Re: color codes to eval

[Andreas Kähäri <andreas.kahari@xxxxxx>]

On Wed, Apr 10, 2024 at 02:39:45PM -0400, Lawrence Velázquez wrote:
> On Wed, Apr 10, 2024, at 12:46 PM, Ray Andrews wrote:
> > var="${red}howdy${nrm}"    # '$(red}' is just a color code, no problem there.
> > print -l $var
> > eval "print -l $var"
> >
> > ... shows:
> >
> > howdy   
> > (eval):1: bad pattern: ^[[31
> >
> > ... Is there a way to feed color codes to eval?
> 
> The issue is not "color codes" per se.  It's the fact that (assuming
> ECMA-48 sequences) you're assembling and evaluating a command that
> contains a word with an unquoted, unpaired "[" character, which zsh
> deems to be an invalid glob (by default).  It's no different from:
> 
> 	% print a[b
> 	zsh: bad pattern: a[b
> 
> 
> > Seems to me I remember 
> > that there's some ${(?) var} ... some flag in there that does it.
> 
> There are a number of possible solutions.
> 
> 	# Avoid the pointless eval in the first place.
> 	print -l $var
> 
> 	# Delay all expansions.
> 	eval 'print -l $var'
> 
> 	# Delay the problematic expansion only.
> 	eval "print -l \$var"
> 
> 	# Delay learning how quoting actually works.
> 	eval "print -l ${(q)var}"
> 
> 	# Leave invalid patterns in the command.
> 	unsetopt BAD_PATTERN
> 	eval "print -l $var"
> 
> 
> -- 
> vq

They could also use print with -P and start using the prompt escape
%F{red}, but that's bypassing the issue rather than handling the
original string.

-- 
Andreas (Kusalananda) Kähäri
Uppsala, Sweden

.