Provided by: passwd_4.8.1-2ubuntu2_amd64
groupadd - 创建一个新组
groupadd [选项] group
The groupadd command creates a new group account using the values specified on the command line plus the default values from the system. The new group will be entered into the system files as needed.
The options which apply to the groupadd command are: -f, --force This option causes the command to simply exit with success status if the specified group already exists. When used with -g, and the specified GID already exists, another (unique) GID is chosen (i.e. -g is turned off). -g, --gid GID The numerical value of the group's ID. This value must be unique, unless the -o option is used. The value must be non-negative. The default is to use the smallest ID value greater than or equal to GID_MIN and greater than every other group. See also the -r option and the GID_MAX description. -h, --help 现实帮助信息并退出。 -K, --key KEY=VALUE Overrides /etc/login.defs defaults (GID_MIN, GID_MAX and others). Multiple -K options can be specified. Example: -K GID_MIN=100 -K GID_MAX=499 Note: -K GID_MIN=10,GID_MAX=499 doesn't work yet. -o, --non-unique 此选项允许添加一个使用非唯一 GID 的组。 -p, --password PASSWORD The encrypted password, as returned by crypt(3). The default is to disable the password. 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, --system 创建一个系统组。 The numeric identifiers of new system groups are chosen in the SYS_GID_MIN-SYS_GID_MAX range, defined in login.defs, instead of GID_MIN-GID_MAX. -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.
The following configuration variables in /etc/login.defs change the behavior of this tool:
/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。
It is usually recommended to only use groupnames that begin with a lower case letter or an underscore, followed by lower case letters, digits, underscores, or dashes. They can end with a dollar sign. In regular expression terms: [a-z_][a-z0-9_-]*[$]? On Debian, the only constraints are that groupnames must neither start with a dash ('-') nor plus ('+') nor tilde ('~') nor contain a colon (':'), a comma (','), or a whitespace (space:' ', end of line: '\n', tabulation: '\t', etc.). On Ubuntu, the same constraints as Debian are in place, with the additional constraint that the groupname cannot be fully numeric. This includes octal and hexadecimal syntax. Groupnames may only be up to 32 characters long. You may not add a NIS or LDAP group. This must be performed on the corresponding server. If the groupname already exists in an external group database such as NIS or LDAP, groupadd will deny the group creation request.
The groupadd command exits with the following values: 0 success 2 invalid command syntax 3 invalid argument to option 4 GID not unique (when -o not used) 9 group name not unique 10 can't update group file