-alertnotify=<cmd>

Runs a shell command when an AppliesToMe() alert is received.
%s in the <cmd> string is replaced with the alert.strStatusBar
message.

src/init.cpp

@@ -301,6 +301,7 @@ std::string HelpMessage()
         "  -rpcconnect=<ip>       " + _("Send commands to node running on <ip> (default: 127.0.0.1)") + "\n" +
         "  -blocknotify=<cmd>     " + _("Execute command when the best block changes (%s in cmd is replaced by block hash)") + "\n" +
         "  -walletnotify=<cmd>    " + _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)") + "\n" +
+        "  -alertnotify=<cmd>     " + _("Execute command when a relevant alert is received (%s in cmd is replaced by message)") + "\n" +
         "  -upgradewallet         " + _("Upgrade wallet to latest format") + "\n" +
         "  -keypool=<n>           " + _("Set key pool size to <n> (default: 100)") + "\n" +
         "  -rescan                " + _("Rescan the block chain for missing wallet transactions") + "\n" +