>perl -wMstrict -le
"my $s = qq{xxx </div>\n</body> xxx};
 print qq{[[$s]]};
 ;;
 my $tags = qr{ </div> \n </body> }xms;
 $s =~ s{ $tags }{gone}xms;
 print qq{[[$s]]};
"
[[xxx </div>
</body> xxx]]
[[xxx gone xxx]]