GROUPMOD(8)

名称
groupmod - modify a group definition on the system

大纲

groupmod [options] GROUP

描述

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

选项

The options which apply to the groupmod command are:

-a, --append
    If group members are specified with -U, append them to the existing member list, rather than replacing it.

-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
    显示帮助信息并退出。

-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.

    您应该确保密码符合系统的密码政策。

-R, --root CHROOT_DIR
    Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory. Only absolute paths are supported. No SELINUX support.

-P, --prefix PREFIX_DIR
    Apply changes in the PREFIX_DIR directory and use the configuration files from the PREFIX_DIR directory. This option does not chroot and is intended for preparing a cross-compilation target. Some limitations: NIS and LDAP users/groups are not verified. PAM authentication is using the host files. No SELINUX support.

-U, --users
    A comma-separated list of usernames to add as members of the group.

    The default behavior (if the -g and -U options are not specified) is defined by the USERGROUPS_ENAB variable in /etc/login.defs.

配置文件

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).

    默认值是 0，意味着组中的成员数没有限制。

    此功能(分割组)允许限制组文件中的行长度。这对于确保 NIS 组的行比长于 1024 字符。

    如果要强制这个限制，可以使用 25。

    注意：分割组可能不受所有工具的支持(甚至在 Shadow 工具集中)。您不应该使用这个变量，除非真的需要。

文件

/etc/group
    组账户信息。

/etc/gshadow
    安全组账户信息。

/etc/login.defs
    Shadow 密码套件配置。

/etc/passwd
    用户账户信息。

退出值

The groupmod command exits with the following values:

0
    E_SUCCESS: success

2
    E_USAGE: invalid command syntax

3
    E_BAD_ARG: invalid argument to option

4
    E_GID_IN_USE: group id already in use

6
    E_NOTFOUND: specified group doesn't exist

9
    E_NAME_IN_USE: group name already in use

10
    E_GRP_UPDATE: can't update group file

11
    E_CLEANUP_SERVICE: can't setup cleanup service

12
    E_PAM_USERNAME: can't determine your username for use with pam

13
    E_PAM_ERROR: pam returned an error, see syslog facility id groupmod for the PAM error message

参见

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