initial support for termios in libroot

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@3171 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/libroot/posix/termios/Jamfile

@@ -0,0 +1,16 @@
+SubDir OBOS_TOP src kernel libroot posix termios ;
+
+KernelMergeObject posix_termios.o :
+	<$(SOURCE_GRIST)>termios.c
+	:
+	-fPIC -DPIC
+	;
+
+
+# there are no files in the kernel
+
+#MergeObjectFromObjects kernel_posix_termios.o :
+#	:
+#	-fPIC -DPIC
+#	;
+

src/kernel/libroot/posix/termios/termios.c

@@ -0,0 +1,77 @@
+/* 
+** Copyright 2003, Daniel Reinhold, [email protected]. All rights reserved.
+** Distributed under the terms of the OpenBeOS License.
+*/
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <termios.h>
+
+
+/* tcdrain - wait for all output to be transmitted */
+int
+tcdrain(int fd)
+{
+	/* Some termios implementations have a TIOCDRAIN command
+	 * expressly for this purpose (e.g. ioctl(fd, TIOCDRAIN, 0).
+	 * However, the BeOS implementation adheres to another
+	 * interface which uses a non-zero last parameter to the
+	 * TCSBRK ioctl to signify this functionality.
+	 */
+	return ioctl(fd, TCSBRK, 1);
+}
+
+
+/* tcflow - suspend or restart transmission */
+int
+tcflow(int fd, int action)
+{
+	/* action will be one of the following:
+	 *   TCIOFF -  input off (stops input)
+	 *   TCION  -  input on  (restart input)
+	 *   TCOOFF - output off (stops output)
+	 *   TCOON  - output on  (restart output)
+	 */
+	return ioctl(fd, TCXONC, action);
+}
+
+
+/* tcflush - flush all pending data (input or output) */
+int
+tcflush(int fd, int queue_selector)
+{
+	return ioctl(fd, TCFLSH, queue_selector);
+}
+
+
+/* tcsendbreak - send zero bits for the specified duration */
+int
+tcsendbreak(int fd, int duration)
+{	
+	if (duration == 0)
+		// Posix spec says this should take ~ 0.25 to 0.5 seconds
+		return ioctl(fd, TCSBRK, 0);
+	
+	/* Posix does not specify how long the transmission time
+	 * should last if 'duration' is non-zero -- i.e. it is up
+	 * to each implementation to decide what to do...
+	 *
+	 * For simplicity, here is it assumed that a positive duration
+	 * of N will mean "N time intervals" where each interval lasts
+	 * from 0.25 to 0.5 seconds. A negative duration will be treated
+	 * as an error.
+	 */
+	if (duration < 0) {
+		errno = EINVAL;
+		return -1;
+	}
+	
+	while (duration-- > 0)
+		if (ioctl(fd, TCSBRK, 0) < 0)
+			return -1;
+	
+	return 0;
+}
+