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.
久久网云怎么样?久久网云好不好?久久网云是一家成立于2017年的主机服务商,致力于为用户提供高性价比稳定快速的主机托管服务,久久网云目前提供有美国免费主机、香港主机、韩国服务器、香港服务器、美国云服务器,香港荃湾CN2弹性云服务器。专注为个人开发者用户,中小型,大型企业用户提供一站式核心网络云端服务部署,促使用户云端部署化简为零,轻松快捷运用云计算!多年云计算领域服务经验,遍布亚太地区的海量节点为...
2022年春节假期陆续结束,根据惯例在春节之后各大云服务商会继续开始一年的促销活动。今年二月中旬会开启新春采购季的活动,我们已经看到腾讯云商家在春节期间已经有预告活动。当时已经看到有抢先优惠促销活动,目前我们企业和个人可以领取腾讯云代金券满减活动,以及企业用户可以领取域名优惠低至.COM域名1元。 直达链接 - 腾讯云新春采购活动抢先看活动时间:2022年1月20日至2022年2月15日我们可以在...
EtherNetservers是一家成立于2013年的英国主机商,提供基于OpenVZ和KVM架构的VPS,数据中心包括美国洛杉矶、新泽西和杰克逊维尔,商家支持使用PayPal、支付宝等付款方式,提供 60 天退款保证,这在IDC行业来说很少见,也可见商家对自家产品很有信心。有需要便宜VPS、多IP VPS的朋友可以关注一下。优惠码SUMMER-VPS-15 (终身 15% 的折扣)SUMMER-...