Ruby class & program to take an image and output it using an iTerm2 escape sequence. Supports all of the iTerm2 image protocol.

iterm2_image.rb

require "base64"

#
# Take an image and output it using an iTerm2 escape sequence.
# Supports all of the iTerm2 image protocol: https://iterm2.com/documentation-images.html
#
# https://gist.github.com/sshaw/3687e4acdc2e1e9080d3dff04474e4e5

module ITerm2
  class Image
    def initialize(image, options = {})
      @options = options.dup
      @options[:inline] = true unless @options.include?(:inline)
      @screen = @options.delete(:screen)
      @image = Base64.encode64(File.read(image))
    end

    def print
      # Respect screen escapes being explicitly turned off
      if !screen_tty? || @screen == false
        puts to_s
        return
      end

      begin
        old = @screen
        @screen = true
        puts to_s
      ensure
        @screen = old
      end
    end

    def to_s
      encode_image
    end

    private

    def screen_tty?
      $stdout.tty? && ENV.include?("TERM") && ENV["TERM"].start_with?("screen")
    end

    def encode_image
      sprintf("%s1337;File=%s:%s%s", start_esc, format_options, @image, end_esc)
    end

    # From imgls: https://raw.githubusercontent.com/gnachman/iTerm2/master/tests/imgls
    def start_esc
      @screen == true ? "\033Ptmux;\033\033]" : "\033]"
    end

    def end_esc
      @screen == true ? "\a\033\\" : "\a"
    end
    # --

    def bool_option(value)
      value == false ? 0 : 1
    end

    def format_options
      @options.map do |name, value|
        case name
        when :preserve_aspect_ratio
          name  = "preserveAspectRatio"
          value = bool_option(value)
        when :inline
          value = bool_option(value)
        when :name
          value = Base64.encode64(value)
        end

        sprintf "%s=%s", name, value
      end.join(";")
    end
  end
end

def iTerm2
  ITerm2
end

if $0 == __FILE__
  require "optparse"

  options = {}
  OptionParser.new do |opts|
    opts.banner = "usage: #{File.basename($0)} [options] file1..."

    opts.on "-d", "--dimension [WIDTHxHEIGHT]" do |d|
      # TODO: Use OptionParser regex support
      if d =~ /(\d+(?:px|%)?)x(\d+(?:px|%)?)/i
        options[:width] = $1
        options[:height] = $2
      end
    end

    opts.on "-i", "--[no-]inline", TrueClass, "Display inline" do |inline|
      options[:inline] = inline
    end

    opts.on "-n", "--name [FILENAME]", "Filename" do |name|
      options[:name] = name
    end

    opts.on "-p", "--[no-]preserve-aspect-ratio", TrueClass do |ar|
      options[:preserve_aspect_ratio] = ar
    end

    opts.on "-w", "--width [WIDTH]", Integer do |w|
      options[:width] = w
    end

    opts.on "-h", "--height [HEIGHT]", Integer do |h|
      options[:height] = h
    end
  end.parse!

  abort "images required" unless ARGV.any?

  ARGV.each { |path| iTerm2::Image.new(path, options).print }
end