'\" t
.\"     Title: useradd
.\"    Author: Julianne Frances Haugh
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 2020-02-07
.\"    Manual: 系统管理命令
.\"    Source: shadow-utils 4.8.1
.\"  Language: Chinese Simplified
.\"
.TH "USERADD" "8" "2020-02-07" "shadow\-utils 4\&.8\&.1" "系统管理命令"
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.SH "名称"
useradd \- 创建一个新用户或更新默认新用户信息
.SH "大纲"
.HP \w'\fBuseradd\fR\ 'u
\fBuseradd\fR [\fI选项\fR] \fI登录\fR
.HP \w'\fBuseradd\fR\ 'u
\fBuseradd\fR \-D
.HP \w'\fBuseradd\fR\ 'u
\fBuseradd\fR \-D [\fI选项\fR]
.SH "描述"
.PP
\fBuseradd\fR
is a low level utility for adding users\&. On Debian, administrators should usually use
\fBadduser\fR(8)
instead\&.
.PP
When invoked without the
\fB\-D\fR
option, the
\fBuseradd\fR
command creates a new user account using the values specified on the command line plus the default values from the system\&. Depending on command line options, the
\fBuseradd\fR
command will update system files and may also create the new user\*(Aqs home directory and copy initial files\&.
.PP
By default, a group will also be created for the new user (see
\fB\-g\fR,
\fB\-N\fR,
\fB\-U\fR, and
\fBUSERGROUPS_ENAB\fR)\&.
.SH "选项"
.PP
The options which apply to the
\fBuseradd\fR
command are:
.PP
\fB\-\-badname\fR\ \&
.RS 4
Allow names that do not conform to standards\&.
.RE
.PP
\fB\-b\fR, \fB\-\-base\-dir\fR\ \&\fIBASE_DIR\fR
.RS 4
The default base directory for the system if
\fB\-d\fR\ \&\fIHOME_DIR\fR
is not specified\&.
\fIBASE_DIR\fR
is concatenated with the account name to define the home directory\&. If the
\fB\-m\fR
option is not used,
\fIBASE_DIR\fR
must exist\&.
.sp
If this option is not specified,
\fBuseradd\fR
will use the base directory specified by the
\fBHOME\fR
variable in
/etc/default/useradd, or
/home
by default\&.
.RE
.PP
\fB\-c\fR, \fB\-\-comment\fR\ \&\fICOMMENT\fR
.RS 4
任何字符串。通常是关于登录的简短描述，当前用于用户全名。
.RE
.PP
\fB\-d\fR, \fB\-\-home\-dir\fR\ \&\fIHOME_DIR\fR
.RS 4
The new user will be created using
\fIHOME_DIR\fR
as the value for the user\*(Aqs login directory\&. The default is to append the
\fILOGIN\fR
name to
\fIBASE_DIR\fR
and use that as the login directory name\&. The directory
\fIHOME_DIR\fR
does not have to exist but will not be created if it is missing\&.
.RE
.PP
\fB\-D\fR, \fB\-\-defaults\fR
.RS 4
看下边，\(lq更改默认值\(rq子节。
.RE
.PP
\fB\-e\fR, \fB\-\-expiredate\fR\ \&\fIEXPIRE_DATE\fR
.RS 4
The date on which the user account will be disabled\&. The date is specified in the format
\fIYYYY\-MM\-DD\fR\&.
.sp
If not specified,
\fBuseradd\fR
will use the default expiry date specified by the
\fBEXPIRE\fR
variable in
/etc/default/useradd, or an empty string (no expiry) by default\&.
.RE
.PP
\fB\-f\fR, \fB\-\-inactive\fR\ \&\fIINACTIVE\fR
.RS 4
密码过期后，账户被彻底禁用之前的天数。0 表示立即禁用，\-1 表示禁用这个功能。
.sp
If not specified,
\fBuseradd\fR
will use the default inactivity period specified by the
\fBINACTIVE\fR
variable in
/etc/default/useradd, or \-1 by default\&.
.RE
.PP
\fB\-g\fR, \fB\-\-gid\fR\ \&\fIGROUP\fR
.RS 4
用户初始登陆组的组名或号码。组名必须已经存在。组号码必须指代已经存在的组。
.sp
If not specified, the behavior of
\fBuseradd\fR
will depend on the
\fBUSERGROUPS_ENAB\fR
variable in
/etc/login\&.defs\&. If this variable is set to
\fIyes\fR
(or
\fB\-U/\-\-user\-group\fR
is specified on the command line), a group will be created for the user, with the same name as her loginname\&. If the variable is set to
\fIno\fR
(or
\fB\-N/\-\-no\-user\-group\fR
is specified on the command line), useradd will set the primary group of the new user to the value specified by the
\fBGROUP\fR
variable in
/etc/default/useradd, or 100 by default\&.
.RE
.PP
\fB\-G\fR, \fB\-\-groups\fR\ \&\fIGROUP1\fR[\fI,GROUP2,\&.\&.\&.\fR[\fI,GROUPN\fR]]]
.RS 4
A list of supplementary groups which the user is also a member of\&. Each group is separated from the next by a comma, with no intervening whitespace\&. The groups are subject to the same restrictions as the group given with the
\fB\-g\fR
option\&. The default is for the user to belong only to the initial group\&.
.RE
.PP
\fB\-h\fR, \fB\-\-help\fR
.RS 4
现实帮助信息并退出。
.RE
.PP
\fB\-k\fR, \fB\-\-skel\fR\ \&\fISKEL_DIR\fR
.RS 4
The skeleton directory, which contains files and directories to be copied in the user\*(Aqs home directory, when the home directory is created by
\fBuseradd\fR\&.
.sp
This option is only valid if the
\fB\-m\fR
(or
\fB\-\-create\-home\fR) option is specified\&.
.sp
If this option is not set, the skeleton directory is defined by the
\fBSKEL\fR
variable in
/etc/default/useradd
or, by default,
/etc/skel\&.
.sp
如果可以，也复制 ACL 和扩展属性。
.RE
.PP
\fB\-K\fR, \fB\-\-key\fR\ \&\fIKEY\fR=\fIVALUE\fR
.RS 4
Overrides
/etc/login\&.defs
defaults (\fBUID_MIN\fR,
\fBUID_MAX\fR,
\fBUMASK\fR,
\fBPASS_MAX_DAYS\fR
and others)\&.

Example:
\fB\-K\fR\ \&\fIPASS_MAX_DAYS\fR=\fI\-1\fR
can be used when creating system account to turn off password aging, even though system account has no password at all\&. Multiple
\fB\-K\fR
options can be specified, e\&.g\&.:
\fB\-K\fR\ \&\fIUID_MIN\fR=\fI100\fR\ \&
\fB\-K\fR\ \&\fIUID_MAX\fR=\fI499\fR
.RE
.PP
\fB\-l\fR, \fB\-\-no\-log\-init\fR
.RS 4
不要将用户添加到最近登录和登录失败数据库。
.sp
By default, the user\*(Aqs entries in the lastlog and faillog databases are reset to avoid reusing the entry from a previously deleted user\&.
.sp
For the compatibility with previous Debian\*(Aqs
\fBuseradd\fR, the
\fB\-O\fR
option is also supported\&.
.RE
.PP
\fB\-m\fR, \fB\-\-create\-home\fR
.RS 4
Create the user\*(Aqs home directory if it does not exist\&. The files and directories contained in the skeleton directory (which can be defined with the
\fB\-k\fR
option) will be copied to the home directory\&.
.sp
By default, if this option is not specified and
\fBCREATE_HOME\fR
is not enabled, no home directories are created\&.
.RE
.PP
\fB\-M\fR, \fB\-\-no\-create\-home\fR
.RS 4
Do no create the user\*(Aqs home directory, even if the system wide setting from
/etc/login\&.defs
(\fBCREATE_HOME\fR) is set to
\fIyes\fR\&.
.RE
.PP
\fB\-N\fR, \fB\-\-no\-user\-group\fR
.RS 4
Do not create a group with the same name as the user, but add the user to the group specified by the
\fB\-g\fR
option or by the
\fBGROUP\fR
variable in
/etc/default/useradd\&.
.sp
The default behavior (if the
\fB\-g\fR,
\fB\-N\fR, and
\fB\-U\fR
options are not specified) is defined by the
\fBUSERGROUPS_ENAB\fR
variable in
/etc/login\&.defs\&.
.RE
.PP
\fB\-o\fR, \fB\-\-non\-unique\fR
.RS 4
允许使用重复的 UID 创建用户账户。
.sp
This option is only valid in combination with the
\fB\-u\fR
option\&.
.RE
.PP
\fB\-p\fR, \fB\-\-password\fR\ \&\fIPASSWORD\fR
.RS 4
The encrypted password, as returned by
\fBcrypt\fR(3)\&. The default is to disable the password\&.
.sp
\fBNote:\fR
This option is not recommended because the password (or encrypted password) will be visible by users listing the processes\&.
.sp
您应该确保密码符合系统的密码政策。
.RE
.PP
\fB\-r\fR, \fB\-\-system\fR
.RS 4
创建一个系统账户。
.sp
System users will be created with no aging information in
/etc/shadow, and their numeric identifiers are chosen in the
\fBSYS_UID_MIN\fR\-\fBSYS_UID_MAX\fR
range, defined in
/etc/login\&.defs, instead of
\fBUID_MIN\fR\-\fBUID_MAX\fR
(and their
\fBGID\fR
counterparts for the creation of groups)\&.
.sp
Note that
\fBuseradd\fR
will not create a home directory for such a user, regardless of the default setting in
/etc/login\&.defs
(\fBCREATE_HOME\fR)\&. You have to specify the
\fB\-m\fR
options if you want a home directory for a system account to be created\&.
.RE
.PP
\fB\-R\fR, \fB\-\-root\fR\ \&\fICHROOT_DIR\fR
.RS 4
Apply changes in the
\fICHROOT_DIR\fR
directory and use the configuration files from the
\fICHROOT_DIR\fR
directory\&.
.RE
.PP
\fB\-P\fR, \fB\-\-prefix\fR\ \&\fIPREFIX_DIR\fR
.RS 4
Apply changes in the
\fIPREFIX_DIR\fR
directory and use the configuration files from the
\fIPREFIX_DIR\fR
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\&.
.RE
.PP
\fB\-s\fR, \fB\-\-shell\fR\ \&\fISHELL\fR
.RS 4
The name of the user\*(Aqs login shell\&. The default is to leave this field blank, which causes the system to select the default login shell specified by the
\fBSHELL\fR
variable in
/etc/default/useradd, or an empty string by default\&.
.RE
.PP
\fB\-u\fR, \fB\-\-uid\fR\ \&\fIUID\fR
.RS 4
The numerical value of the user\*(Aqs ID\&. This value must be unique, unless the
\fB\-o\fR
option is used\&. The value must be non\-negative\&. The default is to use the smallest ID value greater than or equal to
\fBUID_MIN\fR
and greater than every other user\&.
.sp
See also the
\fB\-r\fR
option and the
\fBUID_MAX\fR
description\&.
.RE
.PP
\fB\-U\fR, \fB\-\-user\-group\fR
.RS 4
创建一个和用户同名的组，并将用户添加到组中。
.sp
The default behavior (if the
\fB\-g\fR,
\fB\-N\fR, and
\fB\-U\fR
options are not specified) is defined by the
\fBUSERGROUPS_ENAB\fR
variable in
/etc/login\&.defs\&.
.RE
.PP
\fB\-Z\fR, \fB\-\-selinux\-user\fR\ \&\fISEUSER\fR
.RS 4
用户登陆的 SELinux 用户。默认为留空，这会造成系统选择默认的 SELinux 用户。
.RE
.SS "更改默认值"
.PP
When invoked with only the
\fB\-D\fR
option,
\fBuseradd\fR
will display the current default values\&. When invoked with
\fB\-D\fR
plus other options,
\fBuseradd\fR
will update the default values for the specified options\&. Valid default\-changing options are:
.PP
\fB\-b\fR, \fB\-\-base\-dir\fR\ \&\fIBASE_DIR\fR
.RS 4
The path prefix for a new user\*(Aqs home directory\&. The user\*(Aqs name will be affixed to the end of
\fIBASE_DIR\fR
to form the new user\*(Aqs home directory name, if the
\fB\-d\fR
option is not used when creating a new account\&.
.sp
This option sets the
\fBHOME\fR
variable in
/etc/default/useradd\&.
.RE
.PP
\fB\-e\fR, \fB\-\-expiredate\fR\ \&\fIEXPIRE_DATE\fR
.RS 4
禁用此用户账户的日期。
.sp
This option sets the
\fBEXPIRE\fR
variable in
/etc/default/useradd\&.
.RE
.PP
\fB\-f\fR, \fB\-\-inactive\fR\ \&\fIINACTIVE\fR
.RS 4
密码过期到账户被禁用之前的天数。
.sp
This option sets the
\fBINACTIVE\fR
variable in
/etc/default/useradd\&.
.RE
.PP
\fB\-g\fR, \fB\-\-gid\fR\ \&\fIGROUP\fR
.RS 4
The group name or ID for a new user\*(Aqs initial group (when the
\fB\-N/\-\-no\-user\-group\fR
is used or when the
\fBUSERGROUPS_ENAB\fR
variable is set to
\fIno\fR
in
/etc/login\&.defs)\&. The named group must exist, and a numerical group ID must have an existing entry\&.
.sp
This option sets the
\fBGROUP\fR
variable in
/etc/default/useradd\&.
.RE
.PP
\fB\-s\fR, \fB\-\-shell\fR\ \&\fISHELL\fR
.RS 4
新用户的登录 shell 名。
.sp
This option sets the
\fBSHELL\fR
variable in
/etc/default/useradd\&.
.RE
.SH "注意："
.PP
The system administrator is responsible for placing the default user files in the
/etc/skel/
directory (or any other skeleton directory specified in
/etc/default/useradd
or on the command line)\&.
.SH "CAVEATS"
.PP
您可能不能想 NIS 组或 LDAP 组添加用户。这只能在相应服务器上进行。
.PP
Similarly, if the username already exists in an external user database such as NIS or LDAP,
\fBuseradd\fR
will deny the user account creation request\&.
.PP
It is usually recommended to only use usernames 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_\-]*[$]?
.PP
On Debian, the only constraints are that usernames must neither start with a dash (\*(Aq\-\*(Aq) nor plus (\*(Aq+\*(Aq) nor tilde (\*(Aq~\*(Aq) nor contain a colon (\*(Aq:\*(Aq), a comma (\*(Aq,\*(Aq), or a whitespace (space: \*(Aq \*(Aq, end of line: \*(Aq\en\*(Aq, tabulation: \*(Aq\et\*(Aq, etc\&.)\&. Note that using a slash (\*(Aq/\*(Aq) may break the default algorithm for the definition of the user\*(Aqs home directory\&.
.PP
用户名不能超过 32 个字符长。
.SH "配置文件"
.PP
The following configuration variables in
/etc/login\&.defs
change the behavior of this tool:
.PP
\fBCREATE_HOME\fR (boolean)
.RS 4
指示是否应该为新用户默认创建主目录。
.sp
此设置并不应用到系统用户，并且可以使用命令行覆盖。
.RE
.PP
\fBGID_MAX\fR (number), \fBGID_MIN\fR (number)
.RS 4
Range of group IDs used for the creation of regular groups by
\fBuseradd\fR,
\fBgroupadd\fR, or
\fBnewusers\fR\&.
.sp
The default value for
\fBGID_MIN\fR
(resp\&.
\fBGID_MAX\fR) is 1000 (resp\&. 60000)\&.
.RE
.PP
\fBHOME_MODE\fR (number)
.RS 4
The mode for new home directories\&. If not specified, the
\fBUMASK\fR
is used to create the mode\&.
.sp
\fBuseradd\fR
and
\fBnewusers\fR
use this to set the mode of the home directory they create\&.
.RE
.PP
\fBLASTLOG_UID_MAX\fR (number)
.RS 4
Highest user ID number for which the lastlog entries should be updated\&. As higher user IDs are usually tracked by remote user identity and authentication services there is no need to create a huge sparse lastlog file for them\&.
.sp
No
\fBLASTLOG_UID_MAX\fR
option present in the configuration means that there is no user ID limit for writing lastlog entries\&.
.RE
.PP
\fBMAIL_DIR\fR (string)
.RS 4
邮箱目录。修改或删除用户账户时需要处理邮箱，如果没有指定，将使用编译时指定的默认值。
.RE
.PP
\fBMAIL_FILE\fR (string)
.RS 4
定义用户邮箱文件的位置(相对于主目录)。
.RE
.PP
The
\fBMAIL_DIR\fR
and
\fBMAIL_FILE\fR
variables are used by
\fBuseradd\fR,
\fBusermod\fR, and
\fBuserdel\fR
to create, move, or delete the user\*(Aqs mail spool\&.
.PP
\fBMAX_MEMBERS_PER_GROUP\fR (number)
.RS 4
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)\&.
.sp
默认值是 0，意味着组中的成员数没有限制。
.sp
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。
.sp
如果要强制这个限制，可以使用 25。
.sp
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。
.RE
.PP
\fBPASS_MAX_DAYS\fR (number)
.RS 4
一个密码可以使用的最大天数。如果密码比这旧，将会强迫更改密码。如果不指定，就假定为 \-1，这会禁用这个限制。
.RE
.PP
\fBPASS_MIN_DAYS\fR (number)
.RS 4
两次更改密码时间的最小间隔。将会拒绝任何早于此的更改密码的尝试。如果不指定，假定为 \-1，将会禁用这个限制。
.RE
.PP
\fBPASS_WARN_AGE\fR (number)
.RS 4
密码过期之前给出警告的天数。0 表示只有只在过期的当天警告，负值表示不警告。如果没有指定，不会给警告。
.RE
.PP
\fBSUB_GID_MIN\fR (number), \fBSUB_GID_MAX\fR (number), \fBSUB_GID_COUNT\fR (number)
.RS 4
If
/etc/subuid
exists, the commands
\fBuseradd\fR
and
\fBnewusers\fR
(unless the user already have subordinate group IDs) allocate
\fBSUB_GID_COUNT\fR
unused group IDs from the range
\fBSUB_GID_MIN\fR
to
\fBSUB_GID_MAX\fR
for each new user\&.
.sp
The default values for
\fBSUB_GID_MIN\fR,
\fBSUB_GID_MAX\fR,
\fBSUB_GID_COUNT\fR
are respectively 100000, 600100000 and 65536\&.
.RE
.PP
\fBSUB_UID_MIN\fR (number), \fBSUB_UID_MAX\fR (number), \fBSUB_UID_COUNT\fR (number)
.RS 4
If
/etc/subuid
exists, the commands
\fBuseradd\fR
and
\fBnewusers\fR
(unless the user already have subordinate user IDs) allocate
\fBSUB_UID_COUNT\fR
unused user IDs from the range
\fBSUB_UID_MIN\fR
to
\fBSUB_UID_MAX\fR
for each new user\&.
.sp
The default values for
\fBSUB_UID_MIN\fR,
\fBSUB_UID_MAX\fR,
\fBSUB_UID_COUNT\fR
are respectively 100000, 600100000 and 65536\&.
.RE
.PP
\fBSYS_GID_MAX\fR (number), \fBSYS_GID_MIN\fR (number)
.RS 4
Range of group IDs used for the creation of system groups by
\fBuseradd\fR,
\fBgroupadd\fR, or
\fBnewusers\fR\&.
.sp
The default value for
\fBSYS_GID_MIN\fR
(resp\&.
\fBSYS_GID_MAX\fR) is 101 (resp\&.
\fBGID_MIN\fR\-1)\&.
.RE
.PP
\fBSYS_UID_MAX\fR (number), \fBSYS_UID_MIN\fR (number)
.RS 4
Range of user IDs used for the creation of system users by
\fBuseradd\fR
or
\fBnewusers\fR\&.
.sp
The default value for
\fBSYS_UID_MIN\fR
(resp\&.
\fBSYS_UID_MAX\fR) is 101 (resp\&.
\fBUID_MIN\fR\-1)\&.
.RE
.PP
\fBUID_MAX\fR (number), \fBUID_MIN\fR (number)
.RS 4
Range of user IDs used for the creation of regular users by
\fBuseradd\fR
or
\fBnewusers\fR\&.
.sp
The default value for
\fBUID_MIN\fR
(resp\&.
\fBUID_MAX\fR) is 1000 (resp\&. 60000)\&.
.RE
.PP
\fBUMASK\fR (number)
.RS 4
文件模式创建掩码初始化为此值。如果没有指定，掩码初始化为 022。
.sp
\fBuseradd\fR
and
\fBnewusers\fR
use this mask to set the mode of the home directory they create if
\fBHOME_MODE\fR
is not set\&.
.sp
It is also used by
\fBpam_umask\fR
as the default umask value\&.
.RE
.PP
\fBUSERGROUPS_ENAB\fR (boolean)
.RS 4
If set to
\fIyes\fR,
\fBuserdel\fR
will remove the user\*(Aqs group if it contains no more members, and
\fBuseradd\fR
will create by default a group with the name of the user\&.
.RE
.SH "文件"
.PP
/etc/passwd
.RS 4
用户账户信息。
.RE
.PP
/etc/shadow
.RS 4
安全用户账户信息。
.RE
.PP
/etc/group
.RS 4
组账户信息。
.RE
.PP
/etc/gshadow
.RS 4
安全组账户信息。
.RE
.PP
/etc/default/useradd
.RS 4
账户创建的默认值。
.RE
.PP
/etc/skel/
.RS 4
包含默认文件的目录。
.RE
.PP
/etc/subgid
.RS 4
Per user subordinate group IDs\&.
.RE
.PP
/etc/subuid
.RS 4
Per user subordinate user IDs\&.
.RE
.PP
/etc/login\&.defs
.RS 4
Shadow 密码套件配置。
.RE
.SH "退出值"
.PP
The
\fBuseradd\fR
command exits with the following values:
.PP
\fI0\fR
.RS 4
success
.RE
.PP
\fI1\fR
.RS 4
can\*(Aqt update password file
.RE
.PP
\fI2\fR
.RS 4
invalid command syntax
.RE
.PP
\fI3\fR
.RS 4
invalid argument to option
.RE
.PP
\fI4\fR
.RS 4
UID already in use (and no
\fB\-o\fR)
.RE
.PP
\fI6\fR
.RS 4
specified group doesn\*(Aqt exist
.RE
.PP
\fI9\fR
.RS 4
username already in use
.RE
.PP
\fI10\fR
.RS 4
can\*(Aqt update group file
.RE
.PP
\fI12\fR
.RS 4
can\*(Aqt create home directory
.RE
.PP
\fI14\fR
.RS 4
can\*(Aqt update SELinux user mapping
.RE
.SH "参见"
.PP
\fBchfn\fR(1),
\fBchsh\fR(1),
\fBpasswd\fR(1),
\fBcrypt\fR(3),
\fBgroupadd\fR(8),
\fBgroupdel\fR(8),
\fBgroupmod\fR(8),
\fBlogin.defs\fR(5),
\fBnewusers\fR(8),
\fBsubgid\fR(5), \fBsubuid\fR(5),
\fBuserdel\fR(8),
\fBusermod\fR(8)\&.