NiFi ReplaceText Regex replace Newline with CRLF

Question

I have a textfile (GetFile-processor) with Unix-style Newline (\n), but need a Windows-style Carriage-Return+LineFeed CRLF (\r\n) in my FlowFile

My ReplaceText-Processor is working

Search value: ((?<!\x0d)\x0a|\x0d(?!\x0a))
Replacement value: ${literal(''):replaceFirst('','\r')}${literal(''):replaceFirst('','\n')}

Question: my RegEx seems to me very complex Do you know an easier way to convert in a FlowFile the \n to \r\n?

Have a nice weekend

Frank

Answer 1

If your file contains \n only, I see no reason to match \r with the pattern.

Use

(?<!\r)\n

Replace with ${literal('\r\n')}.

EXPLANATION

--------------------------------------------------------------------------------
  (?<!                     look behind to see if there is not:
--------------------------------------------------------------------------------
    \r                       '\r' (carriage return)
--------------------------------------------------------------------------------
  )                        end of look-behind
--------------------------------------------------------------------------------
  \n                       '\n' (newline)