Getting Started with Linux basics

One, the process of command line operation

1. Input command (can use various channels to send commands), enter the end

1. The command is interpreted and executed by the interpreter

2. Display the results in a way that the product needs

Second, command prompt

[Email protected]:~$

Changru: Currently logged in User name

Changru-virtualbox: Current host name

~: Indicates the current position

$ after: Used to receive commands

The $ in prompt indicates that the current logged on user is a normal user

The # in the prompt indicates that the current logged on user is the root user

Iii. three elements of the order

Command option Parameters

Three elements separated by a space

Command: Represents the action to be performed do

Options: Indicates how you want to perform the operation.

Option to-start

Parameters: The object that represents the execution of the action who

Note: If an option or parameter is not provided, the default value is treated as

Iv. Common Commands--auxiliary class commands

1.pwd self-positioning

Usage examples:

$pwd

/home/changru

Prints the absolute path of the current directory

Absolute path: directory path structure with/start

Relative path: A directory path structure that is not/begins with

2. man help manual Query command

form of Use:

Mans command

Usage examples:

$man pwd

3.Claer Clear Screen command

4.su Select/Switch User

5.sudo (change body)

When permissions are insufficient, use sudo temporarily to become the root user

form of Use:

sudo command [option] [ARG]

Note: Only users who are inside the sudo user group can use the sudo command.

V. Common commands--file directory class commands

1.ls (list) lists file information for the specified or default directory

form of Use:

ls [options] [directory name]

Instance:

$ls

$ls-A

$ls/home/changru/Desktop

$ls./Desktop. Represents itself. Represents the previous level of the directory

$ls-L

D rwx R-x R-x 3 Changru changru 4096 July 10:45 Desktop

Common options:

-A: Displays all files, including. and. ）

- L: Show detailed information for the listed files

- H: Display file information in a more readable manner (typically used in conjunction with-L)

- D: Displays information about the directory itself rather than directory content (typically used with-l)

Bin Home Sbin Boot

2.CD directory jump

form of Use:

CD Destination directory path

Common usage Scenarios:

Quick Home Directory: CD or CD ~

Skip to the top level directory: CD. (equivalent to a previous page)

Quick Jump between catalogs: cd directory path

Note: The CD command works with the LS command to complete the view of the entire directory structure

3.mkdir Create a directory

form of Use:

mkdir path to the directory to be created

Instance:

$mkdir ~/linux (absolute path) where ~ represents/home, so is the absolute path

$ls

Common scenarios:

To create a directory under the specified directory: mkdir path

Recursively creating directories: Mkdir-p Path

4.rmdir Delete directory (directory must be empty)

5. file to view the files type specified

In Unix-like operating systems, the file extension only acts as a hint and does not affect the file type.

Use form: File file name

6.Touch

Use form: Touch file path

Instance:

$touch hello.c

If the specified file does not exist, an empty file with the same name is created.

7.RM Deletes the specified file or directory

form of Use:

Delete normal file: RM file path

Delete directory file: Rm-rf directory path (-RF can be forced to delete as long as permissions are sufficient)

Practice One:

1) in the home directory of the currently logged in user, create a project catalog Sq-qq

2) in the SQ-QQ directory, create the directory bin, Src, lib, include, test

3) Create file in Sq-qq directory readme, license, Makefile

4) Create files in src directory linklist.c, linklist.h, MAIN.C, Makefile

8.CP Copy the specified file or directory to the specified directory

form of Use:

CP Source Dest

Common usage scenarios

1) file-to-directory replication presupposes that the destination directory must exist

CP/ETC/PASSWD ~/linux/

Destination Directory exists: Copy to specified directory

The destination directory does not exist: The change is 2)

2) file to file copy file to specified directory and rename

CP/ETC/PASSWD ~/test

Destination directory does not exist: copy and rename

Destination Directory exists: copy content and replace

3) directory to directory Note: The copy directory needs to be added with the-r option

Cp-r ~/sq-qq/~/linux/(-R can copy files and folders)

Destination Directory exists: Copy the directory to the current directory

Destination directory does not exist: Copy directory to top level of destination directory and rename

Exercise two:

1) Create a Weibo directory in the home directory of the currently logged-in user

2) Create the sina_weibo.h in the Weibo directory

3) Copy the Weibo directory to the Include directory under the SQ-QQ directory

9.MV move files or directories to the specified directory

Use form: MV Source dest

Common usage Scenarios:

A) file to directory

MV ~/PASSWD ~/linux/

Destination directory file exists: Simple file Move operation

Destination directory file does not exist: change to case B)

B) file to file

MV ~/PASSWD ~/linux/hahaha

Destination file does not exist: Move and rename

Destination file exists: Move and overwrite

Note: The file moves in place to achieve the effect of renaming

MV Hello.c MAIN.C

C) directory to Directory

MV ~/sq-qq/~/linux/

Destination directory file exists: Move directory data to the specified directory

Destination directory file does not exist: Move directory to top level of destination directory and rename

Vi. Common Commands--File content class operations

1.cat

2.head

3.tail

4.more displays multiple rows of data in a paginated manner

5.less displays multiple rows of data in a paginated manner

Vii. Common Commands-user and group management

1.PASSWD Modify the password for the specified user

form of use: passwd username

Common usage Scenarios:

By default, the Ubuntu system does not activate the root user and needs to use passwd to modify the root user password.

sudo passwd root

Added:/etc/passwd files in the system

2.adduser/useradd

Use form: sudo adduser user name

Common usage Scenarios:

A) Create A new User: sudo adduser user name

B) Add an existing user to the existing group: sudo adduser username Group name

3.deluser/userdel

Use form: sudo deluser user name

Common usage scenarios: sudo deluser-remove-home

Viii. Common Commands--permission-related

The whole Linux system's permission system is mainly for the file owner, the file belongs to the group, other users of the read, write, execute permissions constitute

Ls-l can view permissions information for normal files

Ls-ld can view permissions information for the directory file itself

D rwx R-x R-x 3 changru changru 4096 July 21 10:45 Desktop

File Owner Permissions file belongs to group permissions Other user rights

READ: Whether it is a normal file or a directory file, read permissions affect the information on the file view

Write: For ordinary files, write permissions affect the content of the file, and for directory files, write permissions affect new and deleted files for that directory.

Execute: For normal files, execute permissions affect whether the file can be loaded into memory run, and for directory files, execute permissions affect whether the directory can be CD (accessed).

1.chmod Modify the permissions of a file without changing the file affiliation

form of use: chmod new permission file name

Permissions can be represented by using three octal numbers

chmod 644 Weixin.h

4 2 1

1 1 1 7

1 0 1 5

1 1 0 6

1 0 0 4

R W X

2.chown changing the owner of a file and the owning person

Use form: sudo chown [user][:group] File name

Common usage Scenarios:

Change only file owner: sudo chown user name file name

Change only the group that the file belongs to: sudo chown: Group name File name

Change both the file owner and the group to which the file belongs:

sudo chown user name: Group name File name

Ix. Loading and unloading software

1. Install the graphical application

A) using Ubuntu's own software center

b) Download the binary installation package for Ubuntu

2. Installation of the command line related tools

A) update of apt-get Update software name

b) apt-get install software name

c) apt-get remove software name removal

d) Apt-get source software name

Practice:

$sudo apt-get Update

$sudo apt-get Install SL (Small train)

X. Compression and archiving

1.zip/unzip

A) Compress the specified file: Zip test.zip hello.c main.c

B) Unzip the file: Unzip dest.zip-d extract Directory

2.bzip2/bunzip2

3.gzip/gunzip

4.tar Archive and Compress (package)

- C Create an archive

- x Solution Archive

- v Show Archive/Unpack process information

- F filename Specifies the input/output file name

-j compressing/extracting files using bzip2

- z compress/unzip files using gzip

- C Directory decompression to the specified directory

A) Create an archive and specify the output file:

TAR-CVF output file name to be compressed file list F must be followed by file name

B) archive from the specified archive file

TAR-XVF Pending Archive file

C) simultaneous compression or decompression using BZIP2 to complete archiving

TAR-CJVF output_filename.tar.bz2 List of compressed files to archive (can include directories)

TAR-XJVF input_filename.tar.bz2

D) simultaneous compression or decompression using GZIP to complete archiving

TAR-CZVF output_filename.tar.gz2 file to archive list of compressed files (can contain directories) new file name

TAR-XZVF INPUT_FILENAME.TAR.GZ2 < Extract to current directory >

The file name to be unzipped

Xi. Mount Mount Umount

Supplemental: Ifconfig NIC Configuration

Evening Practice:

1. Install tree, vim from the command line

2. Download the Atom Text Editor installation package Atom*.deb

3. Be familiar with the commands you have learned

4. Try to install using SL, Cowsay fun Software

Getting Started with Linux basics