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HomeSystem TutorialLINUXLinux users are divided into three categories: 1. User management commands

Linux users are divided into three categories

1. User management commands (1) useradd—new user account

Sentence pattern

useradd (选项)用户名

Options

-ccommentAdd comments to new users

-dhome_dir specifies a name for the home directory (if you do not want to use the login name as the home directory name)

-eexpire_date specifies the date an account expires in YYYYY-MM-DD format

-finactive_days specifies the number of days after the account password expires that the account will be disabled; 0 means that the account will be disabled as soon as the password expires

Use -1 to disable this function

-ginitial_group specifies the GID or group name of the user login group

-Ggroup...Specify one or more additional groups to which the user belongs in addition to the login group

-k must be used together with -m. Is there a future for learning linux? Download the linux system image and copy the contents of the /etc/skel directory to the user's HOME directory

-mCreate the user's HOME directory

-M does not create the user's HOME directory (only used when creation is specified in the default settings linux sets user group permissions)

-nCreate a new group with the same name as the user's login name

-rCreate system account

linux设置用户组权限_linux用户组和权限管理_linux组权限

-ppasswd specifies a default password for a user account

-sshell specifies the default login shell

-uuid specifies a unique UID for the account

Example—Create a new user zhangsan, the user group is net04

[root@localhost /]# useradd -g net04 zhangsan

(2) passwd—Set or change the user’s password and password attributes

Sentence pattern

passwd (选项)用户

Options

-kkeepnon-expiredauthenticationtokens

-lTurn off the account password. The effect is equivalent to usermod-L. Only root has the right to use this.

-uRecover account password. The effect is equivalent to usermod-Ulinux setting user group permissions, and only root has the right to use it.

-gChange the group password. Equivalent command of gpasswd.

-f Modifies the user information accessed by the finger command.

-d关掉使用者的密码认证功能,使用者在登陆时将可以不用输入密码,只有具备root权限的使用者方可使用.

linux设置用户组权限_linux用户组和权限管理_linux组权限

-S显示指定使用者的密码认证种类,只有具备root权限的使用者方可使用.

实例—设置与更改属性

[root@localhost /]# passwd zhangsan

(3)usermod命令—修改用户的属性(超级用户可用)

句型

usermod (选项)用户名

选项

-c更改用户账号的备注文字。

-d登陆目录>更改用户登录时的目录。

-e更改账号的有效时限。

-f更改在密码过期后多少天即关掉该账号。

-g更改用户所属的群组。

-G更改用户所属的附加群组。

-l更改用户账号名称。

-L锁定用户密码,使密码无效。

linux设置用户组权限_linux组权限_linux用户组和权限管理

-s更改用户登录后所使用的shell。

-u更改用户ID。

-U解除密码锁定

实例—将zhangsan改为zhangs

[root@localhost /]# usermod -l zhangs zhangsan

(4)userdel命令—删除指定的用户帐号(超级用户可用)

句型

userdel (选项)用户名

(5)su命令—切换用户身分

句型

su 用户名

(6)id命令—查看用户的UID、GID和用户所属用户组的信息

句型

id 用户名

(7)whoami命令—查看当前用户名

句型

whoami [--help][--version]

(8)w命令—查看当前登入系统用户和详尽信息二、用户组管理类命令(1)groupadd—新建组群(超级用户可用)

句型

groupadd (选项)用户组名

选项

-g:指定用户组ID

-o:准许组ID号不惟一(2)groupmod命令—修改指定用户组的属性(超级用户可用)

句型

groupmod (选项)用户组名

选项

-g:指定新的用户组ID

-n:指定新的用户组名子

-o:准许组ID号不惟一(3)groupdel命令—删除指定的用户组(超级用户可用)

句型

linux用户组和权限管理_linux设置用户组权限_linux组权限

groupdel 用户组名

三、文件权限管理类命令(1)chmod命令—修改文件的访问权限

句型

chmod (模式)文件

模式

对象:u文件所有者、g同组用户、o其他用户

操作符:+降低、-删掉、=赋于

权限:r读、w写、x执行、s设置用户ID

实例—取消同组用户对file文件的写入权限

[root@localhost /]# chmod g-w file

将pict目录的访问权限设置为775

[root@localhost /]# chmod 775 pict

(2)chown命令—将指定文件的拥有者改为指定的用户或用户组

句型

chown (选项)(所有者/组) 文件

(3)chgrp命令—改变文件的所属用户组

句型

chgrp(选项)(组)文件

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