Using awk seems to be more clear and is independent of whitespace type:
DNSMASQ_OPTS="$DNSMASQ_OPTS `mawk -- '{ printf " --trust-anchor=.,%d,%d,%d,%s", $5, $6, $7, $8 }' $ROOT_DS`"
However, using [[:space:]] also works, but looks ugly:"`sed -e 's/.*IN[[:space:]]DS[[:space:]]/--trust-anchor=.,/' -e s/" "/,/g $ROOT_DS | tr '\n' ' '`"
