Shulou(Shulou.com)06/03 Report--

The first experience of DAY01 Linux system

Linux introduction

Linux system installation (CentOS 7.4)

The operation interface of Linux system

1) graphical desktop

2) Command line operating environment

Configure the network

DAY02 plays the Linux command line

Manage directories and files

Use the vim editor to create and modify files

Manage user and group accounts

1. Command line foundation

1. Command format

Basic usage

Command word [option]... [parameter 1] [parameter 2]...

[] indicates that the content inside is optional.

When executing a command, the command word must exist, and options and parameters are optional

There must be spaces between command word option parameters

Analysis of each component

Option: used to regulate the mode of execution

A single character is usually used-

The word is commonly used--

Eg:

# ls-l

# ls-help

Parameter: the operation object of the command, such as the storage path of the document, user name, etc.

two。 Command line editing skills

Tab key

Function: the completion of a command or path. If the input uniquely identifies a command or path, tab will automatically complete it at one time. If it is not unique, tab2 displays all commands or paths that begin with the input

Take a wrong picture

3. Shortcut key

Ctrl + l: clear the entire screen

Ctrl + c: discard the command line of the current edit

Esc+.: pastes the parameters of the previous command

Second, browse directories and files

1.ls command

Format: ls [options]... [directory or file path]

Common command options

-A: including the name. Hidden document at the beginning

-l: display in long format

-h: must be used with-l to provide readable units of capacity (K, M, etc.)

-d: displays the properties of the directory

Eg:

# ls / root

# ls-l / root

# ls-A / root

# ls-lh / root

Add:

Absolute path: path that begins with /

Relative paths: paths that do not begin with /

Wildcard characters * and?

* match any 0-multiple characters

? Match any single character

Eg:

# ls / dev/tty*

# ls / dev/tty?

# ls / dev/tty??

2.cat command

View the contents of the file

# cat / etc/resolv.conf / / View the DNS address

# cat / etc/redhat-release / / View the mini version of the system

Third, create directories and files

1.mkdir command

Create a directory

-p Recursive create directory

Eg:

[root@localhost /] # cd / opt/

[root@localhost opt] # ls

[root@localhost opt] # mkdir ntd1711

[root@localhost opt] # ls

[root@localhost opt] # mkdir ntd1712

[root@localhost opt] # ls

[root@localhost opt] # mkdir ntd1801/group1/huangsir

[root@localhost opt] # mkdir-p ntd1801/group1/huangsir

[root@localhost opt] # ls

[root@localhost opt] # ls ntd1801/

[root@localhost opt] # ls ntd1801/group1/

[root@localhost opt] # ls-R ntd1801/

Question and answer question

a. How many directories have been created by the following command?

b. Where are these directories created?

# mkdir-p ntd1802/ group2 / xushuai excuse me

2.touch command

Create a file

Touch file name...

Eg:

# cd / vod/movie/cartoon

# mkdir-p / vod/movie/cartoon

# cd / vod/movie/cartoon/

# touch Mulan.mp4 NeZhaNaoHai.mp4

# ls-lh * .mp4

Copy, move, delete

1.cp command

Format: cp [options]... The original document... Target path

Common command options

-r: recursive, this option is required when copying directories

-p: keep the permissions, modification time and other attributes of the original file unchanged

Eg:

[root@localhost ~] # ls-ld / backup

[root@localhost ~] # mkdir / backup

[root@localhost ~] # ls-ld / backup

[root@localhost] # cp-r / boot/grub2 / etc/host.conf / backup/

[root@localhost ~] # ls-ld / backup/*

[root@localhost ~] # cp / boot/ / backup/

[root@localhost ~] # ls-ld / backup/*

[root@localhost] # cp-r / boot/ / backup/

[root@localhost ~] # ls-ld / backup/*

2.rm deletion

Format: rm [options]... File or directory...

Common command options

-r,-f: recursive deletion (including directories), forced deletion

Eg:

[root@localhost ~] # ls-ld / backup/*

[root@localhost ~] # rm / backup/host.conf

[root@localhost] # rm-f / backup/grub2/

[root@localhost ~] # rm-rf / backup/grub2/

[root@localhost ~] # rm-rf / backup/boot/

[root@localhost ~] # ls-ld / backup/*

3.mv move or rename

Format: mv [options]... The original document... Target path

Eg:

[root@localhost ~] # ls-l / vod/movie/cartoon/Mulan.mp4

[root@localhost ~] # mv / vod/movie/cartoon/Mulan.mp4 / backup/

[root@localhost ~] # ls-l / backup/

[root@localhost ~] # mv / backup/Mulan.mp4 / backup/HuaMulan.mp4

[root@localhost ~] # ls-l / backup/

IV. Vim text Editor

1. Three modes

Command mode: the default mode after the file is opened. You can only view the contents of the file and cannot modify it.

Input mode: can be edited and modified

Last line mode: save exit

two。 Handover

Command mode-- > input mode press I key

Command mode-- > last line mode press: key

Input mode and last line mode-- > command mode press ESC

Note: input mode and last line mode cannot be switched directly, but need to go through command mode

3. Vim filename

Open this file if filename exists

Create this file if filename does not exist

Experiment

1. Create a new file hello.sh in the / root/ directory

1) enter the content "Hello World!!"

2) use the cat command to confirm the contents of the file after saving

two。 Modify the system file / etc/hosts

1) add a line of "127.0.0.1 www.baidu.com" at the end

2) use the ping command to test connectivity to www.baidu.com, and observe the results

# ls / root/hello.sh

# vim / root/hello.sh

Press the I key

Enter Hello WorldCraft entries!

Press the ESC key

Press:

Wq!

# ls / root/hello.sh

# cat / root/hello.sh

4. Command mode operation

Cursor inline adjustment

^ = Home key move the cursor to the beginning of the line

$= End key move the cursor to the end of the line

Adjustment between lines of cursor

Gg jumps to the first line of the file

G jumps to the last line of the file

Copy, paste, delete

Yy copies the current line

# yy copy is currently down # lines

P paste under the current cursor

Delete deletes the single character where the current cursor is located

Dd deletes (cuts) the current line

# dd Delete (cut) the current cursor down to # line

Find

/ world the current cursor looks down for world

N next

Eg:

[root@ntd1711 ~] # rm-rf / tmp/*

[root@ntd1711 ~] # mkdir / tmp/test01

[root@ntd1711 ~] # cp / etc/mail.rc / tmp/test01/

[root@ntd1711 ~] # ls / tmp/test01/mail.rc

[root@ntd1711 ~] # vim / tmp/test01/mail.rc

5. Last line mode operation

W save

Q exit

Wq saves and exits

: wq! Force save and exit

W / root/xxx.file saves the current file as / root/xxx.file

R / root/xxx.file loads the / root/xxx.file file into the current file

6. Find and replace

: s/old/new replaces the current line with new as the first old

: s/old/new/g replaces all old in the current line with new

: n s/old/new/g m s/old/new/g replaces all old in line n-m to new

:% s/old/new/g replaces all old in the file as new

U undo

Eg:

[root@ntd1711 test01] # ls / etc/passwd / tmp/test01/passwd

[root@ntd1711 test01] # cp / etc/passwd / tmp/test01/

[root@ntd1711 test01] # ls / etc/passwd / tmp/test01/passwd

[root@ntd1711 test01] # vim / tmp/test01/passwd

Enter in the last line mode

/ root

: s/root/feige

U

: s/root/feige/g

U

: 1,10s/root/feige/g

U

:% s/root/feige/g

U

: q!

Show and close line number

: set nu | nonu

Managing users and groups

1. User management

a. User classification

Super user: administrator account root uid is 0

System users: system services generate uid ranges from 1 to 999

Ordinary user: the account created by the administrator himself, uid range: 1000-60000

b. Create a user

# id account name to verify whether this account exists in the system

# useradd account name create account

c. Set password

# setting password for passwd account

d. Modify account information

# usermod

-l change the login name of the new account and the old account

e. Delete an account

# userdel account Delete account

-r delete along with the home directory

Summary:

When a normal user is created by default, a folder with the same name is created under / home.

This folder is the home directory where the user was created.

Eg:

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # useradd nvshen

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # passwd nvshen

[root@ntd1711 ~] # id miaodt

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # usermod-l miaodt nvshen

[root@ntd1711 ~] # id miaodt

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # usermod-l nvshen miaodt

[root@ntd1711 ~] # id miaodt

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # userdel nvshen

Experiment:

1. Create a new user account named nvshen and set the password to 1234567

Test remote login to the local system as user nvshen

two。 Migrate this user's home directory to the / opt/nvshen directory

Log in to the local system remotely as user nvshen to confirm the location of the current pwd working directory

3. Completely delete the user account named nvshen

Check its ID information and view the results of the prompt. Check whether the home directory is available

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # useradd nvshen

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # passwd nvshen

[root@ntd1711 ~] # ssh nvshen@127.0.0.1

[nvshen@ntd1711 ~] $pwd

[nvshen@ntd1711 ~] $whoami

[nvshen@ntd1711 ~] $exit

[root@ntd1711 ~] # ls-ld / opt/nvshen

[root@ntd1711 ~] # ls-ld / home/nvshen/

[root@ntd1711] # usermod-d / opt/nvshen nvshen

[root@ntd1711 ~] # ls-ld / opt/nvshen

[root@ntd1711 ~] # mv / home/nvshen/ / opt/

[root@ntd1711 ~] # ls-ld / opt/nvshen

[root@ntd1711 ~] # ssh nvshen@127.0.0.1

[nvshen@ntd1711 ~] $pwd

[nvshen@ntd1711 ~] $exit

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # ls-ld / opt/nvshen/

[root@ntd1711 ~] # userdel nvshen

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # ls-ld / opt/nvshen/

two。 Group management

a. Create a group

# groupadd group name

-g gid specifies gid when creating a group

b. Add delete members to the group (users)

# gpasswd

-a: add the specified user as a group member

-d: removes the specified member user from the group

c. Delete a group

# groupdel

Eg:

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # useradd nvshen

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # groupadd-g 600 stugrp

[root@ntd1711 ~] # gpasswd-a nvshen stugrp

[root@ntd1711 ~] # id nvshen

[root@ntd1711 ~] # groupdel stugrp

[root@ntd1711 ~] # id nvshen

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