diff -urN cui106/key.c cui107/key.c
--- cui106/key.c	Thu Mar 27 22:10:00 2014
+++ cui107/key.c	Sat Apr 12 22:00:00 2014
@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/time.h>
 #include <termios.h>
 
 #define KEY_FD	0
@@ -30,11 +31,25 @@
 	tcsetattr(KEY_FD, TCSANOW, &bak);
 }
 
+static int
+readable_chk(int fd)
+{
+	fd_set rfs;
+	struct timeval tm;
+
+	FD_ZERO(&rfs);
+	FD_SET(fd, &rfs);
+	tm.tv_sec = 0;
+	tm.tv_usec = 100*1000;
+	return select(fd+1, &rfs, NULL, NULL, &tm) > 0;
+}
+
 int
 cui_key_get(void)
 {
 	unsigned char uc;
 
+	if(!readable_chk(KEY_FD)) return 0;
 	if(read(KEY_FD, &uc, 1) != 1) return 0;
 	return uc;
 }