Linux Learning Notes (ii) system common commands and some concepts

Root user (Administrator) is the most privileged user (Universe invincible)

Liunx command line use format

command-[options] [parameters]

Option to invoke the specific function of the command

Parameters are object, file, directory name, etc. of command operation

TAB key: Auto-complete

Backslash \ Forced line break

Shortcut key ctrl+l: Clear Screen

Shortcut key CTRL + C: Cancel execution of this command

Get command Help:

Command--help

Man command

Shutdown and restart commands

Restart:

Shutdown-r now

Shutdown-r +15 "WARNING: System will restart in 15 minutes"

Reboot

Init 6

Shutdown:

Shutdown-h now

Init 0

LS View the file under the current path

Command options:

-l display in long format

-a displays all information about the file, including hidden files

-D Display the directory itself property

-R recursive display of content

-H already (k,m) display content

CD Switch Directory

PWD View the path to the current directory

mkdir creating a directory parameter-p for recursive creation

Du view directory and file space occupancy parameters:-A statistics all files,-H displays the information in K,m,-s only counts the total amount of space occupied by each parameter

Touch New Empty file

CP Copy parameter:-R recursively copies the entire directory,-P keeps the properties of the source file unchanged

RM (use with CAUTION!!! Delete parameter:-F forcibly Delete does not make reminders,-R recursive Delete

MV Move, if the target location and source file directory want to hear, then the equivalent of renaming

Find lookup, equivalent to a search under Windows. Parameters:-name Search by file name,-size file size Find,-user by file owner find,-type by file type search

* Wildcard Characters

Cat Displays the entire contents of the file, equivalent to Winddows Open text

More Paging mode display file contents, enter next page, b previous page, q exit

Head to view a portion of the file at the beginning. Format head-n file name, n shows how many lines to start with

Tail and head In contrast, display the end of the file, tail-n filename, tail-f file name can track changes in real-time files

Compression command:

gzip-d file name

Gzip-9 file name

bzip-d file name

Bzip-9 file name

-9: Indicates a high compression ratio

-D: Unzip compressed files

Tar pack, unpack

tar [options] Package name source file

tar [options] Package name-C Destination Directory

Parameters:

-C Create a package file in. tar format

-X unpack the. tar format package file

-V output when packaging or unpacking the details

-F means using an archive file

-P preserves original file and directory permissions when packaging

-t list view files within packages

Tar command

Parameters:

-C Unpack the target folder when you specify the release

-Z Call the GZIP program for compression or decompression

-j Call bZIP Program for compression or decompression

Unzip unzip the zip-format package

Zip compression

User: Superuser (root), normal user and program user

Groups: Basic groups (private groups), additional groups (public groups)

UID (user identily, subscriber representation number)

GID (group identify, set number)

1~499 Uid,gid is reserved for program users by default

UID and GID numbers used by normal users/groups are between 500~6000

User account File:

Basic information for saving users ' accounts

File Location:/etc/password

Each row corresponds to one user's account record

1: User's account name

2, User password

3, UID of the user

4, GID of the basic group account

5, user's full name

6, Host Directory

7, Login Shell information

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Linux Learning Notes (ii) system common commands and some concepts