Create new signal for notification of new blocks. Use w/ -blocknotify

src/init.cpp

@@ -367,6 +367,14 @@ std::string LicenseInfo()
            "\n";
 }
 
+static void BlockNotifyCallback(const uint256& hashNewTip)
+{
+    std::string strCmd = GetArg("-blocknotify", "");
+
+    boost::replace_all(strCmd, "%s", hashNewTip.GetHex());
+    boost::thread t(runCommand, strCmd); // thread runs free
+}
+
 struct CImportingNow
 {
     CImportingNow() {
@@ -1184,6 +1192,9 @@ bool AppInit2(boost::thread_group& threadGroup)
 #endif // !ENABLE_WALLET
     // ********************************************************* Step 9: import blocks
 
+    if (mapArgs.count("-blocknotify"))
+        uiInterface.NotifyBlockTip.connect(BlockNotifyCallback);
+
     // scan for better chains in the block chain database, that are not yet connected in the active best chain
     CValidationState state;
     if (!ActivateBestChain(state))