]> gpasswd 1 User Commands gpasswd administer the /etc/group and /etc/gshadow files file gpasswd option group The gpasswd command is used to administer /etc/group, and /etc/gshadow. 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 a system administrator with a group name only prompts for the new password of the group. 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 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. This tool only operates on the /etc/group and /etc/gshadow files. file. Thus you cannot change any NIS or LDAP group. This must be performed on the corresponding server. The following configuration variables in /etc/login.defs change the behavior of this tool: &ENCRYPT_METHOD; &MAX_MEMBERS_PER_GROUP; &MD5_CRYPT_ENAB; &SHA_CRYPT_MIN_ROUNDS; /etc/group Group account information. /etc/gshadow Secure group account information. newgrp1 , groupadd8 , groupdel8 , groupmod8 , grpck8 , group5 , gshadow5 .