thank you Peter, I made a mistake in the example code:

file="filename.txt"
a="*$file*"

should have been:

file="filename.txt"
a='*$file*'

with single quotes the behaviour is changed:

zsh -fc 'file= filename.txt; a="*$file*"; print "$a"'

gives:

*filename.txt*

instead with single quotes:

zsh -fc 'file= filename.txt; a=''*$file*''; print "$a"'

gives

*$file*

I would like the second example to somehow give the result of the first,
since I am trying to pass the string from another context where the
variable $file is not already defined

thanks

Pier Paolo Grassi
linkedin: https://www.linkedin.com/in/pier-paolo-grassi-19300217
founder: https://www.meetup.com/it-IT/Machine-Learning-TO


Il giorno mar 30 lug 2019 alle ore 15:19 Peter Stephenson <
p.stephenson@samsung.com> ha scritto:

> On Tue, 2019-07-30 at 14:28 +0200, Pier Paolo Grassi wrote:
> > Hello, is it possibile to do only variable expansion inside a string, eg:
> >
> > file="filename.txt"
> > a="*$file*"
>
> If you run zsh -f, you'll see that that's exactly what you normally get,
> just
> by running
>
> print "$a"
>
> --- no eval.
>
> My best guess is you have the option globsubst set and when you tried
> to print the result, you didn't use double quotes at that point, i.e.
> you had something like
>
> print $a
>
> and the *filename.text* got expanded at that point.
>
> So the original code is actually fine.
>
> pws
>
>