Basic Linux Essentials-linux 11 article brief

1>, ls:list directory contents list Contents

-L: Long format

File type

-: Universal Documents

D: Catalog file

B: Block devices (blocks)

C: Character file (character)

L: Compliant with link file (symbolic link files)

P: Command pipeline file (socket)

[Email protected] ~]# ls-ld/tmp

DRWXRWXRWT. 5 root root 4096 November 10:36/tmp

File permissions + Master (owner) + genus (group) + File size (size, Unit bytes)

-A: Shows all protections. Start with hidden files

. Current directory: Parent Directory

-H: Unit conversion

-D: Display the directory's own properties

-R: Reverse Display

-R: Recursive display

-i:index Nod,inode

--full Time: Show Details

[Email protected] ~]# ls/tmp/-al--full time

LS: Unable to access time: No file or directory

/tmp/:

Total Dosage 40

DRWXRWXRWT. 5 root root 4096 2016-11-14 08:26:25.138197188 +0800.

Dr-xr-xr-x. Root root 4096 2016-11-08 09:12:14.244789696 +0800..

DRWXRWXRWT. 2 root root 4096 2016-11-08 09:12:13.873794359 +0800. Ice-unix

DRWX------. 2 root root 16384 2016-07-20 00:21:08.000000000 +0800 lost+found

DRWX------. 2 root root 4096 2016-11-14 08:26:25.138197188 +0800 ssh-djisj35919

-rw-r--r--. 1 root root 2016-11-10 14:32:13.405295895 +0800 tmp.txt

-rw-r--r--. 1 James Root 2016-11-10 15:26:34.029648704 +0800 t.txt

2>, Cd:change directory

CD ~username: Specify the user's home directory

CD-: Current directory and previous directory switch

[Email protected] ~]# cd/etc/

[Email protected] etc]# CD-

/root

[Email protected] ~]# CD-

/etc

Pwd:printing working directory displays the current working directory

[Email protected] ~]# pwd

/root

3>, Command type:

Built-in command (shell built-in), internal, built-in

External command: An executable file with a command name under a path of the file type

4>, type: display specifies which type to belong to

5> variable assignment of environment variables

[Email protected] ~]# echo $PATH

/usr/lib64/qt-3.3/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

[Email protected] ~]# echo $HISTSIZE

1000

[Email protected] ~]# echo $SHELL

/bin/bash

/etc/shells

/bin/sh

/bin/bash

/sbin/nologin

/bin/dash

/bin/tcsh

/bin/csh

6>, printenv: Viewing environment variables

7>, bash Memory Cache command, hit count

[[email protected] ~]# hash

Hits command

4/bin/bash

1/bin/cat

3/bin/vi

1/usr/bin/man

1/usr/bin/printenv

7/bin/cut

15/bin/ls

8>, command line cursor jump

CTRL + A: Jump to the beginning

Ctrl+e: End of line

Ctrl+u: Deleting the beginning of a line

Ctrl+k: Delete End of line

Ctrl+l: Clear Screen

9>, Command history:

History

-A: Append to/root/.bash_history

-C: Clear command history

-D: Delete the command at the specified location

-W: Cover/root/.bash_history

Command history Usage Tips

!n: Execute nth in the command history

!-n: Executes the last nth rule in the command history

!: Executes the previous line

!string: Executes the last command in the command line that starts with the specified string

!$: Reference the last parameter of the previous command

Echo: Standard output Screen output

Line break

[Email protected] etc]# ECHO-E "The year was 2016.\ntoday is 14"

The year is 2016.

Today is 14

10>, File system

/boot: System boot related files, such as kernel, init, and Grub (bootloader)

/dev: Device files

Block devices

Character device

/etc: Configuration file

/home: User House directory, each user home directory usually defaults to/home/username

/root: Administrator's home directory

/lib: library file

Static Library. A

Dynamic Library. dll. So (Shared object)

/lib/modules: Kernel module files

/media: mount point directory, mobile device

/MNT: mount point directory, additional temporary file system

/OPT: Optional directory, third-party program installation directory

/proc: Pseudo file system, kernel mapping file

/sys: Pseudo file system, property mapping file related to hardware device

/tmp: Temp file,/var/tmp

/var: a variable file

/bin: Executable file, user command

/sbin: Managing Commands

/usr:shared,read-only

/user/bin

/usr/sbin

/usr/lib

/usr/local:

Usr/local/bin

Usr/local/sbin

Usr/local/lib

11>, naming rules:

Length not exceeding 255 characters

cannot be used/

Strictly case-sensitive

12>,su:switch User Switch users

[email protected] etc]# su Jameszhan

sh-4.1$

This article is from the "James Zhan Linux Advanced ops" blog, so be sure to keep this source http://jameszhan.blog.51cto.com/10980469/1872788

Basic Linux Essentials-linux 11 article brief