Additional csv option for quote_char

This will allow users to configure a different quoting char in cases where the data may not exactly fit the csv standard.

A common example may be to completely ignore the quote char, and to do this a null \x00 char can be used instead.
Another example may be csv with ' as the quote char instead of "

lib/logstash/filters/csv.rb

@@ -24,6 +24,11 @@ class LogStash::Filters::CSV < LogStash::Filters::Base
   # Optional.
   config :separator, :validate => :string, :default => ","
 
+  # Define the character used to quote CSV fields. If this is not specified
+  # the default is a double quote '"'
+  # Optional.
+  config :quote_char, :validate => :string, :default => '"'
+
   # Define target for placing the data
   # Defaults to writing to the root of the event.
   config :target, :validate => :string
@@ -57,7 +62,7 @@ class LogStash::Filters::CSV < LogStash::Filters::Base
 
       raw = event[@source].first
       begin
-        values = CSV.parse_line(raw, :col_sep => @separator)
+        values = CSV.parse_line(raw, :col_sep => @separator, :quote_char => @quote_char)
 
         if @target.nil?
           # Default is to write to the root of the event.

spec/filters/csv.rb

@@ -35,6 +35,38 @@ describe LogStash::Filters::CSV do
     end
   end
 
+  describe "custom quote char" do
+    config <<-CONFIG
+      filter {
+        csv {
+          quote_char => "'"
+        }
+      }
+    CONFIG
+
+    sample "big,bird,'sesame street'" do
+      insist { subject["column1"] } == "big"
+      insist { subject["column2"] } == "bird"
+      insist { subject["column3"] } == "sesame street"
+    end
+  end
+
+  describe "null quote char" do
+    config <<-CONFIG
+      filter {
+        csv {
+          quote_char => "\x00"
+        }
+      }
+    CONFIG
+
+    sample 'big,bird,"sesame" street' do
+      insist { subject["column1"] } == 'big'
+      insist { subject["column2"] } == 'bird'
+      insist { subject["column3"] } == '"sesame" street'
+    end
+  end
+
   describe "given columns" do
     # The logstash config goes here.
     # At this time, only filters are supported.