Common Linux Commands

The current user switches to the root user

su
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Switching common Users

Su user nameCopy the code

Mkdir Creates folders recursively

mkdir -p /home/keith/demo/hello
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Cp Copy command

cp -r /home/.bashrc /keith/ # recursively copy /home/.bashrc to/Keith /
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Tar Compression and decompression command

tar -czvf /home/.bashrc # Compress /home/.bashrc file
tar -xzvf /home/.bashrc Unzip /home/.bashrc
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Grep text search command

grep -n hello a.txt # search for the hello string in a.t_t and display the line number
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Find File search command

Linux terminal shortcuts

Move the cursor quickly to the end of the line: Ctrl + A Move the cursor quickly to the end of the line: Ctrl + E move the cursor to the left: Ctrl + B move the cursor to the right: Ctrl + F delete the previous character: Ctrl + H delete the previous word: Ctrl + W delete the entire line: Ctrl + u

Vim editor

Displays the line number of the Vim editor:

:set nu
:set nonu # Do not display editor line number
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To specify the line number: : |, for example, to line 927

: 927 |Copy the code

Look for a character, such as external_url

/external_url
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Common operations in common mode

dd # remove
yy # copy
p # paste
u # Undo the previous step

gi Quickly skip to the last edit and enter insert mode
gg Move to the beginning of the file
G Move to the last line of the file
ctrl + o # Quick return

h # Move left
j # Move down
k # Move up
l Move to the right

0 # move to the beginning of the line
$ # Move to end of line

# word is a word separated by a non-null character and word is a word separated by a whitespace character
w/W # Move to the next word/ word beginning,
e/E # Move to the next word/WORLD end
b/B # Back to the beginning of last word/ word
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Vim window operations

Open multiple files simultaneously using vim: vim file1 file2… In normal mode, enter :ls to switch files in the buffer. The following methods are available:

  • Use :b n to jump to the NTH buffer

  • Jump to the previous buffer: :bpre

  • Jump to the next buffer: :bnext

  • Jump to the first buffer: :bfirst

  • Jump to the last buffer: : Blast

  • Jump to buffer: : b name with b name

Open multiple Windows simultaneously: Split horizontally: Ctrl + W + S or: SP Split vertically: Ctrl + W + V or :vs

  • Toggle between Windows: Ctrl + W

  • Switch to the left window: Ctrl + W + H

  • Switch to the lower window: Ctrl + W + J

  • Switch to the top window: Ctrl + W + K

  • Switch to the right window: Ctrl + W + L

Set the size of the window:

  • To make the window bigger: Ctrl + w + =

  • To make the window smaller: Ctrl + w + –

There are commands about firewalls

Viewing the Firewall Status

systemctl status firewalld.service
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Enabling the Firewall

systemctl start firewalld.service
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Disabling the firewall

systemctl stop firewalld.service
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Disabling the Firewall

systemctl disable firewalld.service
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The SSH remote login function is enabled for Centos

Reference: https://www.cnblogs.com/travis-li/p/12550370.html

  • Ensure that Centos install openssh server, installed in the terminal input yum list | grep openssh server. –

If it is not installed, run yum install openssh-server

  • Open the sshd_config file in /etc/ssh, remove the PasswordAuthentication # and change it to yes; Remove Port #; Remove the # from PermitLocalCommand and change it to yes

  • To start the SSD service, enter service SSHD start

SSH start command: service SSH start SSH stop command: service SSHD stop SSH restart command: service SSHD restart SSH view command: service SSHD statusCopy the code
  • Check whether the SSHD service is open: ps – e | grep SSHD

How can I set the permission of the root user to a common user in Linux

  • Switch to the superuser :su

  • Open the /etc/sudoers file

vim /etc/sudoers
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  • Find the root ALL=(ALL) ALL row and insert a new row below that saying Keith ALL=(ALL) ALL, assuming that Keith is the user to whom root is to be enabled

  • Input: wq! exit

  • Exit superuser exit