From 0cc9b20c15460213e488bf5e70963b941482f628 Mon Sep 17 00:00:00 2001
From: William Harrington <kb0iic@berzerkula.org>
Date: Tue, 14 Jan 2025 16:06:02 -0600
Subject: Add source.

---
 sdk/dev/inkey.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 sdk/dev/inkey.c

(limited to 'sdk/dev/inkey.c')

diff --git a/sdk/dev/inkey.c b/sdk/dev/inkey.c
new file mode 100644
index 0000000..1003905
--- /dev/null
+++ b/sdk/dev/inkey.c
@@ -0,0 +1,76 @@
+/*
+ * Wait and read single byte input from device.
+ * $Id$
+ * Copyright (c) 1997 by Tycho Softworks.
+ * For conditions of distribution and reuse see product license.
+ */
+ 
+#include <dev/tty.h>
+#include <std/select.h>
+#include <std/poll.h>
+
+#ifndef	SYS_POLL_H_MISSING
+#define	USE_POLL
+#endif
+
+#ifndef	POLL_H_MISSING
+#define	USE_POLL
+#endif
+
+#ifdef	USE_POLL
+
+int	inkey(fd_t fd, int timeout)
+{
+	struct	pollfd	poller;
+	uchar	buf;
+	
+	poller.fd = fd;
+	poller.revents = 0;
+	poller.events = POLLIN ;
+	
+	if(!poll(&poller, 1, timeout))
+		return -1;
+		
+	if(poller.revents & (POLLERR | POLLHUP))
+		return -1;
+		
+	if(read(fd, &buf, 1) != 1)
+		return -1;
+		
+	return buf;
+}
+				
+#else
+
+int	inkey(fd_t fd, int timeout)
+{
+	fd_set	inp,out,exc;
+	struct	timeval timer;
+	uchar	buf;
+	
+	FD_ZERO(&inp);
+	FD_ZERO(&out);
+	FD_ZERO(&exc);
+	
+	FD_SET(fd, &inp);
+	FD_SET(fd, &exc);
+	
+	timer.tv_sec = timeout / 1000;
+	timer.tv_usec = timeout % 1000;
+	
+	if(!select(fd + 1, &inp, &out, &exc, &timer))
+		return -1;
+		
+	if(FD_ISSET(fd, &exc))
+			return -1;
+			
+	if(FD_ISSET(fd, &inp))
+	{
+		if(read(fd, &buf, 1) != 1)
+			return -1;
+			return buf;
+	}
+	return -1;
+}
+
+#endif
-- 
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