adding --network-id option to eth cli

eth/main.cpp

@@ -146,6 +146,7 @@ void help()
  << " --listen <port> Listen on the given port for incoming connections (default: 30303)." << endl
  << " -r,--remote <host>(:<port>) Connect to remote host (default: none)." << endl
  << " --port <port> Connect to remote port (default: 30303)." << endl
+ << " --network-id <n> Only connect to other hosts with this network id (default:0)." << endl
  << " --upnp <on/off> Use UPnP for NAT (default: on)." << endl
 #if ETH_JSONRPC || !ETH_TRUE
  << "Work farming mode:" << endl
@@ -515,6 +516,7 @@ int main(int argc, char** argv)
  unsigned short remotePort = 30303;
  unsigned peers = 5;
  bool bootstrap = false;
+ unsigned networkId = 0;
 
  /// Mining params
  unsigned mining = 0;
@@ -668,6 +670,15 @@ int main(int argc, char** argv)
  return -1;
  }
  }
+ else if (arg == "--network-id" && i + 1 < argc)
+ try {
+ networkId = stol(argv[++i]);
+ }
+ catch (...)
+ {
+ cerr << "Bad " << arg << " option: " << argv[i] << endl;
+ return -1;
+ }
  else if (arg == "--benchmark-warmup" && i + 1 < argc)
  try {
  benchmarkWarmup = stol(argv[++i]);
@@ -1034,6 +1045,7 @@ int main(int argc, char** argv)
  c->setForceMining(forceMining);
  c->setTurboMining(minerType == MinerType::GPU);
  c->setAddress(coinbase);
+ c->setNetworkId(networkId);
  }
 
  cout << "Transaction Signer: " << sigKey.address() << endl;