Re: incorrect brace expansion when using default values

[Tatavarty Kalyan]

On 9/6/06, Chris F.A. Johnson <cfajohnson@gmail.com> wrote:
> On 2006-09-06, Andreas Schwab wrote:
> > prj@po.cwru.edu (Paul Jarc) writes:
> >
> >> Mike Frysinger <vapier@gentoo.org> wrote:
> >>> this little bit of code doesnt work right:
> >>> foo() { echo "${1:-a{b,c}}" ; }
>
>   The first '}' is interpreted as the end of the parameter expansion.
>
> >>
> >> Brace expansion happens before parameter expansion (man bash,
> >> EXPANSION).
> >
> > Brace expansion doesn't come into play here, because the braces are
> > quoted.
>
>   Quote them, and they do expand:
>
> $ foo() { echo "${1:-"a{b,c}"}" ; }
> $ foo
> ab ac
>
>   However, there is a problem:
>
> $ foo 1
> 1 1
>
>   Where is the second '1' coming from?

It seems

foo() { echo "${1:-"a{b,c}"}" ; } expands to

foo() { echo ${1:-ab} ${1:-ac} ; }

> --
>   Chris F.A. Johnson                      <http://cfaj.freeshell.org>
>   ===================================================================
>   Author:
>   Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)
>
>
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