require 'exifr'
include EXIFR

def pp(fname)
  jpeg = JPEG.new(fname)
  ks = %w(width height comment bits)
  ks += jpeg.exif.keys.map{|a|a.to_s}.sort{|a,b|a<=>b} if jpeg.exif?

  l = []
  ks[0..3].each do |k|
    v = jpeg.send(k)
    l << [k, v] if v
  end
  ks[4..-1].each do |k|
    v = jpeg.exif[k.to_sym]
    l << [k, v] if v
  end
  l.delete_if{|k,v|v.nil?}
  
  puts "#{fname}:"
  f = "  %#{l.sort{|a,b|a[0].size <=> b[0].size}.last[0].size}s = %s\n"
  l.each{|k,v|puts f  % [k, [v].flatten.map{|t|t.to_s}.join(', ')]}
end

if ARGV.size == 0
  STDERR.puts "Usage: #{$0} FILE .."
elsif ARGV.size == 1
  pp ARGV[0]
else
  ARGV.each do |fname|
    pp fname
    puts
  end
end