Basic Linux Learning

Program: Instruction + data

Computer architecture

CPU: Calculator + controller + Register

Controller: Receive control instruction [Control bus]

Memory: Storage

Memory: Addressing storage devices

Input | output (I/O): HDD

Polling and interrupts

Polling: CPU checks for keyboard events every 1ms

Interrupt: Triggers an electrical signal to notify the CPU of a keyboard event

Principle of program Locality

Time: visited recently also visited

Space: Data adjacent to the access data is thought to be cached together with access

Cpu:time Slice Time Slice

Memory: Segmented

Shell: human-computer interface

Graphical GUI

Command line CLI

Kernel Features:

Process Management

Memory management

File system

Network management

Hardware Drivers

Security mechanisms

File format:

-Normal file

D catalog File

Block B Device File block

C-Character device files Charactor

L Symbolic Link files symbolic link file

P Piping File Pipe

s socket file socket

Time command

Date Display system time

Clock Display hardware time

Hwclock-w change hardware time to system time

Hwclock-s write hardware time to system time

Root file System Feature Description:

Boot/boot system related such as: kernel, INITRD, etc.

/dev Device files

Block device random Access data block

Character Device linear access

Device number: Main device number and secondary device number

/etc configuration File location

Home Directory

/root Administrator Home Directory

/lib library files and kernel module files

/media mount point directory (mobile HDD)

/MNT mount point Directory (additional temporary files)

/misc Miscellaneous Collections

/opt Optional directory (third-party program installation directory)

/proc pseudo file system (kernel mapping file)

/sys pseudo file System (mapping of hardware-related properties)

/tmp temporary file (the system automatically deletes one months without access)

/var changeable files

/bin executable file, user command (System boot related)

/sbin executables, administration commands (System boot related)

/usr

/usr/bin system available, function-related

/usr/sbin system available, function-related

/usr/local/bin third-party orders

/usr/local/sbin third-party orders

Basic Linux Learning