Linux User Management related

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Four files associated with a user

/etc/passwd

/etc/shadow

/etc/group

/etc/gshadow

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Look at the simulation:

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Already in the user's home directory.

Try again, command aliases

originally this user grep did not define a command alias

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Now let's modify the. Bash_profile file to see if the new user will copy the past

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Delete the original first, indicating that a process is in use,kill off

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new, and then with grep, there's a color display

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Summarize the role of Skel:

1, you can put the content of the notice to Skel, let the person who log in to see

2. Unified initialization of new user environment variables

3. Interview questions: Causes of-bash-4.1$ problems and solutions

-bash-4.1$ Home directory environment variables are gone.

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Understand the next

[Email protected] ~ 22:04:59] #cat/etc/login.defs

UMASK 077

Directory Permissions 777-077 700 permissions

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Changed the default Shell to tcsh .

Add new users, the default is the Tcsh .

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You can also change this:

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Instance:

Customize user's home directory, shell type, user group to which they belong, etc.

Add user Test90, and set its user comments to Hell Linux,uid specified as 888, belong to the user group ROOT,TEST80,TEST70 members, its shell is/bin/sh, set home directory for/TEST90

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Groupadd

Documents related to it

/etc/group user group related files

/etc/gshadow user group encryption related files

-G xx Specify GID

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Non-interactive password change

Example 1:

Create 6 user stu01-stu06 in bulk, and set a random 8-bit password that requires no shell looping

Can only be implemented with commands and pipelines

http://oldboy.blog.51cto.com/2561410/1608552

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666

Example 2:

Require curry users can not change the password within 7 days, 60 days after the password must be modified, 10 days before the expiration of the notification curry users,

Users are not allowed to log on for 30 days after expiration.

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This can also be

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Cat/etc/shadow

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Read the shadow file mainly

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Some view commands

W Show who's logged on and what they aredoing

Who show who's logged on

Last shows the history of user login

/var/log/wtmp

Lastlog Displays the user's most recent logon situation

/var/log/lastlog

Groups see in which group

Id

Users

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When the SU command is executed without any parameters, it indicates that you want to switch to the root user, but doing so will encounter some problems, because although

is to switch to the root user, but did not change to the root user login environment, the user default login environment, can be found in the/etc/passwd, including home directory, Shell type, etc., the more standard operation method is Su-root

If you directly su words, though it is Root , but the view information displays the environment variable information or Curry,:

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That's OK.

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http://oldboy.blog.51cto.com/2561410/1053606/

by su and the Su- on the difference between learning Linux operation and Maintenance methods

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#visudo = vim/etc/sudoers equivalent to

But the first one has the grammar check function, generally uses the first one.

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To write a command full path

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When executing, add sudo to the front

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This article is from the "11745576" blog, please be sure to keep this source http://11755576.blog.51cto.com/11745576/1983280

Linux User Management related