From baaa0348a9627634699c34af6f285cdf910c6958 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Revol?= <revol@free.fr>
Date: Fri, 26 Mar 2010 19:47:23 +0000
Subject: [PATCH] Implemented ioctl(FIONREAD) on tty devices. Untested.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35960 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/add-ons/kernel/drivers/tty/tty.cpp | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/add-ons/kernel/drivers/tty/tty.cpp b/src/add-ons/kernel/drivers/tty/tty.cpp
index ed6eebd9c0..5c4b6dd05c 100644
--- a/src/add-ons/kernel/drivers/tty/tty.cpp
+++ b/src/add-ons/kernel/drivers/tty/tty.cpp
@@ -17,6 +17,7 @@
 #include <signal.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
@@ -1739,6 +1740,26 @@ tty_ioctl(tty_cookie* cookie, uint32 op, void* buffer, size_t length)
 			return B_OK;
 		}
 
+		case FIONREAD:
+		{
+			int toRead = 0;
+
+			// release the mutex and grab a read lock
+			locker.Unlock();
+			ReaderLocker readLocker(cookie);
+
+			status_t status = readLocker.AcquireReader(0, 1);
+			if (status >= B_OK)
+				toRead = readLocker.AvailableBytes();
+			else if(status != B_WOULD_BLOCK)
+				return status;
+
+			if (user_memcpy(buffer, &toRead, sizeof(int)) != B_OK)
+				return B_BAD_ADDRESS;
+
+			return B_OK;
+		}
+
 		case TCWAITEVENT:		// BeOS (uint*)
 								// wait for event (timeout if !NULL)
 		case TCVTIME:			// BeOS (bigtime_t*) set highrez VTIME