York University
Statistical Consulting Service

S-Plus short course                                   October 8, 1999


Summary of vi commands and Regular Expressions
===============================================

Command:  vi filename

Two modes: command -> insert:   i    insert (before) current character
                                I    insert (before) current line
                                a    append (after) current character
                                A    append (after) current line
                                o    add new line after current line
                                O    add new line before current line

	   insert -> command    ESC


In insert mode:

	Backspace  to erase last character
	Ctrl-W     to erase last word

In command mode:

  Basic:

	x     delete one character
	r     replace one character
	s     delete one character and enter insert mode (until ESC)

  Motions (= objects):

	h     left one character    |  These 4 keys are under the
	l     right one character   |  fingers of the right hand
	j     down one line         |  if you shift your hand left
	k     up one line           |  by one key from its normal position.
				    |  If you're lucky the arrows will work
				    |  but hjkl always works in vi.

	w     to beginning of next word
	b     to beginning of word (previous word if already at beginning)
        0 (zero) to beginning of this line
        ^     to first non-blank character in this line
	$     to end of this line
	G     to end of file
	1G    to line 1
	5G    to line 5
	}     to next paragraph
	)     to next sentence
	/re   (re is a regular expression) to next occurrence of re
	?re   to previous occurrence of re
	n     to repeat last search (/ of ?)
	N     to repeat last search (/ of ?) reversing direction
	fc    (c is any character) forward on line to next c
	;     repeat previous "f"
	tc    (c is any character) forward on line to char preceeding next c
	%     to balancing brace (one of [{(< or >)}] )


  Operations on objects:
	                        Special forms:
	c    change             cc    line       C    to end of line
	d    delete             dd    line       D    to end of line
	y    yank to buffer     yy    line       Y    line
	!    filter through command       !!   filter line

        e.g.     cw changes a word
                 dG deletes to the end of file
		 d0 delete to beginning of line
		 {!}fmt  filter the current paragraph through the unix
		        command fmt

		 !!spell  find mispelled words in current line (use 'u'
			  to get the line back after seeing the mispelled words)

  Other commands:

	.   repeat last action
	mx  mark location as 'x'
	'x  move to location marked 'x'
	p   put buffer after current location
	P   put buffer before current location
	J   join lines together (watch out when you press j after "caps lock")
	u   undo last change
	U   undo changes to current line
	ZZ  write and exit
	^L  refresh screen


  "EX" commands: (all these commands are preceded by a ":")

        :wq              write and exit
	:w               write and continue
	:e filename      edit filename instead of current file
	:e #             edit last active file
	                 (note that Ctrl-^ toggles between two files)
	:ab jb Jonathan Brown
			 defines an abbreviation
	:map ^A !}fmt^V^M  creates a macro invoked by Ctrl-A
	:s/re/replacement/ substitute regular expression "re" with 
			   "replacement" in current line (once)
	:s/re/replacement/g  ibid but in every occurrence on line
	:g/re1/s/re2/replacement/g
			   substitute re2 with replacement in every
			   line that contains regular expression "re2"
	:!ls -al         executes command ls -al
	:l               "list" line showing invisible characters


Setting options:

	:set  ai     autoindent (e.g. for programming"
	:set  noai   often crucial when copying an X buffers
	:set  sm     automatically show "match" for )}>]
	:set  nosm


Initialization file:

  Create a ".exrc" in your home directory or in the current directory
  to initialize vi. Here are some example of what I have in mine.
  Note that ^V (Control-V)  means "verbatim" and to enter a control
  character you preceed it with ^V in insert mode. Thus to enter 
  what you see as "^V^M" below, you actually type "^V^V^V^M".
  The first pair of of ^V's enters one ^V and "^V^M" enters ^M.
  The ^M is a carriage return that ends the macro so it is executed.
  Without it, you have to hit "Enter" after pressing the macro key.
  Also note that you don't use ":" to preceed each command as you would
  have to if you were executing these commands from vi.

	" some lines from my .exrc file
	set autoindent autowrite showmatch wrapmargin=0 report=1 exrc
	"note that this is how you enter a comment
	"set shell=/usr/local/bin/tcsh
	set shell=/bin/sh
	"set tmp=/tmp
	map  
   {!}fmt
	map!  !!bend
o	
	ab   hh  <a href=  

  Note that you can also have .exrc files in each directory to perform
  special initializations for that directory. For example, in this directory
  I have:

	ab sp S-Plus


==========================================================================

    Regular Expressions Summary: (works for sed also):

        c     matches the character c
        \c    turns off special meaning for c
        *     zero or more previous match
        .     any single character
        ^     start of a line
        $     the end of a line
        [xyz] any character from the set xyz (can use a-z A-Z)
        [^xyz] any character NOT in the set xys
        \(...\)  tagged expression
        \n       nth tagged expression
  

Replacement patterns:

	all characters as is except:
	&      stands for whole matched expression
	\n     nth tagged expression
	/      ends pattern
	\c     gives c its normal meaning, e.g. \& \/ 


Using vi for command line editing in S-Plus (in UNIX):
=====================================================

  To edit a previous command from the command line, use:

      ESC 

  you are now in vi command mode and you can scroll up through
  previous commands with:

      k

  After modifying a command use "Enter" to execute the result. 
  The commands most commonly used are:

      w b h SPACE  to move to an error
      cw           to replace a word
      x            to delete a letter
      i a          to add something