TCPIP sockets in c#

Many great working examples on TCPIP sockets... in C#


http://www.java2s.com/Code/CSharp/Network/AsyncTcpServer.htm

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/*C# Network Programming by Richard BlumPublisher: Sybex ISBN: 0782141765*/
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
public class FixedTcpSrvr
{
private static int SendData(Socket s, byte[] data)
{
int total = 0;
int size = data.Length;
int dataleft = size;
int sent;
while (total < size)
{
sent = s.Send(data, total, dataleft, SocketFlags.None);
total += sent;
dataleft -= sent;
}
return total;
}
private static byte[] ReceiveData(Socket s, int size)
{
int total = 0;
int dataleft = size;
byte[] data = new byte[size];
int recv;
while (total < size)
{
recv = s.Receive(data, total, dataleft, 0);
if (recv == 0)
{
data = Encoding.ASCII.GetBytes("exit ");
break;
}
total += recv;
dataleft -= recv;
}
return data;
}
public static void Main()
{
byte[] data = new byte[1024];
IPEndPoint ipep = new IPEndPoint(IPAddress.Any, 12008);
Socket newsock = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
newsock.Bind(ipep);
newsock.Listen(10);
Console.WriteLine("Waiting for a client...");
Socket client = newsock.Accept();
IPEndPoint newclient = (IPEndPoint)client.RemoteEndPoint;
Console.WriteLine("Connected with {0} at port {1}",
newclient.Address, newclient.Port);
string welcome = "Welcome to my test server";
data = Encoding.ASCII.GetBytes(welcome);
int sent = SendData(client, data);
for (int i = 0; i < 5; i++)
{
data = ReceiveData(client, 9);
Console.WriteLine(Encoding.ASCII.GetString(data));
}
Console.WriteLine("Disconnected from {0}", newclient.Address);
client.Close();
newsock.Close();
}
}

My Location - Google Mobile Maps

So you don't have GPS but your phone can run JAVA apps... or Python apps..

Google Maps for mobiles can use the GSM tower (cell) id to look up roughly where you are... it plots you on Google Map (for mobile) to within a few km (at worst).

So if Google have access to some database of Cell Tower ID - Lat/Long can we access that data too?

Well.. you can buy it.. or try to use Google's dataset.

In the background the Google maps application uses this website to post your Cell ID

http://www.google.com/glm/mmap

Neil Young written a demo C# app to make use of this to get a lat/long for a given Cell id.
(copy of source at end of this article)
http://maps.alphadex.de/datafiles/fct0e1b11782832f02.cs

Excellent article on his webstie: http://maps.alphadex.de/index.php?section=mylocation

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Yahoo have something similar but no where near as populated or dense cell data.
http://developer.yahoo.com/yrb/zonetag/locatecell.html



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using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.IO;
using System.Diagnostics;
/*
* Sample code to obtain geo codes from a cell info
* "GSM/UMTS" setting revealed by smuraro, thanks!
*/
/* (c) "Neil Young" (neil.young@freenet.de)
*
* This script/program is provided "as is".
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* GNU General Public License, see .
*/
namespace GMM {
class Program {
static byte[] PostData(int MCC, int MNC, int LAC, int CID, bool shortCID) {
/* The shortCID parameter follows heuristic experiences:
* Sometimes UMTS CIDs are build up from the original GSM CID (lower 4 hex digits)
* and the RNC-ID left shifted into the upper 4 digits.
*/
byte[] pd = new byte[] {
0x00, 0x0e,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00,
0x00, 0x00,
0x00, 0x00,
0x1b,
0x00, 0x00, 0x00, 0x00, // Offset 0x11
0x00, 0x00, 0x00, 0x00, // Offset 0x15
0x00, 0x00, 0x00, 0x00, // Offset 0x19
0x00, 0x00,
0x00, 0x00, 0x00, 0x00, // Offset 0x1f
0x00, 0x00, 0x00, 0x00, // Offset 0x23
0x00, 0x00, 0x00, 0x00, // Offset 0x27
0x00, 0x00, 0x00, 0x00, // Offset 0x2b
0xff, 0xff, 0xff, 0xff,
0x00, 0x00, 0x00, 0x00
};
bool isUMTSCell = ((Int64)CID > 65535);
if (isUMTSCell)
Console.WriteLine("UMTS CID. {0}", shortCID ? "Using short CID to resolve." : "");
else
Console.WriteLine("GSM CID given.");
if (shortCID)
CID &= 0xFFFF; /* Attempt to resolve the cell using the GSM CID part */
if ((Int64)CID > 65536) /* GSM: 4 hex digits, UTMS: 6 hex digits */
pd[0x1c] = 5;
else
pd[0x1c] = 3;
pd[0x11] = (byte)((MNC >> 24) & 0xFF);
pd[0x12] = (byte)((MNC >> 16) & 0xFF);
pd[0x13] = (byte)((MNC >> 8) & 0xFF);
pd[0x14] = (byte)((MNC >> 0) & 0xFF);
pd[0x15] = (byte)((MCC >> 24) & 0xFF);
pd[0x16] = (byte)((MCC >> 16) & 0xFF);
pd[0x17] = (byte)((MCC >> 8) & 0xFF);
pd[0x18] = (byte)((MCC >> 0) & 0xFF);
pd[0x27] = (byte)((MNC >> 24) & 0xFF);
pd[0x28] = (byte)((MNC >> 16) & 0xFF);
pd[0x29] = (byte)((MNC >> 8) & 0xFF);
pd[0x2a] = (byte)((MNC >> 0) & 0xFF);
pd[0x2b] = (byte)((MCC >> 24) & 0xFF);
pd[0x2c] = (byte)((MCC >> 16) & 0xFF);
pd[0x2d] = (byte)((MCC >> 8) & 0xFF);
pd[0x2e] = (byte)((MCC >> 0) & 0xFF);
pd[0x1f] = (byte)((CID >> 24) & 0xFF);
pd[0x20] = (byte)((CID >> 16) & 0xFF);
pd[0x21] = (byte)((CID >> 8) & 0xFF);
pd[0x22] = (byte)((CID >> 0) & 0xFF);
pd[0x23] = (byte)((LAC >> 24) & 0xFF);
pd[0x24] = (byte)((LAC >> 16) & 0xFF);
pd[0x25] = (byte)((LAC >> 8) & 0xFF);
pd[0x26] = (byte)((LAC >> 0) & 0xFF);
return pd;
}
static void Main(string[] args) {
if (args.Length < 4) {
Console.WriteLine("Usage: gmm MCC MNC LAC CID [\"shortcid\"]");
return;
}
string shortCID = ""; /* Default, no change at all */
if (args.Length == 5)
shortCID = args[4].ToLower();
try {
String url = "http://www.google.com/glm/mmap";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(new Uri(url));
req.Method = "POST";

int MCC = Convert.ToInt32(args[0]);
int MNC = Convert.ToInt32(args[1]);
int LAC = Convert.ToInt32(args[2]);
int CID = Convert.ToInt32(args[3]);
byte[] pd = PostData(MCC, MNC, LAC, CID, shortCID == "shortcid");
req.ContentLength = pd.Length;
req.ContentType = "application/binary";
Stream outputStream = req.GetRequestStream();
outputStream.Write(pd, 0, pd.Length);
outputStream.Close();
HttpWebResponse res = (HttpWebResponse)req.GetResponse();
byte[] ps = new byte[res.ContentLength];
int totalBytesRead = 0;
while (totalBytesRead < ps.Length) {
totalBytesRead += res.GetResponseStream().Read(ps, totalBytesRead, ps.Length - totalBytesRead);
}
if (res.StatusCode == HttpStatusCode.OK) {
short opcode1 = (short)(ps[0] << 8 ps[1]);
byte opcode2 = ps[2];
System.Diagnostics.Debug.Assert(opcode1 == 0x0e);
System.Diagnostics.Debug.Assert(opcode2 == 0x1b);
int ret_code = (int)((ps[3] << 24) (ps[4] << 16) (ps[5] << 8) (ps[6]));

if (ret_code == 0) {
double lat = ((double)((ps[7] << 24) (ps[8] << 16) (ps[9] << 8) (ps[10]))) / 1000000;
double lon = ((double)((ps[11] << 24) (ps[12] << 16) (ps[13] << 8) (ps[14]))) / 1000000;
Console.WriteLine("Latitude: {0}, Longitude: {1}", lat, lon);

Process p = new Process();
p.StartInfo.FileName = "iexplore";
Console.WriteLine("\nClose map window to exit\n");
p.StartInfo.Arguments = String.Format(
"http://maps.google.de/maps?f=q&hl=de&q={0},{1}&ie=UTF8&z=15",
lat.ToString().Replace(',','.'), lon.ToString().Replace(',','.'));
p.Start();
p.WaitForExit();
}
else
Console.WriteLine("Error {0}", ret_code);
}
else
Console.WriteLine("HTTP Status {0} {1}", res.StatusCode, res.StatusDescription);
}
catch (Exception) {
throw;
}
}
}
}