Re: [Review Request] Arrays and their usage

[René Neumann <lists@xxxxxxxxx>]

> Here's my take on answering this (repeating some of what has
> already been said).

Greatly appreciated!

> First, I'd say: `...` form of command substitution should really
> be banned these days. That's really a broken heritage from the
> Bourne shell. There's not good reason to keep using it these
> days. The main problem with it is the handling of backslash
> inside it (and the awkward nesting and the fact that it's less
> legible, etc...).

Fun fact: I prefer `...`, because I find it more legible, especially in 
the x=`cmd y z` form¹. But TIL, that `` and $() are not interchangable. 
Up to now, I thought the one is syntactic sugar for the other.

> The sed command could be written:
>
>    sed -n 's/pkgname = //p'

Good catch, thanks
> Then, leaving `...` (or the better $(...)) unquoted performs
> IFS-splitting, so you're left with the same kind of conundrum as
> you get in POSIX shells when you leave any form of expansion
> ($param, $((arith)) as well there!) unquoted though at least
> zsh doesn't perform globbing there:
>
> [...]
>
> pkgs=(
>    ${(f)"$(
>      makepkg --printsrcinfo |
>       sed -n 's/pkgname = //p'
>    )"}
> )

Thank you for this detailed explanation. Not relying on IFS seems a good 
thing to do, although the rest of the script probably does here and there².
Also thanks for this example of code structuring. /me likes.
(NB though: The linebreak for the two pipe elements was inserted for 
this email only, with me hoping, that backslash newline was the correct 
thing to do ;))

> The more idiomatic zsh variant to that ksh syntax would be:
>
> pkgs=( $DATABASE/$^pkgs )
>
> (same as rc's pkgs = ( $DATABASE/$pkgs )).

What does 'rc' stand for?

Again, thanks for this effort!

- René

¹ Longer story: $() is easily confused with ${}. Also, `...` is more "in 
the background" and I let my highlighting make it clear to me, that I'm 
in a subcommand. I would always prefer $() in large complex expressions 
though, because.

² Although one could argue that setting IFS to something else than $'\n' 
WILL break a lot of stuff, so one can expect it to be sane.