BASH: BOURNE AGAIN SHELL

BASH Features

BASH: BOURNE AGAIN SHELL

 when you login to the Server using any CLI based tool OR login to the CLI mode you can see as like below screen. 

$ sign = local user/non-privilege user
# sign = Administrator/Privileged user

bash Command prompt explanation

Shells can be changed based the user compatibility and requirements, most of default shell is 'BASH'  

shells List

Command Line Completion:

Single Tab – it will provide the best option

Double Tab – it will provide all the possible options (Autocompletes)

Command Line Editing:

Ctrl+a            -           It moves cursor to the Home line position

Ctrl+b            -           Moves the cursor back one character

Ctrl+c            -           Sends the signal SIGINT to the current task, which aborts and close it.

Ctrl+d            -           Close current shell prompt

Ctrl+e            -           It will move a cursor to end of the bash

Ctrl+f             -           Moves cursor forward one character

Ctrl+g            -           Abort the research and restore the original file

Ctrl+h            -           Deletes the previous character (Same as backspace)

Ctrl+k            -           It is used to delete the command from the courser to line home position

Ctrl+l             -           Clear the screen

Ctrl+u            -           Clears the line content before the cursor and copies it into the clipboard

Ctrl+y            -           Yank the content from the cursor position

Ctrl+z            -           Sends the signal SIGTSTP to the current task, which suspend it

Ctrl+Shift+c -           Copy selected text

Ctrl+Shift+v            -           Paste the copied content

Ctrl+Shift+t             -           Tab

Ctrl+Shift+n            -           New Terminal

Ctrl+Shift+w            -           Close Tab

Ctrl+Shfift+q           -           Close a Terminal

Alt+b              -           Moves the cursor backward one word

Alt+c              -           Capitalizes the character under the cursor and moves to the end of word

Alt+d              -           Cut the word after the cursor

Alt+f               -           Moves the cursor forward one word

Alt+l               -           Lowers the case of every character from the cursor’s position to the end

Alt+.               -           Insert the last argument to the previous command

Command Line History: Command line history will be saved, when you execute any command in terminal.
 

$ history        -           this command will display all the previous executed commands

$ history –c   -           Clear the command history

$ !<number> -          it executes mentioned number command

Note: Default history size is 1000 commands

history Command Output

$ !<charectar>         -           it will display/execute matching character command

$ !!                              -           it will execute last executed command

Sophisticated prompt control:

?          -           It will replace a single character

Example:       rm –rf a?        -           it will delete the files with two characters

                        Rm –rf a??     -           it will delete the three characters files after “a”

*          -           replace multiple number of characters

Example:       rm –f  a*        - it will remove all the files which are starting with “a”

Piping and Redirecting:

Redirecting input and output from standard stream to user defined place

1.    Input RD       -0                                 <         

2.    Output RD -1              Values        >          Symbols

3.    Error RD       -2                                 >

Example:       $ sort < <file name>

                        $ wc < <file name>

                        $ history > f2

                        $mkdir d1 2> e1

sort Command Output

Piping sending output or one command as a input to the another command 

| pipe

pipe Symbol

Page related command:

            Less: is used to see the command output page by page in up and down way

            More: we can’t go upward downward, just see the output fit to the screen
 

less and more Command Output