The OSI seven layer model and some common commands and rights management of Linux inherit the previous article

OSI seven-layer model

Application Layer: User interface

Presentation layer: Data representation, security, compression.

Session Layer: Establish, manage, abort session

Transport layer: reliable and unreliable transmission, error detection before transmission, flow control

Network layer: Logical address addressing for routing between different networks

Data Link layer: Group frame, hardware address addressing, error validation function

Physical layer: Transmission of bitstream between device and device, physical interface, electrical characteristics, etc.

Linux Common commands

1) CP Copy

CP Source file target Location

-R Copy Directory

-P Joint File attribute copy

-D If the source file is a linked file, copy the link property

-A equals-pdr

Example: CP aa/tmp/formerly copied

CP aa/tmp/bb renamed Copy

2) Cut or rename

Mv

MV Source File Destination location

Mv/root/aa/tmp

MV AA BB

Linux does not differentiate file types by extension, but with some exceptions

Three Rights Management

1 Permission Bits

-rw-r--r--1 root root 0 08-11 01:45 AA

The permission bit is 10 bits

First bit: Represents the file type

-Normal file

D catalog File

L Link File

Nine-bit master permission U master privilege g other person permissions O

R-Read 4

W Write 2

X execution 1

2 Modify Permissions

chmod

chmod u+x aa aa file owner plus execute permission

chmod u-x AA

chmod g+w,o+w AA

chmod U=rwa AA

chmod 755 AA

chmod 644 AA

4 Generic and Group commands

Chown user name filename Change file owner

Chown user1 AA user1 must exist

Chown user1:user1 aa Change Genus master simultaneous change group

Useradd User name Add user

passwd User Name setting password

CHGRP Group name File name modify the owning group of the file

This article is from the "title, Good Tangle" blog, please be sure to keep this source http://zhuangyi.blog.51cto.com/10089695/1638416

The OSI seven layer model and some common commands and rights management of Linux inherit the previous article