"Linux Summary" linux command learning Three

Character processing commands: tr--convert or delete characters

TR [OPTION] ... SET1 [SET2]

Conversions are not words, but characters are converted one by one

-D: Delete all characters that appear in the character set

Eg:tr AB AB

Bash Extreme Features

Shell: Shell

Gui:gnome,kde,xfce

Cli:sh,csh,ksh,bash,tcsh,zsh

Bash:

1. Command history

2. Management, redirection

3. Command aliases

4. Command line editing

5. Command line expansion

6. File name wildcard

7. Variable

8. Edit

Command line editing

Cursor Jump:

CTRL + A: Jump command header

ctrl+e: Jump command line End

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

-D OFFSET [n]: Delete command at specified position

-W: Error command history in history file

The use of command history tips

!n: Executes the nth command in the command history

!-n: Executes the last 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,.: Ibid.

ALT +.: Ibid.

Command aliases

Alias:alias [-P] [Name[=value] ...]

Aliases defined in the shell are valid only for the current shell life cycle, and the valid range of aliases is only the current shell process;

Ualias Cmdalias Deleting aliases

Command substitution: $ (commands), Counter-reference: ' Command '

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

Bash quotation marks for titles

": Command substitution

"": weak reference, can implement variable substitution

': Strong reference, can not implement variable substitution

File name wildcard, globbing

*: Any character of any length

?: any single character

[]: matches any single character within the specified range

[: Alnum:] : Numbers and uppercase and lowercase letters

[: Alpha:]: Uppercase and lowercase letters

[: Blank:]:

[: Cntrl:]:

[:d igit:]: Number

[: Graph:]

[: Lower:]: lowercase letters

[:p rint:]

[:p UNCT:]: Punctuation

[: Space:]: white space character

[: Upper:]: Uppercase

[: Xdigit:]

[^]: matches any single character outside the specified range

"Linux Summary" linux command learning Three