Quotes.sed

#  Escape newlines inside quoted strings.

/^[^'#]*'[^']*$/{
   /^[^"]*'/{
      :singlequote
      s/$/\\/
      n
      /'/ ! b singlequote
      }
   }
/^[^"#]*"[^"]*$/{
   /^[^']*"/{
      :doublequote
      s/$/\\/
      n
      /'/ ! b doublequote
      }
   }