GROUPMOD(8)              System Management Commands              GROUPMOD(8)

NAME         top

       groupmod - modify a group definition on the system

SYNOPSIS         top

       groupmod [options] GROUP

DESCRIPTION         top

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

OPTIONS         top

       The options which apply to the groupmod command are:

       -g, --gid GID
           The group ID of the given GROUP will be changed to GID.

           The value of GID must be a non-negative decimal integer. This
           value must be unique, unless the -o option is used.

           Users who use the group as primary group will be updated to keep
           the group as their primary group.

           Any files that have the old group ID and must continue to belong
           to GROUP, must have their group ID changed manually.

           No checks will be performed with regard to the GID_MIN, GID_MAX,
           SYS_GID_MIN, or SYS_GID_MAX from /etc/login.defs.

       -h, --help
           Display help message and exit.

       -n, --new-name NEW_GROUP
           The name of the group will be changed from GROUP to NEW_GROUP

       -o, --non-unique
           When used with the -g option, allow to change the group GID to a
           non-unique value.

       -p, --password PASSWORD
           The encrypted password, as returned by crypt(3).

           Note: This option is not recommended because the password (or
           encrypted password) will be visible by users listing the

           You should make sure the password respects the system's password

       -R, --root CHROOT_DIR
           Apply changes in the CHROOT_DIR directory and use the
           configuration files from the CHROOT_DIR directory.


       The following configuration variables in /etc/login.defs change the
       behavior of this tool:

       MAX_MEMBERS_PER_GROUP (number)
           Maximum members per group entry. When the maximum is reached, a
           new group entry (line) is started in /etc/group (with the same
           name, same password, and same GID).

           The default value is 0, meaning that there are no limits in the
           number of members in a group.

           This feature (split group) permits to limit the length of lines
           in the group file. This is useful to make sure that lines for NIS
           groups are not larger than 1024 characters.

           If you need to enforce such limit, you can use 25.

           Note: split groups may not be supported by all tools (even in the
           Shadow toolsuite). You should not use this variable unless you
           really need it.

FILES         top

           Group account information.

           Secure group account information.

           Shadow password suite configuration.

           User account information.

EXIT VALUES         top

       The groupmod command exits with the following values:


           invalid command syntax

           invalid argument to option

           specified group doesn't exist

           specified group doesn't exist

           group name already in use

           can't update group file

SEE ALSO         top

       chfn(1), chsh(1), passwd(1), gpasswd(8), groupadd(8), groupdel(8),
       login.defs(5), useradd(8), userdel(8), usermod(8).

COLOPHON         top

       This page is part of the shadow-utils (utilities for managing
       accounts and shadow password files) project.  Information about the
       project can be found at ⟨⟩.  If
       you have a bug report for this manual page, see 
       ⟨⟩.  This page was
       obtained from the project's upstream Git repository 
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       If you discover any rendering problems in this HTML version of the
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shadow-utils 4.4                 02/18/2017                      GROUPMOD(8)