Dark horse programmer - software testing - stage 07 2-linux and database -09-24-linux command learning steps, wildcards, absolute paths, relative paths, common commands for files and directories, file

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Ten . Instruction of command learning method

Here to ls Command as an example

ls :  Show which files are in the current path 
ls -a :  Display all files in the current path ( Contains hidden files ( File name to . At the beginning ))
ls -l :  Displays the details of the file in the current path 
ls -al :  Displays the details of the file in the current path ( Contains hidden files )

 Be careful : 
1.  The combined form of command options is :  Command body  - Options 1 Options 2
2.  There must be a space between the command body and the option 
3.  The function of command options is generally used to expand the main function of the command 

 Learning methods :
1.  Make clear the meaning of the command body first 
2.  Find command options according to actual needs and help commands 
3.  Unused options ,  Try to build your own scene ,  See the effect after the test 
4.  Which makes perfect ,  Compared with memorizing commands ,  It's more reasonable to practice frequently !

ls Command use effect screenshot 1

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-GxOdKubV-1656605764333)(Linux And the database day01 Lecture notes .assets/image-20200523113447394.png)]

ls Command use effect screenshot 2

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-VKIqrqwH-1656605764334)(Linux And the database day01 Lecture notes .assets/image-20200523113505239.png)]

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General operation of virtual machine : Show hidden files

Open the option as shown in the figure

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-4lR2iODO-1656605764335)(Linux And the database day01 Lecture notes .assets/ima