regular expression should split , that are contained outside the double quotes in a CSV file?

Question

This is the sample

\"abc\",\"abcsds\",\"adbc,ds\",\"abc\"

Output should be

abc
abcsds
adbc,ds
abc

Answer 1

This answer has a C# solution for dealing with CSV.

In particular, the line

private static Regex rexCsvSplitter = new Regex( @",(?=(?:[^""]*""[^""]*"")*(?![^""]*""))" );

contains the Regex used to split properly, i.e., taking quoting and escaping into consideration.

Basically what it says is, match any comma that is followed by an even number of quote marks (including zero). This effectively prevents matching a comma that is part of a quoted string, since the quote character is escaped by doubling it.

Keep in mind that the quotes in the above line are doubled for the sake of the string literal. It might be easier to think of the expression as

,(?=(?:[^"]*"[^"]*")*(?![^"]*"))