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Date: Sat, 26 Sep 2015 15:37:15 +0200
Message-ID: <CAHYJk3QegiGeqwiw834TVW+tFzvW5+HKV0cvopDyxOJnrZ6LYQ@mail.gmail.com>
Subject: Re: question about parameter expansion
From: Mikael Magnusson <mikachu@gmail.com>
To: Dmitri Vereshchagin <dmitri.vereshchagin@gmail.com>
Cc: Zsh Users <zsh-users@zsh.org>
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On Sat, Sep 26, 2015 at 12:18 PM, Dmitri Vereshchagin
<dmitri.vereshchagin@gmail.com> wrote:
> Hello.
>
> Here is a code sample I would like to rewrite using parameter expansion
>
>   if (( ${+foo} )); then
>     bar=
>   else
>     bar=baz
>   fi
>
> Cannot find it in the docs, but I suppose there is a way to do that.  Am
> I right?
>
> Thanks.
>
> --
> Dmitri Vereshchagin

You have to think outside the box for this one,
bar=${${${+foo}#1}//0/baz}

-- 
Mikael Magnusson