>perl -wMstrict -le "my $rx = qr{ foo/bar }xms; print $rx; ;; my $str = 'xx foo/bar yy'; eval qq{ print q{match} if \$str =~ \$rx; my \$ry = q{$rx}; print qq{captured '\$1'} if \$str =~ m/(\$ry)/; }; $@ and die qq{eval err: $@}; " (?^msx: foo/bar ) match captured 'foo/bar'