groupadd(1M)

NAME

groupadd — add a new group to the system

SYNOPSIS

groupadd [-g gid [-o]] group

DESCRIPTION

The groupadd command creates a new group on the system by adding the appropriate entry to the /etc/group file. The groupadd command must be used with the group argument, which is the name of the new group. The name consists of a string of printable characters that may not include a colon (:) or newline (\n).

Options

The groupadd command uses the following options:

-g gid: Specify the group ID for the new group. gid must be a non-negative decimal integer less than MAXUID as defined in the <param.h> header file. By default the next available unique group ID in the valid range is allocated. Group IDs in the range 0-99 are reserved.
-o: Allow the gid to be non-unique (that is, a duplicate).

NIS

The groupadd command is aware of NIS user entries. Only local groups may be added with this command. Attempts to add an NIS group will result in an error. NIS groups must be administered from the NIS server. If groupadd is used on a system where NIS is installed, it may fail with the error

group x is not unique

(return value 9) if the group specified is not present in the local /etc/group file, but is an NIS group (see group(4)). NIS groups are also checked when verifying uniqueness of the new gid, which may result in the error

GID # is not unique 

(return value 4).

RETURN VALUE

The groupadd command exits with one of the following values:

0: No error.
2: Invalid command syntax.
3: Invalid argument supplied to an option.
4: gid is not unique (when -o is not used).
9: group is not unique.
10: Cannot modify the /etc/group file.
11: /etc/passwd file or /etc/ptmp file busy. Another command may be modifying the /etc/passwd file.
12: Unable to open /etc/ptmp file or /etc/passwd file is non-existent.

EXAMPLES

Add the group project1 to the /etc/group file.

groupadd project1 

Add the group project12 to the /etc/group file with the group ID 111 as long as no group currently exists with a group ID of 111.

groupadd -g 111 project12 

WARNINGS

Because many users may try to write the /etc/passwd file simultaneously, a password locking mechanism was devised. If this locking fails after subsequent retrying, groupadd terminates.

FILES

/etc/group 
/etc/ptmp 

STANDARDS CONFORMANCE

groupadd: SVID3