Linux Learning Note 04

Sort text: Sort (does not affect the order of the source files only affect the display order)

-N: Numeric sorting

-R: Descending

Uniq

-C: Shows the number of rows in a file that repeats

-D: Show only duplicate rows

Text statistics: WC (word count)

Character processing commands: TR--Convert or delete characters

Bash and its features:

1. command history, Command completion
   

2. Pipe, redirect

3. Command aliases

4. Command line editing

5. Command line expansion

6. File name wildcard

7. Variable

8. Programming

command-line editing:

Cursor Jump:

CTRL + A: Skip to the beginning of the command

Ctrl+e: Jump to the end of the command line

Ctrl+u: Delete the cursor to the beginning of the command line

CTRL+K: Delete the cursor to the end of the command line

Ctrl+l: Clear Screen

Command history:

View command history: Historical

-C: Empty command history

-W: Save the Command history to the history file

Environment variables

Path: Command Search Path

Histsize: Command history buffer size

The use of command history tips:

!n: Executes the nth command in the command history

!! : Executes the previous command

!string: The most recent command in the command history that starts with a specified string

!$: Reference the last parameter of the previous command

Esc.

Command completion: Search the PATH environment variable specified by each of the paths with the string we give the beginning of the executable file, if more than one, two times tab, you can give the list: otherwise it will be directly complete

Path completion: Searches for each file name under the starting path we give, and tries to complement the entire

Command aliases

Alias

Command substitution: $ (command), anti-quote: ' command '

To replace a subcommand in a command with the process of executing the result

BASH-supported quotes

": Command substitution

"": weak reference, can implement variable substitution

': Strong reference, do not complete variable substitution

File name wildcard,

*: Any character of any length

？ : Any single character

"": matches any single character within the specified range

Linux Learning Note 04