command substitution word joining

command substitution word joining

[Daniel Shahaf]

Consider:

% () { print -r - ${(q)@} } <(:)x
/proc/self/fd/11x

I can't see any use-case for appending the 'x' as part of the same word.

Re: command substitution word joining

[Mikael Magnusson]

echo --input-file=<(:)
--input-file=/proc/self/fd/13
I could imagine some command taking multiple filenames with ,
separation perhaps? But you can't prepend anything with =(:).

On Sat, Mar 3, 2018 at 12:45 AM, Daniel Shahaf <d.s@daniel.shahaf.name> wrote:
> Consider:
>
> % () { print -r - ${(q)@} } <(:)x
> /proc/self/fd/11x
>
> I can't see any use-case for appending the 'x' as part of the same word.



-- 
Mikael Magnusson

Re: command substitution word joining

[Bart Schaefer]

On Fri, Mar 2, 2018 at 9:33 PM, Mikael Magnusson <mikachu@gmail.com> wrote:
> echo --input-file=<(:)
> --input-file=/proc/self/fd/13
> I could imagine some command taking multiple filenames with ,
> separation perhaps? But you can't prepend anything with =(:).

You can prepend an assignment:

% foo==(:)
% print $foo
/tmp/zshdewoIj

Re: command substitution word joining

[Daniel Shahaf]

Bart Schaefer wrote on Fri, Mar 02, 2018 at 21:50:32 -0800:
> On Fri, Mar 2, 2018 at 9:33 PM, Mikael Magnusson <mikachu@gmail.com> wrote:
> > echo --input-file=<(:)

Ah, thanks.

> > --input-file=/proc/self/fd/13
> > I could imagine some command taking multiple filenames with ,
> > separation perhaps? But you can't prepend anything with =(:).
> 
> You can prepend an assignment:
> 
> % foo==(:)
> % print $foo
> /tmp/zshdewoIj

This loses the O_EXCL atomicity guarantee:

% x==(:)
% ls $x 
ls: cannot access '/tmp/zshioVJpt': No such file or directory

It does work as a precommand assignment, though:

% x==(:) eval 'ls $x' 
/tmp/zsh37OnHf