$_ = "Goodbye\\; Good luck\\, and thanks for all the fish!\\\n\\\n";

print "<$_>\n";

s/\\([;,\n])/$+/g;            # Does work

print "<$_>\n";

##</code><code>##

$_ = "Goodbye\\; Good luck\\, and thanks for all the fish!\\n\\n";

print qq{<$_>\n};

s/(\\.)/qq{"$1"}/eeg;

print qq{<$_>\n};