vi for the Forgetful

Invoking the Editor

     vi  filename      Begin editing at first line
     vi  +n  filename  Begin editing at nth line

Getting out of Input Mode

     ESC

Getting out of vi

     :q!               Quit without saving any changes
     :x                Quit after saving changes

Adding Text (enter input mode)

     i                 Insert text before cursor
     a                 Insert text after cursor
     A                 Append text to the current line
     o                 Insert text on a new line after the current line
     O                 Insert text on a new line before the current line

Deleting text

     x                 Delete current character
     nx                Delete n characters
     dd                Delete current line
     ndd               Delete n lines
     D                 Delete rest of line

Inserting a File

     :r  filename

Moving the Cursor Around

     $                 Move cursor to end of line
     nG                Move to the nth line
     $G                Move cursor to the end of the file

Searching

     / pattern         Locate the given pattern
     n                 Repeat the last search

Moving and Changing Text

     nyy               Yank n lines into a buffer
     p                 Puts the buffer into the file after the cursor
     P                 Puts the buffer into the file before the cursor
     :s/old/new/       Substitute for one occurrence
     :1,$s/old/new/g   Substitute globally
     :1,$s/old/new/gc  Substitute globally and confirm substitutions
     :e!               Wipe out all editing changes