Some of my LINUX notes and LINUX notes

Some of my LINUX notes and LINUX notes
Ctrl + Alt + T open the terminal
Ctrl + Alt + F2/F7 open/close the graphic user interface
Open shell: ctrl + alt + t
Create a folder: mkdir c_code
Create a notepad Editor: gedit hello. c
Compilation: gcc hello. c-o hello
Run:./hello
Shutdown-h now shut down immediately
Shutdown-r now restart now
Reboot restarts now
Logout
Clear Screen
Cat viewing only cannot be modified
Cd .. go back to the upper-level directory
Cd/return to the root directory
Cd. Return to the current directory
Switch startx to the graphic user interface
Ls Installation Method: tar-zxvf Installation File
Switch to the Administrator:
Su
Su-
Su root
Su-root
Ubuntu switch: sudo su
Method 1 for switching the root user
Run the sudo su command.
After executing the above command, we will be asked to enter the current password.


How to exit the root user
After switching to the root user, we only need to execute the exit command to exit the root user account.




The second method to switch to the root user account
You can run the sudo-I command to switch normal users of the current user to the root user mode.


After executing the command, we usually need to enter our password. This is because I just switched do to the root user,
Therefore, the system does not require a password. Generally, when we switch back and forth to the root user within 10 minutes, the system does not prompt to enter the password, and then requires us to enter the password again.


Vi Editor:
Vi hello. java
Input I (to insert mode)
Enter the Esc key to enter the command mode
Input; [wq indicates to exit and save q! Exit and do not save]
Compile javac hello. java
Run java hello




Linux File System: root home bin sbin mnt etc var boot
Root: stores related files of the rooty user.
Home: stores files of common users.
Bin: directory for storing Common commands
Sbin: You must have certain permissions to use commands.
Mnt: default directory for mounting the optical drive and soft drive
Etc: stores configuration-Related Files
Var: stores constantly changing files
Boot: stores boot-related files.


Pwd: displays the current path

Useradd Username
Eg: useradd xiaoming Add User James
Passwd User Name
Eg: passwd xiaoming change xiaoming Password
Userdel user name delete user
Userdel xiaoming delete user xiaoming
Userdel-r xiaoming


Inti [1, 0123456]


Cd: Change directory
Ls: Lee's files and directories
Ls-a: Show Hidden Files
Ls-l display long list format
Mkdir resume directory
Rmdir Delete directory
Touch: Empty resume File
Cp: Copy command
Cp-r dir1 dir2 recursive Copy command
Move the music video file and the file name
Rm deletes a file or directory
Rm-rf delete all contents (including directories and files) r recursive f forced


| In linux and unix systems | it refers to the pipeline command, that is, to hand over the result of a command | the subsequent command is processed


More: displays the file content, with pagination
Less: displays the file content, with pagination
Grep content in the text


The man command is equivalent to the help Command in dos.
Find search files and directories






How to Develop C Programs in linux: Create a folder: mkdir c_code
Create a notepad Editor: gedit hello. c
Compilation: gcc hello. c-o hello
Run:./hello


How to add a group in linux: groupadd libin
View all groups in linux: vi/etc/group
Cat/etc/group is not modified
Create a user and specify the group to which the user is assigned.
Useradd-g group name Username




View all user information in linux: vi/etc/passwd
Cat/etc/passwd



-Rw-r -- indicates the operation permissions of various users on the file.
"-" Indicates the file type.
The owner of the "rw-" file has permissions on the file.
"R --" permission on the file in the file group
"R --" permissions of users in other groups on the file


There are three types of permissions: r is readable and expressed in 4.
W can be written in 2
X can be executed in 1 Representation




Environment configuration file:/etc/profile environment configuration file
./Eclipse & indicates running in the background




VirtualBox Virtual Machine linux shared folder:
1. device-> shared folder
2. File System-media folder-sf _ Virtual Machine shared folder (no permission)
3. system settings-User Account-Unlock
4. Terminal: sudo adduser libin vboxsf
5. Restart


Mount command: mount [-parameter] device name mount point
Note: mount/mnt/cdrom
Uninstall command: umount device name




View disk usage df [-parameter]
View the partition in which the directory is located
Df [full directory]
View partition details in linux: fdisk-l
In windows,. bat is a batch file.






View the current shell: env [change the command to display the environment variables of the current operating system]


Env | more MPs queue command, displayed by PAGE




Chsh-s enter a new shell such as/bin/csh.


Wildcard character: ls/bin/* sh: displays all files ending with sh in the binfile.


View User: who am I




Command complementing function: Enter 'mk 'directly and press the 'tab' twice to display all commands starting with mk.
Cat p. Press the 'tab 'key twice to display all files or directories starting with p.


View history commands: history
1. history 5: displays the last five commands used.
2 .! 5: run the command with the historical number 5.
3 .! Ls executes the last command starting with 'LS.


Route data (up to 30): tracert www.baidu.com


Linux: ifconfig
Windows: ipconfig




View the rpm package installation file: rpm-qa




Task Manager: ps-aux
Kill process number: kill Process
Kill-9 process no.: Force kill Process
Dynamic Monitoring: top
Show route table: route








 
I recently took the RHCT test for Linux and want to take some study notes online as my reference materials?

Are you just registering for the exam?
There is a lot of content!
 
What kind of linux laptops are there?

There is no need to buy a pre-installed Linux notebook for Linux ......

Many low-price laptops are Linux. Of course, it is not absolute. Some advanced configurations with relatively high prices will also be installed with Linux to reduce the price.
However, the advanced configuration is more inclined to be preinstalled with the Windows Vista platinum edition.