1GROUPMEMS(8) System Management Commands GROUPMEMS(8)
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6 groupmems - administer members of a userĀ“s primary group
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9 groupmems -a user_name | -d user_name | [-g group_name] | -l | -p
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12 The groupmems command allows a user to administer his/her own group
13 membership list without the requirement of superuser privileges. The
14 groupmems utility is for systems that configure its users to be in
15 their own name sake primary group (i.e., guest / guest).
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17 Only the superuser, as administrator, can use groupmems to alter the
18 memberships of other groups.
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21 The options which apply to the groupmems command are:
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23 -a, --add user_name
24 Add an user to the group membership list.
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26 If the /etc/gshadow file exist, and the group has no entry in the
27 /etc/gshadow file, a new entry will be created.
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29 -d, --delete user_name
30 Delete a user from the group membership list.
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32 If the /etc/gshadow file exist, the user will be removed from the
33 list of members and administrators of the group.
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35 If the /etc/gshadow file exist, and the group has no entry in the
36 /etc/gshadow file, a new entry will be created.
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38 -g, --group group_name
39 The superuser can specify which group membership list to modify.
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41 -l, --list
42 List the group membership list.
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44 -p, --purge
45 Purge all users from the group membership list.
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47 If the /etc/gshadow file exist, and the group has no entry in the
48 /etc/gshadow file, a new entry will be created.
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51 The groupmems executable should be in mode 2770 as user root and in
52 group groups. The system administrator can add users to group groups to
53 allow or disallow them using the groupmems utility to manage their own
54 group membership list.
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56 $ groupadd -r groups
57 $ chmod 2770 groupmems
58 $ chown root.groups groupmems
59 $ groupmems -g groups -a gk4
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63 The following configuration variables in /etc/login.defs change the
64 behavior of this tool:
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66 MAX_MEMBERS_PER_GROUP (number)
67 Maximum members per group entry. When the maximum is reached, a new
68 group entry (line) is started in /etc/group (with the same name,
69 same password, and same GID).
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71 The default value is 0, meaning that there are no limits in the
72 number of members in a group.
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74 This feature (split group) permits to limit the length of lines in
75 the group file. This is useful to make sure that lines for NIS
76 groups are not larger than 1024 characters.
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78 If you need to enforce such limit, you can use 25.
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80 Note: split groups may not be supported by all tools (even in the
81 Shadow toolsuite). You should not use this variable unless you
82 really need it.
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85 /etc/group
86 Group account information.
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88 /etc/gshadow
89 secure group account information
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92 chfn(1), chsh(1), passwd(1), groupadd(8), groupdel(8), useradd(8),
93 userdel(8), usermod(8).
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97System Management Commands 07/24/2009 GROUPMEMS(8)