Do you need more than 1k of additional source to wrap the line parsing in a loop? I doubt it.
See: https://github.com/semitrivial/csv_parser/blob/master/split....
Though I suppose that's the naive approach. You could combine the two into a single file by, like you say, wrapping the row-parser in a (clever, non-trivial) outer loop, and it probably wouldn't take anywhere near 1000 characters to do that...
In some variants of CSV. There isn’t agreement on the format. For example, https://www.ietf.org/rfc/rfc4180.txt says
“While there are various specifications and implementations for the CSV format (for ex. [4], [5], [6] and [7]), there is no formal specification in existence, which allows for a wide variety of interpretations of CSV files.”
That RFC doesn’t even agree with itself, saying
“1. Each record is located on a separate line, delimited by a line break (CRLF).”
but then following that up with:
“6. Fields containing line breaks (CRLF), double quotes, and commas should be enclosed in double-quotes”
This is the "mathematical a", which does not mean "exactly one" but "at least one, and we don't care how many, we already did the interesting work". Like in "this problem has a solution".
Btw. you are not handling escaped double quotes in strings at all, and if you would do that you'd also need to count the number of backspaces. Oh, and no need to escape double quotes in single quotes ('\" could just be '"').