CsvSeparatorDetector

Add this line to your application's Gemfile:

gem 'csv_separator_detector'

And then execute:

$ bundle

Or install it yourself as:

$ gem install csv_separator_detector

begin
  content = File.read('/path/to/csv.file')
  separator = CsvSeparatorDetector.new(content).call # => ';'
rescue CsvSeparatorDetector::Error
  # we couldn't reliably determine separator.
end

This class knows a few common csv delimiters and tries to parse given content using them (by passing each delimiter as col_sep option to CSV from stdlib). Then it tries to make sense of the result. All rows turned out to be just one column wide? That's likely because we used comma separator and the file is tab-delimited.

Bug reports and pull requests are welcome on GitHub at https://github.com/stulentsev/csv_separator_detector.