Vim

How to edit or create a file with the Vim text editor

$ vim file.txt    # create a text file and open it in Vim

Enter insert mode (edit): i
Enter insert mode and create a new line below the cursor: o
Save file: Esc then :w then Enter
Quit file: Esc then :q then Enter
Quit file without saving: Esc then :q! then Enter
Save and quit: Esc then :wq then Enter OR Esc then :x then Enter
Show line numbers: Esc then :set number (or :se nu)
Go to the last line: Shift + G
Go to the first line: gg
Copy a line: yy (or 3yy to copy 3 lines)
Select multiple lines (visual line mode): Shift + V then use j/k to move down/up
Copy lines 10 to 20: :10,20y
Paste line above: Shift + P
Paste line below: p
Cut (delete) a line: dd
Search for a pattern: /pattern then Enter
Undo: u
Redo: Ctrl + R
Replace all occurrences of a word: :%s/name/new_name/g
Replace a literal dot in a pattern (example: replace name.main with name.rg): :%s/name\.main/name\.rg/g