#!/usr/bin/awk -f
#
#   quotes_dq2fq  --  Oliver Fromme  <olli@fromme.com>
#
#   Convert US-ASCII double quotes to French quotes,
#   i.e. "foo bar" becomes »foo bar«.
#   NOTE:  It is important that all quotes in the text
#   are balanced, i.e. the number must be even, every
#   opening quote must have a closing quote, and they
#   must not be nested within each other.
#

{
	line = $0;
	while (quote = index(line, "\"")) {
		newquote = is_open ? "«" : "»";
		line = \
		    substr(line, 1, quote - 1) \
		    newquote \
		    substr(line, quote + 1);
		is_open = !is_open;
	}
	print line;
}

#--