> I tried to work something out in /bin/sh, but it's not evident since
> /bin/sh does not have associative arrays,

You can often use 'eval' to implement them by token pasting names. eg:
	while read tag value
	do
	    eval tag_$tag=\$value
	done
	# later
	for tag in $tag_list
	do
	    eval value=\$tag_$tag
	    echo tag $tag = $value
	done

If the tags contain non-alphanumerics you have a slight problem,
specific characters can be deleted by:
	IFS="<invalid_chars>"
	set -- $tag
	IFS=
	tag="$*"
Or replaced with (for example) an underscore with the similar
	IFS="<invalid_chars>"
	set -- $tag
	IFS=_
	tag="$*"
(Remember to reset IFS for teh next line)

> and "for" parses netstat's output word by word instead of line by line.
IFS is your friend here... add:
nl='
'
near the top of the script, then add IFS=$nl before the 'for'.
You may want to reset it afterwards (default is space/tab/newline).

	David

-- 
David Laight: david@l8s.co.uk