pwd - print out the name of the current working directory "print working directory"
cd - change directory
ls - List the contents of the directory
3.1 Understanding the file system tree (inverted tree)
Linux organizes all files in a hierarchical directory structure, and all files form a tree-shaped directory ( called a folder in Window )
The first-level directory of the file system is called the root directory
The root directory and subdirectories contain files and subdirectories
The linux system has only a single file system tree, no matter how many storage devices are " mounted " to the computer
3.2 Current working directory
When logging in to the system for the first time, the current working directory is the Home directory. Log in to the system as an ordinary user. The Home directory is the only place where files can be written.
3.3 List the contents of the directory
ls -l
3.4 Absolute path
cd /home/user_Lin/test #The path starting from the root directory
3.5 relative path
. # Indicates the current working directory
.. #Indicates the upper level directory
cd ./user_Lin/test #The path starting from the current working directory
cd ..
3.6 Change the current working directory
About cd shortcut commands
cd # switch directory to Home
cd-# Switch to the previous WD
cd ~user_name # switch to user_name's home directory
Rules about file names
The maximum length of a Linux file name is 255 characters
The file name cannot contain'/' and'/0', because they have special meaning to the Linux kernel
touch filename # can create a file
And what has a special meaning to Shell:? * [] '"` | <;> \ ()% $! &
- File names beginning with "." are hidden files
- File names and command names are case sensitive
- Linux no file extension
- Support long file name "." "," "-" spaces, (do not use spaces, tabs, control characters)
There may be characters with special meanings that can create files normally in the system, but may cause errors in actual operations