using System;

public class Program

{

    public static void Main()

    {

        string yourString = "echo 'foo' | sed '/foo/d;'";

        char[] delimiters = new char[] { '|' };

        string result = string.Join(",", yourString.Split(delimiters, StringSplitOptions.RemoveEmptyEntries));

        Console.WriteLine("Result: " + result);

    }

}