$line =~ s/^([^#]*)#.*$/$1/;

##</code><code>##

$line =~ s/^
           (           # grab this stuff in $1
             (
             [^#"]*    # prefix of non-#s, non-"s
             (\"       # start of string
               [^\"]*  # content of string
              \")?     # end of string
             [^#"]*    # suffix
             )*        # grab many prefix-string-suffixes
           )
           \#          # start of comment
           .*
           $
          /$1/x;