Command line SVG optimizer and base64 converter for CSS, based on https://gist.github.com/mrinterweb/11303706

svgoptimize

#! /usr/bin/env ruby

# nokogiri is required below unless --no-modify option is specified
require 'optparse'
require 'tempfile'

@options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: svgoptimize [options] <path-to-svg-file>"

  opts.on('-v', '--verbose', 'verbose logging') do |v|
    @options[:verbose] = true
  end
  opts.on('-q', '--quiet', 'only result output is displayed') do |v|
    @options[:quiet] = true
  end
  opts.on('--no-modify', 'disables svg xml element removal') do |v|
    @options[:skip_xml_optimization] = true
  end
  opts.on('-c', '--copy', 'copies the output to the system clipboard') do |v|
    @options[:copy_to_clipboard] = true
  end
  opts.on('--css', 'wraps the output in a background css rule') do |v|
    @options[:css_wrap] = true
  end
end.parse!

path = ARGV[0]
unless path
  puts "you must specify a path to the svg file you'd like to be optimized."
  exit 1
end

unless File.exist?(path)
  puts "path to file does not exist."
  exit 1
end

def log(str, mode=:normal)
  if @options[:quiet]
    nil
  elsif mode == :normal
    puts str
  elsif @options[:verbose] && mode == :verbose
    puts str
  end
end

def kb(total_bytes)
  sprintf "%.2f KB", total_bytes / 1024.0
end

def size_to_kb(file)
  kb file.size
end

input_file = File.open(path)
tmp_file = Tempfile.new("svg-optimize-#{File.basename(path)}")
tmp_file.write(input_file.read)
tmp_file.rewind
log "using temp file: #{tmp_file.path}", :verbose

log "Input file: \n#{input_file.read}", :verbose
log "Input SVG file size: #{size_to_kb(input_file)}"

unless @options[:skip_xml_optimization]
  require 'nokogiri'
  xml = Nokogiri::XML(tmp_file.read.gsub(%r~.*<svg ~mi, '<svg '))
  %w[description title].each do |node_name|
    xml.css(node_name).remove
  end

  tmp_file.truncate(0)
  tmp_file.rewind
  # xml.remove_namespaces!
  extraneous_attributes = xml.root.attributes.reject { |k| %w[version viewBox].include?(k) }.keys
  extraneous_attributes.each { |attr| xml.root.delete(attr) }
  xml_str = xml.to_xml(save_with: Nokogiri::XML::Node::SaveOptions::NO_DECLARATION).gsub(/>\s+</, "><")
  tmp_file.write(xml_str)
  tmp_file.rewind
  log `cat #{tmp_file.path}`, :verbose
  log "file size: #{`ls -lh #{tmp_file.path}`}", :verbose
end

base64tmp = Tempfile.new('svg-base64')
`cat #{tmp_file.path} | openssl base64 | tr -d '\n' > #{base64tmp.path}`
result = `cat #{base64tmp.path}`

log "Optimized size: #{kb result.length}"
log ""
if @options[:css_wrap]
  result = "background: url(data:image/svg+xml;base64,#{result}) 0 0 no-repeat;"
  f = File.open(base64tmp.path, 'w')
  f.write(result)
  f.close
end

puts result

if @options[:copy_to_clipboard]
  clipboard_cmd = case RUBY_PLATFORM
                  when /darwin/
                    'pbcopy'
                  else
                    'xclip'
                  end

  `cat #{base64tmp.path} | #{clipboard_cmd}`
  puts "\n output copied to clipboard"
end