vi is a full-screen text editor for Unix and Linux operating systems. 

Modes

vi has two modes of operation:

• command mode (normal)
• insert mode

12 Important Commands

Switch Modes

• Switch from Command Mode to Insert Mode
  • i - insert to the left of the cursor
  • a - insert after the cursor


• Switch from Insert Mode to Command Mode
  • <Esc>

Editing

• Cursor Movement
  • arrow keys (up, down, left, right)


• Common Commands
  • x - delete character under cursor
  • u - undo last command
  • /string - find character string


• Ending Edit Session
  • :wq - save changes and quit
  • :q! - quit without saving changes

Copy and Paste from a Web Page

To copy text directly from a web page into a file named filename use the following commands:

1. Copy from the selected part into the clipboard using the mouse or <Ctrl>c
2. Start vi: vi filename<Enter>
3. Switch to insert mode: i
4. Paste from the clipboard using the mouse or <Ctrl>v
5. Switch to command mode: <Esc>
6. Save and quit: :wq<Enter>

Other Useful Commands

• Navigation
  • #G - go to line number # (default is the last line)
  • <Ctrl>f - move forward to the next screen
  • <Ctrl>b - move backward to the previous screen
• Copy and Paste
  • yw - copy from the cursor to the end of word (copies to buffer)
  • yy - copy the current line (copies to buffer)
  • p - paste buffer contents after (or below) the cursor
  • P - paste buffer contents before (or above) the cursor
• Delete
  • dw - delete from the cursor to the end of word (copies to buffer)
  • dd - delete the current line (copies to buffer)
• Editing
  • o - open a new line below the cursor
  • O - open a new line above the cursor
  • r - replace character under cursor (eg. rw)
• Others
  • . - repeat the last command that changed the file
  • n - repeat the last /string (find) command
  • J - join current and following line
• Most commands can be preceded by number of repetitions (eg. 27dd)