Getting Started with 1.1-linux system basics

How to obtain a release version of CentOS:

1. http://mirrors.aliyun.com/

2. http://mirrors.sohu.com/

3. http://mirrors.163.com/

Terminal:

User interaction with the host, the device must be used:

1. Physical Terminal: Direct access to the computer's display and keyboard equipment:/dev/console

2. Virtual Terminal: A virtual implementation of the Software method attached to the physical terminal, CentOS6 default boot 6 virtual terminal

   ctrl+alt+f[n]:[1,6]

   Graphics Terminal: A software-based terminal that is attached to a physical terminal, but provides additional desktop environments

   Device file path:/dev/tty[n]

   
   

   Ctrl+alt+f7 (provided that the graphics terminal has been started before)

3. Analog Terminal: Open command line interface under graphical interface, or remote open interface based on SSH protocol or Telnet protocol

   Device file path:/dev/pts/[n][0,oo]

View current terminal devices: TTY

Interactive interface: After you start the terminal, attach an interactive application to the end device

Gui:

X Protocol,window manger,desktop

Desktop

GNOME (C,GTK)

KDE (C++,QT)

XFCE (Lightweight desktop)

Cli:

Shell program:

SH (Bourn)

CSH (near the C language style shell)

Tcsh

Ksh (Korn)

Bash (Bourn again shell), GPL

Zsh

Displays the currently used shell:

# echo ${shell}

Displays all the shells that the current system can use:

#cat/etc/shells

Command prompt: (prompt)

[Email protected] ~]#

[[Email protected] ~]:P S1

Admin: #

Normal User: $

View the definition of the environment variable PS1:

[[email protected] ~]# echo ${PS1}

[\[email protected]\h \w]\$

Command:

Input command, enter:

Draw the shell program to find the executable program or code corresponding to the typed command and parse it and submit it to the kernel to allocate resources to run it (as one or more processes).

There are two types of commands that can be executed in the shell:

Built-in command: comes from the shell and is provided in a command form

External command: There is a corresponding executable program file under a file system path of the current system

Which,whereis

Differentiate between built-in or external commands:

# type COMMAND

[[Email protected] ~]# type cd

CD is a shell builtin

To run the command:

Command format:

COMMAND [OPTIONS ...] [ARGUMENTS ...]

Options: Enable or disable one or some of the features of a command

Short options:-char For example:-l,-h

Multiple short options can be combined using, for example:-l,-h combined with:-LH

Long options:--word For example:--long,--human-readable

Parameters: The Action object of the command (supplying data to the command)

Attention:

1. Multiple options, as well as multiple arguments and commands should be separated by whitespace characters

2. Cancel command execution: Ctrl + C

File system:

Windows: Organizing files in a Dogan way \ c \   D:\ E:\

Linux: Organizing files in a single way

The file has two types of data:

Meta Data: Metadata

Statistics: Data

1. File names are strictly character-sensitive: File1,file1,file1 are different files

2. File names can use any character except/unexpected, and special characters are not recommended

   /: With directory, path delimiter

3. The file name can be no longer than 255 characters in length

4. All files starting with. are hidden files

Path:

Absolute path: The path starting from the root directory

Relative path: The path starting from the current position

How the current position is represented:

(1)./:./sysconfig/network-scripts

(2) Omit the above symbol: sysconfig/network-scripts

Present directory: Current directory, also known as working directory

Pwd:printing working Directory

.. : Represents the top level directory of the current directory

Lsb:linux Standard base (Linux standards Library)

Linux Standard Base , abbreviated to LSB) is a a joint project for Linux distributions under the Linux Foundation structure that targets the Linux operating system to match the specifications and standards of the software system architecture, or file system architecture standards. LSB extends them in some areas based on POSIX, Unified UNIX Specifications , and other open standards.

Command Summary: Ls,cd,type,tty,cat,which,whereis,pwd,echo

Command:

(1) File system Related:

Directory Management

File Management

File View

Document writing

(2) System Management Related:

。。。

Getting Started with 1.1-linux system basics