-Martin
On Tue, 5 Aug 2025 at 02:17, Stan Marsh <[email protected]> wrote:
> (I am talking about things like ${var:-default value})
>
> I have long wished there was a substitution for "substitute a string if
> var is unset
> else substitute nothing".
I've wondered about that myself at times.
I like the idea, but I'm currently undecided whether I would support “*” as
the indicator symbol. In any case, I think that it's important that the
chosen symbol not be valid as the first character of a numeric expression,
including reasonable future enhancements.
> In fact, even better would be a generalized if-then-else, so you could do
> something
> like:
>
> echo ${var*var is set to $var*var is not set}
>
That extra level doesn't seem compelling, since we could just write:
${foo+Foo is set}${foo*Foo is unset}
I assume you would also want both colon and non-colon versions?
${foo*Foo is unset}
${foo:*Foo is empty or unset}
-Martin
