Summary of Linux commands and shortcut keys

Log in to the Linux system after entering the password, you want to delete ctrl+u Delete all the input before, (is uppercase U)

IP a view IP (full ifconfig addr)

Systemctl Restart Networkmanager.service Start command

Dhclient dynamic acquisition of IP addresses

Control+o (ctrl+o) Sign Out

Control+l (ctrl+l) Clear screen can also use the command clear

Device class information is in the/dev directory

Top View memory Information

Who view all current online users

WhoAmI See who you are uname-r view kernel version number
-A View all version information

Systemctl Stop/start firewalld.service Stop/start firewall

Systemctl enable/disable firewalld.service Allow/disable firewall boot

CD-Only Transfer home directory
Cd. Switch to current directory
Cd.. Switch to the previous level directory
Cd.. /.. Switch to the top level two directory
Cd.. /.. /.. Switch to the top level three directory
。。。。。。
cd– switch to the most recently switched directory

Su-username Switching users

PWD Displays the directory where you are currently

cd/etc/yum.repo.d/. repo file storage for this folder is the Yum source address;
cd/etc/yum.repos.d/Modify or create a new. Repo file within a folder, specify the following
[Base] Casual
Name=lk Casual
Baseurl=file:///lk a new directory of your own designation
Enabled=1 enabled
Gpgcheck=0

Install package: Take Lsb_release as an example yum Whatprovides lsb_release takes the Lsb_release toolkit name from the version number, and then installs: Yum Install lsb_release_xx Installation Kit, Enter the toolkit name instead of the name of the command; Use Lsb_release to view operating system information after successful installation;

DirName Gets the directory name removes the file name (not the directory part) from the given file name that contains the absolute path, and then returns the remaining path (directory part)
Input: Dirname/etc/sysconfig/network-scripts/ifcfg-eth0
/etc/sysconfig/networt-scripts
Output:/etc/sysconfig/network-scripts/
/etc/sysconfig/

BaseName gets the base name from the file name of the Godin containing the absolute path to the left part of the directory, or the colleague removes the content of a suffix (the directory part), and then returns the remainder (not part of the directory)

MV Move or rename file

CP Copy or rename file

Mount CD mount/dev/cdrom/New directory mount the optical drive file to the new directory specified
23.tty is also teletypewriter. You can see which endpoints are connected PTS/1 ... pts is a pseudo-terminal
can also be considered as a virtual terminal, Linux generally default to 6, tty1-7, respectively, corresponding to Alt-f1/f6, starting from F7, F7-F12 is a graphics terminal, you can open multiple characters or graphics terminal at the same time without affecting each other
24.echo Echo, that is, display Eg:echo $SHELL display the current SHELL
25.cat/etc/shells display all variables used by the system
Cat command: View the file, which means showing how many shell types the system supports by default
26. User prompt, take [[email protected] ~]# as an example
[[: Normal identifier
\u Root: User currently in use
@ @: normal identifier
\h localhost: host name
\w ~: Current working directory (not full current directory, abbreviated)
]]: normal identifier
\$ #: User ID (Root is #, normal user is $)
27.30.[[email protected] ~]# echo $PS 1
[\[email protected]\h \w]\$ are both escape characters, in the shell's PS1 environment variable definition, no longer represents a simple combination of slash letters, is an escape character

  export PS1=‘[\[email protected]\h \W]\$‘   更改’’的内容可以更改用户提示符

Export command: Set environment variables for the current system
The default modification does not take effect and needs to be written to the. BASHRC variable.

    vi .bashrc    export PS1=‘\[\e[1;35m\][\[\e[1;33m\]\[email protected]\h \[\e[1;31m\]\w\[\e[1;35m\]]\[\e[1;36m\]\$‘     改变账号颜色    PS1=‘\e[31m[\[email protected]\h \W]\$ \e[0m‘    \e \033\u 当前用户    \h 主机名简称\H 主机名    \w 当前工作目录\W 当前工作目录基名    \t 24小时时间格式\T 12小时时间格式    \! 命令历史数\# 开机后命令历史数

A 28.type command that displays the type of the specified command, judging whether the specified command is an internal command or an external command;
29.which command: The directory where the execution program of the command is often seen;-a view all paths containing the command;
30.date Display system time;
Hwclock Display hardware time,-W to the system time calibration,-s to the hardware time is quasi-calibration;
Cal displays the current calendar; y Displays the calendar for one year;
file format for viewing files;
chmod +x filename To execute permissions on the file;
U+r to master Read permission
G+w Write permission to the genus Group
A+x to perform permissions on other users
Du-sh./View the total file size of the directory
Info is also information for finding commands, but it's too informative to use man for info
Example: Man bash, man ls

  echo $PS 1à[\[email protected]\h \w]\$ enable command option-E, if the following character appears in the string, it is handled in particular, not as a general text output ECHO-E ' aaa\n ' \a warns \b Backspace bar \c finally does not add newline symbol \ n newline and the cursor moves to the beginning of the line \ r Enter, that is, the cursor moves to the beginning of the line, but does not wrap \ t insert tab \ \ insert \ character \0nnn insert nnn (octal) The ASCII character represented by Echo-e "\033[43;31mred color\033[0m" \xhh inserted in HH (hexadecimal) represented by the ASCII word export $SP 1= "[\[email protected ]\h \w]\$ Change the escape character to change the style of the command prompt PS1 set the character color in the format: ps1= ' \e[31m[\[email protected]\h \w]\$ \e[0m ' F B 30 4    0 Black 31 41 Red 32 42 green 43xxx34 44 Blue 35 45 purplish red 36 46 Cyan Blue 37 47 white vim ~/.BASHRC source ~/.BASHRC Reload will be permanently saved or reopen the shell will restore or. ~/.BASHRC points can also be used instead of source  

31. Folder function functions:
/boot: Boot file directory, kernel file (vmlinuz), boot loader (bootloader,grub) are stored in this directory;
/bin: Basic command for all users, can not be associated to a separate partition, OS boot will be used by the program;
/sbin: The basic command of the management class, cannot be associated to the independent partition, the OS starts the program which will use;
/lib: Basic shared library files and kernel module files that the program relies on at startup;
/LIB64: storage location for secondary shared library files dedicated to x86_64 systems
/etc: Configuration file directory;
/home/username: Home directory for ordinary users;
/root: Administrator's home directory;
/media: Portable mobile device mount point;
/MNT: Temporary file mount point;
/dev: Device files and special file storage locations;
/OPT: The installation location of the third-party application;
/SRV: Data used by services running on the system;
/tmp: Historical file storage location;

32. File system different file colors:

• White Plain file (plain executable file)
  L Light Green Connection file (similar to Windows shortcut)
  D Blue Catalog File
  P Dark xxx Pipe file (related to redirection)
  Bxxx Block Execution file
  Cxxx Character device files
  s pink socket (socket) file (IP found host, port found program, IP and port number)
  Green: Executable file
  Red: Compress files
  Vi/etc/dir_colors changing the file type color

Summary of Linux commands and shortcut keys