名称

       groupmod - modify a group definition on the system

大纲

       groupmod [选项] 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:

       -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
           现实帮助信息并退出。

       -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.

       -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.

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: specified group doesn't exist

       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).