added to portfwd tool - Windows keyboard fix (#1035)

* added to portfwd tool - Windows keyboard fix

* is it just a hick-up

tools/n2n-portfwd.c

@@ -26,6 +26,7 @@
 #define SOCKET_TIMEOUT          2
 #define INFO_INTERVAL           5
 
+// REVISIT: may become obsolete
 #ifdef WIN32
 #define STDIN_FILENO            _fileno(stdin)
 #endif
@@ -156,10 +157,12 @@ int get_port_from_json (uint16_t *port, json_object_t *json, char *key, int tag,
 
 
 // -------------------------------------------------------------------------------------------------------
+// PLATFORM-DEPENDANT CODE
 
 
+#if !defined(WIN32)
 // taken from https://web.archive.org/web/20170407122137/http://cc.byexamples.com/2007/04/08/non-blocking-user-input-in-loop-without-ncurses/
-int kbhit () {
+int _kbhit () {
 
     struct timeval tv;
     fd_set fds;
@@ -172,6 +175,7 @@ int kbhit () {
 
     return FD_ISSET(STDIN_FILENO, &fds);
 }
+#endif
 
 
 // -------------------------------------------------------------------------------------------------------
@@ -311,7 +315,7 @@ reset_main_loop:
     // read answer packet by packet which are only accepted if a corresponding request was sent before
     // of which we know about by having set the related tag, tag_info
     // a valid sock address indicates that we have seen a valid answer to the info request
-    while(keep_running && !kbhit()) {
+    while(keep_running && !_kbhit()) {
         // current time
         now = time(NULL);