--- gforth/engine/io.c	2010/02/14 18:13:31	1.40
+++ gforth/engine/io.c	2012/07/22 22:24:50	1.44
@@ -1,6 +1,6 @@
 /* direct key io driver
 
-  Copyright (C) 1995,1996,1997,1998,1999,2002,2003,2006,2007,2008,2009 Free Software Foundation, Inc.
+  Copyright (C) 1995,1996,1997,1998,1999,2002,2003,2006,2007,2008,2009,2010 Free Software Foundation, Inc.
 
   This file is part of Gforth.
 
@@ -55,6 +55,7 @@ typedef unsigned int uint32_t;
 #include "io.h"
 
 #ifndef MSDOS
+#include <poll.h>
 #if defined (__GNUC__)
 #  define alloca __builtin_alloca
 #else
@@ -663,8 +664,7 @@ int gf_ungottenc(FILE *stream)
 long key_avail (FILE *stream)
 {
   int tty = fileno (stream);
-  fd_set selin;
-  static struct timeval now = { 0 , 0 };
+  struct pollfd fds = { tty, POLLIN, 0 };
   int chars_avail;
 
   if (gf_ungottenc(stream))
@@ -673,9 +673,15 @@ long key_avail (FILE *stream)
   if(!terminal_prepped && stream == stdin)
     prep_terminal();
 
-  FD_ZERO(&selin);
-  FD_SET(tty, &selin);
-  chars_avail = select(1, &selin, NULL, NULL, &now);
+#if defined(FIONREAD) && !defined(_WIN32)
+  if(isatty (tty)) {
+    int result = ioctl (tty, FIONREAD, &chars_avail);
+  } else
+#endif
+  {
+    chars_avail = poll(&fds, 1, 0);
+  }
+#ifndef __ANDROID__
   if (chars_avail > 0) {
     /* getc won't block */
     int c = getc(stream);
@@ -683,6 +689,7 @@ long key_avail (FILE *stream)
       return 0;
     gf_ungetc(c, stream);
   }
+#endif
   return (chars_avail == -1) ? 0 : chars_avail;
 }