Pay particular attention to the way the  \ (backslash) character interpolates into a single-quoted string, and how many of them you need to use to get a  \\ double-backslash into the actual string (and printed).

>perl -wMstrict -le
"$_ = 'Goodbye\; Good luck\, and thanks for all the fish!\\\\n\\\\n';
 print;
 s{ \\(.) }{$1}xmsg;
 print;
"
Goodbye\; Good luck\, and thanks for all the fish!\\n\\n
Goodbye; Good luck, and thanks for all the fish!\n\n
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