Unless you're worried that $line might include things that could be interpolated and shouldn't be, you could just evaluate the whole $line in double quotes:

    no warnings 'uninitialized';
    $line = eval qq{"$line"};
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Update: Probably the most hazardous thing might be any double-quotes that were in the file. If the lines will be free of unbalanced braces, this would be better:

    $line = eval "qq{$line}";
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