Using the vi editor

This is a short guide to using vi, a full screen editor available in Unix.
You can run vi in any window that emulates a VT100 terminal, including an
xterm window.  A nearly identical editor, vim, is available for PC's.

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Invoking vi:

vi <filename>        enters vi (to edit the specified file)

vi -r <filename>     enters vi, recovers version of file most 
                     recently saved by the system in the case
                     that vi had been abnormally aborted.

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vi Modes:

Command mode----allows you to move the cursor, delete text, move text,
                or enter either of the other two modes.  This is the
                mode in force when you enter vi.

Insert mode----allows you to insert characters.

Last line mode---allows you to search for patterns, to write the file, or
                 to exit without updating the file.  Its name derives from
                 the fact that, when in this mode, the cursor appears on
                 the last line of the screen.
              

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When in command mode:

 1. Moving the cursor: 

    use the arrow keys, or

    j           down one line
    k           up one line
    h           left one position
    l           right one position

    25G         (for example) go to line 25

    CNTRL-f     forward one "screen"
    CNTRL-b     backward one "screen"


 2. To enter insert mode:

    i           insert at current location
    I           insert at beginning of current line
    o           make a new line below and insert there
    O           make a new line above and insert there
    a           insert following current location
    A           insert at end of current line


 3. To delete text:

    x           delete current character
    X           delete previous character
    dw          delete to end of word 
    dd          delete current line
    6dd         (for example) delete the next 6 lines (including current one)


 4. To move text:

    yy          "yank" current line
    4y          (for example) to "yank" current line, plus next 4 lines 
    p           "put" (insert) most-recently "yanked" or deleted lines
    J           append next line onto the end of current line
 

 5. To enter last line mode

    :           (a colon)


 6. To "undo" most recent command:

    u           (the letter)


 7. To refresh screen (in case it gets garbled)

    CNTRL-L


 8. To exit from vi and save file:

    ZZ

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When in insert mode:

  ESC           (escape key) return to command mode


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When in last line mode:

  ESC                  (escape key) return to command mode

  r <file name>        inserts contents of named file at cursor position

  w                    writes file (without leaving vi)
  w <file name>        writes to named file (without leaving vi)
  w! <file name>       overwrites to named file (without leaving vi)

  q                    quit (exit from) vi
  q!                   quit without updating file (since last write)

  /<string>            find next occurrence of the string
  ?<string>            find previous occurrence of the string