c:\@Work\Perl\monks>perl -wMstrict -le
"use Data::Dump qw(pp);
 ;;
 for my $s (qq{yz}, qq{yz\n}) {
   $s =~ m{ (.) \z }xms;
   printf qq{in %s matched %s \n}, pp($s), pp($1);
   }
"
in "yz" matched "z"
in "yz\n" matched "\n"