groupmod 8 System Management Commands groupmod modify a group definition on the system groupmod options GROUP The groupmod modifies the definition of the specified GROUP by modifying the appropriate entry in the group database. The options which apply to the groupmod command are: -g, --gid GID Specify the new group ID for the GROUP. The numerical value of the GID must be a non-negative decimal integer. This value must be unique, unless the -o option is used. Values between 0 and 999 are typically reserved for system groups. Any files which the old group ID is the file group ID must have the file group ID changed manually. -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 non-unique value. /etc/group Group account information. /etc/gshadow Secure group account information. 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 chfn1 , chsh1 , passwd1 , gpasswd8 , groupadd8 , groupdel8 , useradd8 , userdel8 , usermod8 .