* update rtmp & rtmp demo

components/basic/port/linux/maix_sys_linux.cpp

@@ -0,0 +1,22 @@
+#include "maix_util.hpp"
+#include "maix_app.hpp"
+#include "signal.h"
+
+namespace maix::sys
+{
+    static void signal_handle(int signal)
+    {
+        const char *signal_msg = NULL;
+        switch (signal) {
+        case SIGINT:
+            maix::app::set_exit_flag(true);
+            raise(SIGINT);
+        break;
+        default: signal_msg = "UNKNOWN"; break;
+        }
+    }
+
+    void register_default_signal_handle() {
+        signal(SIGILL, signal_handle);
+    }
+}