vim.md

VIM

VIM (Vi IMproved) is an open source lightweight, powerful, and popular (modal) text editor available for Debian based Linux, RPM based Linux, and Windows. (Note: MacOS is BSD distro - Debian based). Other editors include vi, nano, pico, emacs, nvi, elvis, ... .

See: https://www.vim.org

Installation on Debian based Linux

First check to see if vim is already installed.

$ which vim

If already installed, you will see the the path displayed, for example:

/usr/bin/vim

If vim not found, install it by typing the following commands at the command prompt:

$ sudo apt-get update 
$ sudo apt-get install vim

To ensure Vim is correctly installed execute below command −

$ which vim

Or yum install vim with yum.

Vim modes

Vim is a modal editor. Keystrokes have different results based on the mode. The modes are:

1. Normal: navigate file and make edits
2. Inssert: for inserting text
3. Replace: for replacing text
4. Visual (plain, line, or block): select text
5. Command: run commands

The mode is displayed in the bottom left corner (unless in normal mode).

Normal Mode

You should be in normal mode most of the time. To enter normal mode, press the ESC key (from any mode).

Movements in normal mode

• hjkl (left, down, up, right)
• words: w (next word), b (beginning of word), e (end of word)
• Lines: 0 (beginning of line), ^ (first non-blank character), $ (end of line)
• Screen: H (top of screen), M (middle of screen), L (bottom of screen)
• Scroll: ^u (up), ^d (down)
• File: gg (beginning of file), G (end of file)
• Line numbers: :{number}<CR> or {number}G (line {number})
• Misc: % (corresponding item)
• Find: f{character}, t{character}, F{character}, T{character}
  • find/to forward/backward {character} on the current line
  • , / ; for navigating matches
• Search: /{regex}, n / N for navigating matches

Insert mode

Used to enter and edit text. The current mode is shown at the bottom left corner of the window. To switch from default command to insert mode press i key.

To exit insert mode, use the escape key, esc.

Command mode

The default mode. Commands include commands in this mode like copy, paste, delete, replace, etc. Vim commands without a colon are executed in command mode. Enter command mode with : from Normal mode. Functionalities in this mode include opening, saving, and closing files. Common commands in this mode include:

• :q quit and close window
• :w save (write) buffer
• :wq save and quit
• :e {filename} open file to edit
• :ls list/show open buffers
• :help {topic}
  • :help :w opens help on the command :w
  • :help w opens help on w movement

To write to buffer:

:w

To quit vim,

:q

To quit without saving changes, type:

:q!

Save changes and quit editor with the command:

:wq

Help

Help is a command, but deserves its own subsection heading.

:help
:help [topic]
:help modes

Command	Meaning
i	insert
o	newline below (insert mode)
O	newline above
d	delete
dw	delete word
u	undo
y	yank, copy
p	paste
yy	copy line
yw	copy word
fo	find "o"
.	repeats last command
4j	down 4 lines
c2w	change 2 words
2dw	delete 2 words

Selection Mode

Essential Vi Commands

Open a file:

vi filename

To go into edit mode: press ESC and type I

To go into command mode: press ESC

To save a file, press ESC and type

:w fileName

To save a file and quit: press ESC and type

:wq

OR

press ESC and type :x

To jump to a line: press ESC and type :the_line_number

To Search for a string: Press ESC and type /wordToSearch

To quit vi: Press ESC and type :q Save the following into a file called hello.sh:

Help

:help
:help [topic]
:help modes

Copy, Cut, and Paste

https://linuxize.com/post/how-to-copy-cut-paste-in-vim/

Encryption

vi /pathtofile/MyFile.txt

Press the ‘Enter’ key. The contents of your file should appear in the terminal window.

Before you enter any Vim command, you should make sure that you’re not in insert mode, so press the Escape key – if you were in insert mode, then you’re now in command mode.

Now, enter:

:X

Vim is case-sensitive, so the X must be capitalized.

Vim will then ask you to create an encryption key, which is essentially the password you'll use to encrypt and decrypt this text file. If you forget this key, then you'll be unable to access your file's contents, so make sure you use something memorable!

Type your encryption key/password, then press the Enter key on your keyboard – rinse and repeat to confirm that this is the encryption key you want to use.

This password isn't applied to your file until you save it, so now's a good time to save your changes by running the following command:

:wq

That's it – the file is encrypted!

If a potential snooper tries to open this file using a regular text-editing app, they'll get an error message. If they try to access this file in Vim using the wrong encryption key, they'll see nothing but scrambled letters, symbols, and numbers.

Accessing an encrypted file

If at some point you need to view or edit a Vim-encrypted file, then you have two options:

Open this file in Vim Vim automatically checks whether a file is encrypted, so if you try to access it through Vim (using the vi filepath/filename command), it'll prompt you to enter your encryption key. Once you've entered your key, the file's contents will appear in the Terminal, ready for you to view and edit.

Remove encryption

To remove encryption from a file:

Open the file in Vim (again, using the vi filepath/filename command). Enter your encryption key when prompted. Enter the following command:

:X

When Vim prompts you to create a new encryption key, press the Enter key twice. Save your changes:

:wq

You'll now be able to open this file in your regular text-editing application.

Change the encryption key

To change the encryption key associated with the file:

Open the file in Vim. Enter your password when prompted. Run the following command:

:X

Type new password then hit the Enter. Save the changes with the command :wq.

Customizing Vim

Vim is customized in the configuration file: ~/.vimrc.

Advanced Vim

• Extend Vim with plugins
• Use multiple windows

:sp / :vsp  # to split windows

Practice Text

def fizz_buzz(limit):
    for i in range(limit):
        if i % 3 == 0:
            print('fizz')
        if i % 5 == 0:
            print('fizz')
        if i % 3 and i % 5:
            print(i)

def main():
    fizz_buzz(10)

The Apple Cat // modem is by far the most expandable modem on the market today.	Of course it's also the choice modem of pirates because of it's
inexpensive half-duplex 1200 baud capabilities.  The expansion module available
for the cat has several very useful functions.	Rather than shelling out $30
bucks for one which you may only use a few of the features this file tells you
how to build just certain features or even the whole package.

   First off you'll need some basic knowledge and tools.  As for the knowledge
you'll need to know how to solder pretty well, you'll also proabibly have to
know DC from Hz and +12V from RS232.  Ok now, If you can handle that that,
you'll need these tools:

Assignment Exercises

This assignment covers some basic Vim commands and features, including searching, visual mode, cut and paste, saving and exiting, undo and redo, and replacing text. Good luck with your practice!

1. Fix the following in fizz buzz:

• Main is never called
• Starts at 0 instead of 1
• Prints 'fizz' and 'buzz' on separate lines for multiples of 15
• Prints 'fizz' for multiples of 5
• Hard-codes 10 instead of taking a command-line argument

2. Open a new file in Vim.

3. Write some text in the file (it can be anything you like).

4. Use the search feature to find a specific word or phrase in the text.

5. Use the visual mode to select a block of text.

6. Cut the selected text and paste it somewhere else in the file.

7. Save the file and exit Vim.

8. Open the file again and make some changes to the text.

9. Use the undo and redo features to undo and redo your changes.

10. Use the replace feature to replace a word or phrase with something else.

11. Save the file and exit Vim.