Re: quote modifier for parameter expansion?

[Sven Wischnowsky <wischnow@xxxxxxxxxxxxxxxxxxxxxxx>]

Peter Stephenson wrote:

> Sven Wischnowsky wrote:
> > Hm. I'm sure I'm missing something again, but could anyone please tell 
> > me what? The patch below (which probably shouldn't be used) just uses
> > the quote()-function from hist.c to make the `q' modifier in parameter 
> > expansion work. The result is almost always a funny looking string in
> > single quotes, but that alone can't be the reason not to use this
> > function.
> 
> Does exactly what I would expect it to.
> 
> % bar="hello'there"
> % print -r $bar:q
> 'hello'\''there'
> 
> Maybe the point is simply it's got limited application, since unless
> it's going into an eval the extra quotes aren't all that useful,
> unlike in history substitution which happens before the quotes get
> swallowed.

But it's also useful if you stuff a string together in a parameter and 
later use the value of that parameter for globbing. With `:q' you can
prevent pattern characters in the original parameters from being
interpreted as a pattern.

That's what makes it useful in functions like pfiles(). Without the
patch below and using:

  zle -C my-comp complete-word main-complete

doing `foo *<TAB>' will give one all files as possible completions.

Of course, this is the same use as with eval (i.e. double evaluation).

Bye
 Sven

--- om/new-completion-examples	Wed Feb  3 16:16:57 1999
+++ Misc/new-completion-examples	Wed Feb  3 17:25:29 1999
@@ -211,7 +211,7 @@
     ppres=( '' )
   fi
 
-  str="$PREFIX*$SUFFIX"
+  str="${PREFIX:q}*${SUFFIX:q}"
 
   if [[ -z "$a[1]" || "$str[1]" = [~/] || "$str" = (.|..)/* ]] then
     a=()

--
Sven Wischnowsky                         wischnow@xxxxxxxxxxxxxxxxxxxxxxx