Array serializer with eval-based indirection for legacy shells.

fmtarr.bash

#!/usr/bin/env bash

typeset -ga bool=([1]=)

# Usage: in_array name outvar
function fmtarr {
	typeset x=1 y max ret=$3
	printf -v "$ret" '%s+=(' "$2"
	eval -- set -- "\"\${!${1}[@]}\"" "\"\${${1}[@]}\"" || return
	((max = $# / 2))
	while
		printf -v y '[%q]=%q' "${@:x:1}" "${@:x + max:1}"
		((x++ < max))
		eval -- "${ret}+=\${y}\${bool[!\$?]+ }\${bool[\$?]+\\)}" \; let "!$?"
	do :
	done
}

function demo {
	typeset -a b a=({a..f})
	typeset v
	fmtarr a b v
	eval -- "$v"
	typeset -p b
}

demo

# vim: set ft=bash fenc=utf-8 ff=unix ts=4 noet :