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 images

And 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.

1. Fork it ( https://github.com/escpos/escpos/fork )
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