Re: [tlug] Bash looping issue

[Romeo Theriault <romeo.theriault@example.com>]

On Wed, Oct 13, 2010 at 00:14, Daniel A. Ramaley <daniel.ramaley@example.com> wrote:

Hello. In the example script below, i define an associative array and
then make a copy of it using a loop to copy each key/value pair. It
seems to work quite nicely... within the loop. Once outside the loop,
the copied array loses its data. The bizarre thing is that if i switch
the loop construct from a "while" to a "for", it works. I'd really like
to use the "while" loop, however, so that in more complicated scripts i
can process the keys in sorted order. (This would be useful, for
example, in building a sorted list of the keys of an associative array.)
I've pasted my sample script and the output below. Any ideas?

Looks like bash is starting the while-read loop in a subshell so you're losing your variable assignments when the subshell exits. This page talks about a few ways around this:

http://fvue.nl/wiki/Bash:_Piped_%60while-read'_loop_starts_subshell

 

-- 
Romeo Theriault