groupmod
modify a group definition on the system
see also :
chfn - chsh - passwd - gpasswd - groupadd - groupdel - useradd - userdel - usermod
Synopsis
add an example, a script, a trick and tips
examples
source
fi
else
chroot . groupmod -n $GROUP_NAME
slocate &>/dev/null
fi
fi
description
The
groupmod command modifies the definition of the
specified GROUP by modifying the appropriate entry in
the group database.
options
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 name.
-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
processes.
You should make
sure the password respects the system's password policy.
-R,
--root CHROOT_DIR
Apply changes in the
CHROOT_DIR directory and use the configuration files
from the CHROOT_DIR directory.
configuration
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.
exit values
The groupmod command exits with the following values:
0
success
2
invalid command syntax
3
invalid argument to option
4
specified group doesn't exist
6
specified group doesn't exist
9
group name already in use
10
can't update group file
files
/etc/group
Group account information.
/etc/gshadow
Secure group account information.
/etc/login.defs
Shadow password suite configuration.
/etc/passwd
User account information.
see also
chfn ,
chsh , passwd , gpasswd ,
groupadd , groupdel ,
login.defs, useradd , userdel ,
usermod .