Vi / Vim Editor

Introduction

• 'vi' is the default editor of RHEL and also the most widely used text editor.

• It is the also used as the default editor by other UNIX variants. 

• 'Vim' (Vi iMproved) is the enhanched version of vi editor, a programmer's text editor.

Modes of operation

Vi / Vim operates in one of the following modes

1. Insert Mode
2. Command Mode
3. Ex Mode
4. Visual Mode

1. Commands of Insert Mode

• i -----> To insert text before the current cursor pointer

• a -----> To insert text after the current cursor pointer

• I -----> To insert text from the beginning of the current line

• A -----> To insert text from the end of the current line

• o -----> To open a New line below the current one

• O -----> To open a New line above the current one

• s -----> Substitute the current character

• S -----> Substitute the current line

• r -----> To replace the current character

• R -----> To replace the current line

• 'Esc'-----> To come out of the current line

2. Commands of Command Mode

 * Cursor Movement

• h -----> To move one character left

• l -----> To move one character right

• j -----> To move one line down

• '<Enter>' -----> To move one line down

• k -----> To move one line up

• O -----> To move to the beginning of the current line

• $ -----> To move to the end of the current line

• gg -----> To move to the top of the file

• G -----> To move to the bottom of the file

• 'N'G -----> To move to Nth line of the file

• w -----> To move one word ahead

• b -----> To move one word back

• ) ----->  To move one sentence ahead

• ( -----> To move one sentence back

• } -----> To move one para ahead

• { -----> To move one para back  

• :set number ----------> To show line number before each line (Temporarily)

3. Commands of Ex - Mode

   * Searching Text

• /text -----> To perform search in forward direction (Top-to-bottom search)

• ?txt -----> To perform search in reverse direction (Bottom-to-top search)

• n -----> To search next occurance of the searched text in forward direction

• N ----->To search must occurance of the searched text in reverse direction

  * Save and exit

• w ----->  To save the changes

• :wq or :x -----> To save the changes into the current file and exit

• :wq <filename> -----> To save the changes in the given file and exit

• :wq ! -----> To forcefully save into the read-only file

• q! -----> To exit without saving the changes

4. Commands of Visual Mode

• V -----> starts line oriented visual mode

• CTRL + V -----> starts block oriented visual mode

• y -----> To copy the selected text

• d -----> To delete the selected text

• p -----> To paste the copied / deleted text

5. To password protect a file (supported in Vim Editor only)

     Example:

          vim file1

          .............

          .............(text)

       Esc

      :X -----> Enter encryption key: mypassword

                                      Retype: mypassword

      :wq -----> Save and exit

6. Modifying / Removing password from a password protected file

    Example:

         vim file1

           password ........

      Esc

     :X -----> Enter Encryption Key (Leave Blank to remove password)

                      Retype :  (Leave blank and press enter)

      :wq -----> Save and Exit

7. Recovering a unsaved data of a file after crash

 Suppose, file1 is the file which was not saved and we want to recover:

    # ls -a 

(This command will show the .swp file of your original file which was

stored in the virtual memory (swap memory)).

    # vi -r .filename.swp 

 (To restore / recover unsaved data of a file)

 :wq (Save the file and exit)

Now, remove the .swp file after data recovery

   # rm .filename.swp 

8. Open the file in Read-Only mode 

# vi -R <filename> 

If you need any further help, go and try

 # man vim  or # vim --help   in your terminal. 

Thankyou.. :)