20165325 preparatory work 3 Linux installation and learning

Linux installation and learning one, VirtualBox and Ubuntu installation Issue one: Ubuntu version in virtual machine

When I set the version of the operating system of the virtual machine, I found that my computer could only set the Ubuntu version of 32-bit. The tutorial chose the 64-bit, do not know what the problem.

However, the tutorial said that only need to choose Ubuntu on the line, there may be no problem.

But I suspect I didn't download and install the latest version of Ubuntu, so in the second I downloaded it and came back to try it.

So here's the question.

First of all, the URL of the previous download failed, I asked the classmate found the new website: http://cn.ubuntu.com/desktop/.

Then the downloaded Ubuntu can't run ...

I think it is because the version is 64, I may not be able to run the virtual machine, so I changed 32, the result is still the same (yes, it is purely blind).

In the online inquiry, we should turn on the settings-processor-extended feature Pae/nx,
But I go to open, but found that it is gray, unable to open.

By further querying, I found that the root cause was because the processor did not turn on virtual technology.
I opened the processor virtual settings in the BIOS, reboot, everything OK?

Yes, crap! is still gray.

No way, I rebuilt the virtual machine, 64bit appeared, set--processor--extended feature pae/nx can be checked.

Issue two: Installing VirtualBox virtual Machine Enhancements

I follow the teacher's tutorial step by step, the process is not anything unusual, but the final installation results show failed.

Go back to take a closer look at the teacher's tutorial, after entering the password will not have, so I think there may be no big problem, just go ahead.

Ii. Learning methods for learning Linux commands

• features of the operating system :

1, through the process, virtual memory and file three important abstract management of the computer's CPU, memory, I/O devices.

2. Provide the shell for the user and provide the system call for the programmer.

• shortcut keys :
  
  In the classmate's blog saw the use of ctrl+d, refer to the Linux CTRL + Z, CTRL + C, ctrl+d differences.
  -command format in Linux : (brackets are optional, i.e. some commands do not require options or parameters)

    command [options] [arguments]

• Man command

  Simple is to help, with the habit on the line should be, with-k,-f use.
  

• Cheat

As the name implies, this is too imba.

The Cheat command is an interactive cheat sheet application that is distributed to Linux command line users under the GNU General Public License. It provides a display of Linux command use cases, including all of the options and short but understandable features of the command.

My understanding is that the example adds a little explanation, is a dictionary.

• a few simple commands :

cd:cd+ return = return to the root directory.

LS: it means list.

Other things are sudo, gedit, find, locate, grep, Whereis, which, and so on.

Iii. Learning and practicing learning basic Linux Basics (new) Course

Experiment One

• The operating system includes the system call and the kernel two parts.
• The development history of Linux.
• What is the difference between Linux and Windows: Linux is more free and offers unlimited possibilities.

Experiment Two

• First question: The understanding of the terminal shell is not very clear.

  A Shell is a software (command parser) that "provides the user with an interface", similar to a DOS command line and later Cmd.exe.

• (/dev/tty introduction, first put in here, I half understand half do not understand)
• Touch command to create a file
• CD into folder directory
• PWD View current path

• Common shortcut keys are as follows

• History command: Up ARROW
• Common wildcard characters

character	meaning
*	Match 0 or more characters
？	Match any one character
[List]	Match any single character in the list
{C1.. C2}	Match all characters in c1-c2 such as {1..10}

• Banner command and installation (an interesting font, similar to Toilet,figlet)

  Experiment Three

• View Users: (Have a little problem ...)

Why is it ignoring me ...?

For a reference link, enter the TTY results as follows:

Don't understand what's going on .....

• su-l [username] Switch User, adduser add new user.
• The concept of root permissions
• Linux password input is not to display any content (blind output)
• User groups: Use the groups command or view the/etc/group file directly to see which user group you are in; Delete user Deluser.
• File permissions: View file permissions ls, change file owner sudo chown [new user] [filename]; modify file permissions: Binary number representation or add and subtract assignment operation

Experiment Four

• FHS Standard: A document standard with two levels of specification.
• Absolute path vs. relative path
• CD ~ Switch back to user's/home/[user name] Directory
• Use the mkdir (make directories) command to create an empty directory
• Use the CP (copy) command to copy a file to the specified directory. To successfully replicate the directory, you need to add the-R or-R parameters to indicate recursive replication.
• Use the RM (remove files or directories) command to delete a file.
• Use the MV (move or rename files) command to move the file (cut). Move the file "File1" to the documents directory.
• Using the CAT,TAC and NL commands to view the files, the first two commands are used to print the file contents to the standard output (terminal), where cat is a positive sequence display and the TAC is displayed in reverse order.
• Use the more and less commands to view the files by paging/head and tail commands.

• $ xeyes                          //贼好玩，hhhh

  Experiment Five
• Create a variable using declare

Where: = Assignment, echo $ to view the value of the variable.

• Variable modification

Experiment Six

• Zip compression wrapper:

Parameters	meaning
-R	Indicates that a recursive package contains all the contents of a subdirectory
-Q	parameter is represented as quiet mode
-O	Represents the output file name
-[1-9]	Indicates the size of the compressive strength
-X	Exclude some specific files
-E	To create an encrypted compressed package
-L	Make Windows Compatible

• Other commands:

Command	meaning
Du	View File Size
Unzip	Unzip the zip file program
rar	Package Compression command
Unrar	Extracting RAR files
Tar	Packaging tools

Experiment Seven

• Additional information about the DU command:

Parameters	meaning
-H	Introduction explanation
-d [NUMBER]	View File Depth
-A	Show all file sizes
-S	Show Totals only

• Other commands:

Command	meaning
Df	command to view disk capacity
Dd	Create a virtual image file
Mkfs	Command format disk
Mount	Command Mount Disk
Fdisk	Command for disk partitioning

Experiment Eight

• Help, man, info, cheat before.
• The main difference between a built-in command and an external command: whether the program exists in the Shell.

20165325 preparatory work 3 Linux installation and learning