Linux-Related Fundamentals knowledge 1

Linux

Development interface Standard:

Abi:application Binary Interface

The ABI describes the underlying interface between the application and the OS, allowing the compiled target code to run without changes in the ABI-compatible system

Api:application Programming Interface

The API defines the interface between the source code and the library, so the same source codes can be compiled in any system that supports this API

Posix:potable Operating system Interface (API defined on the operating system)

A series of API standards defined by the IEEE on the operating system

POSIX-compatible programs can be compiled and executed on other POSIX operating systems

"Hardware plateform: (Hardware platform)

CPU Platform: X86,arm,powerpc,power (IBM), Ultraspace,alpha,... "

Server three major operating systems:

Windows,linux,unix

Linux is a Unix-like operating system (Unix-like): Complete linux=linux kernel (kernel) + GNU tool (application)

Gnu/linux:

Kernel: Kernel;

GNU (GPL,LGPL Open Source protocol): Applications

Other open source agreements: Apache (ASF), Bsd,mit, ...

Release version: Redhat,debian,suse

CentOS, RedHat

Debian->ubuntu

SUSE->opensuse

ArchLinux

Mac OS X:

Linux Philosophy thought:

• All documents (including hardware), 99.9%

• Small, single-use programs

• Link programs to accomplish complex tasks together

• Avoid confusing user interfaces

• Configuration data is stored in text

Linux use:

Create process: User-based shell (shell) request to kernel, boot program from kernel

Shell: A program in which a user interacts with a computer

Kernel: Kernel:https://www.kernel.org/

Version 4.17.9:

4:major, major version number

17:minor, minor version number

Development version: The second digit is the cardinality

Stable version: The second digit is an even number

9:release, Release number

The release version number is not synchronized with the kernel version number:

Open Sourse software and code for Everyone

Free distribution of software and source code

Ability to modify and create derivative products

Open Source protocol: Be sure to check out the open source protocol before using open source code

Interactive Interface :

After starting the terminal, attach an interactive application to the end device

Gui:graphical User Interface (GUI interface): GNOME,KDE,XFCE

Cli:command lines Interface (command line interface): Sh->bsh->csh->bash->zsh

What is shell:sh->bsh->csh->bash->zsh

The shell is the user interface of the Linux system and provides an interface for users to interact with the kernel. It receives the command entered by the user and feeds it into the kernel to execute

The shell is also known as the Linux command interpreter (interpreter)

What is a program:

Program: is an executable static file

Process: A program that is running

program = instruction + data

program = algorithm + data structure

Algorithm-centric, data structures serve algorithms: procedural programming (EX;C)

Data-centric, algorithmic services to data structures: Object-oriented Programming (Ex:java)

Terminal Terminal

1. Device Terminal: Keyboard mouse Monitor

2. Physical Terminal: Console Console (/dev/console)

3. Virtual Terminal: (tty:teletypewriters,/dev/tty# #为 "1-6" TTY can have N, ctrl+alt+f "1-6"

4. Graphic Terminal: (/dev/tty7) startx,xwindows;

Centos6:ctrl+alt+f7

CentOS 7: At which terminal to boot, which virtual terminal is located

5. Serial Terminal: (/dev/ttys#) TTYs

6. Pseudo Terminal: (pty:pseudo-tty,/dev/pts/#) pty,ssh remote connection

View current terminal devices: # TTY

Linux under two big tree-shaped structure: adding and deleting changes

1. File System tree

/(root directory)

All documents

Program Files:/bin,/sbin,/usr/bin,/usr/sbin,/usr/local/bin,/usr/local/sbin

Landing into the shell, every moment in a path (directory)

2. Process Tree

Init

Bash shell

The GNU Bourne-again Shell (bash) is one of the most important tool software in the GNU program and is currently the Linux standard Shell, compatible with SH

CentOS Default Usage

Displays the currently used Shell:echo ${shell}

Displays all shell:cat/etc/shells used by the current system

bash tips for using :

Command line expansion: {},~

> Command Replacement: $ (commands), ' command '

> Command Completion: $PATH

> Path Completion: Path search from the specified starting position

> Command history:. bash_history

Histcontrol

-ignoredups

-ignorespace

-ignoreboth

Command Help :

Internal command: 1.help command

2.man Bash

External command: 1.command--help

2.commadn-h

2. User manual (Manual): Man command

3. Information page: info command (query related documents)

4. Help documentation for the program itself: Readme,install,changelog

5. Official Document: Documentation

6.Google:

http://tldp.org

Http://www.slideshare.net

http://www.google.com

Linux-Related Fundamentals knowledge 1