Flat is a library to make processing Flat Flies as easy as CSV files. Easily process flat files with Flat. Specify the format in a subclass of Flat::File and read and write until the cows come home.

Add this line to your application's Gemfile:

gem 'flat'

And then execute:

$ bundle

Or install it yourself as:

$ gem install flat

A simple example for a flat file class for grabbing information about people might look like this:

# Actual plain text, flat file data, 29 bytes
#
#           10        20
# 012345678901234567890123456789
# Walt      Whitman   18190531
# Linus     Torvalds  19691228

class People < Flat::File

  add_field :first_name, width: 10, filter: :trim
  add_field :last_name,  width: 10, filter: ->(v) { v.strip }
  add_field :birthday,   width: 8,  filter: BirthdayFilter
  pad       :autoname,   width: 2

  def self.trim(v)
    v.strip
  end

end

p = People.new

p.each_record(open('somefile.dat')) do |person|

  puts "First Name: #{person.first_name}"
  puts "Last Name : #{person.last_name}"
  puts "Birthday : #{person.birthday}"

  puts person.to_s
end

Consult the RDocs for additional examples, and information on Filters and Formatters.

1. Fork it!
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

I had been looking for a library to handle flat files in a manner similar to the CSV library and stumbled upon the following:

• flat_filer (http://rubygems.org/gems/flat_filer)
• flat_filer (https://github.com/xforty/flat_filer)
• flat_filer (https://github.com/cheapRoc/flat_filer)

They all appeared to be abandoned so I decided to resurrect them with my own spin on the implementation.

Copyright (c) 2014 Mel Riffe

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.