parameter expansion with `:` does not work

[lisa-asket]

> From: Greg Wooledge <greg@wooledge.org>
> To: bug-bash@gnu.org
> Subject: Re: parameter expansion with `:` does not work
> Date: 08/07/2021 00:44:09 Europe/Paris

> On Thu, Jul 08, 2021 at 12:37:07AM +0200, lisa-asket@perso.be wrote:

> >From: Dennis Williamson <dennistwilliamson@gmail.com>
> >$ : ${foo:-bar}
> >$ : ${foo:=bar}
> >The first form is a substitution and the second form is an assignment.

> So you used `:` at the beginning and it worked?

> Are you incapable of seeing the difference between the two lines?

> I weep for the human race. There's no telling what you're even seeing
> on your monitor (assuming you can see, and aren't using a screen reader).
> You're clearly using some mail user agent that works like Microsoft Outlook,
> and there's no guessing what it's doing to the messages you receive.



We're only good when we're dead ! :)



> If you literally cannot see the difference between :- and := in the
> above example, then all is lost, and there is nothing more we can say

> to you. Because you can't see it.



Yes I can see one has :- and the other has  :=



But I also noticed : at the front, with someone saying that the command does not

exist in Gnu Bash.