NIFI - remove header and footer lines from CSV

[#1]

I am attempting to remove multiple header and footer/trailer lines from a CSV.  The CSVReader will only allow me to skip the first line, which isn't enough,and I don't see any way to skip trailer records.  Is my only option to use an ExternalScript processor and handle it outside of nifi? Like a shell script with head and tail?

[#2]

@JohnYaya  if you can show a sample, it would be very helpful.

If your header and footer is static, and always predictable for a specific file you can replaceText and get "in between" lines using those static header/footer matches with a very creative regex...

[#3]

Well, I'm trying to put together a fairly generic service to ingest files.  One of the reqs is to be able to strip off any header or trailer lines.  Files can come from any number of sources, so I don't think there will be any kind of pattern for a regex.