Title: Using vi, the Unix Visual Editor
Course: UNIX Operating System I (13673)

Using vi, the Unix Visual Editor

Description
You will learn to use vi, the full screen editor found on nearly all Unix systems. Basic commands are covered, including those that enable you to insert, delete, change, replace, and copy text, and to move around within and between files. In addition, you will learn how to set editing options for your files, temporarily or permanently, globally or locally.
What You Will Learn
You will learn (1) how to start and end vi edit sessions, (2) how to move around in a file, (3) how to enter new text, (4) how to modify, move, and delete old text, and (5) how to read from and write to files other than the one you are editing.
Instructor
Rick Ells
Prerequisites
R105 or equivalent knowledge.
Table of Contents

A. Vi Basics
1. About vi
2. Starting vi
3. vi Modes
4. Basic Cursor Movement
5. Entering, Deleting, and Changing Text
6. Setting Basic Options in vi
7. Exiting vi
8. Basics Summary

B. Intermediate Vi
1. More On Cursor Movement
2. Entering Text Mode
3. Commands and Objects
4. Replacing and Changing Text
5. Deleting Text
6. Copying and Pasting Text
7. Other Useful Commands
8. Buffers
9. Copying, Deleting, or Moving Text Using Line Numbers
10. Searching for Text
11. Substitutions

C. Advanced Vi
1. Writing to and Reading from Files
2. More About Options
3. Customizing vi Sessions
4. Creating a .exrc File
5. Abbreviations & Mapping

D. Tips and Tricks
1. Making vi an Editor in Pine
2. vi-ing More Than One File
3. Moving the Left Margin
4. Issuing Shell Commands From vi
5. Double Spacing a File

A. VI BASICS

1. About vi
vi is Found on Nearly Every Unix Computer
  - vi is the standard Unix editor
  - Other documents on vi:
    - How To Use The vi Editor
    - Vi Reference
    - Mastering the VI editor - University of Hawaii at Manoa
    - Vi Lovers Home Page
    - Visual Editor (vi): A Tutorial - University of Southwestern Louisiana
vi is Powerful and Fast
  - Your terminal displays a section of the file you are editing
  - vi can do anything you want
  - You don't need to remove your fingers from the standard typing keys-the keys themselves give commands to vi
vi Stays Out of Your Way
  - vi has no menus
  - vi commands are short
2. Starting vi
Open a file with vi. Type: vi myfile.txt
  - If myfile.txt does not exist, a screen will appear with just a cursor at the top followed by tildes (~) in the first column.
  - If myfile.txt does exist, the first few line of the file will appear.
  - The status line at the bottom of your screen shows error messages and provides information and feedback, including the name of the file.
3. vi Modes
Command Mode
  - Command mode is the mode you are in when you start (default mode)
  - Command mode is the mode in which commands are given to move around in the file, to make changes, and to leave the file
  - Commands are case sensitive: j not the same as J
  - Most commands do not appear on the screen as you type them. Some commands will appear on the last line: : / ?
Insert (or Text) Mode
  - The mode in which text is created. (You must press <Return> at the end of each line unless you've set wrap margin.)
  - There is more than one way to get into insert mode but only one way to leave: return to command mode by pressing <Esc>
When in doubt about which mode you are in, press <Esc>
4. Basic Cursor Movement


    From Command Mode

    k    Up one line

    j    Down one line

    h    Left one character

    l    Right one character (or use <Spacebar>)

    w    Right one word

    b    Left one word





NOTE: Many vi commands can take a leading count (e. g., 6k, 7e).
5. Entering, Deleting, and Changing Text


    From Command Mode

    i    Enter text entry mode

    x    Delete a character

    dd   Delete a line

    r    Replace a character

    R    Overwrite text, press <Esc> to end



6. Setting Basic Options in vi
Displaying Line Numbers

    From Command Mode

    :set nu    Display line numbers

    :set nonu  Hide line numbers


Setting Right Margin

    From Command Mode

    :set wm=number  Set Wrap Margin number of spaces from right
                              edge of screen

    :set wm=10      Set Wrap Margin 10 spaces from right edge
                              of screen

    :set wm=0       Turn off Wrap Margin


7. Exiting vi
  - To exit you must be in command mode-press <Esc> if you are not in command mode
  - You must press <Return> after commands that begin with a : (colon)

    From Command Mode

    ZZ     Write (if there were changes), then quit

    :wq    Write, then quit

    :q     Quit (will only work if file has not been changed)

    :q!    Quit without saving changes to file


8. Basics Summary


    UNIX   ---> vi file --->  COMMAND  ---> i I a A o O --->  TEXT
    SHELL  <---- ZZ <-------  MODE     <------ <Esc> <------  MODE



A Basic vi Session
  1. To enter vi, type: vi filename <Return>
  2. To enter insert mode, type: i
  3. Type in the text: This is easy.
  4. To leave insert mode and return to command mode, press: <Esc>
  5. In command mode, save changes and exit vi by typing: :wq <Return>
You are back at the Unix prompt.

B. INTERMEDIATE VI

1. More On Cursor Movement

    From Command Mode

    e    Move to end of current word

    $    Move to end of current line

    ^    Move to beginning of current line

    +    Move to beginning of next line

    -    Move to beginning of previous line


    G    Go to last line of the file

    :n   Go to line with this number (:10 goes to line 10)


    <Ctrl>d   Scroll down one-half screen

    <Ctrl>u   Scroll up one-half screen

    <Ctrl>f   Scroll forward one full screen

    <Ctrl>b   Scroll backward one full screen


    )         Move to the next sentence

    (         Move to the previous sentence

    }         Move to the next paragraph

    {         Move to the previous paragraph


    H         Move to the top line of the screen

    M         Move to the middle line of the screen

    L         Move to the last line of the screen


    %         Move to matching bracket:  ( { [ ] } )


2. Entering Text Mode

    From Command Mode

    i    Insert text before current character

    a    Append text after current character

    I    Begin text insertion at the beginning of a line

    A    Append text at end of a line

    o    Open a new line below current line

    O    Open a new line above current line


3. Commands and Objects

    Format                         Example

      operator number object          c2w

      number operator object          2cw


    Operators

      c   change

      d   delete

      y   yank


    Objects and Locations

      w           one word forward

      b           one word backward

      e           end of word

      H, M, L     top, middle, or bottom line on screen

      ), (        next sentence, previous sentence

      }, {        next paragraph, previous paragraph

      ^, $        beginning of line, end of line

      /pattern/   forward to pattern



4. Replacing and Changing Text

    From Command Mode

    r        Replace only the character under the cursor.
                    (Note: using r you remain in command mode.)

    R        Beginning with the character under the cursor,
                    replace as many characters on this line as you
                    want. (You are in overtype mode until you
                    press <Esc>

    cw       Beginning with the character under the cursor,
                    change a word to whatever you type.  (You are
                    in insert mode until you press <Esc>)

    c$       Beginning with the character under the cursor,
    C               change a line to whatever you type. (You are
                    in insert mode until you press <Esc>)


5. Deleting Text

    From Command Mode

    x       Delete a character

    dw      Delete an alphabetic word and the following space
                   (6dw deletes six words)

    dW      Delete a blank-delimited word and the following space

    dd      Delete a line (6dd deletes six lines)

    d$      Delete all characters to the end of the line.
    D

    d}      Delete all characters to the end of the paragraph.

    :5,30d  Delete lines 5 through 30


Deleted text goes into a temporary buffer that is replaced each time you delete (or copy) more text. The current contents of the buffer can be put back into your file.
6. Copying and Pasting Text

    From Command Mode

    yy        Copy (yank) the current line

    6yy       Copy (yank) six lines, beginning with the current line

    yw        Copy the current word

    p         Put the text after the cursor position

    P         Put the text before the cursor position


Copied text goes into a temporary buffer that is replaced each time you copy (or delete) more text. Only the current contents of the temporary buffer can be put back into your file. As a result, when you use copy (y), use the put (p) command immediately.
A yank and put procedure using colon commands:
  1. :5,10y Copy lines 5-10
  2. Move cursor
  3. :put Put after cursor
7. Other Useful Commands

    From Command Mode

    .    Repeat last command

    n.   Repeat last command n number of times

    J    Join next line to current line

    u    Undo last single change

    U    Restore current line

    ~    Change letter's case (capital to lower and vice versa)


8. Buffers
Temporary Buffer
Deleted or copied text goes into a temporary unnamed buffer. The contents of the temporary buffer may be retrieved by using the p or P commands.

    p   Put words from temporary buffer after cursor or
               put lines from temporary buffer below current line

    P   Put words from temporary buffer before cursor or
               put lines from temporary buffer above current line


Lettered Buffers
There are 26 lettered buffers (a-z). Contents of a lettered buffer are saved until you copy or delete more characters into it, or until you quit your current vi session.


  From Command Mode

  "ayy     Copy (yank) a line into buffer a

  "Ayy     Appends to buffer a

  "a10yy   Copies 10 lines into buffer a

  "a10dd   Deletes 10 lines of text into buffer a

  "ap      Put contents of lettered buffer a below the current line


Both temporary and lettered buffers last only for the current vi session.
9. Copying, Deleting, or Moving Text Using Line Numbers
  - These commands start with a colon (:) and end with a <Return> or <Enter>
  - <Ctrl>g shows the line number of the current line
  - The basic form of colon commands is
:beginning_line, ending_line command destination
where destination is the line after which you want the text placed.


  From Command Mode

  :5,10 co 105   Copy lines 5-10 to the line after 105

  :5,20 m $      Move lines 5-20 to end of file

  :7,300 d       Delete lines 7-300 (to buffer)


10. Searching for Text

  From Command Mode

  /text   Search forward (down) for text (text can include spaces
                      and characters with special meanings.)

  ?text   Search backward (up) for text

  n       Repeat last search in the same direction

  N       Repeat last search in the opposite direction

  fchar   Search forward for a charcter on current line

  Fchar   Search backward for a character on current line

  ;       Repeat last character search in the same direction

  %       Find matching ( ), { }, or [ ]


11. Substitutions
The simplest way to do substitutions over a range of lines, or throughout the file, is to use the s colon command. The basic form of this command is the following:


       :n1,n2s/old/new/gc

       n1 is the beginning line

       n2 is the ending line number

       s means to substitute text matching the pattern (old)
                with text specified by (new)

       g (global) is optional.  It indicates you want to substitute
                all occurrences on the indicated lines.  If you use
                g, the editor substitutes only the first occurrence
                on the indicated lines.

       c (confirm) is optional.  It indicates you want to confirm
                each substitution before vi completes it.


  From Command Mode

  :%s/old/new/g     Substitutes old with new throughout the file

  :.,$s/old/new/g   Substitutes old with new from the current
                           cursor position to the end of the file

  :^,.s/old/new/g   Substitutes old with new from the beginning
                           of the file to the current cursor position

  :&                 Repeats the last substitute (:s) command


C. ADVANCED VI

1. Writing to and Reading from Files

  From Command Mode

  :w file           Write current file to file

  :w>>file          Append current file to file

  :5,10w file       Write lines 5 through 10 to file

  :5,10w>>file      Append Lines 5 through 10 to file

  :r file           Read a copy of file into current file

  :!ls              See a list of files in your current directory


2. More About Options

  From Command Mode-within vi for the current file only

  :set all        Display all options

  :set            Display current settings of options

  :set nooption   Unset option

  :set ai         Set Auto Indentation during text entry

  :set ic         Set Ignore Case during searches

  :set nu         Show line Numbers

  :set sm         Show Matching ( or { when ) or } is entered

  :set wm=10      Set Wrap Margin 10 spaces from right edge of screen



3. Customizing vi Sessions
Options can be set four ways:
  1. During a vi session


      :set nu



  2. In a .exrc file in your home directory.

      Sample contents of a .exrc file

        set nu
        set ai
        set wm=10



  3. In a .exrc file in a subdirectory.
  4. By setting the EXINIT environmental variable.

      Example of setting the EXINIT environmental variable

        setenv EXINIT "set nu ai ic"



On the Uniform Access systems (Homer, Saul, Mead, Alcott), the EXINIT environmental variable is used to set the shell within which the vi editor operates. Since the EXINIT environmental variable, if it has been defined, overrides anything set by a .exrc file, customizing vi on these computers requires redefining EXINIT. For example, to add numbering and auto indent, you would take the following steps:
    1. Check to see what EXINIT is set to:

	      % printenv EXINIT
                set shell=/bin/csh


This response indicates that the shell is set to the C shell.
    2. Reset EXINIT:

	      % setenv EXINIT "$EXINIT nu ai"
              % printenv EXINIT
                set shell=/bin/csh nu ai


Order of Precedence
  1. If a .exrc file exists in the current directory, vi reads it when beginning a session.
  2. If no .exrc file exists in the current directory, vi checks the home directory for a .exrc file. If such a file exists, vi reads it when beginning a session.
  3. If no .exrc file is found, vi uses its defaults.
  4. Values set in the EXINIT environmental variable override any values set in a .exrc file.
4. Creating a .exrc File
  1. At the system prompt, type: vi .exrc
  2. Type the following commands, each on a separate line:



      set ai
      set ic
      set nu
      set wm=8


Do not leave blank lines at the beginning or end of the .exrc file.
  3. When you are finished, type: <Esc> ZZ
5. Abbreviations & Mapping
Abbreviations are text strings that automatically expand into larger strings during insert mode.

  From Command Mode

  :ab UW University of Washington


Mapping defines a single key to execute a sequence of keystrokes when the single key is pressed in command mode. In the following example,the @ key is mapped to replace the current word with "University of Washington". The <Control>v allows you to enter the <Esc> key into the command sequence.

  From Command Mode

  :map @ cwUniversity of Washington <Control>v <Esc> <Return>


Mapping can also be used to call commands external to vi, such as sort or fmt. In the following example, the @ sign is mapped to the sort command, so that the current paragraph (indicated by the }) will be sorted. The <Control>v allows you to enter the <Return> key into the command sequence. The second <Return> completes the map command.

  From Command Mode

  :map @ !}sort <Control>v <Return> <Return>


Note: You can also put abbreviation and mapping commands in your .exrc file.

D. TIPS AND TRICKS

1. Making vi an Editor in Pine
  1. In your home directory, type: vi .pinerc
  2. Find the line that reads


       editor=


  3. Change it to read


       editor=vi


  4. Write and quit the file. (ZZ or :wq)
  5. Start Pine
  6. In Pine in Compose mode, when you are ready to enter message text, you will see there is an option available called Alt Edit. (Alternate Editor). To evoke the Alternate Editor mode, press: <Cntrl><Shift>_
When finished editing in vi, exit vi and you will be returned to the compose screen.
2. vi-ing More Than One File
You can edit more than one file at a time with vi.

  From The Unix Shell Prompt

  vi file1 file2   vi two (or more) files at the same time

  From Command Mode

  :n               Move to file2 from file1

  :rew             Rewind back to file1

  :e!              Restore original file1 file2 (start all over)

  ZZ               Save and quit file. (Must be done for each file.)


3. Moving the Left Margin
When you print a file you may want the left margin moved to the right. This leaves room for a three-hole punch.

  From Command Mode

  :1,$>               Move entire file 1 shift width (eight spaces)
		      to the right

  :1,$<               Move entire file eight spaces to the left

  :%s/^/        /g    Insert any number of spaces at the
                      beginning of each line in the entire file.
                      Simply press the space bar the
                      desired number of times.

  :20>>                Moves next 20 lines over 1 shift width.


4. Issuing Shell Commands From vi
You can issue a single shell command while in the vi editor. For example, to list the files in your directory (ls), follow these steps:

  From Command Mode

  :w     Write changes to your file (just in case).

  :!ls   List contents of your current directory on the screen.

  Press <Return> to return to vi.


You can issue many shell commands by temporarily leaving the vi editor.

  From Command Mode

  :w     Write changes to your file.

  :sh    Return to the shell to enter a number of commands
         without leaving vi.

  Press <Control>d to return to vi editing.


5. Double Spacing a File
Occasionally, you may want a double spaced version of your file for editing or review.

  In Command Mode

  :w original.backup Save a backup copy of the original file

  :%! sed G          Double space the entire file.

  :1,5! sed G        Double space the lines from 1-5.


Â© Copyright 1996 University of Washington Computing & Communications.
Permission to reprint or adapt sections from these class notes for noncommercial purposes is granted, provided that the source is acknowledged. Inquiries may be submitted to rells@cac.washington.edu.

Class notes URL: http://weber.u.washington.edu/~rells/R110/
Last Modified: February 24, 1997