Basic linux commands

Basic linux commands
Basic Linux commands (all files)


Command Format:
Command [Option] [parameter]


Note: Use spaces to separate commands, options, and parameters. The limit can only be 256 characters.


Help
Man manual eg. man

Man command/function name/header file

Ls list content list directory content (windows: dr)
Ls-a displays all files (including hidden files, which usually start)
Ls-l displays detailed information about the file.
Drwxrwxr-x 2 tarena 4096 April 23 11:10 Pre


--A common file that stores data in a certain format (binary or text)
D: directory file. B: block device files that provide buffer direction for the device. C: character device file, without caching. P: MPS queue file for inter-process communication.
S: socket file, network communication between processes. L: a symbolic link file pointing to another file (equivalent to a shortcut in windows ).


Owner group others
Tarena others
Rwx r-x


R: 4 0100 read
W: 2 0010 write
X: 1 0001 executed

Clear screen ctrl + L (windows: cls)

Pwd prints the current working directory

Cd change directory switch path switch directory
/: Root directory
./: Current Directory
../: Upper-level directory/parent directory
~ : Main directory of the current user

1) absolute path: Path to be traversed from the root directory
2) Relative Path: Path to be traversed from the current directory

Create a folder using mkdir

Touch creates a file and modifies the last modification time of the file.

Rm delete file

Rm-r: delete a non-empty folder

Rmdir Delete empty folder

Cp copy
Cp file_name dir_name: copy the file to the specified path
Cp file_name dir_name/newfile_name rename or overwrite copy
Cp-r dir_name another_name is required to copy the directory-r

Cp-all dir_name another_name: Copy all content to the specified directory according to the original dependency.

Mv move rename (rename)
Mv file_name dir_name
Mv file_name dir_name/newfile_name

Mv file_name newfile-name

Chmod
Chmod [u/g/o/a] [+-=] [r/w/x] filename

=: Only one of the permissions is retained. Others are deleted.

Cat file_name display file content

Head file_name displays the first 10 lines of File Content

Head-n file_name: N rows

Tail file_name displays the last 10 lines of File Content

More file_name split display file content

Space: one screen flip down

Press Enter: Next line

History displays executed commands
!! Repeat the previous command
! N repeat the n-line command

! First letter search up, last executed command

Wc file statistics
Count and display the number of bytes, characters, and rows of the specified file.
Wc [Option] file_name
Wc-l file_name: number of lines displayed line

Wc-w file_name: number of characters displayed in word

Wc-c file_name: number of bytes displayed

; The end of a semicolon statement, usually used to link Multiple commands for execution
| The pipeline uses the output result of the previous program or command as the input of the next program or command
History | more
Users
Who logon to the local system user details
Who am I displays information of the current user

Whoami displays the name of the current user

Ps detects the working status of a process
-E: display all processes
-F: displays detailed processes.
-H: No title is displayed.
A. display the program running on the terminal.
R: displays running processes.
X displays the processes without control terminals.
Detailed format of u display
Aux displays details of all processes
Top
Kill the PID to terminate the specified PID Process
-9 The SIGKILL signal forces the killing Program

Redirection
> Write Truncation

> Append data to the end

File Link
Ln [options] source [dest]
Ln [options] source [dest]
Ln [options] source... directory


Hard Link
Ln [path name]/[file name] [path name]/hard link name


Bash shortcut
Ctrl + l clear screen
Ctrl + a locate the start of the command
Ctrl + e go to the end of the command
Ctrl + d Exit and end command
Ctrl + c interrupt program
Ctrl + z hangs the command being executed
Ctrl + shift + c copy
Ctrl + shift + v Paste