A ruby implementation of ESC/POS (thermal) printer command specification.
Add this line to your application's Gemfile:
gem 'escpos'
# see https://github.com/escpos/escpos-image
gem 'escpos-image' # add this if you want to print PNG imagesAnd then execute:
$ bundle
Or install it yourself as:
$ gem install escpos
@printer = Escpos::Printer.new
@printer.write "Some text"
@printer.to_escpos # returns ESC/POS data ready to be sent to printer
# on linux this can be piped directly to /dev/usb/lp0
# with network printer sent directly to printer socket
# with serial port printer it can be sent directly to the serial port
@printer.to_base64 # returns base64 encoded ESC/POS data
# using report class
# my_report.rb:
class MyReport < Escpos::Report
  def item(text)
    @count ||= 0
    @count += 1
    quad_text "#{@count}. #{text}"
  end
end<% # my_report.erb: %>
<%= item "First item" %>
<%= item "Second item" %>
<%= item "Third item" %># usage:
report = MyReport.new 'path/to/my_report.erb'
@printer.write report.render
@printer.cut!
# @printer.to_escpos or @printer.to_base64 contains resulting ESC/POS data- text: Normal text formatting
 - encode: Encode text for the printer
 - encoding, set_encoding, set_printer_encoding: Set printer encoding
 - double_height: Double height text
 - quad_text, big, title, header, double_width_double_height, double_height_double_width: Double width & Double height text
 - double_width: Double width text
 - underline, u: Underlined text
 - underline2, u2: Stronger underlined text
 - bold, b: Bold text
 - left: Align to left
 - right: Align to right
 - center: Align to center
 - invert, inverted: Color inverted text
 - black, default_color, color_black, black_color: Default Color (Usually black)
 - red, alt_color, alternative_color, color_red, red_color: Alternative Color (Usually Red)
 - barcode: Print barcode
 - partial_cut: Partially cut the paper (may not be available on all devices)
 - cut: Fully cut the paper (may not be available on all devices)
 
Bug reports and pull requests are welcome on GitHub at https://github.com/escpos/escpos.
- Fork it ( https://github.com/escpos/escpos/fork )
 - Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create a new Pull Request
 



