1GROUPMOD(8)               System Management Commands               GROUPMOD(8)
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NAME

6       groupmod - modify a group definition on the system
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SYNOPSIS

9       groupmod [options] GROUP
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DESCRIPTION

12       The groupmod command modifies the definition of the specified GROUP by
13       modifying the appropriate entry in the group database.
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OPTIONS

16       The options which apply to the groupmod command are:
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18       -g, --gid GID
19           The group ID of the given GROUP will be changed to GID.
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21           The value of GID must be a non-negative decimal integer. This value
22           must be unique, unless the -o option is used.
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24           Users who use the group as primary group will be updated to keep
25           the group as their primary group.
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27           Any files that have the old group ID and must continue to belong to
28           GROUP, must have their group ID changed manually.
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30           No checks will be performed with regard to the GID_MIN, GID_MAX,
31           SYS_GID_MIN, or SYS_GID_MAX from /etc/login.defs.
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33       -h, --help
34           Display help message and exit.
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36       -n, --new-name NEW_GROUP
37           The name of the group will be changed from GROUP to NEW_GROUP name.
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39       -o, --non-unique
40           When used with the -g option, allow to change the group GID to a
41           non-unique value.
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43       -p, --password PASSWORD
44           The encrypted password, as returned by crypt(3).
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46           Note: This option is not recommended because the password (or
47           encrypted password) will be visible by users listing the processes.
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49           You should make sure the password respects the system's password
50           policy.
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52       -R, --root CHROOT_DIR
53           Apply changes in the CHROOT_DIR directory and use the configuration
54           files from the CHROOT_DIR directory.
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CONFIGURATION

57       The following configuration variables in /etc/login.defs change the
58       behavior of this tool:
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60       MAX_MEMBERS_PER_GROUP (number)
61           Maximum members per group entry. When the maximum is reached, a new
62           group entry (line) is started in /etc/group (with the same name,
63           same password, and same GID).
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65           The default value is 0, meaning that there are no limits in the
66           number of members in a group.
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68           This feature (split group) permits to limit the length of lines in
69           the group file. This is useful to make sure that lines for NIS
70           groups are not larger than 1024 characters.
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72           If you need to enforce such limit, you can use 25.
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74           Note: split groups may not be supported by all tools (even in the
75           Shadow toolsuite). You should not use this variable unless you
76           really need it.
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FILES

79       /etc/group
80           Group account information.
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82       /etc/gshadow
83           Secure group account information.
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85       /etc/login.defs
86           Shadow password suite configuration.
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88       /etc/passwd
89           User account information.
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EXIT VALUES

92       The groupmod command exits with the following values:
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94       0
95           success
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97       2
98           invalid command syntax
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100       3
101           invalid argument to option
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103       4
104           specified group doesn't exist
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106       6
107           specified group doesn't exist
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109       9
110           group name already in use
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112       10
113           can't update group file
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SEE ALSO

116       chfn(1), chsh(1), passwd(1), gpasswd(8), groupadd(8), groupdel(8),
117       login.defs(5), useradd(8), userdel(8), usermod(8).
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121shadow-utils 4.1.5.1              03/14/2019                       GROUPMOD(8)