Associative arrays are local by default

Question

Associative arrays seem to be local by default when declared inside a function body, where they should be global. The following code

#!/bin/bash  f() {     declare -A map     map[x]=a     map[y]=b }  f echo x: ${map[x]} y: ${map[y]} 

produces the output:

x:  y: 

while this

#!/bin/bash  declare -A map  f() {     map[x]=a     map[y]=b }  f echo x: ${map[x]} y: ${map[y]} 

produces the output:

x: a y: b 

---

Is it possible to declare a global associative array within a function? Or what work-around can be used?

Answer 1

From: Greg Wooledge
Sent: Tue, 23 Aug 2011 06:53:27 -0700
Subject: Re: YAQAGV (Yet Another Question About Global Variables)

bash 4.2 adds "declare -g" to create global variables from within a function.

Thank you Greg! However Debian Squeeze still has Bash 4.1.5

Answer 2

Fine, 4.2 adds "declare -g" but it's buggy for associative arrays so it doesn't (yet) answer the question. Here's my bug report and Chet's confirmation that there's a fix scheduled for the next release.

http://lists.gnu.org/archive/html/bug-bash/2013-09/msg00025.html

But I've serendipitously found a workaround, instead of declaring the array and assigning an initial value to it at the same time, first declare the array and then do the assignment. That is, don't do this:

declare -gA a=([x]=1 [y]=2) 

but this instead:

declare -gA a; a=([x]=1 [y]=2)