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

I. Knowledge review:

All IT knowledge is based on the OSI seven-layer model (TCP/IP four-layer).

Agreement: (provisions)

Application layer protocol: http https(B/S) ssh telnet smtp pop3 imap ftp tftp dns dhcp

Transport layer: tcp udp --port

Network layer: Routing protocol is routed protocol (IPv4 IPv6) x.x.x.

Data link layer: Ethernet protocol MAC ff:ff Globally unique

Physical layer: electrical signal of 01

Linux directory structure

Disk Management for Linux

fdisk --partition (logical boundary) written to file system;-l naming of disk

mkfs -t //Specifies the file system format;

mount The mount point of the device to be mounted [Storage devices must be mounted on Linux systems]

umount Device/mount point to mount on

df -h

/etc/fstab for boot automount

/ /bin /sbin

/etc

/usr /usr/local/

/var

/opt

/sys /proc

/tmp

/lib /lib64

/home /root

/cdrom /media /mnt

Common commands for directory file operations:

ls file wildcard globbing ? [ ] ^ $

cd . .. ~ -Absolute path and relative path

grep

regular expression

1. String matching. [] [^] [:digit:] [:alpha:] ...

Number 2, matching? {m} {m,n} {0,n} {m,}

3. Position anchoring ^ $ \b

4. Group (ab) abab

ab abbbbb

.*

-v

-i

^$ --blank line

mkdir -pv Create multi-level subdirectories simultaneously

rm -r

rmdir delete empty directory

tree -L -d

II. File related commands 1. Create and delete operations

Touch modify timestamp stat (atime mtime ctime), create file if it doesn't exist

-C

MMDDhhmm[CC]YY.ss

top --> View progress [CPU: sy ur]

-a

Rm

find [Range]-file d -name a* [file properties]

-exec command {}\;

-ok command {}\;

| xargs command;

【Mkdir -pv】

2. Copy and move files

Cp -a //Copy all file attributes together

Mv move 1, Move file 2, Modify file name

mv a b

mv /tmp/a /root/

filename extensions

{}

Create directory Name_Student ID Zhao Yun 00001

mkdir {Zhao Yun, Shi Lei}{00001,00002}

Zhao Yun_00001

Zhao Yun_00002

Shi Lei_00001

Shi Lei_00002

3. View file contents

Cat View everything in a file at once

cat /etc/init.d/

More //man command

/

?

q

Less in more clearance, view large files, we use less

Tail Default View Countdown 10 Lines

-n // tail -n 20 File name simplification: -20

-f Do not exit the file, view the file content in real time

Head View line head

-n // head -n 20 File name simplification: -20

4. Other

Echo -e -n

echo $PATH

-n // print("Hello World",end='\t') print("Hello World")

print("Hello World")

-e Identification\t \n \r

echo -n -e "Hello World \t"

Redirect> and>>

fd file identifier

0 --Standard input

1 --Standard output

2 --Error output

Program = Instruction + Data

code variable

Where does the data in the variable come from? Where does the data executed by the code go?

Specification: Default standard input is--keyboard standard output is--display

III. input redirection

And redirection is used to change input and output.

Give the following documents to the previous command for execution;

tr command, replace the previous content with the following content

tr abc ABC

>EOF

IV. Error output redirection

2> FD (file identifier) is required

2>> Added error redirect output

Extended optimization:

cat a.txt>/dev/null

cat.a txt2>/dev/null

& >/dev/null Assign output to/dev/null whether the command executes correctly or not

&>>[General]

v. Pipeline:

command1|command2|command3|command4|......

Output the execution result of the previous command to the next command for execution;

Linux Thinking: Combining Small Functions to Complete Complex Functions

tail -7/etc/fstab|cut -d' ' -f1

cut

-d Specify delimiter ' '

-f Get column 1 - 3 1,3 1 1

VI.Linux Remote

###I. View or configure network card information

Network card and IP address

ifconfig

Without this command, we need to install net-tools

apt install net-tools

If the NIC does not work, we need to modify the default NIC configuration file;

/etc/network/interfaces

vim /etc/network/interfaces

1. Dynamic- dhcp

auto eth0

iface eth0 inet dhcp

[If you modify the configuration file, you need to restart the service]

/etc/init.d/networking restart

2, static-manual configuration

address 192.168.94.10

netmask 255.255.255.0

gateway 192.168.94.1

II. remote management mechanism

1. Ssh enables listening on Ubuntu's ssh port;

tcp-22

netstat -tnl // t -- tcp protocol n --do not parse

If not: apt install opensh-server-y

/etc/init.d/ssh start

[Ubuntu can only use ordinary users for remote connection by default]

ssh teacher@192.168.94.10

Under centos, you can log in remotely directly using root user;

ssh root@192.168.94.10

2. No password remote login [See screenshot]

VII. 1. Basic concepts of users and permissions

chmod rwx 7 r-- 4 -w- 2 --x 1 rw-

rwx

111

chown modify parent and group

root:root

chown teacher: files

chown :teacher file

chown techaer:teacher files

2. Command of user management terminal

useradd

userdel

3. Group Management Terminal Command

groupadd

groupdel

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.