Re: improving '{...}' in bash?

[Martin D Kealey]

On Tue, 23 Jul 2024, 15:50 Harald Dunkel, <harald.dunkel@aixigo.com> wrote:

> Hi folks,
>
> This feels weird:
>

Did you read the manual before trying any of these?

        % echo x{1,2}x
>         x1x x2x
>         % echo x{1}x
>         x{1}x
>

Why are you trying to use a multiplier syntax when you don't have more than
one option?

Be aware that brace expansion occurs before variable expansion, so you
can't put a brace-style list in a variable and then expect it to be
expanded; brace expansion is only intended to be used with literals, and
nobody would both to write such a literal.

Besides this, the shell is *required* not to replace braces *except* for
the few express patterns described in the manual.

        % echo x{1..3,5}x
>         x1..3x x5x
>

That's what I would expect, yes.

I would have expected "x1x" and "x1x x2x x3x x5x".


Not when it's missing the second pair of braces; perhaps you intended to
use `echo x{{1..3},5}x`?

-Martin