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.

现实帮助信息并退出。

The name of the group will be changed from GROUP to NEW_GROUP name.

When used with the -g option, allow to change the group GID to a non-unique value.

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。

Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.

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.

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。

组账户信息。

安全组账户信息。

Shadow 密码套件配置。

用户账户信息。

E_SUCCESS: success

E_USAGE: invalid command syntax

E_BAD_ARG: invalid argument to option

E_GID_IN_USE: specified group doesn't exist

E_NOTFOUND: specified group doesn't exist

E_NAME_IN_USE: group name already in use

E_GRP_UPDATE: can't update group file

E_CLEANUP_SERVICE: can't setup cleanup service

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

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