linux用户管理命令(添加,删除,修改) Linux user managementcommands (add, del et e, modi fy)
Linux forced landing users kicked off
View users landing in machines
[root@sunsyk w~]#
16:29:02 up 2 days, 2:35, 5 users, load average: 0.03, 0.05,
0.01
USER, TTY, FROM, LOGIN@, IDLE, JCPU, PCPU, WHAT
Root pts/1 : 0, Tue15, 2days, 1:44, 0.04s, -bash
Root pts/2: 0, Tue15, 46:42m, 0.05s, 0.05s, Bash
Root pts/3: 0, Tue15, 2days, 0.02s, 0.02s, Bash
Root, pts/4, 172.20.52. 114, 14: 17, 58:48, 0. 16s, 0.03s,sqlplus
Root, pts/5, 172.20.52. 114, 15:31, 0.00s, 0.03s, 0.00s, wI put the pts/1 out (only root to kick off the user)[root@sunsyk pkill -kill -t pts/1 ~]#
[root@sunsyk pkill -kill -t pts/2 ~]#
[root@sunsyk pkill -kill -t pts/3 ~]#
See is not kicked off
[root@sunsyk w~]#
16:34:16 up 2 days, 2:40, 2 users, load average: 0, 0.05, 0.02USER, TTY, FROM, LOGIN@, IDLE, JCPU, PCPU, WHAT
Root, pts/4, 172.20.52. 114, 14: 17, 1 :04m, 0. 16s, 0.03s,sqlplus
Root, pts/5, 172.20.52. 114, 15:31, 0.00s, 0.03s, 0.00s, wLog in as the login command:
During the user login system, you can also change the identitywith the "login" command and even log on to other hosts inaddition to the "Su-" command. If you use the "login" commandto change the identity, as long as the input will change theusername directly in the command: [root@ns1 root]# loginCaroline - > change user name is Caroline, if you want to logon the other host, need to use the "-h"parameter to the "login"command: [root@ns1 root]# login-h linux2 - >Linux2 login forthe host.
Log in as the rlogin command:
Inaddition to using the login command, rlogin can alsobe usedto log on to remote hosts, and its usage is simple. Here is an
example of a connection to linux2. jschouse.com:
[root@ns1 root]# rlogin linux2. jschouse.com - >linux2. jschouse. com login
Password: is in the same name - > * login default, so there isno "login" informat ion
Login incorrect- > if the name used to login with the username,can directly press the "Enter", and ignore the errori nformat ion
Login: Jack - > to enter a different username
Password: * - > password
The use of /etc/nologin files:
If you want to only root can log on the host, other account cannot log in, you can add a file named "nologin" in the /etcdirectory in the file, as long as the random input characterscan be found in the file system as long as there will preventother users login.
System logout:
The front is introduced to change the identity in the "login"command, and can log on the other host, and login relative tothe command "logout", it can make the currently logged on userlog off the system, so that other users login. The use of thiscommand is simple. You can log on to the system as long as you
enter "logout": [root@ns1 root]# logout
As described earlier, the Linux system is a multi-useroperating system, and each user' s access to the system needsto be set by the system administrator. This section describessome of the commands that the system administrator manages forusers and user groups.
4.6. 1 creates new users
The useradd command (also using addUser) is used to create anew user account with the following commands:
Table 4 - 19 useradd command common options
Common phenomenon
Significance
-d
Sets the landing directory for new users
-e
Set the new user' s stop date, the date format is MM/DD/YY-f
A few days after the account has expired permanent suspension.The value is 0 when the account is immediately stopped. When
duty is -1, this function is turned off. The default value is-1
-g
Enable new users to join groups
-G
Add new users to a new group. Each group is separated by commas,which must not be enclosed in blank words
-s
Specifies the login Shell for the new user
-u
Sets the ID value for new users
When a new user is created successfully, a line of informationabout that user is added to the /etc/passwd file, formatted asfollows:
[user name: [password] : [UID] : [GID] : [identity description] :[home directory] [landing Shell]
One of the fields is divided into 7 parts by the colon ":".Because less than 500 of the UID and GID are generally the systemitself retained, do not do ordinary users and groups of signs,
so the new increase in users and groups are generally UID andGID greater than 500.
For example, use the following command:
Root@localhost root useradd user1 #
A user named userl will be created, and the user managementcommand has been introduced, and no more is introduced here.The result of executing the useradd command is shown in figure11-13.
4.6.2 sets and modifies user password passwd
The passwd command is used to set and modify user commands. Onlysuper users and users can change their passwords themselves,and other ordinary users do not have the right to modify otheruser passwords. Its order is as follows:
# passwd username.
To avoid entering passwords, it is noticed howmany bits, Linuxdoes not use a password like Windows echo [shown as *] , so theinput of these characters is invisible. For example, to setpasswords for new userl users, use the following command:Root@localhost root passwd user1 #
According to the system prompted information, enter thepassword two times, the system will display:
Passwd: : all, authentication, tokens, updated, successfullyIndicates that the change password succeeded. The new user' sjob is completed only after the user has set the password,otherwise the user name cannot be used to log on.
4.6. 3 modify user information usermod
The usermod command is used to modify user information, and itscommand format is as follows:
# usermod option: user name.
The common command option, 11-20, is shown.
Table 4-20 common options for usermod commands
Common options
Significance
-d
Update the user' s new login directory
-e
Set the new user' s stop date, the date format is MM/DD/YY-f
A few days after the account has expired permanent suspension.The value is 0 when the account is immediately stopped. Whenduty is -1, this function is turned off. The default value is-1
-g
Update user new user to join group
-G
Define the user as a group of groups members. Each group uses"?"" Separate from blank words
-l
To change the name of the user login, the user at the same timethe directory name will follow the change into a new name-s
Specify a new user Shell
-u
The user ID value must be the unique ID value. The user directorytree document directory the userID will automatically changeon the support directory document is to manually changeFor example, the following command modif ies user information:
Root@localhost root usermod- d/home/user2 s/bin/bash user2 -#
Set the home directory path for user name user2 at/home/user1,and the Shell setting for login to /usr/bin/gcc.
In general, the usermod command modifies user accountinformation with reference to the commands section. However,usermod does not allow changing the user account name on theline, so when using usermod to change user account information,You must verify that this name has not been executed on thec omputer.
4.6.4 new group groupadd
The groupadd command is used to create a new group of users,and the commands are as follows:
# groupadd options: user name.
Common options are:
-g:GID value. Unless the -o parameter is used, the value mustbe unique, not the same, and the value must not be negative.The GID value is preset to be minimum, not less than 500 andincreased sequentially. 0 - 499 is traditionally reserved forsystem account usage.
柚子互联官网商家介绍柚子互联(www.19vps.cn)本次给大家带来了盛夏促销活动,本次推出的活动是湖北十堰高防产品,这次老板也人狠话不多丢了一个6.5折优惠券而且还是续费同价,稳撸。喜欢的朋友可以看看下面的活动详情介绍,自从站长这么久以来柚子互联从19年开始算是老商家了。六五折优惠码:6kfUGl07活动截止时间:2021年9月30日客服QQ:207781983本次仅推荐部分套餐,更多套餐可进...
近日华纳云发布了最新的618返场优惠活动,主要针对旗下的免备案香港云服务器、香港独立服务器、香港高防御服务器等产品,月付6折优惠起,高防御服务器可提供20G DDOS防御,采用E5处理器V4CPU性能,10Mbps独享CN2 GIA高速优质带宽,有需要免备案香港服务器、香港云服务器、香港独立服务器、香港高防御服务器、香港物理服务器的朋友可以尝试一下。华纳云好不好?华纳云怎么样?华纳云服务器怎么样?...
GreenCloudVPS最近在新加坡DC2节点上了新机器,Dual Xeon Silver 4216 CPU,DDR4内存,10Gbps网络端口,推出了几款大硬盘VPS套餐,基于KVM架构,500GB磁盘起年付30美元。除了大硬盘套餐外,还加推了几款采用NVMe硬盘的常规套餐,最低年付20美元。不过需要提醒的是,机房非直连中国,尤其是电信用户ping值感人,包括新加坡DC1也是如此。大硬盘VPS...