4poc · July 1, 2021 13:53 · Aug 20, 2013 · Aug 20, 2013 · Aug 20, 2013
diff --git a/gistfile1.rb b/gistfile1.rb
@@ -31,6 +31,8 @@ def ping
     len = socket.read(2).unpack('n').first
     resp = decode_string(socket.read(len*2)).split("\u0000")
 
+    socket.close
+
     if resp.shift != "\u00A71"
       raise 'unexpected server response fields'
     end

diff --git a/gistfile1.rb b/gistfile1.rb
@@ -36,11 +36,11 @@ def ping
     end
 
     return {
-      :protocol_version => resp.shift,
+      :protocol_version => resp.shift.to_i,
       :minecraft_version => resp.shift,
       :motd => resp.shift,
-      :current_players => resp.shift,
-      :max_players => resp.shift
+      :current_players => resp.shift.to_i,
+      :max_players => resp.shift.to_i
     }
   end
 

diff --git a/gistfile1.rb b/gistfile1.rb
@@ -0,0 +1,67 @@
+require 'socket'
+
+##
+# Pings a minecraft server and returns motd and playercount.
+# Works with ruby >=1.9.3/2.0.0
+#
+# More information and sample code here:
+# http://wiki.vg/Server_List_Ping
+##
+class MinecraftPing
+  def initialize(host, port=25565)
+    @host = host
+    @port = port
+  end
+
+  def ping
+    socket = TCPSocket.open(@host, @port)
+    # packet identifier & payload ...
+    socket.write([0xFE, 0x01, 0xFA].pack('CCC'))
+    socket.write(encode_string('MC|PingHost'))
+    socket.write([7 + 2 * @host.length].pack('n'))
+    socket.write([74].pack('c'))
+    socket.write(encode_string(@host))
+    socket.write([@port].pack('N'))
+
+    # read server response
+    if socket.read(1).unpack('C').first != 0xFF # Kick packet
+      raise 'unexpected server response packet'
+    end
+
+    len = socket.read(2).unpack('n').first
+    resp = decode_string(socket.read(len*2)).split("\u0000")
+
+    if resp.shift != "\u00A71"
+      raise 'unexpected server response fields'
+    end
+
+    return {
+      :protocol_version => resp.shift,
+      :minecraft_version => resp.shift,
+      :motd => resp.shift,
+      :current_players => resp.shift,
+      :max_players => resp.shift
+    }
+  end
+
+  private
+
+  def encode_string(s)
+    begin
+      [s.length].pack('n') + Iconv.conv('utf-16be', 'utf-8', s)
+    rescue
+      [s.length].pack('n') + s.encode('utf-16be').force_encoding('ASCII-8BIT')
+    end
+  end
+
+  def decode_string(s)
+    begin
+      Iconv.conv('utf-8', 'utf-16be', s)
+    rescue
+      s.force_encoding('utf-16be').encode('utf-8')
+    end
+  end
+end
+
+puts MinecraftPing.new('aztec.geekosphere.org').ping.inspect
+puts MinecraftPing.new('night.no-ip.org', 25565).ping.inspect