irf@kuling.UUCP (Bo Thide) (01/01/88)
The standard UNIX visual display editors vi(1), vedit(1), view(1)
are *much* more powerful than you would think in the first place.
In fact, just like Emacs can be put in a vi mode, vi can be put
in a kind of Emacs mode as shown by the following first attempt to do so.
If only vi was improved in four ways:
1. Make 'h' and 'l' wrap around to other lines
2. Remove the silly left movement of the cursor when changing from
input to command mode (which makes a command behave differently
when issued at the leftmost column than in any other column!)
3. Increase the size of the macro stack by at least a factor of 2
4. Make 'j' and 'k' ALWAYS move vertically down or up (also if the
line moved to is empty!)
I would say vi would be the best editor of all. The full emulation
of Emacs, WordPerfect and other editors/word processors would then
be a piece of cake... (if you really need that).
Comments on my 'evi' script are most welcome.
--Bo
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
# EVI -- The Emacs mode VI or the Expert's VI
#
# by
#
# Bo Thide'
# Swedish Institute of Space Physics
# S-755 90 Uppsala, Sweden
# UUCP: ..enea!kuling!irfu!bt or bt@irfu.UUCP
#
# evi 0.1, Jan 1, 1988
#
#
# This is a test version of an advanced macro package
# providing an Emacs-like, modeless user interface to the
# vi(1) display editor family. Run as a Bourne shell script
# 'evi' replaces the existing EXINIT string by another EXINIT
# string consisting mainly of macros in input mode (":map!")
# that emulate a subsest of Emacs (or Word Perfect) commands
# as exactly as possible. Then vi(1) is run, with the new
# EXINIT string, through an exec(1) command. Since ESC is a
# reserved (unmappable) character in vi(1) the meta key is
# used to map 8-bit characters. This works for the HP-UX
# vi(1) but will not work for other versions of UNIX that only
# support 7-bit ASCII editors and shells.
#
# A limiting factor for the number of commands emulated is the
# size of the vi(1) macro buffer. The current size of the
# macro package is nearly maximum for HP-UX. Other versions
# of vi(1) are known to have smaller buffers.
#
# Unfortunately the vi(1) commands 'h' and 'l' cannot move the
# cursor to another line (I consider this a serious drawback!)
# so special tricks have been used to emulate line wrap-around
# for the Emacs C-f and C-b commands. So, for instance, will
# the C-b command (in vi(1) input mode) at the beginning of a
# line cause an error (beep or flash!) that will take you
# into vi(1) command mode. However, since the vi(1) command
# 'b' can back to the previous line I have included a command
# mode macro (:map ^B bA) which backs to the last position of
# the previous line and places vi(1) in input mode again so
# that subsequent C-b commands work as expected. A nuisance
# with vi(1) is that changing from input to command mode will
# reposition the cursor one step left. This is really stupid
# and causes strange cursor movements at the beginning of a
# line. I have found no way to fool vi(1) here!
#
# Hitting ",," toggles between vi and Emacs modes letting you
# change mode instantaneously. Many commands are missing from
# the Emacs mode and hence vi mode is the only way to get what
# you want.
#
# The following script has been run through 'cat -tv' in order
# that it can be e-mailed safely. Insert the proper CTRL and
# META sequences where needed!
#
EXINIT="map! ^V^V ,,^F,,\
|map! M-v ,,^B,,\
|map! ,, ^[:so /users/res/bt/vi/e-mode.unmap^[:\"Vi mode^[\
|map! ^A ^[I\
|map! ^D ^[lxi\
|map! ^E ^[A\
|map! ^V^H ^[xi\
|map! ^K ^[lDa\
|map! ^L ^[lmzz.\`zi\
|map! ^N ^[ja\
|map! ^O ^[o\
|map! ^P ^[ka\
|map! ^^ ~\
|map! M-a ^[l(i\
|map! M-b ^[bi\
|map! M-e ^[l)i\
|map! M-f ^[lwi\
|map! M-d ^[ldwi\
|map! M-k ^[ld)i\
|map! M-h ^[dbxi\
|map! M-> ^[GA\
|map! M-< ^[1GI\
|map! ^X: ^[:so /users/res/bt/vi/e-command.map^[mzLo^[:\
|map! ^X^C ^[ZZ\
|map! ^_ ^X:\"Type /regexp<CR>^[I/\
|map! ^R ^X:\"Type /regexp<CR>^[I?\
|map! M-5 ^X:\"Type /old/new/[g]<CR>^[I:%substitute///g^[2hi\
|map ,, :so /users/res/bt/vi/e-mode.map^[:\"Emacs mode^[i\
|map ^D xJi\
"
export EXINIT
echo "$CLEAR$TSL$REV Vi mode --- Hit ,, to toggle between Emacs and Vi modes --- $SGR0$FSL"
sleep 1
exec /usr/bin/vi $*
-------------------------------cut here-------------------------------------
In the above $CLEAR, $TSL and $REV are strings containing necessary escape
sequences, evaluated at login time, for clearing the screen, moving to the
status line and entering reverse video mode, respectively. Similarly, $SGR0
and $FSL unsets graphics rendition and moves the cursor back from the status
line. All these strings are to be provided at your discretion through suitable
tput(1) calls. If not provided, the help text will appear in the next line
on the screen. Their absence will not affect the functionality of 'evi'.
For some obscure reason (at least for me) certain mappings/unmappings
cannot be done in the script itself but have to be introduced by a :source
command (see lines containing ":so" above). Here follows all source files
needed (each filtered through 'cat -tv' to make them e-mailable):
-(e-mode.map)---------------------cut here-------------------------------------
map! ^B ^[hli
map! ^F ^[la
map ^A I
map ^B bA
map ^E A
map ^F +I
map ^K ddi
map ^V^H k$Ja
map ^N ji
map ^P ki
map M-a (i
map M-d dwi
map M-f +I
map M-k d)i
-(e-mode.unmap)-------------------cut here-------------------------------------
unmap! ^B
unmap! ^F
unmap ^B
unmap ^E
unmap ^F
unmap ^V^H
unmap ^N
unmap ^P
unmap M-d
-(e-command.unmap)----------------cut here-------------------------------------
:map! ^M ^["zdd`z@z:so /users/res/bt/vi/e-ctrlm.unmap^[:"Emacs mode^[i
-(e-ctrlm.unmap)------------------cut here-------------------------------------
:unmap! ^M