1GROUPMOD(8) System Management Commands GROUPMOD(8)
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6 groupmod - modify a group definition on the system
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9 groupmod [options] GROUP
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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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16 The options which apply to the groupmod command are:
17 -g, --gid GID
19 The group ID of the given GROUP will be changed to GID.
20 The value of GID must be a non-negative decimal integer. This value
22 must be unique, unless the -o option is used.
23 Users who use the group as primary group will be updated to keep
25 the group as their primary group.
26 Any files that have the old group ID and must continue to belong to
28 GROUP, must have their group ID changed manually.
29 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.
32 -h, --help
34 Display help message and exit.
35 -n, --new-name NEW_GROUP
37 The name of the group will be changed from GROUP to NEW_GROUP name.
38 -o, --non-unique
40 When used with the -g option, allow to change the group GID to a
41 non-unique value.
42 -p, --password PASSWORD
44 The encrypted password, as returned by crypt(3).
45 Note: This option is not recommended because the password (or
47 encrypted password) will be visible by users listing the processes.
48 You should make sure the password respects the system's password
50 policy.
51 -R, --root CHROOT_DIR
53 Apply changes in the CHROOT_DIR directory and use the configuration
54 files from the CHROOT_DIR directory.
55 -P, --prefix PREFIX_DIR
57 Apply changes in the PREFIX_DIR directory and use the configuration
58 files from the PREFIX_DIR directory. This option does not chroot
59 and is intended for preparing a cross-compilation target. Some
60 limitations: NIS and LDAP users/groups are not verified. PAM
61 authentication is using the host files. No SELINUX support.
62
64 The following configuration variables in /etc/login.defs change the
65 behavior of this tool:
66 MAX_MEMBERS_PER_GROUP (number)
68 Maximum members per group entry. When the maximum is reached, a new
69 group entry (line) is started in /etc/group (with the same name,
70 same password, and same GID).
71 The default value is 0, meaning that there are no limits in the
73 number of members in a group.
74 This feature (split group) permits to limit the length of lines in
76 the group file. This is useful to make sure that lines for NIS
77 groups are not larger than 1024 characters.
78 If you need to enforce such limit, you can use 25.
80 Note: split groups may not be supported by all tools (even in the
82 Shadow toolsuite). You should not use this variable unless you
83 really need it.
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86 /etc/group
87 Group account information.
88 /etc/gshadow
90 Secure group account information.
91 /etc/login.defs
93 Shadow password suite configuration.
94 /etc/passwd
96 User account information.
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99 The groupmod command exits with the following values:
100 0
102 E_SUCCESS: success
103 2
105 E_USAGE: invalid command syntax
106 3
108 E_BAD_ARG: invalid argument to option
109 4
111 E_GID_IN_USE: specified group doesn't exist
112 6
114 E_NOTFOUND: specified group doesn't exist
115 9
117 E_NAME_IN_USE: group name already in use
118 10
120 E_GRP_UPDATE: can't update group file
121 11
123 E_CLEANUP_SERVICE: can't setup cleanup service
124 12
126 E_PAM_USERNAME: can't determine your username for use with pam
127 13
129 E_PAM_ERROR: pam returned an error, see syslog facility id groupmod
130 for the PAM error message
131
133 chfn(1), chsh(1), passwd(1), gpasswd(8), groupadd(8), groupdel(8),
134 login.defs(5), useradd(8), userdel(8), usermod(8).
135shadow-utils 4.8.1 11/16/2020 GROUPMOD(8)