hexdump snaps

lib/array.rb

@@ -5,6 +5,9 @@
 # AND DUUUUH .scan() IS BASICALLY ALREADY
 # .groups_of()
 # TODO: get rid of it?!
+# update: no
+# .scan(/../) works on strings and groups_of works on arrays
+# so it has its purpose
 class Array
   def groups_of(max_size)
     return [] if max_size < 1

lib/bytes.rb

@@ -1,10 +1,42 @@
 # frozen_string_literal: true
 
+require_relative 'array'
+
 # turn byte array into hex string
 def str_hex(data)
   data.unpack1('H*').scan(/../).join(' ').upcase
 end
 
+def data_to_ascii(data)
+  ascii = ''
+  data.unpack('C*').each do |c|
+    ascii += c < 32 || c > 126 ? '.' : c.chr
+  end
+  ascii
+end
+
+def hexdump_lines(data, width = 2)
+  byte_groups = data.unpack1('H*').scan(/../).groups_of(4)
+  lines = []
+  hex = ''
+  ascii = ''
+  w = 0
+  byte_groups.each do |byte_group|
+    hex += '  ' unless hex.empty?
+    hex += byte_group.join(' ')
+    ascii += data_to_ascii(str_bytes(byte_group.join).pack('C*'))
+    w += 1
+    next unless w >= width
+
+    w = 0
+    lines.push("#{hex}     #{ascii}")
+    hex = ''
+    ascii = ''
+  end
+  lines.push("#{hex}     #{ascii}") unless hex.empty?
+  lines
+end
+
 # turn hex string to byte array
 def str_bytes(str)
   str.scan(/../).map { |b| b.to_i(16) }

lib/game_client.rb

@@ -182,8 +182,9 @@ class GameClient
     # TODO: add get_raw(size)
     data = u.get_raw
     puts 'snap:'
-    p str_hex(data.pack('C*'))
-    p data
+    hexdump_lines(data.pack('C*')).each do |hex|
+      puts hex
+    end
 
     # ack every snapshot no matter how broken
     @ack_game_tick = game_tick

spec/07_bytes_spec.rb

@@ -3,6 +3,25 @@
 require_relative '../lib/bytes'
 
 describe 'Bytes', :bytes do
+  context '#data_to_ascii' do
+    it 'Should encode printable and non printable chars"' do
+      expect(data_to_ascii("\x01\x41\x41\x01\x41\x42")).to eq('.AA.AB')
+    end
+  end
+  context '#hexdump_lines' do
+    it 'Should work with default width"' do
+      ex = ['01 41 02 03  03 03 03 03     .A......', '03 03 03 03  03 ef     ......']
+      expect(hexdump_lines("\x01\x41\x02\x03\x03\x03\x03\x03\x03\x03\x03\x03\x03\xef")).to eq(ex)
+    end
+    it 'Should work with width 1"' do
+      ex = ['01 41 02 03     .A..', '03 03 03 03     ....', '03 03 03 03     ....', '03 ef     ..']
+      expect(hexdump_lines("\x01\x41\x02\x03\x03\x03\x03\x03\x03\x03\x03\x03\x03\xef", 1)).to eq(ex)
+    end
+    it 'Should work with width 40"' do
+      ex = ['01 41 02 03  03 03 03 03  03 03 03 03  03 ef     .A............']
+      expect(hexdump_lines("\x01\x41\x02\x03\x03\x03\x03\x03\x03\x03\x03\x03\x03\xef", 40)).to eq(ex)
+    end
+  end
   context '#str_hex' do
     it 'Should format "\xFF" to "FF"' do
       expect(str_hex("\xFF")).to eq('FF')