Basic Structure and terminal control of Linux operating system

Basic Structure and terminal control of Linux operating system

 

Basic Linux Operating System Structure

1. Kernl Kernel
2. Modules Module
3. Lib Library
4. shell tool (Application)
5. Tools (applications) the same level of applications

 

This system can be divided into four parts in structure:

 

1. Linux kernel is the heart of the system and the core program for running programs and managing hardware devices. It mainly includes:
File Management
Device management
Memory Management
Module Management
Network Management
Process Management
Generally, user commands passed in from the runtime database and system programs are accepted, and the results are returned to the user after execution.

 

2. during runtime databases and system programs, they encapsulate the functional interfaces provided by the kernel, add these functions to certain permissions, and then provide them to common user processes through their own application interfaces.
3. Linux Shell is a system program, but it has different functions than general system programs working in the background. It faces users.
Shell is a command interpreter that interprets user-input commands and sends them to the kernel.
Red Hat Linux supports several different shells:
Bourne shell: Developed by Bell Labs
BASH: it is the Bourne Again shell of GNU. This is the default shell of Red Hat Linux (default)
Korn Shell: The Development of The Bourne Shell, most of which are compatible with the Bourne Shell
C Shell: the BSD version of SUN Shell
4. The utility program is used by the user to complete a specific tool.

 

System startup sequence
Hardware
Internal kernl (kernel) | module (can be freely added)
The kernel BIOS and kernl are at the same level. When the system is started, the BIOS directs kernl
Empty 8139 (NIC module) BIOS hardware embedded language, can communicate directly with the hardware, do operations
Room

 

Use API (application interface) lib (library interface)
User-Defined
An empty APP may call the interface provided by the most basic operating system, or the interface provided by the Library.
A shell is a type of application. It is one of the tools that provide interaction between people and machines.
Bytes
Apache shell kde (desktop environment)
Gui (graphical user interface)
Root: ls-l/boot/vmlinuz-2.6.32-279.el6.i686 can view version Kernel
Root: uname-a can also be viewed
2.6 is the version number, 32 is the 2.6 version of 32nd, and 279th is the representative of EL. This is the official version officially modified by RedHat.
2.4 2.5 2.6 concurrent development of the kernel, both under development
Even version kernel is stable version Kernel
The odd version kernel is the experimental version kernel.

 

Kernel.org official Kernel
Kernel leads the development of linux
Module location
Root: ls/lib/modules/2.6.32-279. el6.i686/kernel
Root: ls/lib/modules/2.6.32-279. el6.i686/kernel/fs

 

In Windows, the graphic interface is written in the kernel, so it runs smoothly.
In Linux, the graphic interface is no longer in the kernel. The graphic interface is equivalent to an APP running and occupies about MB of memory.

 

Root: whoami shows your Logon account
Root: who is he: shows who you are and what ports are there to log on
Root: w indicates who is logged on to the port.
Root: ls/dev/tty? Displays several simulated serial ports

Root: ls/dev/ttyS? Displays several actual physical serial ports

Root: echo 575129>/dev/pts/1 send 575129 to the user logging on to port pts/1

Root: skill-9 pts/2 indicates the user logging on to port pts/2.

 

 

If you do not need to connect to so many terminals, You can edit
Root: vi/etc/inittab
Root: startx --: 1 start the second graphic interface

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