method

filter

Ruby latest stable (v2_5_5) - 0 notes - Class: CSV

filter(input=nil, output=nil, **options) public

This method is a convenience for building Unix-like filters for CSV data. Each row is yielded to the provided block which can alter it as needed. After the block returns, the row is appended to output altered or not.

The input and output arguments can be anything CSV::new() accepts (generally String or IO objects). If not given, they default to ARGF and $stdout.

The options parameter is also filtered down to CSV::new() after some clever key parsing. Any key beginning with :in_ or :input_ will have that leading identifier stripped and will only be used in the options Hash for the input object. Keys starting with :out_ or :output_ affect only output. All other keys are assigned to both objects.

The :output_row_sep option defaults to $INPUT_RECORD_SEPARATOR ($/).

Show source

# File lib/csv.rb, line 1099
  def self.filter(input=nil, output=nil, **options)
    # parse options for input, output, or both
    in_options, out_options = Hash.new, {row_sep: $INPUT_RECORD_SEPARATOR}
    options.each do |key, value|
      case key.to_s
      when /\Ain(?:put)?_(.+)\Z/
        in_options[$1.to_sym] = value
      when /\Aout(?:put)?_(.+)\Z/
        out_options[$1.to_sym] = value
      else
        in_options[key]  = value
        out_options[key] = value
      end
    end
    # build input and output wrappers
    input  = new(input  || ARGF,    in_options)
    output = new(output || $stdout, out_options)

    # read, yield, write
    input.each do |row|
      yield row
      output << row
    end
  end

filter

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