands gpasswd administer the /etc/group file gpasswd option group The gpasswd command is used to administer the /etc/group file (and /etc/gshadow file if compiled with SHADOWGRP defined). Every group can have administrators, members and a password. System administrator can use the -A option to define group administrator(s) and the -M option to define members and has all rights of group administrators and members. gpasswd called by a group administrator with a group name only prompts for the group password. If a password is set the members can still newgrp1 without a password, and non-members must supply the password. Group passwords are an inherent security problem since more than one person is permitted to know the password. However, groups are a useful tool for permitting co-operation between different users. Except for the -A and -M options, the options cannot be combined. The options which apply to the gpasswd command are: -a user Add the user to the named group. -d user Remove the user from the named group. -r Remove the password from the named group. Only group members will be allowed to use newgrp to join the named group. -R Restrict the access to the named group. Only group members will be allowed to use newgrp to join the named group. -A user,... Set the list of administrative users. -M user,... Set the list of group members. /etc/group Group account information. /etc/gshadow Secure group account information. newgrp1 , gshadow5 , groupadd8 , groupdel8 , groupmod8 , grpck8 , group5 .