1GROUPMEMS(8) System Management Commands GROUPMEMS(8)
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6 groupmems - administer members of a user'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 their 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 a 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 -h, --help
42 Display help message and exit.
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44 -l, --list
45 List the group membership list.
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47 -p, --purge
48 Purge all users from the group membership list.
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50 If the /etc/gshadow file exist, and the group has no entry in the
51 /etc/gshadow file, a new entry will be created.
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53 -R, --root CHROOT_DIR
54 Apply changes in the CHROOT_DIR directory and use the configuration
55 files from the CHROOT_DIR directory.
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58 In this operating system the groupmems executable is not setuid and
59 regular users cannot use it to manipulate the membership of their own
60 group.
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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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97shadow-utils 4.9 11/19/2021 GROUPMEMS(8)