Getting Started with Linux

Alias, clock, simple commands, bash shortcut keys, help

Alias definition aliases

Defines the alias name, which is equivalent to executing the command value

Alias Name= ' VALUE '

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Aliases defined on the command line, valid only for the current shell process

If you want to be permanently valid, define it in the configuration file

For the current user only: ~/.BASHRC

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Valid for all users:/ETC/BASHRC

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Undo Alias: Unalias

UNALIAS[-A] name [name ...]

-A cancels all aliases

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Two types of clocks for Linux

System clock: Run by the Linux kernel through the CPU's operating frequency

Hardware clock: Motherboard

Related commands

Date display and set system time

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Date +%s

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Date-d @1509536033

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Hwclock,clock: Display Hardware clock

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-S,--hctosys to calibrate the system clock, whichever is the hardware clock

-W,--SYSTOHC to calibrate the hardware clock, whichever is the system clock

Time zone:/etc/localtime

Show Calendar: Cal–y

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Simple command

Shutdown: Halt, Poweroff

Restart: reboot

-F: Force, do not call shutdown

-P: Power off

Shutdown or restart: shutdown

shutdown [OPTION] ... Time [MESSAGE]

-r:reboot

-h:halt

-c:cancel

Time: No designation, default equivalent to +1

Now: Immediately, equivalent to +0

+m: Relative time notation, a few minutes later

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HH:MM: Absolute time indication, specify time

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User login Information View command:

WHOAMI: Displays the currently logged in active user

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Who: All current logon sessions for the system

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W: All current logon sessions and actions made by the system

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Vnano text Editing

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echo command

Function: Display characters

Syntax: Echo [-nee][string]

Description: Echo will send the input string to standard output. The output string is separated by a white space character, and a newline number is added at the end

Options:

-E (default) does not support \ Interpret feature

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-N Not wrap line

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-e enable \ character interpretation function

Show variables

echo "$VAR _name" variable is replaced with weak reference

Echo ' $VAR _name ' variable does not replace, strong reference

Bash's shortcut keys

Ctrl+l Clear Screen

Ctrl+s blocking the current output of the screen, locking

CTRL + C terminate command

CTRL + Z Hang command

Alt+r Delete the current entire row

Ctrl+w to the top of the word from the cursor to the left

Alt+d right from cursor to end of word

Help

Whatis

Show a short description of the command

Working with databases

Cannot be used immediately after installation

makewhatis| MANDB Production Database

Examples of Use:

Whatiscal or Man–f cal

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Help

Show usage Summary and parameter list

Use of most but not all of the

Example:

Date--help

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Usage:date[option] ... [+FORMAT]OR:DATE[-U|--UTC|--UNIVERSAL][MMDDHHMM[[CC]YY][.SS]]

[] indicates an option

Caps or <> indicates changes in data

... Represents a list

X |y| Z means "x or Y or z"

-abc means-a-b–c.

{} means grouping

Mans

file that provides command help

Manual page stored in/usr/share/man

Almost every command has a man's "page"

The man page is grouped into different "chapters"

Collectively known as Linux manuals

Configuration file for man command:/etc/man.config| Man_db.conf

Manpath/path/to/somewhere: Indicates the man file search location

Man-m/path/to/somewhere command: Searches the command command's hand pages to the specified location and displays

Chinese man needs to install package MAN-PAGES-ZH-CN

1: User command

2: System call

3:C Library Call

4: Equipment files and special files

5: Configuration file format

6: Game

7: Miscellaneous

8: Commands for managing classes

9:linux Kernel API

View Man manual page

Man [Chapter] keyword

List all Help

Man–a keyword

Search Man Manual

Man-kkeyword List all matching pages

Using the Whatis database

Equivalent to Whatis

man–f keyword

Print the path to the man Help file

man–w [Chapter] Keyword

Get help with online documentation

Third-party Application official documentation

http://www.nginx.org

http://tomcat.apache.org

http://httpd.apache.org

http://www.python.org

Available through the official documentation CD or website of the release version

Installation guides, deployment guides, virtualization guides, and more

Red Hat Knowledge Base and official online documentation

Http://kbase.redhat.com

Http://www.redhat.com/docs

Http://access.redhat.com

Getting Started with Linux