[conspire] vi/ex :r! cal

[Rick Moen]

Quoting Michael Paoli (Michael.Paoli at cal.berkeley.edu):

> Hmmmmmm....,
> 
> And I'm used to doing more typically, something like:
> :r !cal
> rather analogous to:
> :w !spell
> which is quite different than
> :w! spell
> and
> :w!spell
> ... but actually in the case of
> :r
> these will all work the same:
> :r!cal
> :r !cal
> :r! cal

http://vimdoc.sourceforge.net/htmldoc/usr_10.html talks about the 
:r !{program} syntax, but not the 
r! {program} one.

I have to confess I picked up the habit of the latter syntax early in my
use of vi without studying any docs, and I'm still more than a little 
unclear about the exact differences.  

:w !spell" shows the output of executable 'spell' without inserting it into
the current buffer.  

:w! spell writes the current buffer contents to new external file ./spell.
:w!spell does the same thing.