From: Chet Ramey
Subject: Re: feature proposal: expand associative arrays in lexicographic order
of keys
Date: Mon, 24 Aug 2026 17:00:16 -0400
>I'm actually struggling to find where the devel branch's doc/bash.1
>bothers to say that the expansion of indexed arrays subscripted by @
>or * is in numerical order of indices and the expansion of associative
>arrays subscripted by @ or * is in arbitrary order.
>It doesn't specify expansion order at all.
I think there should be something in the docs about this.
Just a simple statement that:
a) Indexed arrays are returned in index (numeric) order.
and
b) Associative arrays are returned in arbitrary (i.e., no) order.
>It makes the most sense to expand indexed arrays in ascending order of
>indices, to sort of mirror C arrays.
Agreed. Note that if this were not true (i.e., if indexed arrays were
returned in arbitrary order), then lots of things would not work as
expected. In particular, I have a script that:
a) Copies "$@" to an (indexed) array.
b) Manipulates that array (modifying elements and/or removing them)
c) Passes that array to an external command (mimicking the usual:
cmd "$@"
idiom).
This would fall apart if the array weren't returned in numerical order.
>It doesn't make sense to impose some kind of ordering on associative
>arrays, which are essentially dicts/hash tables.
This is something upon which reasoned men can disagree. I have long
argued in the GAWK group(s) that GAWK *should* return arrays in sorted
order, primarily because another AWK implementation with which I am
familiar does and it turns out to be quite useful. I was met with the
expected resistance from folks who maintained that "No, associative
arrays are just hash tables; they have no order". Of course, this was
all before GAWK did (eventually) implement array sorting (in a few
different flavors, as it turns out).
>>When expansion order matters at all, this is liable to be what the
>>shell programmer would prefer. ${!assoc[@]} expanding in lexicographic
>>order would make for a slight improvement in one of my scripts, at
>>least.
>This is not a feature that has been in great demand (or any demand,
>really), especially not sorting in lexicographic order for keys.
I'm surprised at this. It is frequently useful and not at all outre.
>If you want to wait for the next devel branch push, I added a -I option
>to the `asort' loadable builtin to sort an associative array by keys
>and assign those keys in order to an indexed array. (The existing -i
>option is like awk's asorti, which sorts by values and then assigns the
----------------^^^
>keys, so it was only a small change.) See if that does what you want
>without any other changes.
FWIW, I could not figure out how to use the bash "asort" extension.
The idiom that I use is like:
mapfile -t < <(for i in "${!MyArray[@]}"; do echo "$i";done | sort)
select pick in "${MAPFILE[@]}"; do ...; done
P.S. Above, indicated by the "----------------^^^", I think you
should have referred to it as "GAWK's asorti()", since the feature is
GAWK-specific (not generic AWK).
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